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MINISTRY OF HEALTH PROTECTION THE REPUBLIC OF UZBEKISTAN TASHKENT MEDICAL ACADEMY “Approved” by Protector on the academic work Prof. Teshaev O.R. _______________________________ «_____»_________________2012 у. Department: Eye diseases (Diseases of vision organs) Subject: Ophthalmology THEME: “Inherited and acquired lens pathology”. Education Methodic Elaboration (for instructors and students of the Higher Medical Schools) Tashkent -2012 y. THEME: “Inherited and acquired lens pathology”. 1. Place and facilities for the classes. A room (dark) used for classes and vision examination in polyclinics. Necessary facilities: a set of tables slides, mileage of a visual organ, the Roth apparatus, the Sivtsev-Golovin table, spheroperimeter, the Rabkin polychromatic tables, and ophthalmoscope. Medicaments (solutions for disinfection, eye droplets, local anasthetics) Eyelid lifters Glass ophthalmic spatulas Binocular magnifiers Slit-lamp Ophthalmoscopes, 13 D magnifiers. TV-video, posters, phantoms and moulages, volonteers and patients. 2. Period of time needed Period of time 5,5 hours 3 . T he a i m Every doctor should know such visual organs pathology as inborn or acquired cataract, which takes place in violation of the transparency of optical media eye, such illness as inborn and acquired cataract. They often are the result of manifestation general diseases as follows: rheumatism, diabetes, tuberculosis, chronic and acute infectious diseases, the thyrioid gland pathology, etc. Physicians should be able to diagnose and treat the patients suffering from this pathology. Prophylaxis of the development of possible complications in these cases is necessary. “Inherited and acquired lens pathology” – need to explore this theme stems from the fact that patients with these pathologies of the vision can go to any specialist. Tasks Every student should know: - classification of the inborn and acquired lens pathology; - etiopathogenesis and diagnostics in the inborn and acquired lens pathology; - clinical manifestations and principles of treatment of the inborn and acquired lens pathology; - complications and prophylactic measures at the inborn and acquired lens pathology. A student of the general practice should be able to diagnose and render initial medical aid in cases of the inborn or acquired lens pathology. SQP should have skills in: Elucidation of complaints and the pathology anamnesis in brief; Preliminary examination of every eye acuity; Examination of the anterior part of an eye and ectropia of the upper eyelid; Examination of all the anterior parts of an eye by using the methods of lateral illumination and biomicroscopy; Examination of the lens by the lateral illumination method; Dripping eye droplets; application of ointments; lavage of the conjunctiva cavity; application of the aseptic bandage definition of the lacrimal ducts permeability, examination of lacrimal secretion, get acquainted with the method of the lacrimal ducts lavation. 4. Motivation Every physician should know the symptomatology of the inborn and acquired lens pathology, some of its forms and types, size, localization, depth of injury, clinical manifestations of cataract, and stage of its development. Lens opacity is accompanied by vision depravation including photo perception. Vision depravation as a rule, results in the development of nystagmus and heterotropia as well as amblyopia. Lens opacity unfortunately results mostly in invalidity of the vision organ of patients. A general practitioner student must be able to diagnose the inborn and acquired lens pathology, know where the patient will be rendered qualified medical aid. 5. Intersubjects and inter subject relations - Knowledge of students on this theme should be good enough and integrated with the other related subjects vertically and horizontally. The theme is vertical integration with anatomy (the nerve system and sensory organs, physiology of the nerve system), histology (ontogenesis and histology of the nerve system and sensory organs), deontology (in the aspects of a doctor-patient interrelation), history of medicine and ophthalmology, pharmacotherapy in ophthalmology. The horizontal integration with: Otorhinolaryngology (the anatomic neighboring and correlation of various ORL diseases and vision organ diseases) Infection diseases and connected with them probable complications in the visual analyzer Diseases of Inner organs ( pathology of AD , diseases of blood and kidneys, collagenoses and others diseases associated with the impairment of visual analyzer) Endocrinology (diavetes mellitus, hypo and hyperthuy disease of hypophysis (pituitary gland) and either endocrinopathy. 6. Content of classes. 6.1 Theory. The lens is biconvex and transparent.It is held in position behind the iris by the suspensory ligament whose zonular fibres are composed of the protein fibrillin which attach its equator to the ciliary body. Disease may affect structure,shape and position. Cataract Opacification of the lens of the eye (cataract) is the commonest cause of treatable blindness in the world.The large majority of cataracts occur in older age as a result of the cumulative exposure to environmental and other influences such as smoking,UV radiation and elevated blood sugar levels.This is sometimes referred to as age-related cataract.A smaller number are associated with specific ocular or systemic disease and defined physico-chemical mechanisms.Some are congenital and may be inherited. OCULAR CONDITIONS Trauma Uveitis High myopia Topical medication (particularly steroid eye drops) Intraocular tumour SYSTEMIC CAUSES Diabetes Other metabolic disorders (including galactosaemia, Fabry’s disease, hypocalcaemia) Systemic drugs (particularly steroids,chlorpromazine) Infection (congenital rubella) Myotonic dystrophy Atopic dermatitis Systemic syndromes (Down’s,Lowe’s) Congenital,including inherited,cataract X-radiation SYMPTOMS An opacity in the lens of the eye: • causes a painless loss of vision; • causes glare; • may change refractive error. In infants, cataract may cause amblyopia (a failure of normal visual development) because the retina is deprived of a formed image. Infants with suspected cataract or a family history of congenital cataracts should be seen as a matter of urgency by an ophthalmologist. SIGNS Visual acuity is reduced. In some patients the acuity measured in a dark room may seem satisfactory, whereas if the same test is carried out in bright light or sunlight the acuity will be seen to fall, as a result of glare and loss of contrast. The cataract appears black against the red reflex when the eye is examined with a direct ophthalmoscope. Slit lamp examination allows the cataract to be examined in detail and the exact site of the opacity can be identified. Agerelated cataract is commonly nuclear, cortical or subcapsular in location. Steroid-induced cataract is commonly posterior subcapsular. Other features to suggest an ocular cause for the cataract may be found, for example pigment deposition on the lens suggesting previous inflammation or damage to the iris suggesting previous ocular trauma. INVESTIGATION This is seldom required unless a suspected systemic disease requires exclusion or the cataract appears to have occurred at an early age. TYPES OF CATARACT: Cortical Sub capsular Nuclear Anterior Posterior TREATMENT Although much effort has been directed towards slowing progression or preventing cataract, management remains surgical. There is no need to wait for the cataract to ‘ripen’. The test is whether or not the cataract produces sufficient visual symptoms to reduce the quality of life. Patients may have difficulty in recognizing faces, reading or achieving the driving standard. Some patients may be greatly troubled by glare. Patients are informed of their visual prognosis and must also be informed of any coexisting eye disease which may influence the outcome of cataract surgery. Cataract surgery. The operation involves removal of most of the lens and its replacement optically by a plastic implant. It is increasingly performed under local rather than general anaesthesia. Local anaesthetic is infiltrated around the globe and the lids or given topically. If social circumstances allow, the patient can attend as a day case, without admission to hospital. The operation can be performed: •Through an extended incision at the periphery of the cornea or anterior sclera followed by extra-capsular cataract extraction (ECCE). The incision must be sutured. •By liquification of the lens using an ultrasound probe introduced through a smaller incision in the cornea or anterior sclera (phacoemulsification).Usually no suture is required.This is now the preferred method in the Western world. Complications of cataract surgery 1 Vitreous loss. If the posterior capsule is damaged during the operation the vitreous gel may come forward into the anterior chamber where it represents a risk of glaucoma or traction on the retina. It requires removal with an instrument which aspirates and excises the gel (vitrectomy).In these circumstances it may not be possible to place an intraocular lens in the eye immediately. 2 Iris prolapse. The iris may protrude through the surgical incision in the immediate postoperative period. It appears as a dark area at the incision site.The pupil is distorted. This requires prompt surgical repair. 3 Endophthalmitis. A serious but rare infective complication of cataract extraction (less than 0.3%). Patients present with: (a)a painful red eye; (b)reduced visual acuity, usually within a few days of surgery; (c)a collection of white cells in the anterior chamber (hypopyon). The patient requires urgent ophthalmic assessment, sampling of aqueous and vitreous for microbiological analysis and treatment with intravitreal, topical and systemic antibiotics. 4 Postoperative astigmatism. It may be necessary to remove the corneal sutures in order to reduce corneal astigmatism.This is done prior to measuring the patient for new glasses but after the wound has healed and steroid drops have been stopped. Excessive corneal curvature can be induced in the line of the suture if it is tight. Removal usually solves this problem and is easily accomplished in the clinic under local anaesthetic with the patient sitting at the slit lamp. Loose sutures must be removed to prevent infection but it may be necessary to resuture the incision if healing is imperfect. Sutureless phacoemulsification through a smaller incision avoids these complications. Furthermore, placement of the wound may allow correction of pre-existing astigmatism. 5 Cystoid macular oedema. The macula may become oedematous following surgery, particularly if this has been accompanied by loss of vitreous. It may settle with time but can produce a severe reduction in acuity. 6 Retinal detachment. Modern techniques of cataract extraction are associated with a low rate of this complication. It is increased if there has been vitreous loss. 7 Opacification of the posterior capsule (Fig.8.4).In approximately 20% of patients clarity of the posterior capsule decreases in the months following surgery when residual epithelial cells migrate across its surface. Vision becomes blurred and there may be problems with glare. A small hole can be made in the capsule with a laser (neodymium yttrium (ndYAG) laser) as an Outpatient procedure. There is a small risk of cystoid macular oedema or retinal detachment following YAG capsulotomy. Research aimed at reducing this complication has shown that the material used to manufacture the lens,the shape of the edge of the lens and overlap of the intraocular lens by a small rim of anterior capsule are important in preventing posterior capsule opacification. 8 If the fine nylon sutures are not removed after surgery they may break in the following months or years causing irritation or infection. Symptoms are cured by removal. Congenital cataract The presence of congenital or infantile cataract is a threat to sight,not only because of the immediate obstruction to vision but because disturbance of the retinal image impairs visual maturation in the infant and leads to amblyopia (see pp.170–171).If bilateral cataract is present and has a significant effect on visual acuity this will cause amblyopia and an oscillation of the eyes (nystagmus).Both cataractous lenses require urgent surgery and the fitting of contact lenses to correct the aphakia.The management of contact lenses requires considerable input and motivation from the parents of the child. The treatment of uniocular congenital cataract remains controversial. Unfortunately the results of surgery are disappointing and vision may improve little because amblyopia develops despite adequate optical correction with a contact lens.Treatment to maximize the chances of success must be performed within the first few weeks of life and be accompanied by a coordinated patching routine to the fellow eye to stimulate visua maturation in the amblyopic eye.Increasingly intraocular lenses are being implanted in children over 2 years old.The eye becomes increasingly myopic as the child grows,however,making choice of the power of the lens difficult. CHANGE IN LENS SHAPE Abnormal lens shape is very unusual. The curvature of the anterior part of the lens may be increased centrally (anterior lenticonus) in Alport’s syndrome, a recessively inherited condition of deafness and nephropathy An abnormally small lens may be associated with short stature and other skeletal abnormalities. CHANGEINLENSPOSITION(ECTOPIALENTIS) Weakness of the zonule causes lens displacement.The lens takes up a more rounded form and the eye becomes more myopic.This may be seen in: •Trauma. •Inborn errors of metabolism (e.g.homocystinuria,a recessive disorder with mental defect and skeletal features.The lens is usually displaced downwards). •Certain syndromes (e.g.Marfan’s syndrome,a dominant disorder with skeletal and cardiac abnormalities and a risk of dissecting aortic aneurysm. The lens is usually displaced upwards).There is a defect in the zonular protein due to a mutation in the fibrillin gene. The irregular myopia can be corrected optically although sometimes an aphakic correction may be required if the lens is substantially displaced from the visual axis.Surgical removal may be indicated,particularly if the displaced lens has caused a secondary glaucoma but surgery may result in further complications. CATARACT—THE WORLD PERSPECTIVE In the developed world cataract surgery is performed when visual symptoms interfere with the quality of life.Worldwide there are in excess of 20 million people blind due to bilateral dense cataract.This represents a huge cause of preventable blindness.The World Health Organization has established Project 2020 to manage this problem;the goal is to remove cataract as a cause of blindness by the year 2020. The new pedagogic technology used at this lesson: “Black box”, “Web-Net” The “Black box” method. It provides the interconnected activity and active participation of every student, the tutor (teacher) involves the whole group in this activity. Every student pulls out a card from the box. In the card there are writer in short complaints and clinical manifestations of a disease (variants are given) Students should determine this preparation; give their answer in details and groud it. To think over the answer it is given 3 minutes. Then the answer is discussed and additional information on clinical characteristics and ways of the disease are given. At the end of this part of classes teacher comments the answers ( its correctness, grounded and level of the students’ activity) This method helps to improve the students’ speech; to obtain the vases of critical thinking as the students are taught to advocate their opinion, analyze answers given by their group-mates participated in the competition. Variants of cards: 1. Diagnosing a disease: acute iridocyclitis Treatment: midriatics, antiinflammation therapy antibiotics therapy. 2. Diagnosing a disease: mature age cataract Treatment: surgery (EEK+IOL) Usage of the “web” method Steps: 1. First, students are given some time for composing questions to the studied theme. 2. The participants sit in a circle 3. One of the participants who is given a clew puts his question ( he should know the detailed answer to it) and holding the end of the thereoat passes the clew 4. A student who has received the clew must answer this question ( the student who has put the question should comment the given answer) and passes the clew to some other student. The participants must go on with asking and answering the questions until all of them are involved in the web. 5. As soon as every student has put his question, the last participant who keeps the clew should return it to the previous one who put him a question and son. The game continues until the “web” is “unfailed”: completely. Note: students should be warned to listen attentively every answer because they don’t know who will be the next. 6.2. Practical part Examination of photo perception. № Content of answer a table Answer is complete Points Answer is not complete No answer 1 It is necessary: ophthalmoscope lamp, 15 7,5 0 2 Every eye is examined separately by closing one eye with a palm or covering detachment. 15 7,5 0 3 The lamp should be adjusted at the left back side from the patient. 15 7,5 0 4 Light of the lamp should be directed by a concave mirror to the examined eye from various sides (up, down, left and right). 15 7,5 0 5 If the patient sees the light and defines its direction properly, his (her) vision acuity is considered to be equal to the photo perception with correct photo projection 15 7,5 0 15 7,5 0 10 5 0 100 points 50 0 1 (vis= pr l. certa) 6 If the patient is wrong in defining the light projection even from one side only, such vision is considered as photo perception with non-correct photo projection. 1 (vis= pr l. incerta) 7 If the patient does not have any photo perception, his (her) vision acuity is considered to be zero (vis=0) Total points Tasks Definition of the vision aquity. № 1 2 3 4 5 6 7 8 Content of answer Necessary facilities: the Roth apparatus, Sivtsev-Golovin table or a table with distant control (Forroptr), pointer. The Roth apparatus and the SivtsevGolovin table or a table with distant control (Forroptr) should be adjusted at the 5 meters distance from the examined person (the tenth line should be at he same level with the patient’s eyes). Every eye should be examined separately by covering the fellow one with a screen. Definition of the vision acuity should be started with indication of optotypes on the tenth line (row) – vis = 1.0, by pointing to optotypes located on various rows (from lower line to upwards). If patients have depraved vision the examination may be started with the first upper row and downwards. The vision acuity is estimated by that row where all the optotypes were defined correctly (the 1-st row = 0,1; the 2-nd = 0,2 etc). If the patient cannot differentiate optotypes on the first row the vision acuity is controlled by showing the hand fingers and then is counted with Snellen’s formula Vis= d where “d” – is a distance D at which the patient can distinguish number of hand fingers D=50 m. In case when things vision is absent, the photo perception should be examined by direction of light. Photo perception might be adequate or wrong. Answer is complete Points Answer is not No answer complete 10 5 0 10 5 0 10 5 0 10 5 0 10 5 0 10 5 0 20 10 0 10 5 0 If the photo perception is absent the vision acuity is considered to be “zero”. 9 10 100 points Total 5 50 points 0 0 points 7. Forms of controlling the level of knowledge, practice and skill. Oral Tests Demonstration of practical skills 8. Criteria for estimation of the current control. № № 1 2 Results in percents and points 96-100% Marks Graduation of a student’s knowledge Excellent “5” 91-95% Excellent “5” Full and correct answer to questions on etiopatogonesis, classification, clinics, principles of treatment, complications and prevention. Summarizes and takes a decision, creative thinking, analyzes independently. Properly solves situational challenges with creative approach, with full explanation of the answer. Takes part actively in interpersonal games, properly takes grounded decisions and summarizes, analyzes. Implementation of practical skills in all stages is error free and complete. Full and correct answer to questions on etiopatogonesis , classification, clinics, principles of treatment, complications and. Creative thinking, analyzes independently. Properly solves situational challenges with creative approach, with explanation of the answer. Takes part actively in interpersonal games, properly takes decisions. Implementation of practical skills in all stages 3 86- 90% 4 81-85% 5 76-80% 6 71-75% 7 66-70% is error free and complete. Excellent “5” Fully highlighted questions on etiopatogonesis , classification, clinics, principles of treatment, complications and prevention, but 1-2 uncertainties in answer. Analyzes independently. Uncertainties while taking decision in solving case studies but with correct approach. Takes part actively in interpersonal games, properly takes decisions. One mistake during whole stages of implementation of practical skills. Good “4” Fully highlighted questions on etiopatogonesis, classification, clinics, principles of treatment, complications and prevention, but there are 2-3 uncertainties and mistakes. Puts into practice, understands point of question, retells confidently, has an exact ideas. Case studies are solved correctly but explanations are not full. Some uncertainties while implementing practical skills along the stages. Good “4” Answer is correct but not fully highlighted. A student knows etiopatogonesis, classification, clinics, principles of treatment, complications, but is not good at prevention. Understands point of question, retells confidently, has an exact ideas. Takes part actively in interpersonal games. Incomplete decisions to case studies. Incomplete implementation of 1st level while taking practical skills. Good “4” Answer is correct but not fully highlighted. A student knows etiopatogonesis , classification, clinics, but is not good at principles of treatment, complications and prevention. Understands point of question, retells confidently, possesses exact ideas. Incomplete decisions to case studies. 1st stage was not completed while implementing practical skills along the stages. Acceptable “3” Correct answer to half of the question. A student knows inetiopatogonesis, classification, but not well at in clinics, principles of treatment, complications and prevention. Understands point of question, 8 61-65% 9 55-60% 10 50-54% 11 46-49% 12 41-45% retells confidently, and possesses insight of particular questions. Case studies are solved correctly but without explanation. 2 stages were not completed while implementing practical skills. Acceptable “3” Correct answer to half of the question. Mistakes in etiopatogonesis , classification, bad at clinics and principles of treatment, confuses in complications and prevention. Retells unconfidently, possesses exact ideas in separate themes. Makes mistakes while solving case studies. 2 stages were absolutely incomplete while implementing practical skills. Acceptable “3” Answer is with mistakes to half of the question. A student makes mistakes in etiopatogonesis, classification, bad at clinics and principles of treatment, confuses in complications and prevention. Retells unconfidently, possesses ideas of theme partially. Case studies are solved incorrectly. Incomplete implementation of 3 stages while taking practical skills. Unacceptable Correct answer to 1/3 of the question. A “2” student does not know in etiopatogonesis, classification, bad at clinics and principles of treatment, confuses in complications and prevention. Case studies are solved incorrectly with wrong approach. Absolutely incomplete 3 stages while implementing practical skills along the stages. Unacceptable Correct answer to 1/4 of the question. A “2” student does not know in etiopatogonesis, classification, bad at clinics and principles of treatment, confuses in complications and prevention. Case studies are solved incorrectly with wrong approach. Absolutely incomplete 4 stages while implementing practical skills along the stages. Unacceptable Correct answer to 1/5 of the question. A “2” student does not know in etiopatogonesis, classification, bad at clinics and principles of treatment, confuses in complications and prevention. Case studies are solved incorrectly with wrong approach. Absolutely 13 36-40% Unacceptable “2” 14 31-35% Unacceptable “2” incomplete 4 stages while implementing practical skills along the stages. Correct answer to 1/10 of the question. A student does not know in etiopatogonesis, classification, bad at clinics and principles of treatment, confuses in complications and prevention. Case studies are solved incorrectly with wrong approach. Absolutely mistakes while implementing practical skills along the stages. There are no answers for the questions. A student does not know in etiopatogonesis, classification, bad at clinics and principles of treatment, confuses in complications and prevention. A student does not know practical skills along the stages. 9. Chronologic Charta of the classes. № Sequence 1. Introduction 2. Analysis of the home-task 3. Curation and reception of patients 4. Kind of the lesson Analysis of the practical part of the lesson 6. Analysis the lessons in the forms of seminars and by making reports on the theme of the obtained know ledge by using interactive methods ( brain ring, snowballs, gallery tour ones). (225 min) 15 min Inquest Explanation 40 min Making a doctor’s round 30 min Mastering of practical skills, methods examination using medical instruments (facilities). 5. Period 30 min Inquest Explanation 30 min Reports, seminar 30 min 7. Facilities for teaching at the lesson: video cassettes, computer programs, situation tasks. 30 min 8. Conclusion made by the teacher, marks gained by every student according to the 100 point system. Home task for the next classes. 20 min Total 225 min 10. Questions for control. 1. 2. 3. 4. 5. A lens. Various types of cataracts. The inborn cataracts. The secondary cataract. Surgical methods of cataract treatment. 11. Literature. Basic: 1. 2. 3. 4. 5. Eroshevsky T.I., Bochkarev A.I. “Eye diseases”, 1989. Kovalevsky E.I., Selected lectures, A text-book – M: Medicine, 1996. Kovalevsky E.I., “Eye diseases” (Atlas) – М.: Medicine, 1985. Khamidova M.Kh. «Kuz kasalliklari», 1996. Fedorov S.N., et al. «Eye diseases»-М. 2000. Supplementary : 1. Doljitch P.N., Eye diseases in the form of questions and answers, 2003. 2. Multivolume handbook on the Eye diseases. 3. Therapeutic ophthalmology. Ed. By Shulpina N.B.