Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
2014 Certified Paraoptometric SelfAssessment Course Lynn E. Lawrence Sr., CPOT, ABOC, COA Disclaimer… Disclaimer: This review course does not prepare you for national examinations, what it does is review key areas from the most national test outlines. To properly prepare for a national examination you should allow yourself ample time to fully review all tested areas for the examination in which you are preparing. This is a free presentation and all images are from the public or approved sources Practice Management Office Management Professional Issues Professional and Paraprofessional Functions Liability and Malpractice… do not go beyond your training Conduct, Confidentiality & Ethics… patient’s will grade you Hygiene and Infection Control OSHA… practice safely at all times Universal Precautions… are they infected? Government Rules and Regulations ANSI Standards… post them/know where they are State Laws… post them and know them Office Procedures Records Management Confidentiality… why is this important? Who owns the chart? … the doctor/office HIPAA… how long must records be kept? Filing systems… what is the most widely used filing system? What is accounts payable mean? What the office owes When does an overdue bill become a bad debt? 90 days Office Procedures/policies Office Procedures Manual “Official rulebook of the practice” Used to clarify the policies of the practice It is a dangerous practice not to have one, or to not know where it is Ensure emergency procedures are taught on a reoccurring basis If your office does not have one contact me at [email protected] for a sample copy Office Procedures Patient Recall Types of recall… what is the best method of recall? Methods of Making appointments… when is the best time to appt a pt? 1 Patient Handling Telephone Techniques…1st contact Greeting… be pleasant and smile Taking messages… best method of messages? Handling requests for information Handling complaints Making appointments Confirming appointments… why? Impress your docs, Patient Handling…builds the practice Public/Professional Relations Types of correspondence and brochures “Welcome to the Practice” Referral letters Consultation letters School reports Legal reports Patient information pamphlet InfantSee and Baby care programs call pts during slow times When and how do you handle a complaining patient? Patient Handling Triage Categories: Emergency-immediate…example Urgent-12-24 hours…example Routine-next available appointment What to you do when you are not sure Know your office policies What does triage mean? What does the acronym SOAPP stand for? Office Finances Book keeping and Banking Procedures Accounts Receivable… owed to you Accounts Payable… what you owe Petty Cash… for small office expenses Deposits… should be done daily Reconciling bank statements… ASAP What is an example of a small office expense? Office Finances Presentation of fees… never apologize for fees Collection… at time of service, before the patient leaves the office It is less manpower intensive to Purpose of Coding Abstract productivity data, drives manpower Manage workload data, demographics Financial restitution from insurance companies Accuracy is a must! Good business practice Good clinical picture for services provided by the Optometrist collect ASAP… What is classified as a “New Patient”? ICD-9 code is used to _________ a classification of disease? 2 New Patient “A ‘New’ Patient is one who has not received any professional service from the physician or another physician of the same specialty who belongs to the same group practice, within the past 3 years.” A CPT code identifies a type of __________ ? Importance of Documentation Proper documentation and proper coding is good business practice. In addition to getting reimbursed for the work you do, it can avoid provoking unpleasant audits and incurring large fines. Established Patient “An ‘Established’ Patient is one who has received professional services from the physician or another physician of the same specialty who belongs to the same group practice within the past 3 years.” (same tax ID) Diagnosis codes should be used at their ________ level of specificity? Confidentiality What is HIPAA? Health Information Portability & Accountability Act Minimum Necessary Principle Requires office to take reasonable steps to limit the use or disclosure of, and request for, PHI to the minimum necessary to accomplish intended purpose What is necessary every time PHI is released? Who enforces fraud in a practice? Privacy Act and HIPAA HIPAA governs the use and disclosure of protected health information (PHI) related to: Privacy Act and HIPAA HIPAA gives individuals the right to: Request restrictions on use or disclosure of their PHI Read and/or obtain copies of their records Amend their records Physical or mental health Know when and to whom their PHI has been disclosed Provision of health care Request alternate confidential communications Lodge complaints Payment for health care Who owns the patient’s chart? Whose rights are being protected? 3 Professional Issues… Professional Issues Hygiene and infection control Hand washing Instrument disinfection Contact lens disinfection Cross-contamination Sterilization things to consider Dress Appearance Office Communications Staff Relationships Office Authority Conflict Resolution Certification Continuing Education How often should you wash your hands? Roger Staubach #12 Dallas Cowboys! Why is it important to conduct yourself as a professional? Tear Film Layers oil aqueous Anatomy and Physiology snot What functions does each layer of the tear perform? Healthy Tears A complex mixture of proteins, mucins, and electrolytes coated by a lipid layer Lipid Secretion: Meibomian Glands Left: Transillumination of eyelid showing meibomian glands • Antimicrobial proteins • Growth factors & suppressors of inflammation Right: Secretion of lipid at lid margin • Soluble mucin helps stabilize tear film • Electrolytes for proper osmolarity (295-300) – pH slightly alkaline (7.4) • The lipid layer restricts evaporation to 5-10% of tear flow – Also helps lubricate Why is a tear salty tasting? Where does a contact lens rest? 4 Lipid Secretion: Meibomian Glands Anatomy What eye is this? (WC Posey, Diseases of the Eye, 1902) Transillumination of meibomian glands What function does the pupil have? How does the lipid layer aid in contact lens wear? (Transillumination image from Dry Eye and Ocular Surface Disorders, 2004) The Eyelid Eyebrows and Eyelashes Eyebrows Thickened ridge of skin with short hairs 7 Layers of the eyelids 1. Skin-thinnest layer 2. Subcutaneous connective tissue 3. Striated Muscle 4. Sub-muscular connective tissue 5. Tarsal plate or fibrous layer 6. Smooth muscle 7. Conjunctiva (Bulbar/Palpebral) How are Hordoleum and Chalazions treated? Lacrimal Apparatus Sometimes a person cannot produce natural tears that they might need some punctal plugs. Diverts perspiration Eyelashes Also protects Sebaceous glands at base of each lash are called Glands of Zeis which produce a lubricating fluid Fluid can harden and clog the gland, producing a stye or painless chalazion. If painful and infected it is called an external hordeolum Cataracts (myotonia) are caused by? Anatomy and Physiology of the Eyeball 3 Layers Fibrous Layer *Cornea *Sclera Vascular Layer *Choroid *Ciliary body *Iris Nerve Layer *Retina *Macula *Optic nerve What are the three main parts of the crystalline lens? What is the main function of each layer? 5 Conjunctiva Sclera An epithelial membrane which covers the anterior sclera and continues to the back surfaces of the lids to form a conjunctival sac Has blood vessels which can burst and cause subconjunctival hemorrhage Three parts White in color Primary function is protection Pierced posteriorly by the optic nerve Acts as insertion points for the six EOMs Junction between the cornea Bulbar Palpebral Fornix - where bulbar and and sclera is called the Limbus palpebral meet What is the total power of the eye? Cornea What is it called when blood vessels grow onto the cornea? What happens when a patient gets a scar in the visual pathway? Index of refraction is 1.37 Approximately .5mm in thickness Transparent Organ (no blood vessels / avascular) Primary function is refraction of light rays Refractive power approx + 45.00 D Name the mucus producing cell? Cornea Composed of 5 layers Epithelium…24 hr healing Outermost layer 5 cell layers thick Heals very quickly Does not scar Bowman's membrane- layer just under the epithelium NOTE: will scar Stroma – middle tissue that forms 90% of the cornea Descemet's membrane- thin elastic layer deep in the cornea Endothelium - only one cell layer thick; lines undersurface of the cornea, where it regulates corneal water content What is the crossover point for the nasal optic nerves? What cranial nerve is tied to corneal sensations? Endothelial detail with nuclei Aqueous Humor Confocal Scanner Epithelial detail with nuclei Which cells do not regenerate Epithelium or Endothelium? Manufactured by ciliary body Characteristics: Clear Watery consistency (99% H2O) Functions Refraction of light Intraocular Pressure (IOP) Probably nourishes posterior surface of the cornea and the crystalline lens Flows from posterior chamber through the pupil into the anterior chamber How does aqueous flow out of anterior chamber? 6 Crystalline Lens Crystalline Lens ...approx 12-14 diopters of power 3 things happen during accommodation: Pupils constrict Eyes converge Functions Lens gets thicker Refraction of light The crystalline lens contains a high degree of protein Accommodation Focus adjustment of the eye Presbyopia is the loss in accommodation Changes in the lens protein causes the lens to lose its transparency which is a condition termed "cataract" Aphakia is the absence of a lens. It can be removed during cataract extraction First noticed around age 40. Due to a loss in flexibility of the lens Name the three main parts of the lens? Ciliary Body Iris Most anterior portion of How much focusing power does the lens have? Located near the base of the vascular layer Gives the eye its color, i.e. blue eyes, brown eyes, etc. Consists of blood vessels, pigment and muscle tissue Regulates light Smaller with age the iris and posterior to it Composed of blood vessels and muscle fibers (ciliary muscle) Cilliary process produces aqueous What does the sphincter muscle control? Ciliary body is attached to suspensatory ligaments called? Nerve Layer - Retina Vitreous Chamber Functions: Visual Receptors are Cones and Rods Cones Refraction of light Internal support Spots in vision may be floaters in the vitreous Produce color vision Give improved acuity Used in day vision = “Photopic” = normal and high levels of illumination Rods…120 million Produce black and white vision Function in dim light = “Scotopic” = low level of illumination Cones and Rods… 6 million Post vitreous detachment How many chambers are inside the eye? Used under mesopic vision = between scotopic and photopic Both rods and cones are used. The _____ is the strongest refractive media and has about ____ diopters of power. 7 The retina (Cranial Nerve II) Pigment epithelium Vitreous Which cranial nerve controls the superior oblique muscle? Retina – 10 layers Outside of eye The levator palpebrae raises the eyelid and is innervated by CN #? Identification of Retinal Layers NFL ILM GCL IPL OPL Pigment epithelium Rods Cones Outer plexiform layer Horizontal cells Stratus OCT™ Bipolar cells IS/OS Amacrine cells RPE/CC IS/OS: Junction of inner and outer NFL: Nerve Fiber Layer ILM: Inner Limiting Membrane photoreceptor segments RPE: Retinal Pigment Epithelium GCL: Ganglion Cell Layer CC: Choriocapillaris Inner plexiform layer Choroid IPL: Inner Plexiform Layer OPL: Outer Plexiform Ganglion cells Nerve fiber layer Cross-sectional image of live tissue; a virtual biopsy Vitreous (inside of eye) Nerve Layer - Retina Nerve Layer - Retina Optic nerve head (optic Ora Serrata disc) No receptors - physiological blind spot Point of exit of optic nerve Appears yellow compared to the orange retina Land mark attachment site for choroid and retina Most anterior portion of retina Nearly all rods How many layers are in the retina? What is Pars Plana? 8 Anatomy and Physiology of the extraocular muscles Extra Ocular Muscles The Extra-ocular Muscles (EOM) Organized into an umbrella- like bundle among the orbital fat, orbital blood vessels and nerves Six muscles associated with eye movements Superior rectus (S.R.) Inferior rectus (I.R.) Medial rectus (M.R.) Lateral rectus (L.R.) Superior oblique (S.O.) Inferior oblique (I.O.) How many cranial nerves control these 6 muscles? Extraocular Muscles Medial Rectus - Most powerful, adduction, CN III Inferior Rectus - Primary is depression, CN III Lateral Rectus - Abduction, CN VI Superior Rectus - Primary is elevation What is the name of the point where the muscles come together? Muscles and Function LR6…SO4…3 Rectus Obliques Intorsion Extorsion Elevation Depression Which muscle close the eye lid and is innervated by cranial #7? An obvious upward/superior deviation of the eye is called? Extraocular Muscles Superior Oblique (SO)- has 3 functions; intorsion, depression and abduction; innervated by the 4th (trochlear) cranial nerve Inferior Oblique (IO)- 3 functions; extorsion, elevation, and abduction; innervated by the 3rd (oculomotor) cranial nerve Extraocular Muscles Medial Rectus (MR)- moves the eye inward from the straight-ahead position (adduction); innervated by the 3rd (Oculomotor) cranial nerve Lateral Rectus (LR)- moves the outward (abduction) from the straight-ahead position; innervated by the 6th (Abducens) cranial nerve Inferior Rectus (IR)- 3 functions; depression, extorsion, and adduction; innervated by the 3rd (Oculomoter) cranial nerve Proper alignment and muscle balance of the eyes is called? A definite and obvious turning of the eye is called? 9 Ocular Motility Muscle Balance Testing Cover Test Version - a conjugate movement of the 2 eyes. Both eyes Cover/uncover remain parallel during the movement Vergence - A disjunctive movement of the 2 eyes Alternating cover Hirschberg Test Convergence Location of corneal reflex Near triad of accommodation, pupil constriction, and convergence Divergence Which test checks for direction when using the cover test? A constant tendency for the eyes to turn from the norm is called? Extraocular Muscles Extraocular Muscles Medial Rectus Toward the nose (adduction) Lateral Rectus Away from the nose (abduction) Superior Rectus Up;towards the nose (elevation) Inferior Rectus Down;away from the nose (depression) Superior Oblique Rotates the top of the eye toward the nose;moves eye down Inferior Oblique Rotates the top of the eye away from the nose; moves eye up Where is the insertion points for these muscles? How many extra ocular muscles are there? Bony Orbit Orbit Openings of the orbit Purpose of openings Transmit arteries and/or veins to and from the orbit Transmit nerves to and from the orbit Types of openings Fissures (crevices/cracks) Foramina (holes) Major openings Optic foramen - II cranial nerve - Optic Nerve Supraorbital fissure - IV cranial nerve - Trochlear Nerve The transition zone between the sclera and the cornea is called? 1. 2. 3. 4. 5. 6. Frontal bone…forehead Ethmoid bone…weakest Palatine bone…smallest Zygomatic bone…strongest Lacrimal bone Maxillary bone The conjunctiva has two divisions, they are? 10 Cranial Nerves LR6SO4 3 Muscles Lateral rectus muscles #6 …abducens nerve Superior Oblique #4 …trochlear nerve All other muscles are controlled by #3 … oculomotor nerve Name the 3 chambers of the internal eye? Visual Pathway Objectives Anatomy Physiology The Orbit - Bones, etc. The Sinuses - Locations Human Body Planes External Structures - Eyelids - Conjunctiva - Eyelashes and Eyebrows Lacrimal System The outer layer of the eyeball is called? Visual Pathway Define the visual pathway Identify structures in the visual pathway Testing used for the visual pathway Identify defects within the visual pathway Anisometropia occurs when there is a _____________? Visual Pathway Physical Physiological Psychological What causes your physiological blind spot? Visual Pathway Visual pathway has seven structures Retina Optic Nerve Optic Chiasm Optic Tract Lateral Geniculate Body (LGB) Optic Radiations Visual Cortex …where vision occurs Antimetropia occurs when __________ ? Aniseikonia occurs when an object viewed by one eye is _________? 11 Optic Chiasm Retina Divided into four quadrants like the brain Temporal fibers do not Fovea at exact center Optic nerve head is located in cross Nasal fibers do cross nasal half Some fibers from the Each quadrant sees the exact macula cross while others do not opposite visual field What is an exudate? What part of the brain does the vision occur? What is papilledema? Visual Field Defects Common types of field defects Blind spots - Areas of blindness in the visual field Hemianopsia - Blindness in one half of the visual field of one or both eyes Homonymous heminopia Homonymous - Involving the nasal half of the visual field of one eye and the temporal half of the visual field of the other eye Incongruous - Is this possible? You be the judge Incongruous homonymous Binasal defect An area of blindness within a visual field is called? Review Questions The point where the upper and lower eyelids meet is called a. ora serrata b. canthus c. joint d. sphinx The blockage of the meibomian gland is called the Review Questions The eyelid will protect your eyes from… a. blinking b. dust particles c. stray tears d. a burning punctum What main muscles raises the eyelid? ___________ when it causes pain, and the _________ when it does not cause pain. Name the five layers of the cornea in order 12 Review Questions The drain port for tears is called? a. canal of Schlemm b. punctum c. lacrimal gland d. zonnule of Zinn In what layer of the eye will chronic diseases normally manifest? What structure prevents a contact from going behind the globe of the eye? Review Questions Review Questions What is the most anterior part of the retina. What is the total power of the Cornea, the crystalline lens assembly, and the overall eye? What is the most posterior layer of the retina? Review What are the layers of a tear film? Opia means what? Where is tear mucin produced? What is the difference between a tropia and a phoria? Why is the tear film important in contact lens wear? The optic nerve is which cranial nerve? Avascular means what? How many extra-ocular muscles are oblique? What function does the Canal of Schlemm have? What does the root word “papill” mean? Review Questions Identify the name for the 3 parts of the conjunctiva Review Questions _________ exist when the foveal lines of sight of the two eyes do not point at the same object. A. binocularity In what layer of the eye will the retina be found? B. strabismus C. conjunctivitis D. FB sensation What is the strongest bone of the bony orbit? Of the following all are anomalies of the binocular system except: What muscle of the lid would be involved in ptosis? A. strabismus B. Amblyopia C. anomalous correspondence D. conjunctivitis 13 Review Questions When the power of the crystalline lens correspond with axial length of the eye, so that parallel light rays are appropriately refracted to focus on the retina is called? A. emmetropia B. ammetropia C. hyperopia D. myopia An opacity of the crystalline lens is known as? A. photophobia B. cataract C. edema D. aphakia Review Questions Which test checks for eye movement and helps detect the dominate eye? A. muscle H B. cover test C. visual acuity D. myopia Glaucoma screening test that used puff of air onto the eye surface: A. NCT B. snellen C. amsler grid D. accommodation Review Questions Which test uses Pseudo Isochromatic Plates? A. IOP B. color test C. cover/uncover D. snellen This checks the power of the eye: A. NCT B. taking case history C. Autorefractor D. taking blood pressure Review Questions Which test is used to check six cardinal position of gaze for motility? A. Muscle H B. APD C. Amsler Grid D. Tropia Examination of the eye is performed by using a slit lamp or another name for slit lamp is: A. non-contact tonometer B. biomicroscope C. pupilometer D. lensometer Review Questions What is a good tear BUT? What device checks the brain-eye connection? What device measures the distance between the pupils? Ophthalmic Optics & Dispensing (20%) What device measures corneal thickness? 14 Face Framing Prescriptions Square face Wide forehead cheek and Oval face Components chin, round and rimless Sphere, cylinder, axis Add power Prism Prism base direction Any style, avoid low temples Diamond face Round face Wide forehead to small chin, choose small shallow ovals, rectangles, or geometrics Large heads and round chins, geometric shapes works well Ordering Heart face Oblong face Wide forehead gradually Long narrow face with a square chin, round or square lens will add dimension narrows to pointed chin, rimless glasses work best What is the Abbe or V-Value of a lens? Prescriptions: Decentration ED Prescriptions: Vertex Power D BL Vertex distance and effective power B Lenses gain minus or lose plus power as they are Decentration calculations A moved closer to the eye. Eye size plus distance between lenses minus patient’s PD divided by 2 Example: 50-22-140 pt pd 60 72 – 60 = 8 / 2 = 4 Conversely lenses gain plus or lose minus as they are moved away from the eye. What is the speed of light in a vacuum? This lens is said to be 50% lighter than glass? Prescriptions: Verification Instruments used to Verify Rx Lensometer Lens power and axis location Presence, amount and direction of prism Geneva Lens Clock Base curve Colmascope or Polariscope Progressive add markings Calipers Lens thickness Prescriptions: Snell’s Law Snell’s Law of Refraction Light traveling from air into denser material is bent toward the normal Light traveling from denser material into air is bent away from the normal Light striking material perpendicular to surface does NOT bend Normal = line perpendicular to the surface of mirror or lens drawn at the point of contact with the light ray, angles are measured from this line to the light ray Frequency is the number of times the crest or trough passes _______? A carrier and a segment describes what type of lens? 15 Prescriptions: Focal Length Calculations… Formula: (in meters) = Prescriptions: Light Rays Rays move from left to right F=1/D Focal length in meters (f ) = 1 / D (reciprocal of power in diopters) Example: The focal length of 2.00 D lens: f = 1 / 2.00 D f = .5 meter Wavelength is measured from _____ to _______ of waves? Prescription: Prism Prescribed when the two eyes do not align properly Can be induced when the optical centers of the lenses do not line up with the patient’s PD Converging Rays Diverging Rays The focal point forms a real image The focal point forms a virtual image Light always deviates toward the ______ of a prism? Prescription: Prism Displaces light Light bends toward base, Image displaced toward apex Prentice’s Rule- used to calculate induced prism Waves of the visual system is measured in _______ of a meter? What is the speed of light in a vacuum? Lenses: Convex & Concave Ophthalmic Lenses Properties of Light Refraction - Prism Plus lenses –prisms stacked base to base Prism bends light towards its base... apex Minus lenses – prisms stacked apex to apex The _____ theory state that light moves as waves like those in water? ...but displaces images towards its apex base 16 Ophthalmic Lenses Ophthalmic Lenses Properties of Light Refraction - Prism Refraction - Prism Minus lenses are prisms placed apex to apex... Plus lenses are prisms placed base to base... Light Rays Light Rays ...resulting in divergence ...resulting in convergence Vision & Ametropias Vision & Ametropias When light is not focused on the retina, an ametropia is present... for example, a myopic eye focuses light in front of the retina... ...a minus powered (diverging) lens shifts the focus back to the retina (focal length of eye + lens) E E E (unaided focal length of eye) Vision & Ametropias Vision & Ametropias A hyperopic eye focuses light behind the retina... ...a plus powered (converging) lens shifts the focus up to the retina (unaided focal length of eye) E E E (focal length of eye + lens) 17 Vision & Ametropias Vision...a&cylindrical Ametropias lens is prescribed to Astigmatism causes light along different axes to focus at different planes... compensate for astigmatism in the eyecreating a common focal point on the retina... E E E E (common focal lengths of eye + lens) (multiple focal lengths in unaided eye) Vision & Ametropias Vision & Ametropias ...as the crystalline lens ages, it loses its flexibility- and its ability to adjust focus... this condition is called presbyopia and typically becomes noticeable around age 40 E E E As previously mentioned, the crystalline lens enables the eye to focus on near objects... E accommodation Lenses: Index of Refraction Definition: A comparison, or ratio, of the speed of light in air to the speed of light in another medium Is a measure of the density of the material Values Speed of light in air in a vacuum: Air= 1.00 Water= 1.33 186,000 mps What is the wavelengths of visible light? Lens Materials: Glass Crown glass Flint glass Hi-Index glass IR: 1.52 IR: 1.65 IR: 1.9 Advantages: More scratch resistant, clearer optics Disadvantages: Heavier, less impact resistant One inch is equal to _______ mm? 18 Lens Materials: Plastic Lens Materials: Polycarbonate CR-39 Hi-Index plastic Polycarbonate IR: 1.49 IR: 1.58-1.70 Advantages: Lighter weight, more impact resistant compared to glass, easily tinted Disadvantages: More prone to scratches, less ultra-violet (UV) protection on untreated lens IR: 1.54-1.60 Advantages: Lighter weight, more impact resistant compared to plastic, naturally filters UV light. Disadvantages: More prone to scratches, chromatic aberration What does a higher index of refraction mean? The given density of any material is called __________? Lens Materials: Trivex™ Lens Options Polarized Trivex ™ Combats reflected glare IR: 1.53 Advantages: Lightest material available; less distortion; as impact resistant as polycarbonite, highly resistant to cracking around holes when used in drill mount frames; quality optics; natural UV protection. Disadvantages: Cannot be tinted darker than #2 The standard index of refraction in the industry is ________? Photochromatic Varies tint, works with UV Shatter resistant Trivex or polycarbonate Wrap-arounds Provides added side protection Lenses: Coatings Scratch Resistant Anti-Reflective Ultra-Violet Mirror Lenses: Tints #1- lightest Transmission 65-80% (greatest light transmission) #2 45-60% #3- darkest Transmission 15-40% (least light transmission) Polarized…filters glare Photochromatic Glass and plastic Which coating is good for patients having a hard time with glare at night? What is a great addition for fishing glasses? 19 Multifocals Frame Types Basic types and styles Styles Materials Add and Intermediate powers Temple styles Children Jump (prism)…slab-off… pts with anisometropia What does the boxing system determine? What part of the pupil is measured for a PAL? Frames: Multifocal Placement 1. Grinding of the distance portion on front of semi-finished lens 2. Semi-finished lens with modified distance portion 3. Grinding of the Rx surface 4. Bifocal lens with slab-off prism Ophthalmic Lenses Lens Types – Bifocals Flat-top bifocals are usually fit: to lower limbus (seg line @ lower lid) decentered 1.5mm in from Far PD Bifocal Seg Height Trifocal Seg Height How is a progressive lens measured? Ophthalmic Lenses Lens Types – Bifocals There are several types of bifocals suited to different needs... Flat Tops FT28 FT35 FT45 Smart Seg* Curve Top (Cosmolit) Executive (E-Line) Round Seg (Kryptok) Blended Ophthalmic Lenses Lens Types – Trifocals Trifocal lenses have three focal lengths... Distance Intermediate Near ...generally, the intermediate ADD is 50% of the near ADD 20 Frames: Parts & Verification Dispensing -Frame Alignment Front- Xing Verification Eyewire size Bridge Temple length How do you determine the frame PD? Coplanar Face form - positive and negative Nose pads - frontal, splay, vertical A negative face form creates what type of fit? Dispensing Fitting Standard alignment Adjustment Pliers Pad angling Needle nose Round-Flat jawed Temple Angling The tool in the picture is used for what purpose? Changing Height or Vertex Distance By changing the vertex distance, you change the focal point of the lens, changing the effective lens power and the lens ability to focus on the retina Common Frame Adjustment Problems - Vertex Distance Increase vertex- bend both end pieces in Decrease vertex- bend both end pieces out Increasing vertex distance effectively raises multi-focal height and vise versa Double D lens are what type of lens? Adjustment Problem/Unequal Vertex Distance Unequal temple spread Decrease temple spread on side that is closer (In - In) Increase temple spread on side that is farther from Move pad arms up will raise height of frame Move pad arms down will lower height of frame Lengthening pad arms will increase vertex distance face (out - out) Unequal temple tension and bends behind ears Shortening pad arms will decrease vertex distance What is the average vertex distance? A test used to determine if a patient has correctable vision? 21 Frame Adjustment - Pantoscopic Angle Increase panto - bend both temples down Decrease panto - bend both temples up Increasing panto will raise the frame front height on the face; however, it will effectively lower the multifocal and vice versa Pre-Testing Procedures (20%) Another name for the swinging flashlight test is? General Info Before using a piece of equipment with an adjustable eyepiece, you MUST adjust it to your eye Before performing a test be sure to know what you are testing and what is WNL Do not erase a medical record Interpupillary Distance Measurement Distance and near PD measuring ruler Pupillometer Monocular PD measurement 1 2 3 4 5 6 7 1st measurement 60 mm 1 2 3 4 5 6 7 2nd measurement 64 mm What is the best method of measuring a PD? A test used to determine defects within the 20 degree of the central macula? Pupillary Responses Pupil Testing Light the pupil for _____ seconds? Assure that the sensory pathway is working Direct and consensual responses to light Response to accommodation Explain the accommodation portion of the PERRLA. Assure that the sensory pathway is working Direct/consensual responses to light Response to accommodation APD What does an positive APD (+MG) identify? 22 Pupillary Response: Recording Example #1 P= pupils are E= equal R= round R= react to L= light and A= accommodation -/+RAPD (relative afferent pupillary defect Example #2: 5mm/4mm 2+ (reaction time) R & R (round & reactive) -/+ RAPD (also called Marcus Gunn pupil) Near Point of Accommodation Ability of the eyes to focus at near Binocular measurement Amplitude of accommodation Binocular or monocular measurement Distance measured in cm This is an ocular motility test that checks at least 6 cardinal positions? AC/A ratio is usually _______ in elderly patients Extra-Ocular Muscle Testing Cover Test Versions Assess heterophoria and heterotropia conjugate movements of the eyes together Vergence disjunctive movements of the eyes Pursuits Movement of the eyes while following a moving target Saccades Two separate tests - unilateral and alternate Tests are performed at distance and near Unilateral test is performed first Jumping movements from one target to another An exotropic patient’s eye would deviate in what direction? An orthophoric patient would have what type of eye deviation? Unilateral Cover Test Determines heterophoria or heterotropia Heterophoria=tendency Heterotropia=constant Determines frequency (constant or intermittent) Unilateral or alternating An alternating cover test determines what? Alternating Cover Test Determines the direction and magnitude of the tropia or phoria Eso-in Exo-out Hyper-up Hypo-down Hyper Exo Eso Hypo A left eye that deviates upward is classified as _______ ? 23 Ocular Motility Muscle-H Test Ocular Motility Patient instructions Appropriate target Proper illumination Proper distance Accurate recording Cover Test Cover Test Pt instructions Eye level position Proper fixation Procedures for cover/uncover Recording accuracy What does the Muscle H test check for? What is the difference between a tropia and phoria? Fusion/Suppression Confrontation Fields Fusion Currently tested on practical exam Performed at arms length Screening for gross visual field defects Blending of 2 images, one from each eye Suppression Subconscious inhibition of an eye’s retinal image Associated with strabismus Comparison of examiners visual field (known) to the patient’s (unknown) What is the highest degree of fusion called? True or False: A heminopsia can be identified performing a confrontation field? Case History ■ Chief Complaint…critical for insurance filing! ■ Reason for visit-recorded in patient’s own words ■ History of present illness ■ Detailed information on chief complaint ■ Medical/ocular history (Dx) ■ Family History (FHx) ■ Social history (age-appropriate) ■ Alcohol? Smoke? Occupation? Live alone? Case History Tested during the CPOT practical exam Components Medical and ocular history Patient Family Occupation and avocation Confidentiality HIPAA…how long are records maintained? Which part of the case history is used with insurance filing? 24 Ocular Symptoms Ocular History Rule out specific ocular problems Always ask how long has pt has symptoms Ask open ended questions and conditions, such as: Itching Burning Glaucoma Tearing Cataracts Redness Keratoconus Irritation Blurred vision Match the diseases to the structure… Other symptoms What is itching usually a sign for allergies? Define Visual Acuity Medications Name The measurement of the ability of the eye to see detail Amount taken Frequency Prescribed for Prescribed by Illegal drugs too! What does 5/400 mean on a visual acuity chart? Why is illegal drug use important? Procedure Always observe patient. No squinting. Why? When do you obtain pinhole acuity? Visual acuity better with one eye or two? Note any consistent pattern in the letters missed by the patient. Why? The Hardest Acuity What is the most difficult acuity you have ever taken Were you prepared for it? Are children difficult? What do you do with the parents? What happens when it is taking too long? What is the definition of acuity? 25 Procedure Patient unable to see Visual Acuity: Snellen Fraction the big “E” Walk up method (15/400, 10/400, 5/400) Count Fingers- CF @ _____ft Hand Motion- HM @______ft Light Location Light Perception How is “no light perception” documented? Types of Acuity Charts Snellen Metric (Bailey-Lovie) Low Vision Charts Illiterate Charts Landolt “C” or rings Tumbling “E” Numerator Represents the testing distance in feet or meters 20/_____; 6/______ Denominator Represents the distance at which the letter subtends a 5-minute angle of arc in distance or meters. Also referred to as the letter size. How would you document a patient that can only see the big “E” at 10 feet? Color Vision Should use pt’s current Rx Types of color vision tests Pseudoisochromatic plates (PIP) Farnsworth D-15 Farnsworth 100 hue Nagel Anomaloscope Lighthouse charts How do you document the PIP color test? Which of these charts is the standard VA chart in the US? Pseudoisochromatic Plates (PIP’s) Ishihara 14, 24, or 38 plates Plate #1 can be read by anyone, even those with color defects What happens if the patient can’t see this plate? Significance 8-10% Males .4% Females Green defect occurs most frequently This is strange due to the color of money Who passes the defected gene that causes color deficiencies? 26 Color Vision Classification Trichromatism Color Vision: Method for Testing Normal color vision Monocular vs. Binocular Protanope- without Prozac I see red Red deficiency Test distance 75 cm (30 inches) Deuteranope- The dew is on the grass Illumination Green deficiency Tritanope- King Titan of the ocean blue Macbeth daylight lamp Blue-yellow deficiency Illuminant C lamp What disease can be ruled out with monocular testing? Which sex (M/F) is most likely to have a color deficiency? Stereopsis Highest degree of depth perception Purpose of test Types of stereo tests Titmus stereo fly Randot Exam Equipment Retinoscope Ophthalmoscope Biomicroscope (Slit lamp) Phoropter Keratometer Fundus Camera Optical Coherence Tomographer Reindeer What type of glasses are used for this test? Visual Acuity Which one of these can be used during objective refraction? Angle of Arc Types and charts Snellen Feinbloom (Low Vision) Pre-school and Illiterate Allen picture cards Tumbling E’s HOTV Used to determine the detail in a letter Each of these arrows indicate one minute of arc When a child really wants glasses but there is no medical reason for them, What is it called? A person with normal color vision is called a _______ ? 27 Procedure Procedure Distance w/out RX Near w/out RX Distance with RX Near with RX Or a variation of the above Patient unable to see the big “E” Walk-up Count Fingers- CF @ _____ft Hand Motion- HM @______ft Light Projection (also known as light location) Light Perception What happens when you fail to identify cc or sc glasses? How many “minutes of arc” is the Big E? Pinhole The pinhole test is used to confirm whether or not refractive error is the cause of decreased visual acuity. 20/30 Procedure Always observe patient. No squinting. Why? When do you obtain pinhole acuity? Is visual acuity better with one eye or two? Note any consistent pattern in the letters missed by the patient. Why? A reduction in vision without any apparent cause is defined as? Conversion Cover Testing Cover Test Determines if there is a Feet to meters Multiply the denominator by .3 tropia Watch eye that is not being covered Cover/Uncover Test Meters to feet Divide the denominator by 3 Add a zero Determines if there is a phoria Watch eye that is being uncovered Direction of Deviation Eso (IN); Exo (Out); Hyper (Up); Hypo (Down) Inflammation of the eyelid is called ________ ? Most floating object identified in a patient’s vision is where in the eye? 28 Cover Test Cover Test Eye Movements Versions Pt instructions Eye level position Proper fixation Procedures for cover/uncover Recording accuracy A conjugate (together) movement of the eyes such that their meridians or lines of reference move in the same direction Vergence A disjunctive movement of the eyes such that the points of reference move in opposite directions. Ex: convergence What direction does the eye turn during adduction? Binocular Vision The ability of the eyes to focus from a near target to a far target is called? Is this a Tropia or Phoria/why? Fusion The act or process of blending, uniting or cohering vision in both eyes Phoria The orientation of one eye in the absence of an adequate fusion stimulus…latent, tendency of the eye to turn Tropia Binocular fixation is not present under normal seeing conditions…mostly obvious What happens when you cover this eye? How would you document this condition? What term is used to identify an out-turning of the eye? Binocular Vision Strabismus Tropia-manifest deviation of the eyes. Phoria is a latent deviation held in check by fusional vergence Frequency- constant/intermittent AC/A Ratio Accommodative convergence to accommodation Near point of convergence Units of prism diopters of convergence over diopters of accommodation What condition is this? What happens when the Right eye is covered? Ex: 4 /1D Explain the relationship between AC/A and the age of a patient? 29 Pupil Testing Eye Dominance Explain test Proper lighting Eye preference Eye used for monocular viewing or sighting Reasons for recording Monovision CTL Perform direct and consensual Swinging flashlight Evaluate near response Recording accuracy Is it required to have corrected vision for pupil testing? The rotation of the eye around an anteroposterior axis, such as fixation is called? Pupil Testing Pupil Testing Relative Afferent Pupillary Defect Adie’s Tonic Pupil-slow response to light Argyll Robertson-no reaction to light; reaction to Anisocoria- unequal pupil sizes “cor” = pupil “aniso”=difference Hippus- “jumping” pupil Most commonly seen in younger patients accommodation How long should the light be held in front on the eye during pupil testing? Congenital color vision defect normally impact vision in ______ eyes? Color Vision Types of tests Pseudo-isochromatic plates (PIP) Farnsworth D-15/100 Hue Nagel Anomoloscope Color Vision Procedure for PIP 30 inches/75cm distance…very important Near Rx Monocular Daylight lamp/Illuminant C lighting Record number of plates correct over number of plates tested (ex: 7/7; 4/7) A test that measures the eyes ability to move toward the midline and maintain binocularity is called _______ ? What is the most common color defect? 30 Stereopsis Keratometry Objective Refraction Procedure Types of tests Stereo Fly Focus eyepiece Randot Adjust instrument for Procedure patient Polaroid filters Alignment Suppression check Patient instruction Recording Primary meridian- 180/secondary- 90 Seconds of arc Take reading Record How much of the central cornea is measured? What is another name for a monochromat? Corneal Topography Measurement of the curvature of the anterior corneal surface. Pachymetry A Pachymeter determines thickness of the cornea by use of ultrasound Refractive surgery Glaucoma diagnosis What corneal disease can detected using this instrument? Tonometry Instruments Applanation- Goldmann…touches patient This is the industry gold std What medication is used during this test? How might IOP pressure be impacted by The thickness of a cornea? Tonometry-indentation Instruments Perkins Hand-held tonometer… touches patient What is the rule for a difference in IOP between the left and right eye? 31 Tonometry Instruments Tonopen… Touches pt Tonometry Instruments Non-contact (“Airpuff)…does not touch patient Significantly growing in use What type of medication is ?used with this test Tonometry Procedure Patient preparation Alignment Measurement Recording mmHg- millimeters of mercury Why is non-contact tonometry so popular? Visual Fields Types of Tests Confrontation Flat Field Tangent Screen Amsler Grid PerimetryGoldmann Bowl Automated What does squinting cause when performing tonometry? Which of these visual field test is the industry standard? Visual Fields Purpose is to determine the extent of the physical space that is visible to an eye in a given position Normal Visual Field parameters 60 degrees superior … up 75 degrees inferior…down 105 degrees temporally…out 60 degrees nasally… in Fixation loses on the HVF identifies a patients ______ ? Terminology Isopter Map of the circumference of a visual filed determined by a test object of a certain size Physiological Blind Spot 15 degrees temporal to fixation Represents the area in the retina occupied by the optic nerve head Scotoma Area of partial (relative) or complete (absolute) blindness within the confines of a normal visual field A during a Humphrey’s Visual Field false negative means what? 32 Special Procedures Ultrasound Terminology Isopter Map of the circumference of a visual filed determined A-Scan…sound waves in a straight line… axial length B-Scan…sound waves radiating… ultrasound Potential Acuity Meter (PAM)…cataracts by a test object of a certain size Physiological Blind Spot 15 degrees temporal to fixation Contrast Sensitivity…cataract, corneal opacity, or other disease Biomicroscopy (Slit Lamp)… Represents the area in the retina occupied by the optic nerve head Scotoma Surgery Area of partial (relative) or complete (absolute) blindness within the confines of a normal visual field Specular microscope What is the power of a lens that focuses light at 20mm? Terminology Hemianopsia-1/2 of visual field Quadranopsia- quadrant Homonymous- same side Congruous- completely identical What is the most posterior part of the retina? Blood Pressure Please understand the procedure Incongruous- not identical Correct position Explain it Hysterical- Tubular defect caused by patient’s Perform it emotional state Document it No more than 3 attempts The swinging flashlight test is used to detect what? What is the speed in which you regulate the release of pressure during the measurement Sphygmomanometry Procedures Interpretation First number=systolic pressure (the amount of force on the artery walls when the heart beats Second number=diastolic pressure (the amount of force when the heart is at rest) Incidence of Hypertension Readings Normal The “normal” for adults is approximately 120mmHg /between 70-80mmHg Abnormal Mild Hypertension 145-159mmHg/90-104mmHg Severe Hypertension 160mmHg or more/100mmHg or more Hypotension Below normal blood pressure What disease is a sure indication for BP? Can a technician determine if a patient has high blood pressure? 33 Abnormal Blood Pressures Systolic greater than 140* Diastolic greater than 90* Difference less than 30 between the Systolic and Diastolic Pressures.* These are general guidelines and may differ from the guidelines that the provider you are employed by uses. A patient is running late and rushes into the office, should the tech take a BP? How Is The Test Performed? Inflate the cuff to approximately 20-30 mmHg (millimeters of mercury) higher than the systolic pressure Open the valve slowly…2-3 secs Record the number from the sphygmomanometer when the pulse is first heard This is the systolic pressure How Is The Test Performed? Wrap the blood pressure cuff around the upper arm about 1 inch above the bend of the elbow Place the earpiece of the stethoscope into your ears Place the head of the stethoscope over the brachial artery Make sure that the valve is closed on the cuff. What ocular motility test checks 6 cardinal positions and is used to detect muscle abnormalities? How Is The Test Performed? Continue releasing the valve The pulse will disappear Record this number This is the diastolic pressure Release the rest of the air and remove the cuff What measurement is stereo testing recorded in? Does cuff size matter? Contact Lens Contact Lenses Pre-fit evaluation Palpebral fissure size…prevents glares issues Visual Iris Diameter- measure limbus to limbus Break up time- BUT- Tear Quality… Good tear BUT 15-20 seconds Minimal tear BUT 10-15 seconds Schirmer Tear test- Tear Quantity… Keratometry, Topography, Refraction Movement of a contact lens upon blinking should be _____ mm? 34 Spectacle Rx -5.00 –1.25 x 180 -5.00 -1.25 -6.25 (-5.75) Fitting Theory On “K”- same Rx Flatter than “K”- Less minus; more plus -5.00 (-4.75) Steeper than “K”- More minus;less plus If there is not enough or too much movement on a contact, what is the problem? Vertex adjusted Rx -4.75 –1.00 x 180 Spectacle RxCL-5.00 –1.25 X 180 Contact Lens Parameters Fitting Theory OZ+ 2SCW+2PCW = OAD Always consider the lacrimal tear layer, aka the Overall Diameter (OAD) lacrimal tear lens when fitting gas permeable lenses. Optical Zone OZ Secondary Curve (SC) Peripheral Curve (PC) Secondary Curve Width (SCW) Peripheral Curve Width (PCW) What is a minimal tear BUT? Ordering Procedures Eye OD OS RX -2.75 – 1.00 x 030 -3.00 – 2.00 x 070 BC Dia 8.7 14.4 8.9 14.0 Brand Remarks AV Toric Ciba Toric What is used to check the fit of a contact lens? TORIC What is a prism ballast used for? 35 Safety First! TRAUMATIC IRIDECTOMY Wash your hands! Procedure must be safe Explain procedure Explain do’s and don’ts Practical exams automatic failure for contact lens station What is the minimal information needed to order contacts? What is the correct term for bacteria free? Care and Handling Techniques Lens Care Systems Clean Rinse Disinfect & Store Protein Removal Why is it important to keep up with current trends? Progressive Evaluations History Visual Acuity Over-refraction Slit Lamp examination True/False: Hygiene is a indicator of contact lens compliance? Insertion and Removal Techniques Soft Patient comfort RGP More difficult Use gravity What is required before handling contact lens? Special Lens Designs Bifocal Toric Front Back Bitoric X-Chrome- color vision Rose K Orthokeratology CRT- Corneal Refractive Therapy Which of the above contacts lens are used with Keratoconus? 36 Contact Lens Complications FUSARIUM GPC- Giant Papillary Bacterial Ulcer Conjunctivitis Contact Lens Induced Papillary Conjunctivitis Keratitis-inflammation of the cornea Abrasion- rubbing off of the superficial layer GPC Acanthoamoeba Pseudomonas Which part of the conjunctiva is infected? Vision Therapy Convergence Insufficiency- difficulty Herpes Fusarium Keratitis What of the above is caused by a virus? Amblyopia Strabismic Due to an eye turn (tropia) Which eye is the dominate eye? turning eyes in Convergence Excess- Esophoria at near/orthophoria at distance What is another name for the high-plus lens magnifier? Vision Therapy Equipment Haidinger Brushes Vectograms Polarized sterogram; one image seen with one eye; the other with the other eye Tranaglyphs Trade name for redgreen targets used for vergences and to eliminate suppression Refractive Due to an uncorrected refractive error Ex Anopsia Non use or prolonged suppression Vision Therapy Eccentric Fixation…present under monocular conditions when retinal fixation is someplace other than the fovea Anomalous Retinal Correspondence … using another area other than the central macula is being used to view an object Tranaglyphs are used to identify what in vision therapy? Red Cap desaturation testing is used to determine what? 37 Low Vision Aids Low Vision Head Borne Microscope Classification Legal Blindness Large field of view, >20/200 BCV in the better eye or >20 degree visual field in the best eye Low Vision Individuals can be helped significantly by vision enhancement aids. Goals are the key to success Goals should be task oriented hands free Hand Held Magnifier Portable Stand Magnifier Stable Keratitis is an inflammation of this structure? Anomalous Retinal Correspondence is ____________ ? Low Vision Aids CCTV’S Electronic magnifier Telescope Magnify objects at distance Non-Optical Large print books, clocks, etc. Modified lighting Review Questions A test used to detect the presence of a phoria or tropia is A. Broad-H test B. interpupillary distance C. Cover test D. alternation exotropia test The central portion of the retina surrounding the fovea, CCTV responsible for acute vision is called? A. macula B. choroids Cornea Ciliary muscle When do headaches occur that come from uncorrected refractive error? Review Questions The distance between the centers of the pupil of each eye is called? A. pd B. retroscopic C. pantoscopic D. IOP Review Questions One of the most important procedures in any eye exam is ________? A. Filing out insurance forms B. taking a case history C. determining the dominate eye D. measuring pupillary distance Condition where the optic nerve is damaged from increased ocular pressure is? A. glaucoma B. blepharitus C. chalazion D. psuedophakia Test distance for color vision testing is: A. 16 inches B. 20 inches C. 25 inches D. 30 inches 38 Review Questions Which term relates to an obvious deviation of an eye? A. ortho B. phoria C. tropia D. bino A duction is defined as the observation of movement of: A. one eye while the opposite eye is occluded B. both eyes in opposite directions C. both eyes the same direction D. one eye while the opposite is opened Review Questions The highest degree of fusion is called A. flat fusion B. superimposition C. stereopsis D. simultaneous perception When the power of the crystalline lens correspond with axial length of the eye, so that parallel light rays are appropriately refracted to focus on the retina is called? A. emmetropia B. ammetropia C. hyperopia D. myopia Review Questions What type of stereo test is done on a monocular patient? Explain the finding of 20/40? Explain CVT 10/14? How is a +APD determined? Ophthalmic Optics and Dispensing (20%) What is a common test given binocularly? Ophthalmic Lenses Properties of Light Movement of Light As light spreads from a point, it forms a wavefront... Wave Theories Wave Theory Light moves like waves from the ocean Corpuscular Theory Light as being minute particles which originate from a light source 20 ft light goes parallel 39 Optical Principles of Light Reflection Visible wavelengths extend from 400-740 A rebounding of light by the surface of a medium nanometers (nm), 400nm being violet and 740nm being red. Light is radiant energy A change of wavelength is perceived as color change. such that it continues to travel in that medium but in an altered direction IN CID EN T RA Y ANGLE OF INCIDENCE NORMAL OR PERPENDICULAR ocular center ANGLE OF REFLECTION 400 500 600 700 Color vision testing is performed ________ correction at ______ inches? Refraction Y RA T EC FL RE What is a common household item that uses this concept? Minus and Plus lens The altering of the pathway of light from its original direction as a result of passing through one refractive medium to another with a different index of refraction Air Air ED Glass Glass Air If a patient develops a disorder after 6 months of age it is termed ________? Minus lens produce a virtual image Plus lens produce a real image Corrects for myopia Thinner in the middle Corrects for hyperopia Diverges light rays Thicker in the middle Minifies images Converges light rays Apex to apex lens Magnifies images Produce virtual focal Base to base lens points Cylinder power on the backside of lens Produces a real focal point Info only slide Visual Anomalies Ametropias An eye with insufficient focal power for its length focuses light in front of the retina... ...this refractive error is known as “hyperopia” uses a plus lens for correction Info only slide Visual Anomalies Ametropias Another refractive error can occur if every axis is not refracted evenly... ...this refractive error is known as “astigmatism” uses a compound lens for correction Info only slide 40 Back surface is called the Visual Anomalies Ametropias As the eye ages, the crystalline lens loses flexibility... ocular surface is close to – 6.00 diopter … minimizes distortion Base Curve Front surface is known as the base curve Base curve becomes steeper with plus lenses and flatter with minus lens ...this results in a condition known as “presbyopia” Should be measured prior Info only slide Info only slide Ophthalmic Lenses Prism Has two flat surfaces which are not parallel Properties of Light Refraction - Prism Has two purposes Deviation Correct curve lens to each order Light deviates towards the base Image is displaced towards the apex Prism bends light towards its base... apex Dispersion Results in chromatic abberrations All prisms break white light into its component colors... True/False: Amblyopia can impact binocularity? Ophthalmic Lenses Plus lenses are prisms placed base to base... ...but displaces images towards its apex base Vision & Ametropias ...a plus powered (converging) lens shifts the focus up to the retina (unaided focal length of eye) Light Rays E E ...resulting in convergence (focal length of eye + lens) 41 Ophthalmic Lenses Vision & Ametropias Minus lenses are prisms placed apex to apex... ...a minus powered (diverging) lens shifts the focus back to the retina (focal length of eye + lens) Light Rays E E ...resulting in divergence (unaided focal length of eye) Frame Selection Frame Measurements Materials Styling The BOXING System A = horizontal B = vertical DBL ED = longest ED Frame size Front, Bridge, Temples D BL B A Where do you begin frame alignment? Pg 153 blue book What is the average vertex distance? Basic Formulas Basic Formulas Box Measurements “B” Measurement Box Measurements Datum Line “DBL” “A” Measurement “FPD” B = 56 Datum (56/2) = 28 Seg Ht = 22 28-22 = 6 down A = 58 DBL = 20 FPD = 78 NPD = 60 (78-60)/2 = 9 in 42 Lens Enhancements Scratch resistant…CR39…12-24 months wear time Anti-reflective…increase light transmission Ultraviolet…filters UV upto 400nm…polycarb! Mirror…reflect light striking the lens Sports Coating…snow, sea, land Tints: pink, yellow, gray, brown, green - Tint #1 – 65-80 light transmission - Tint #2 – 45-60 light transmission - Tint #3 – 15-40 light transmission Photochromatic…change due to radiant energy Dispensing Fitting Standard alignment Adjustment Pliers Pad angling Needle nose Round-flat jawed angling Can be glass or plastic (1989) The higher the index of refraction, the _______ the lens material? What does “DBL” stand for? Special Prescription Considerations Aphakia High minus…myodisc Industrial/Occupational ANSI standards Occupational bifocals Other What is a balanced lens? T/F An Aphakic lens is a high minus lens? Index of Refraction= n Speed of light in air (in a vacuum) 186,000 miles per second Standard reference in the optical industry n= 1.530 Index of Refraction (n) of materials is determined by how much the material changes the speed of light when it passes through Air- n=1.00 Plastic- n= 1.49 Cornea - n= 1.37 Formula for index of refraction is ___speed of light in air________ speed of light in the material How much lights slows down when passing through a material = index of refraction This type of lens forms a virtual focal point? Focal Length Calculations D = 1/f’ Diopters = ¼ meters = 0.25D F= power in Diopters f’= focal length in meters The shorter the focal length the greater the power The greater the focal length the lesser power Prescriptions: Prentice’s Formula Prentice’s Prism Formula – if the patient is not looking through the optical center of the lens that has power, they are looking through prism Optical Center This type of lens forms a real focal point? Induced Prism When the axial length of the eye corresponds with the power of the crystalline lens, it is called _______ 43 Prescriptions: Prentice’s Formula Prism = Power x Decentration in cm Prism = lens power (in diopters) multiplied by d in cm (Where d = amount the patient PD varies from the major reference point in cm) Apex …the image is deviated toward the apex Base…light deviates toward the base Spherical Lens A lens with the same curvature across the surface Toric /Cylindrical Lens A lens that differs in curvature across the surface Cylinder axis is aligned with sphere power and the EX: -4.00(power) x .5cm (decentration in cm) = 2 prism diopters total cylinder power is 90 degrees away Sphero-cylindrical lens: are also called compound lens The higher the power, the more critical the measurement A person with a esotropic eye requires base _____ prism? “Blephar” is a root word meaning _______ ? Multifocals Progressive Add Lenses (PAL) A lens that has more than one focus distance Fused multifocals One-piece multifocals Distance zone Carrier lens Minimizes image jump Transition zone Near zone Larger lines means more image jump 7mm 17mm No vision zone 28mm Segment or add power “Kerat” is a root word meaning ___________ ? The area is which a patient can see on a PAL is called _____ _______ ? Terminology Optical Cross Diagram that denotes the dioptric power in the two principal meridians of a lens Front surface power + back surface power equals the power of the lens The purpose of the optical cross is to understand the concept of the lensometer, transposition and the make up of the lens Diopter … the measure of lens power or amount of surface curvature The steeper the curve the greater the power/the flatter the curve the lesser the power Optical Center … no deviation of light and no prism Datum line = half of the “B” measurement Equivalent power …Add half of the cylinder to the sphere power Refractive power …Power of the lens Effective power… Back vertex power Vertex distance Distance along the line of sight from the back surface of the lens to the cornea What two parts of an Rx denotes astigmatism? What type of lens has the same power is all axis? 44 Power Cross… Optical Cross… Cartesian coordinate systems front and back surface measurements Base Curve +6.00 -7.50 -7.00 +6.00 Front - 1.00 - 1.25 Use algebra (those in the same axis) to determine total lens power Rx is -1.00 – 0.50 x 180 on a +6.00 base curve Optical Cross minus cylinder (1 min) - 2.50 1 090 + 3.25 + 1.75 110 2 030 +3.25 4 035 - 1.25 + 2.50 Optical Cross minus cylinder 090 - 2.50 -1.25 -1.25 X 090 025 -1.75 120 125 110 115 -4.25 - 2.50 3 2 090 + 1.75 + 2.50 030 4 - 2.75 020 - 1.25 180 025 1 - 2.50 090 -2.50 + 1.25 X 180 +3.25 4 035 - 2.75 +3.25 -1.50 X 020 +3.25 030 115 3 025 -2.75 -1.50 X 115 -1.75 5 125 035 +3.25 – 5.00 X 125 + 3.25 + 1.75 110 2 -4.25 115 3 020 - 2.75 025 -4.25 + 1.50 X 025 +1.75 + 1.50 X 110 030 +3.25 -1.75 -1.75 5 - 1.25 020 -4.25 Optical Cross plus cylinder 120 120 2 +2.50 – 3.75 X 030 180 1 + 1.75 110 - 1.25 + 2.50 Optical Cross plus cylinder (1 min) - 1.25 + 3.25 4 5 If you don’t get all of these correct, please see me after class + 3.25 180 1 3 020 031 To take an RX off the Optical Cross in Minus Cylinder Form: Start with the most plus sphere power (use your number line) Your axis is “married” to your sphere Your cylinder is the distance traveled between the sphere and number 90 degrees away (same as using the power wheel on the lensometer) - 1.25 115 -4.25 - 2.75 120 121 090 Measure back surface in horizontal and vertical directions 180 +1.50 090 Measure front surface in the horizontal and vertical directions - 1.25 180 Total lens power Back 090 090 - 2.50 - 4.50 -1.50 + 2.50 125 - 1.25 -1.25 + 3.75 X 120 035 5 125 -1.75 + 5.00 X 035 45 Prescriptions: Optical Cross Optical cross is a diagram that denotes the dioptric power in the two principal meridians of a lens. One meridian is the sphere power One meridian is the cylinder power Hint: Think of the value of the numbers as they are read off of the lensometer wheel. Optical Cross Steps Step 1 draw a number line - ------------------------------- + 3 2 1 0 1 2 3 Step 2 read the question (plus or minus cylinder) Start in the direction of the less power…document it Document the axis of this power Calculate the distance traveled from set number to termination…this is the cylinder power is the lens What ocular condition does a patient wearing – 4.00 DS lens have? What type of contact lens is used to correct for astimatism? Prescriptions: Optical Cross Optical Cross Example Prescriptions: Transposition Transposition Step 1 = Combine the sphere and cylinder power + 3.00 Plus cylinder notation: +3.00 +2.00 x 090 180 + 5.00 Minus cylinder notation: +5.00 -2.00 x 180 090 Hint: The sphere is “married” to the axis; the cylinder is the distance between the numbers on the cross mathematically Step 2 = Change the sign of the cylinder Step 3 = Change the axis by 90 degrees Hint: When combining positive and negative numbers, think in terms of money. Example: -2.00 combined with +0.50 If you are $2.00 “in the hole” and you deposit $0.50, what is your balance? Answer: $1.50 “in the hole”, or -1.50. Prescriptions: Transposition (1 min) Prescriptions: Transposition -1.00 +2.00 X 160 = -1.00 +2.00 X 160 = +1.00 -2.00 x 070 +1.25 -0.75 x 030 = +1.25 -0.75 x 030 = +0.50 +0.75 x 120 Plano +1.00 x 090 = Plano +1.00 x 090 = +1.00 -1.00 x 180 Transposition Examples Transposition Examples 46 Optical Cross Optical Cross - 2.50 - 4.50 - 1.25 +1.50 121 090 031 180 - 2.50 - 4.50 - 1.25 +1.50 121 090 031 180 To take an RX off the Optical Cross in Minus Cylinder Form: To take an RX off the Optical Cross in Minus Cylinder Form: Step 1 Start with the most plus sphere power (use your number line) Step 1 Start with the most plus sphere power (use your number line) Step 2 Your axis is “married” to your sphere Step 2 Your axis is “married” to your sphere Step 3 Your cylinder is the distance traveled between the Step 3 Your cylinder is the distance traveled between the sphere and number 90 degrees away sphere and number 90 degrees away L -1.25 – 3.25 X 090 R +1.50 – 4.00 X 121 Find the answers to the above equations, you 1 minute Find the answers to the above equations Transposition Transposition 1 Minute Drill Step 1 = Combine the sphere and cylinder power Step 1 = Combine the sphere and cylinder power mathematically Step 2 = Change the sign of the cylinder Step 3 = Change the axis by 90 degrees EX: +2.00+1.00x080 +3.00-1.00x170 The purpose of transposition is to change the same prescription into a different form Transposition 1 Minute Drill Step 1 = Combine the sphere and cylinder power mathematically Step 2 = Change the sign of the cylinder Step 3 = Change the axis by 90 degrees 1. + 1.75 – 0.75 X 030 2. – 2.25 + 1.00 X 170 3. – 1.75 + 2.00 X 125 a. + 1.00 + 0.75 X 120 a. – 1.25 – 1.00 X 080 a. + 0.25 – 2.00 X 035 mathematically Step 2 = Change the sign of the cylinder Step 3 = Change the axis by 90 degrees 1. + 1.75 – 0.75 X 030 2. – 2.25 + 1.00 X 170 3. – 1.75 + 2.00 X 125 Spherical Equivalent -Step 1 Take half the cylinder and add algebraically to sphere - Step 2 Drop the cylinder and axis and write sphere only EX. -2.00 -0.50 X 145 (half the cylinder) -0.25 (add to sphere) 0.25 + 2.00 Answer: -2.25 Sph 47 Spherical Equivalent 1 Minute drill Spherical Equivalent 1 Minute drill -Step 1 Take half the cylinder and add algebraically to sphere - Step 2 Drop the cylinder and axis and write sphere only -Step 1 Take half the cylinder and add algebraically to sphere - Step 2 Drop the cylinder and axis and write sphere only 1. – 2.25 – 1.00 X 120 2. + 1.00 – 2.00 X 090 3. + 0.75 – 1.50 X 150 1. – 2.25 – 1.00 X 120 2. + 1.00 – 2.00 X 090 3. + 0.75 – 1.50 X 150 a. – 1.75 Sph b. Plano c. Plano (no glasses) Prescriptions: Decentration Decentration 1 minute drill Decentration calculations Decentration calculations Eye size plus distance between lenses minus patient’s PD divided by 2. Eye size plus distance between lenses minus patient’s PD divided by 2. Example: 52-20-145 pt PD 62 1. 48 – 22 – 145 52+ 20 – 62 = 10 / 2 = 5 2. 52 – 22 – 145 pt/pd 64 pt/pd 66 3. 58 – 20 – 140 pt/pd 67 Remember the measurements are in mm Decentration 1 minute drill Decentration calculations Eye size plus distance between lenses minus patient’s PD divided by 2. 1. 48 – 22 – 145 pt/pd 64 pt/pd 66 3. 58 – 20 – 140 pt/pd 67 2. 52 – 22 – 145 Remember the measurements are in mm Prescriptions: Prentice’s Formula Prentice’s Prism Formula – if the patient is not looking through the optical center of the lens that has power, they are looking through prism a. 3mm a. 3.5mm a. 6.6mm Remember the measurements are in mm Optical Center Induced Prism 48 Prentice’s Formula Prentice’s 1 minute drill Prentice’s rule Prentice’s rule (Please check mm) D X d (mm) = ________ 10 = prism in diopters D= lens power in diopters d = decentration D X d (mm) = ________ 10 (Please check mm) 1. How many prism diopters are in: 2.5 diopters and 4mm 2. How many prism diopters are in: 3 diopters and 6mm 3. How many prism diopters are in: 5 diopters and 5mm = prism in diopters D= lens power in diopters d = decentration Prentice’s 1 minute drill Prentice’s rule = prism in diopters D= lens power in diopters d = decentration D X d (mm) = ________ 10 (Please check mm) 1. How many prism diopters are in: 2.5 diopters and 4mm a. 1 2. How many prism diopters are in: 3 diopters and 6mm a. 1.8 3. How many prism diopters are in: 5 diopters and 5mm a. 2.5 Prescriptions: Focal Length Calculations Formula: f (in meters) = 1/D Focal length in meters (f) = 1 / D (reciprocal of power in diopters) Example: The focal length of 2.00 D lens: f = 1 / 2.00 D f = .5 meter Focal Length Calculations Focal Length Calculations F = 1/f’ F = 1/f’ (meters) F= power in Diopters f’= focal length in meters Example: F = 1/20(m) = .5 diopters (meters) F= power in Diopters f’= focal length in meters 1. what is the power of a lens with a 20cm focal length? 2. what is the power of a lens with a 40 cm focal length? 3. what is the power of a lens with a .8m focal length? Make sure you read the questions carefully? Make sure you read the questions carefully? 49 Focal Length 1 Minute drill F = 1/f’ (meters) 1. what is the power of a lens with a 20cm focal length? 1. 5 diopters 2. what is the power of a lens with a 40 cm focal length? 1. 2.5 diopters 3. what is the power of a lens with a .8m focal length? 1. 1.25 diopters Reading Prescription -Take the “add” portion of the prescription and algebraically combine it to the sphere of the Rx -Keep the cylinder and axis the same Ex. -3.00 -1.00 x 090 -2.00 -0.75 X 180 Add power +2.25 Reading Rx: -0.75 -1.00 X 090 +0.25 -0.75 x 180 Make sure you read the questions carefully? Vertex Distance A distometer is used to determine the vertex distance, which is the distance from the anterior cornea to the back of the lens. More plus power is required as a lens comes closer to the retina. Conversion Feet to meters Multiply the denominator by .3 Meters to feet Divide the denominator by 3 Add a zero One meter = 39.6 inches … or use 40 inches … one inch is equal to 025 meters Optometric Math MULTIPLICATION AND DIVISION OF LIKE AND UNLIKE SIGNS When Multiplying or dividing two numbers with like signs i.e., both plus (+) or both (-) the answer will always be a plus (+) sign. This means that if you multiply or divide two plus (+) numbers you will get a plus (+) answer and if you multiply or divide two minus numbers you will get a plus (+) answer Optometric Math MULTIPLICATION AND DIVISION OF DECIMALS A decimal number is just a whole number and a fraction written together in decimal form. Any multiplication or division by 10, 100, 1000, etc. simply moves the decimal place to the left or right. For example, multiplying a decimal by 10 would move the decimal point 1 place to the right 7.75 x 10 = 77.5 50 Optometric Math Optometric Math MULTIPLICATION OF DECIMALS. Decimals are multiplied exactly like whole numbers and then the decimal point is added. For example, you would multiply 25 x 25 in this way: DIVISION OF DECIMALS. Divisions may be written in the form a=c c b or a/b = c or b/a where "a" is the DIVIDEND, "b" is the DIVISOR, and "c" is the QUOTIENT. As with multiplication, you divide decimals exactly like you do whole numbers and then you find the decimal place. For example: dividing 126 by 6 gives 21 as an answer. Optometric Math METRIC SYSTEM The metric system is based on decimals. Changing from one unit to another requires only the movement of the decimal place. The table below shows the meter, which is the standard unit of length, and the parts of a meter that we will be concerned with in Optometry. It also shows the standard abbreviations and the number of units in a meter. 1 meter (m) = 1 meter decimal is relatively easy. Note in the table above that there is a difference of 2 zeros between centimeters and meters, 3 zeros between millimeters and meters, and 1 zero between millimeters and centimeters. This means that when converting between: If you need a length, in inches, converted to centimeters or millimeters, first convert the inches to meters (divide by 40) then convert to the desired unit by moving the decimal place. Conversely, if you wish to convert from cm or mm to inches, then first convert to meters by moving the decimal and multiply by 40 to convert the meters to inches. a. Meters and centimeters move the decimal 2 places. b. Meters and millimeters move the decimal 3 places. place Optometric Math Deciding on which direction (right or left) to move the decimal 100 centimeters (cm) = 1 meter 1000 millimeters (mm) = 1 meter Converting inches into meters Dealing with the problem of how many places to move the c. Centimeters and millimeters move the decimal 1 10 decimeters (dm) = 1 meter requires thinking about whether you should have more or less of the unit that you desire. For example, if you are given a length in meters and require the length in centimeters, then you must have more centimeters than you had meters because each centimeter is smaller than each meter. This means that you would move the decimal 2 places TO THE RIGHT. Conversely if you were converting from centimeters to meters, you have to move the decimal place to the left 2 places. A meter is much larger unit of length than a centimeter, thus you would have to have fewer meters than you had centimeters. All of the possible metric conversions you will have to make are listed on the next page: Memorize them; if necessary Optometric Math When Converting m to cm cm to mm m to mm mm to m mm to cm cm to m Move Decimal 2 places right 1 place right 3 places right 3 places left 1 place left 2 places left 51 Optometric Math 1 Min drill Convert the unit of length on the left to the units requested on the right. 1. 42 m _____cm _____m 2. 500 mm _____cm 3. 80 in _____mm _____in Convert to SVN or Near Rx only + 1.25 – 0.75 X 125 + 1.75 – 1.00 X 090 Add 1.50 New Rx +2.75 -0.75 X 125 +3.25 – 1.00 X 090 - 1.50 – 1.50 X 035 - 0.75 – 1.00 X 150 Add 2.00 1. 42 m 3. 80 in 5. 200 mm Convert the unit of length on the left to the units requested on the right. 2. 500 mm 4. 0.025 cm Optometric Math Step 1 Add the add power to the sphere power and write it as the new sphere power Step 2 Write the new complete Rx Sph, Cyl, and Axis 4200 cm 4. 0.025 cm 5. 200 mm .5m 200cm .0025 mm 8in Convert to SVN or Near Rx only 1 min drill + 3.25 – 0.75 X 125 + 1.75 – 1.00 X 090 Add 2.50 - 4.50 – 1.50 X 035 - 1.75 – 1.00 X 150 Add 2.00 Step 1 Add the add power to the sphere power and write it as the new sphere power Step 2 Write the new complete Rx Sph, Cyl, and Axis New Rx +0.50 -1.50 X 035 +1.25 – 1.00 X 150 Convert to SVN or Near Rx only Math Formulas Cont… + 3.25 – 0.75 X 125 Step 1 Add the add power to the sphere power and write it as the new sphere power Prentiss Rule Step 2 Write the new complete Rx Sph, Cyl, and Axis Transpose plus/minus cylinder + 1.75 – 1.00 X 090 Add 2.50 New Rx +5.75 -0.75 X 125 +4.25 – 1.00 X 090 - 4.50 – 1.50 X 035 - 1.75 – 1.00 X 150 Add 2.00 Convert focal length to Diopters Convert diopters length to focal Convert to Near Rx Calculate the optical cross Calculate decentration New Rx -2.50 -1.50 X 035 +0.25 – 1.00 X 150 52 Review Questions 3 minutes -1.00 -1.00 x 090 transpose Answer______________ - 0.50 -2.00 x 008 transpose Answer______________ -1.00 -1.50 x 160 transpose Answer______________ - 5.00 -3.00 x 088 transpose Review Questions -1.00 -1.00 x 090 transpose Answer -2.00 + 1.00 X 180 - 2.50 + 1.50 x 103 transpose Answer______________ Answer -2.50 + 2.00 X 098 -1.00 + 0.50 x 162 transpose Answer______________ Answer -2.50 + 1.50 X 070 Answer______________ Answer - 0.50 – 0.50 X 072 + 2.50 + 2.50 x 103 transpose Answer pl – 2.50 X013 Answer – 8.00 + 3.00 X 178 -2.50 + 1.00 x 029 transpose Answer______________ Review Questions 1 minute drill Put the following Rx on the Optical Cross -2.00 -1.00 x 080 -1.00 + 0.50 x 162 transpose - 5.00 -3.00 x 088 transpose Answer______________ -3.00 -1.50 x 095 transpose Answer – 1.00 – 1.50 X 013 -1.00 -1.50 x 160 transpose + 2.50 + 2.50 x 103 transpose Answer______________ - 2.50 + 1.50 x 103 transpose - 0.50 -2.00 x 008 transpose -3.00 -1.50 x 095 transpose -2.50 + 1.00 x 029 transpose Answer – 1.50 – 1.00 X 119 Answer – 4.50 + 1.50 005 Review Questions Put the following Rx on the Optical Cross -3.00 – 2.50 x 107 -2.00 -1.00 x 080 -3.00 – 2.50 x 107 -3.00 090 -2.00 080 -5.50 -300 Review Questions 90 Seconds Give the spherical equivalent to the following prescripts -2.00 -1.00 x 080 -1.00 -2.00 x 010 +2.00 -1.00 x030 -3.00 – 0.50 x 070 +3.00- 1.00 x 060 Answer ____________________ Answer ____________________ Answer ____________________ Answer ____________________ Answer ____________________ 017 107 Review Questions Give the spherical equivalent to the following prescripts -2.00 -1.00 x 080 -1.00 -2.00 x 010 +2.00 -1.00 x030 -3.00 – 0.50 x 070 +3.00- 1.00 x 060 Answer -2.50 Sph Answer –1.50 Sph Answer +1.50 Sph Answer –3.25 Sph Answer +2.50 Sph 53 Review Questions Convert the following Rx to Near Vision Only aka NVO, SVN, reading glasses -2.00 -1.00 x 080 -1.50 -2.00 x 180 +3.00 OU Answer ________________ ________________ -1.00 – 0.50 x 010 -2.00 -0.75 x 100 +1.25 OU Answer________________ ________________ -4.00 -0.25 x 090 -1.00 -0.50 x 098 +2.00 OU Answer ________________ ________________ +2.50 -1.00 x 090 +1.00 -0.75 x 180 +2.25 OU Answer ________________ ________________ Review Questions 1 minute drill Transpose the following Rx from plus cylinder form to minus Review Questions Convert the following Rx to Near Vision Only aka NVO, SVN, reading glasses -2.00 -1.00 x 080 -1.50 -2.00 x 180 +3.00 OU Answer + 1.00 -1.00 X 080 + 1.50 -2.00 X 180 -1.00 – 0.50 x 010 -2.00 -0.75 x 100 +1.25 OU Answer +0.25 -0.50 X 010 -0.75 -0.75 X 100 -2.00 +1.00 x 090 Answer ______________ -1.00 +3.00 x 070 Answer ______________ -1.00 +1.50 x 010 Answer______________ - 0.50 +2.00 x 145 Answer______________ -3.00 +2.00 x 095 Answer______________ Review Questions 1 minute drill Convert the following prescription from minus cylinder to plus cylinder format -1.00 -1.00 x 090 Answer______________ - 0.50 -2.00 x 008 Answer______________ -1.00 -1.50 x 160 Answer______________ - 5.00 -3.00 x 088 Answer______________ -3.00 -1.50 x 095 Answer______________ -4.00 -0.25 x 090 -1.00 -0.50 x 098 +2.00 OU Answer -2.00 -0.25 x 090 +1.00 -0.50 x 098 +2.50 -1.00 x 090 +1.00 -0.75 x 180 +2.25 OU Answer +4.75 – 1.00 x 090 +3.25 – 0.75 x 180 Review Questions Transpose the following Rx from plus cylinder form to minus cylinder form cylinder form -2.00 +1.00 x 090 Answer – 1.00 – 1.00 x 180 -1.00 +3.00 x 070 Answer + 2.00 – 3.00 X 160 -1.00 +1.50 x 010 Answer + 0.50 – 1.50 x 100 - 0.50 +2.00 x 145 Answer + 1.50 – 2.00 x 055 -3.00 +2.00 x 095 Answer -1.00 – 2.00 x 005 Review Questions Convert the following prescription from minus cylinder to plus cylinder format -1.00 -1.00 x 090 Answer – 2.00 + 1.00 x 180 - 0.50 -2.00 x 008 Answer – 2.50 + 2.00 x 098 -1.00 -1.50 x 160 Answer - 2.50 + 1.50 x 070 - 5.00 -3.00 x 088 Answer – 8.00 + 3.00 x 178 -3.00 -1.50 x 095 Answer – 4.50 + 1.50 x 005 54 Prescriptions: Optical Cross Optical cross is a diagram that denotes the dioptric power in the two principal meridians of a lens. Optical Cross Steps Step 1 draw a number line - ----------------------3 2 1 0 1 2 3 + Step 2 read the question (plus or minus cylinder) Start in the direction of the less power…document it Document the axis of this power Hint: Think of the value of the numbers as they are read off of the lensmeter wheel. Prescriptions: Transposition Transposition Calculate the distance traveled from set number to termination Prescriptions: Transposition -1.00 +2.00 X 160 +1.00 -2.00 x 070 +1.25 -0.75 x 030 +0.50 +0.75 x 120 Plano +1.00 x 090 +1.00 -1.00 x 180 Step 1 = Combine the sphere and cylinder power mathematically Step 2 = Change the sign of the cylinder Step 3 = Change the axis by 90 degrees Hint: When combining positive and negative numbers, think in terms of money. Example: -2.00 combined with +0.50 If you are $2.00 “in the hole” and you deposit $0.50, what is your balance? Transposition Examples Answer: $1.50 “in the hole”, or -1.50. Optical Cross Transposition - 2.50 - 4.50 - 1.25 +1.50 121 090 180 mathematically 031 To take an RX off the Optical Cross in Minus Cylinder Form: Start with the most plus sphere power (use your number line) Your axis is “married” to your sphere Your cylinder is the distance traveled between the sphere and number 90 degrees away Step 1 = Combine the sphere and cylinder power Step 2 = Change the sign of the cylinder Step 3 = Change the axis by 90 degrees EX: +2.00+1.00x080 +3.00-1.00x170 The purpose of transposition is to change the same prescription into a different form 55 Spherical Equivalent Prentice’s Formula -Half the cylinder and add algebraically to sphere -Drop the cylinder and axis and write sphere only Prentice’s rule EX. -2.00 -0.50 X 145 (half the cylinder) -0.25 (add to sphere) 0.25 + 2.00 Answer: -2.25 Sph D X d (mm) = ________ 10 = prism in diopters D= lens power in diopters d = decentration Prescriptions: Decentration Decentration calculations Eye size plus distance between lenses minus patient’s PD divided by 2. Example: 52-20-145 pt PD 62 52+ 20 – 62 = 10 / 2 = 5 Refractive Status of the Eye and Binocularity (12%) Common Ocular Diseases Amblyopia Ametropia Anisometropia Aphakia ARMD Astigmatism Blepharitis Cataracts Chalazion Conjunctivitis Diabetic Retinopathy Emmetropia Floaters Emmetropia Glaucoma Hyperopia Hordeolum Keratoconus Myopia Pinguecula The refractive condition where parallel light rays focus on the retina when the eye is at rest The image of an object at 2,000 yards focuses directly on the fovea Psuedophakia Ptygerium Retinal Detachments Subconjunctival Hemorrhage What is the medical term when an “other than normal” ocular condition exist? 56 Hyperopia A refractive condition where parallel light rays focus behind the retina when the eye is at rest Termed farsightedness Patient may have 20/20 vision at distance and near What type of lens is used to correct hyperopia? Astigmatism Myopia A refractive condition where parallel light rays focus in front of the retina when the eye is at rest Termed nearsightedness Patient may have 20/20 vision at near, but distance vision will be reduced Myopia is corrected with what type of lens? Astigmatism A refractive condition where different meridians of the eye have different powers Corrected by lenses which incorporate cylinder power Usually due to different curvatures of the cornea TRUE/FALSE: A cylindrical lens correct for astigmatism? What type of astigmatism cannot be corrected with lens? Seeing is: VISION… ability to see detail SIGHT… ability to see ACCOMMODATION…ability to see from far to near FACILITY… ability to move your eyes around and still see TRUE/FALSE: A 60 y/o has a high AC/A ratio? Astigmatism Simple- one ray is focused on the retina; the other is focused either in front of (myopic) or behind (hyperopic) Compound- both rays are focused in front of (myopic) or behind (hyperopic) Mixed- one ray is focused in front (myopic) and one ray is focused behind (hyperopic) Irregular is caused by a defect in the visual pathway A lost of accommodation around the age 40 describes __________ ? 57 Presbyopia Reduction in the ability to accommodate Occurs normally with age Reduction in lens elasticity Refractive vs. Axial Refractive causes of myopia, hyperopia and astigmatism refer to the fact that the “error” lies within the shape of the cornea and/or the lens Axial causes refer to the length of the eyeball itself being the cause of the “error” Reduction in strength of the ciliary muscle The average axial length of an eyeball is _________ ? Using the Worth 4-Dot test, if only two or three lights are seen ______ is indicated? Amblyopia Components of an Optical Prescription Prism A condition in which reduced visual acuity with no Prism is used to correct blurry or double apparent cause and not correctable by refractive means Often referred to as “lazy Eye” It is generally treatable even after age eight Scientists are exploring whether treatment for amblyopia in older children and adults can improve vision vision due to deviated eyes Label the conditions in each of these pictures What is the clinical definition of amblyopia? A Anisometropia Condition of unequal refractive state of the two eyes An-not: iso-same: metric-measure A child may learn to alternate his or her vision, that is, to use one eye for distance and one eye for near Being treated today by the use of contact lenses If the difference in the refractive error of the two eyes is slight, binocular vision is easily attained B Aniseikonia Difference in the size of the two retinal images, Inherent aniseikonia caused by the refractive condition of the two eyes Acquired aniseikonia occurs as a result of the effects of corrective lenses Both are related to anisometropia What part of a Rx is used to correct for 15 diopters of strabismus? What is the condition characterize by unequal refractive status between eyes? 58 Amblyopia Pinhole Effect Reduced Visual Acuity Eliminates peripheral light rays which increases the depth of focus Hides the patient’s myopia or hyperopia and enhances their central visual acuity Similar to squinting No Apparent Cause Not Correctable With Refractive Means Strabismic- Amblyopia Ex Anopsia Abnormal binocularity, resulting in suppression of one eye Refractive Uncorrected refractive error that remains uncorrected for a significant period of time When is the pinhole test used? Arteries carry blood ____ the heart and veins carry blood ____ the heart? Glaucoma Cataracts Increased intraocular pressure Increased cupping (cup to disc ratio) Decrease in peripheral vision What is a cataract? What is the clinical definition of glaucoma? Corneal Problems Foreign Body Retinal Problems Foreign Body with Rust Ring Abrasions Dystrophy Keratoconus Ulcer Corneal Ulcer Confrontation visual field testing compares the _____ visual field with the ______ visual field? Diabetic Retinopathy Retinal Tears/Detachment Retinitis Pigmentosa Macular Degeneration Hypertensive Retinopathy Occlusions Cytomegalovirus Toxoplasmosis Histoplasmosis Normal Retina A hyperoptic ocular deviation has the eye turning ______? 59 Diabetes Conjunctivitis Fluctuations with vision Bleeding in retina The “infamous” pink-eye Numerous causes: Bacteria Viruses Allergies Toxic Reactions (chemicals) Often difficult to diagnose exact etiology Exudates What is the most accurate measure of intraocular pressure? The white spot in this photo come from ________ deposits? What do you think? Ocular Emergencies/Disease What is an Eye Emergency Comfort Zone Time Organic Matter Testing Internal Disease External Disease 1 Testing Time 4 Asepsis Techniques 2 Referral Process Where are office emergency procedure written? 3 What do you think? What is wrong in these photos? RPE Herpetic Dendrite Large C/D ratio Extreme Blood Pressure/ retinal bleeding Papilledma Torturous vessels 60 The External Eye Dry Eye Keratitis sicca Can be associated with systemic inflammatory disorders, such as arthritis and lupus Sjogren’s Syndrome Treatment options Eye Drops (artificial tears, cyclosporine) Punctal Plugs Cautery of punctae Sub-marginal Ulcer Thorns from plants Visual Cortex Use of this over the counter medication can cause dry eyes? Visual Field Defects Located in the occipital lobe of the brain Broadmann's areas 17, 18, and 19 A small segment of the cortex corresponds to each minute area of the retina Visual interpretation Radiations carry visual impulses from the LGB What is an absolute scotoma? Common types of field defects Blind spots - Areas of blindness in the visual field Hemianopsia - Blindness in one half of the visual field of one or both eyes Homonymous - Involving the nasal half of the visual field of one eye and the temporal half of the visual field of the other eye Visual interpretations take place in the ________ portion of the brain? Drop Instillation TPA – vs DPA Therapeutic Pharmaceutical Application…when the problem is known and you treat the condition Clean hands Explain procedure Diagnostic Pharmaceutical Application…when the problem is unknown and you treat the symptoms Remember safety Inspect bottle Check expiration date What is wrong with this picture? Phenylephrine is used to stimulate the _________ muscle? 61 Pharmacology: Diagnostic Agents Mydriatic Drugs Phenylephrine (Neo-Synephrine, Mydfrin) Strength: 2.5%, 10% Effective: 4-6 hours Systemic Side Effects: Irregular heart beat, headache, hypertension, cardiac arrest (very rare) Action: Stimulates the iris dilator muscle Pharmacology: Diagnostic Agents Cycloplegic Drugs Tropicamide (Mydriacyl) Strength: 0.5%, 1% Effective: 5-6 hours Systemic Side Effects: Uncommon Cyclopentolate paralyzes both the ________ and ________ ? Therapeutic medications are use to _________ disease? Pharmacology: Diagnostic Agents Cycloplegic Drugs Cyclopentolate (Cyclogel) Strength: 1.0% and 2.0% Effective 24 hours Side Effects: Dry mouth, excitation, facial flushing, tachycardia, angle closure due to dilation Action: Paralyzes the sphincter muscle of the iris (dilation) and the ciliary muscle (prevent accommodation) Pharmacology: Diagnostic Agents Stains Fluorescein…used to stain cornea surface Strips Mixed with anesthetic Injected (angiography) Rose Bengal…used to stain dead cells _________ pharmaceutical applications drugs are used to treat symptoms? Mydriacyl is used to ________ the pupil? Pharmacology: Anesthetics Commonly used anesthetics: Proparacaine 0.5% Tetracaine 0.5% Lidocaine 1.0%-5.0% Benoxinate plus fluorescein (Fluress) Proparacaine plus fluorescein (Fluoracaine) Pharmacology: Therapeutic Agents Miotics Action: contraction of the iris sphincter muscle (pupil constriction) Use: lowering of intraocular pressure by improving drainage of the aqueous humor through the trabecular meshwork. What is the typical duration for routine anesthetics? Fluoracaine is a combo drug that uses ________ and ________ ? 62 Pharmacology: Therapeutic Agents Glaucoma Treating Drugs Adrenergic-blocking agents Timolol, Betaxolol, Levobunolol Adrenergic-stimulating agents Epinephrine Dipiverfrin Carbonic Anhydrase Inhibitors Acetazolamide Methazolamide Dorzolamide Pharmacology: Therapeutic Agents Glaucoma Treating Drugs Alpha Agonists Apraclonidine Brimonidine Protaglandin Analogs Bimatoprost Latanoprost Travoprost Miotic medications are used to ________ the pupil? Timilol is a beta-blocker medication used in the treatment of _______ Pharmacology: Therapeutic Agents Antibiotics Antivirals Antifungals Corticosteroids…prevents swelling Non-steroidal Anti-inflammatory Drugs (NSAIDS) Decongestants Antihistamines Mast Cell Stabilizers Lubricants Objectives Determine Types Procedures Testing Eligibility Terminology Definitions Ophthetic is a medication used to _________ the eye? Lasers (directed energy) Broad Beam Lasers A broad beam laser uses a relatively large beam diameter (from 6.0 to 8.0 millimeters) that can be manipulated to ablate the cornea. The broad-beam laser results in the shortest procedure time. This speed creates less likelihood of overcorrection and decentration - a complication caused by movement of the pupil. A disadvantage is an increased possibility of center islands - a complication related to ablation. However, ophthalmologists have learned to decrease the incidence of center islands by using several short laser pulses to ablate the cornea instead of one longer one. Lasers Cont… Spot Scanning Lasers These systems have the potential to produce the smoothest ablations and use radar technology to track the eye's movement. They also have the potential to treat irregular astigmatism and link to topography. These lasers must be linked to eye tracking to ensure proper centration 63 Terminology Pictures Flap Procedures- surgeon cuts a flap in the cornea in order to access the underlying tissue LASIK – Laser-Assisted In Situ Keratomileusis Keratomileusis…treats nearsighted, farsighted, and astigmatism…flap in the stroma, then uses an eximer laser to remove material flap LASEK – Laser Epithelial Keratomileusis… cuts flap in the epithelial only. For those who flat or thin corneas Epi-LASEK – surgeon does not use blade or alcohol, but uses an epikeratome which separates epithelial layers and crates a epithelial sheet ALK – Automated Lamellar Keratoplasty…treats high levels of nearsightedness and mild farsightedness 1 Can you identify the type of procedure? 2 Call it Pictures Can you identify the type of procedure? 2 1 Lasik RK Call it cataract Call it glaucoma 64 Call it Call it keratoconus neovascularization Call it Call it PVD Macular Degeneration Call it Questions Farsighted What is the purpose of the fitting triangle? Which tonometers require an anesthetic? What instrument is used to obtain a prescription from a contact or ophthalmic lens? What is the heaviest lens material? Retinal detachment 65 Questions What is the difference between acuity and accommodation? Spell the scientific name for your eyelid ______________? What percentage of water is in a low water content ______ or high water content _______ contact lens. Review Questions The point where the upper and lower eyelids meet is called? Questions The person who normally grinds lenses is called a(n) _________________? What is the difference between a mydriactic and miotic? What is the definition of the word “plano”? Review Questions The eyelid will protect your eyes from what? What main muscles raises the eyelid? The blockage of the meibomian gland is called the ___________ when it causes pain, and the _________ when it does not cause pain? What is a good tear break up time? What is amblyopia? Review Questions What is the difference between visual acuity and accommodation? What is decentration? Convert to spherical equivalent - 1.50 – 1.00 X 180 - 2.25 – 1.50 X 120 What is the main layer of the eye lid? Review Questions Which is the heaviest lens material? What is the ora serrata Name a test performed binocularly? What comprises the vascular layer? Through a prism the image deviates which way? _________ is the merging of images from each eye into one image? Name one of two indentation tonometers 66 Review Questions Review Questions The drain port for tears is called? Identify the name for the parts of the conjunctiva on the eye and back of the eyelid What is the difference between abduction and adduction? Where is the eye normally resting on a eso patient? What is the total power of the eye_____, the cornea _____ and the crystalline lens____? Transpose this Rx + 1.25 + 1.25 X 090 - 1.75 + 2.00 X 180 What is the strongest bone of the bony orbit? Review Questions Review Questions What are the layers of a tear film? -1.00 -1.00 x 090 Answer______________ Where is tear mucin produced? Answer______________ Answer______________ Why is the tear film important in contact lens wear? - 2.50 -1.50 x 103 - 0.50 -2.00 x 008 -1.00 -0.50 x 162 Answer______________ -1.00 -1.50 x 160 Answer______________ + 2.50 -1.50 x 103 - 5.00 -3.00 x 088 Answer______________ -2.50 -1.00 x 029 Answer______________ What is stereopsis? -3.00 -1.50 x 095 Answer______________ Answer______________ Review Questions Review Opia means what? Transpose the following Rx to Near Vision Only aka NVO, SVN, reading glasses -2.00 -1.00 x 080 -1.50 -2.00 x 180 +3.00 OU Answer ________________ ________________ -1.00 – 0.50 x 010 -2.00 -0.75 x 100 +1.25 OU Answer________________ ________________ What is the difference between a tropia and a phoria? -4.00 -0.25 x 090 -1.00 -0.50 x 098 +2.00 OU Answer ________________ ________________ +2.50 -1.00 x 090 +1.00 -0.75 x 180 +2.25 OU Answer ________________ ________________ Avascular means what? How many extra-ocular muscles are oblique? 67 Review Questions Review Questions Identify the name for the parts of the conjunctiva on the eye and back Where does aqueous drain? What drug is used to slow aqueous production? of the eyelid____ and on the ball of the _____ and where they join ______? What test checks your central 20 degrees? Name the five parts of the cornea? What is the difference between versions and vergence? Name the parts of a frame? Analyph glasses are used with what test? What is the strongest bone of the bony orbit? Questions A Corneal Topography is used to determine the ______ ________ of a cornea? Corneal Topography is used in diagnosis and treatment of _______ and _____ _____? The most accurate map is the _____? The _____ map uses Snell’s Law? Pachymetry is used to measure _____ ____? Pachymetry is used to diagnosis and treat _______ and Test Tips _______? How To Study Provide enough time to cover all subjects Interactive Flash cards Study Pace Don’t cram…study like you want to pass the test Notes Study, break, review, preview, and study Tape record notes No more than two hours a one time Study groups Environment Scented candles Use travel time to study Record your notes Active learning Keep body and mind awake 68 Before the Test Find the location of test early Don’t arrive too early on the day of the test Build your confidence by reviewing condensed notes Be patient when you are handed the test, your time doesn’t start right away Remain calm How to take a Multiple Choice Test Recommended References “Self Study Course for Optometric Assisting” by AOA Paraoptometric Section “The Ophthalmic Assistant” by Stein & Slatt (8 th Edition-Stein, Stein & Freeman) “System for Ophthalmic Dispensing” by Brooks and Borish “Dictionary of Eye Terminology by Cassin & Solomon YoYoBrain Web site More Test Taking Tips Take your time but be aware of the time Memory dump Answer easy questions first Mark difficult questions, return to them later Multiple choice are T/F question arranged in groups Only one totally correct answer Eliminate obvious false choices Pick the most complete answer Look for contextual clues Graphics Provided By: Eyemaginations Essilor (Pete Hanlin) *The first hour = 50 questions Read all the questions and answers completely Mark your answer sheet carefully Once you mark your answer, don’t go back and change it without good reason Good Luck! [email protected] The person who makes a success of living is the one who sees his goal steadily and aims for it unswervingly. That is dedication. Cecil B. DeMille (1881 - 1959) 69