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Transcript
Chapter 11 Eyes Physical Examination Preview Eyes Measure visual acuity, noting the following: Near vision Distant vision Peripheral vision Inspect the eyebrows for the following: Hair texture Size Extension Eyes (Cont.) Inspect the orbital area for the following: Edema Redundant tissues or edema Lesions Eyes (Cont.) Inspect the eyelids for the following: Ability to open wide and close completely Eyelash position Ptosis Fasciculations or tremors Flakiness Redness Swelling Palpate the eyelids for nodules. Eyes (Cont.) Inspect the orbits. Pull down the lower lids and inspect palpebral conjunctivae, bulbar conjunctiva, and sclerae for the following: Color Discharge Lacrimal gland punctum Pterygium Eyes (Cont.) Inspect the external eyes for the following: Corneal clarity Corneal sensitivity Corneal arcus Color of irides Pupillary size and shape Pupillary response to light and accommodation, afferent pupillary defect, swinging flashlight test Nystagmus Eyes (Cont.) Palpate the lacrimal gland in the superior temporal orbital rim. Evaluate muscle balance and movement of eyes with the following: Corneal light reflex Cover-uncover test Six cardinal fields of gaze Eyes (Cont.) Ophthalmoscopic examination Lens clarity Red reflex Retinal color and lesions Characteristics of blood vessels Disc characteristics Macula characteristics Depth of anterior chamber Anatomy and Physiology The Eye Transmits visual stimuli to the brain for interpretation Occupies orbital cavity/anterior aspect exposed Direct embryologic extension of the brain Attached by four rectus muscles/two oblique muscles Innervated by cranial nerves III, IV, and VI Connected to brain by cranial nerve II External Eye Composed of five structures Eyelid Conjunctiva Lacrimal gland Eye muscles Bony skull orbit External Eye: Functions Eyelids Distribute tears over eye surface Limit amount of light entering the eye Protect the eye from foreign bodies Conjunctiva Protects the eye from foreign bodies and desiccation External Eye: Functions (Cont.) Lacrimal gland Produces tears that moisten the eye External Eye: Functions (Cont.) Eye muscles Each eye is moved by six muscles. Superior, inferior, medial, and lateral rectus muscles Superior and inferior oblique muscles They are innervated by cranial nerves III (oculomotor), IV (trochlear), and VI (abducens). External Eye: Functions (Cont.) The oculomotor nerve controls: Levator palpebrae superioris (which elevates and retracts the upper eyelid) All extraocular muscles, except for the superior oblique muscle and the lateral rectus muscle External Eye: Functions (Cont.) The superior oblique is the only muscle innervated by the trochlear nerve. The lateral rectus muscle is the only muscle innervated by the abducens nerve. Internal Eye Composed of three layers Outer fibrous layer Sclera posteriorly and cornea anteriorly Middle layer Choroid posteriorly and ciliary body/iris anteriorly Inner layer Retina Internal Eye (Cont.) Five major structures Sclera Cornea Iris Lens Retina Internal Eye (Cont.) Sclera White of the eye Avascular Supports internal eye structures Cornea Continuous with the sclera anteriorly Clear Sensory innervation for pain Major part of the refractive power of the eye Internal Eye (Cont.) Uvea Iris, ciliary body, and choroids comprise the uveal tract. The iris is a circular, contractile muscular disc containing pigment cells that produce the color of the eye. Dilates/contracts to control amount of light traveling through the pupil to the retina The ciliary body produces the aqueous humor and contains the muscles controlling accommodation. The choroid is a pigmented, richly vascular layer that supplies oxygen to the outer layer of the retina. Internal Eye (Cont.) Lens A biconvex, transparent structure located immediately behind the iris Supported circumferentially by fibers arising from the ciliary body Contraction or relaxation of the ciliary body changes its thickness. Changes in lens thickness allow images from varied distances to be focused on retina Internal Eye (Cont.) Retina Sensory network of the eye Transforms light impulses into electrical impulses, which are transmitted through: Optic nerve Optic tract Optic radiation Visual cortex Consciousness in the cerebral cortex Internal Eye (Cont.) Retina Cortex interprets impulses as visual objects. Major landmarks of the retina include: Optic disc, from which the optic nerve originates, together with the central retinal artery and vein Macula, or fovea, is site of central vision Internal Eye (Cont.) Infants and Children Eye forms during the first 8 weeks of gestation. May become malformed due to maternal drug ingestion or infection Lacrimal drainage is complete at birth. By 2 to 3 weeks of age, the lacrimal gland begins producing the full volume of tears. Infants and Children (Cont.) Vision development depends on nervous system maturation and occurs over time Term infants hyperopic [20/400] Peripheral vision fully developed at birth Central vision develops later By 3 to 4 months of age, binocular vision development complete By 6 months, vision developed sufficiently so that the infant can differentiate colors The globe of eye grows as child’s head and brain grow, and adult visual acuity achieved at about 4 years of age Pregnant Women Hypersensitivity and changes are seen in the refractory power of the eye. Tears contain an increased level of lysozyme, resulting in a greasy sensation and perhaps blurred vision for contact lens wearers. Corneal edema/thickening occurs. Diabetic retinopathy may worsen. Intraocular pressure falls. Subconjunctival hemorrhages may occur/resolve spontaneously. Older Adults The major physiologic eye change that occurs with aging is a progressive weakening of accommodation (focusing power) known as presbyopia Loss of lens clarity and cataract formation Review of Related History History of Present Illness Red eye (presence of conjunctival redness) Difficulty with vision Pain History of eye surgery History of recent illness or similar symptoms in the household Allergies Secretions Medications Past Medical History Trauma Eye surgery Chronic illness that can affect vision Hypertension/atherosclerotic cardiovascular disease (ASCVD) Diabetes mellitus Glaucoma Inflammatory bowel disease Thyroid dysfunction Autoimmune diseases HIV Family History Retinoblastoma (retinal cancer) Often an autosomal dominant disorder Glaucoma, macular degeneration, diabetes, hypertension, or others that may impact vision or eye health Color blindness, cataract formation, retinal detachment, retinitis pigmentosa, or allergies affecting the eye Nearsightedness, farsightedness, strabismus, or amblyopia Personal and Social History Employment exposure Activities Use of protective devices during work or activities that might endanger the eye Corrective lenses History of cigarette smoking (a risk factor for cataract, glaucoma, macular degeneration, thyroid eye disease) Infants and Children Preterm Symptoms of congenital abnormalities, including failure of infant to gaze at mother’s face or other objects; failure of infant to blink when bright lights or threatening movements are directed at the face Strabismus some or all of the time Infants and Children (Cont.) Young children Excessive rubbing of the eyes, frequent hordeola, inability to reach for and pick up small objects, night vision difficulties School-age children Necessity of sitting near the front of the classroom to see the board; poor progress in school not explained by intellectual ability Pregnant Women Presence of disorders that can cause ocular complications such as pregnancy-induced hypertension (PIH) or diabetes Symptoms indicative of PIH Diplopia, scotomata, blurred vision, or amaurosis Use of topical eye medications that may cross placenta Older Adults Visual acuity Decrease in central vision, distortion of central vision, use of dim or bright light to increase visual acuity, complaints of glare, difficulty in performing near work without lenses Excess tearing Dry eyes Development of scleral brown spots Nocturnal eye pain Sign of subacute angle closure and a symptom of glaucoma Examination and Findings Equipment Snellen eye chart Rosenbaum/Jaeger near vision card Penlight Cotton wisp Ophthalmoscope Eye cover, gauze, or opaque card Visual Testing Test for: Central vision Near vision Peripheral vision Visual Testing (Cont.) Use Snellen chart. Test each eye individually. Test with and without corrective lenses. If vision less than 20/20, conduct pinhole test. This maneuver permits light to enter only central portion of lens Should result in an improvement in visual acuity by at least one line on the chart if refractive error is responsible for the diminished acuity Visual Testing (Cont.) Near vision Use Rosenbaum pocket screener Each eye tested individually Color vision Rarely tested in the routine physical examination Visual Testing (Cont.) Peripheral vision Estimate with confrontation test. Accurate measurement requires instrumentation. External Examination Examination performed in systematic manner beginning with appendages and moving inward Techniques Inspection Palpation External Examination (Cont.) Surrounding structures Inspect eyebrows for size, extension, and hair texture. Inspect orbital area for edema, puffiness, and sagging tissue below orbit. External Examination (Cont.) Eyelid inspection Inspect closed lid for fasciculations and tremors. Check ability to close completely/open widely. Observe margin for flakiness, redness, and swelling. Look for eyelashes. Note eye opening. Ptosis Note any eversion or inversion of lids. External Examination (Cont.) Eyelid palpation Palpate for nodules. Palpate the eye itself through closed lids. Digital palpation tonometry Pain External Examination (Cont.) Conjunctivae inspection Usually inapparent, clear, and free of erythema Inspect lower portion by pulling down lower lid External Examination (Cont.) Conjunctivae inspection (Cont.) Upper lid is inspected only if foreign body is in the eye. Look for redness/exudate. Look for pterygium. Abnormal growth of conjunctiva that extends over the cornea from the limbus External Examination (Cont.) Cornea Examine clarity of the cornea by shining light on it. Cornea is normally avascular; blood vessels should not be present. Inspect for corneal arcus (arcus senilis). Composed of lipids deposited in the periphery of the cornea External Examination (Cont.) Cornea (Cont.) Test sensitivity (cranial nerve V) by touching the cornea with a cotton wisp to elicit blink (cranial nerve VII). External Examination (Cont.) Iris and pupil Inspect iris for pattern, color, and shape. Test for direct/consensual light response. Test pupils for accommodation. The pupils should constrict when the eyes focus on the near object. Estimate pupil size and compare for equality. External Examination (Cont.) Lens Inspect for transparency/clarity. Sclera Examine to ensure that it is white. Inspect for senile hyaline plaque. Lacrimal apparatus Inspect lacrimal gland. Palpate lower orbital rim near inner canthus. Extraocular Eye Muscles Test eye movements using six cardinal fields of gaze. Check for nystagmus. Note lid lag. Note exposure of sclera above iris. Extraocular Eye Muscles (Cont.) Use corneal light reflex to test extraocular muscle balance. If imbalanced, perform cover-uncover test. Ophthalmoscopic Examination Inspection of interior eye with ophthalmoscope permits visualization of: Optic disc Arteries Veins Retina Ophthalmoscopic Examination (Cont.) Visualize red reflex. Opacities appear as black densities. Examine Fundus Vascular supply Disc margins Macula Ophthalmoscopic Examination (Cont.) Look for unexpected findings such as: Myelinated nerve fibers Papilledema Glaucomatous cupping Drusen bodies Cotton wool bodies Hemorrhages Infants Note symmetry, muscle balance, and presence of red light reflex. Inspect lids for swelling and epicanthal folds. Inspect lid level covering eye. Note eye spacing. Inspect sclera, conjunctiva, pupil, and iris. Infants (Cont.) Test cranial nerves. Vision: observe object preference/focus/tracking Optical blink: note closure and head response to bright light Corneal reflex: same as adult Funduscopic examination is deferred until infant is 2 to 6 months old (unless visual problems). Red reflex should be elicited in all newborns. Children External structure inspection same as for infant Visual acuity tested with Snellen E game at 3 years of age Visual acuity tested in younger children by observing activities Peripheral vision tested in cooperative child Cranial nerve tests same as for adult Funduscopy requires patience Pregnant Women Retinal examination helps differentiate between chronic hypertension and pregnancy-induced hypertension (PIH). Vascular tortuosity, angiosclerosis, hemorrhage, and exudates may be seen in patients with a long-standing history of hypertension. PIH changes include segmental arteriolar narrowing with a wet, glistening appearance indicative of edema. Cycloplegic and mydriatic agents should be avoided unless retinal disease is suspected. Systemic absorption Abnormalities External Eye Exophthalmos Bulging of eye anteriorly out of orbit Episcleritis Inflammation of the superficial layers of the sclera anterior to the insertion of the rectus muscles External Eye (Cont.) Band keratopathy Deposition of calcium in the superficial cornea Corneal ulcer Disruption of the corneal epithelium and stroma External Eye (Cont.) Extraocular muscles Strabismus: Both eyes do not focus on an object simultaneously. Paralytic strabismus: One or more extraocular muscles or their nerve supply is impaired. Nonparalytic strabismus: Patient can focus with either eye but not with both simultaneously. May be a sign of increased intracranial pressure Internal Eye Horner syndrome Triad of ipsilateral miosis, mild ptosis, and loss of hemifacial sweating Results from interruption of sympathetic nerve supply to the eye Cataracts Opacities in the lens Internal Eye (Cont.) Diabetic retinopathy (background) Dot hemorrhages or microaneurysms and the presence of hard and soft exudates Diabetic retinopathy (proliferative) Development of new vessels as result of anoxic stimulation Internal Eye (Cont.) Lipemia retinalis Occurs when the serum triglyceride level exceeds 2000 mg/dL Internal Eye (Cont.) Retinitis pigmentosa Autosomal recessive disorder in which the genetic defects cause cell death predominantly in the rod photoreceptors Internal Eye (Cont.) Glaucoma Disease of the optic nerve resulting from increased intraocular pressure Nerve cells die, producing a characteristic appearance of the optic nerve (increased cupping). Internal Eye (Cont.) Chorioretinal inflammation Inflammatory process involving both the choroid and the retina Visual Fields Visual field defects Defective vision or blindness in a single eye Visual Fields (Cont.) Visual field defects (Cont.) Bitemporal hemianopia is caused by a lesion, most commonly a pituitary tumor, interrupting optic chiasm. Visual Fields (Cont.) Visual field defects (Cont.) Homonymous hemianopia can be caused by a lesion arising in optic nerve radiation on either side of the brain. Children Retinoblastoma Embryonal malignant tumor arising from retina Children (Cont.) Retinopathy of prematurity Disruption of normal progression of retinal vascular development in preterm infant Children (Cont.) Retinal hemorrhages in infancy Occurs in infant victims of shaken-baby syndrome Children (Cont.) Swollen eyes in newborn Drawing a line between eyes to examine for Mongolian slant Keeping Well Age-related macular degeneration is the leading cause of visual impairment and blindness in patients older than 65 years. Middle-age and older patients should be reminded that studies have demonstrated preservation of vision with the reduction of age-related macular degeneration in individuals taking highdose antioxidants plus zinc. Question 1 Corneal sensitivity is controlled by which of the following cranial nerves? A. CN III B. CN IV C. CN V D. CN VI Question 2 Which of the following is a genetic eye disorder that should be included in the history and physical examination, under family history, for all members of the affected families? A. Constrictive iritis B. Retinal cancer C. Oval pupils D. Retinal hemorrhages Question 3 In infants pseudostrabismus is usually caused by: A. Flattened nasal bridge B. CN III, IV, and VI C. Ptosis D. Intellectual disability Question 4 When testing corneal sensitivity controlled by cranial nerve V, you should expect the patient to respond by: A. Brisk blinking B. Copious tearing C. Pupil dilation D. Reflex smiling Question 5 Calcium deposits in this superficial corneal is called: A. Arcus senilis B. Retinoblastoma C. Band keratopathy D. Lipemia retinalis