Kanski OSCE PDF

1) a) Choroideremia. The mode of inheritance is X-linked recessive so that affected males cannot pass the gene to their sons but all daughters are carriers. b) Choroideremia is not associated with any known biochemical abnormality. c) His mother will...

1) a) Choroideremia. The mode of inheritance is X-linked recessive so that affected males cannot pass the gene to their sons but all daughters are carriers. b) Choroideremia is not associated with any known biochemical abnormality. c) His mother will be a carrier and will have mild fundus changes in the form of patchy peripheral retinal atrophy and mottling of the retinal pigment epithelium. 2) a) Gyrate atrophy of the retina and choroid. b) Patients with gyrate atrophy have an inborn error of the mitochondrial matrix enzyme ornithine-delta- aminotransferase. This leads to increased levels of ornithine in" the plasma, urine, cerebrospinal fluid and aqueous. Treatment with pyridoxine (vitamin B6) and a diet low in proteins and arginine may be beneficial. c) The mode of inheritance is autosomal recessive. d) Patients with gyrate atrophy may also have: Myopia Vitreous degeneration Cystoid macular edema Complicated cataract. 3) a) The macula shows a 'bicycle wheel-like' appearance pathognomonic of congenital retinoschisis. With time visual acuity continues to decline and non-specific atrophic macular changes ensue. b) The inheritance is X-linked recessive. c) Between 50-70% of patients with macular schisis also have peripheral retinoschisis in which the inner leaf is extremely thin and consists only of the internal limiting membrane and the retinal nerve fiber layer. Complications of peripheral retinoschisis are: Large defects in the inner layer—very common Vitreous hemorrhage—uncommon Retinal detachment—uncommon. d) Nil. 4) a) The signs are: complete lack of fundus pigment Absence of foveal landmarks Optic disc hypoplasia. b) Tyrosinase-negative (complete) oculocutaneous albinism. c) Other abnormalities include: A diaphenous blue iris that trans-illuminates completely. Myopic or hypermetropic refractive errors Strabismus Anomalous retinogeniculate projections so that many of the temporal hemi retinal fibers decussate in the chiasm with the nasal hemi retinal fibers. d) Two potentially lethal forms of albinism are: Chediak-Higashi syndrome characterized by susceptibility to infections. Hermansky-Pudlak syndrome with a predisposition to bruising and bleeding. 5) a. Best's vitelliform macular dystrophy. b. Inheritance is autosomal dominant with variable penetrance and expressivity. c. The five stages of Best's disease are: Stage 1—previtelliform (normal fundus but abnormal EOG) Stage 2—vitelliform (egg-yolk stage) as shown in this case Stage 3—pseudohypopyon (part of lesion becomes absorbed) Stage 4—vitelliruptive (scrambled-egg) Stage 5—end stage is characterized by one of the following: Hypertrophic macular scar Atrophic macular scar Vascularized fibrous macular scar. d. Visual acuity is usually no worse than 6/60. 6) a. Choroidal naevus. b. Most choroidal naevi are hypofluorescent due to blockage of background choroidal fluorescence. c. Over 90% of choroidal naevi are located posterior to the equator. d. Very rare complications of choroidal naevi are: Secondary choroidal neovascularization Malignant transformation. 7) a. Myelinated nerve fibers. b. The condition is not hereditary. c. The condition is bilateral in about 20% of cases. d. Males are more frequently affected. Vision may be affected as follows: By macular involvement with reduction of visual acuity Peripheral myelination will cause corresponding scotomas which may be relative or absolute. 8) a. Krukenberg spindle. b. Pigmentary glaucoma. c. Pigmentary glaucoma is not hereditary. d. Other anterior segment features include: Slit-like iris Trans illumination defects An excessively deep anterior chamber with a posterior bowing of the mid peripheral iris Circumferential hyper pigmentation of the posterior trabecular meshwork Pigment granules within iris furrows and on both surfaces of the lens. 9) a. Congenital Ecropion uveae. b. The patient should have regular measurement of intraocular pressure because a significant percentage of cases develop glaucoma between early childhood and puberty due to an associated angle anomaly. c. Neurofibromatosis type 1. 10) a. Asteroid hyalosis. b. Most eyes with asteroid hyalosis have normal or near normal visual acuity. c. Most patients do not have any underlying systemic disease although a small percentage may have diabetes. Cholesterolosis bulbi (synchysis scintillans) differs from asteroid hyalosis because:  It is usually unilateral whilst asteroid hyalosis is bilateral in 25% of cases. It usually follows a vitreous hemorrhage. The particles are more mobile within the vitreous. 11) a. Tilted discs. b. Tilled discs are not inherited. c. Eyes with tilted discs frequently have associated inferionasal ectasia of the fundus which gives rise to upper temporal visual defects. However unlike the field defects due to chiasmal compression, they do not obey the vertical midline. d. The headaches are incidental. 12) a. Pediculosis. The picture shows nits (eggs laid by the female) firmly attached to the lashes. b. The eyelashes should be smothered with liquid paraffin and the nits physically peeled off with cotton wool buds. This should be done every day for a week. c. Pediculosis humanis has three main varieties: Capitis—infesting the head Corporis—infesting the body and clothes Pubis—infesting the genital and other hairy parts of the body. 13) a. No, since these are the only lesions and there is no dermatomal distribution to the vesicular eruption. b. Primary herpes simplex infection. c. The ophthalmic ointment contains a much lower concentration of acyclovir than the cream. The cream should therefore be applied directly to the lesions but care should be taken to avoid the eyes. 14) a. Traumatic right superior oblique palsy. b. The compensatory head posture would be: Head tilt to the left Face turn to the left Chin depression. c. When appropriate, surgical correction will depend on whether hypertropia or torsion is the main deviation. For hypertropia: (i) Weakening of the ipsilateral inferior oblique, (ii) Weakening of the contralateral inferior rectus. For torsion (excyclotropia): (i) Harada-Ito procedure. (ii) Plication of the paretic muscle. 15) a. Severe rubeosis iridis. b. Ischemic central retinal vein occlusion. c. Neovascular glaucoma caused by secondary synechial angle-closure by fibrovascular tissue in the angle. This typically develops about three months following central retinal vein occlusion (100-day glaucoma). d. Other causes of rubeosis iridis are: Proliferative retinopathies (i) Diabetic—the risk is increased by cataract and vitreous surgery  (ii) Sickle cell disease. Carotid artery disease including carotid-cavernous fistula. Chronic intraocular inflammation. 16) a. Left Brown's superior oblique tendon sheath syndrome. b. Ten percent of cases are bilateral. c. Most congenital cases do not require treatment. Indications for surgery include the presence of a hypotropia in the primary position and an anomalous head posture. The most frequently used procedure is superior oblique tenotomy with or without ipsilateral inferior oblique recession. d. Similar motility defects may be due to: acquired Brown's syndrome due to trauma or tenosynovitis of the superior-oblique- trochlear apparatus Inferior oblique palsy Entrapment of the inferior oblique muscle in a blow-out fracture of the orbital floor. 17) a. Anterior ischemic optic neuropathy. This is a segmental or generalized infarction within the prelaminar or laminar portion of the optic nerve caused by occlusion of the posterior ciliary arteries. b. The three main causes of anterior ischemic optic neuropathy are as follows: Giant cell arteritis is a common cause in the elderly. The non-arteritic type typically occurs in hypertensive individuals between the ages of 45-65 who have absent or small optic cups. Auto-immune optic neuropathy occurs in younger patients with systemic lupus erythematosus or some other collagen vascular disease. c. In this elderly patient it is important to exclude the possibility of giant cell arteritis by performing: ESR—a normal value does not necessarily exclude giant cell arteritis. Test for C-reactive protein which is invariably raised in giant cell arteritis. Temporal artery biopsy to obtain histological confirmation. 18) a. Buphthalmos (large, Ox eyes) and left exotropia. b. Autosomal recessive with incomplete penetrance. c. Gonioscopy shows absence of the angle recess with cither a flat or a concave insertion of the iris into the surface of the trabecular meshwork. d. Treatment of most cases is by goniotomy with a success rate of about 85%. e. The main causes of visual impairment are: Optic nerve damage Anisometropic amblyopia Corneal scarring Cataract Lens subluxation. 19) a. Duane's syndrome type-1 characterized by limitation of abduction but normal adduction. b. About 20% of cases are bilateral. c. Some children with Duane's syndrome have perceptive deafness with an associated speech disorder. d. Most cases do not require surgery. Indications for surgery are: To overcome an anomalous head posture  To enlarge the field of single binocular vision To correct cosmetically unacceptable up shoots or down shoots. 20) a. Central retinal vein occlusion. b. The three main types of central retinal vein occlusion are: Ischemic Non-ischemic In young adults. c. Underlying factors may be systemic and ocular. Systemic underlying factors include: (i) Old age (ii) Hypertension (iii) Blood dyscrasias associated with hyperviscosity. Ocular factors include: (i) Raised intraocular pressure (ii) Congenital anomaly of the central retinal vein (iii) Periphlebitis as in Behcet's disease and sarcoidosis. 21) a. The main atypical types of retinitis pigmentosa are: Sector—involving one quadrant or one half of each fundus With exudative vasculopathy—bilateral telangactatic vascular anomalies, serous retinal detachment and lipid deposition in the retinal periphery Pericentric Retinitis punctata albescens. b. The three main macular lesions are: Atrophic maculopathy » cellophane maculopathy Cystoid macular edema which may respond to Acetazolamide. c. Associated ocular lesions include: Optic disc drusen Open-angle glaucoma Posterior subcapsular cataracts Keratoconus Myopia Intermediate uveitis. 22) a. Stargardt's fundus flavimaculatus. b. Inheritance is usually autosomal recessive. c. The four main patterns are: Maculopathy without flecks Maculopathy with perifoveal flecks Maculopathy with diffuse flecks (as shown here) diffuse flecks without maculopathy. d. There are no associated ocular lesions. 23) a. Lacquer cracks are large breaks in Bruch's membrane, b. The main types of maculopathy are: Myopic degeneration involving the macula Neovascular maculopathy associated with lacquer cracks Macular hemorrhage unassociated with lacquer cracks  Macular hole. c. Other ocular complications are: Vitreous degeneration Rhegmatogenous retinal detachment due to either macular or peripheral retinal holes Posterior staphylomas increased prevalence of primary open-angle glaucoma and steroid responsiveness Posterior subcapsular cataract and early onset nuclear sclerosis. d. Uncommon systemic associations include: Marfan's syndrome. Ehlers-Danlos syndrome. Stickler's syndrome. 24) a. Occlusion of the cilioretinal artery. b. Emboli can be seen in both the superior and inferior branches of the artery. The possible causes of retinal embolism are: Carotid artery disease which may give rise to three types of emboli: (i) Cholesterol (Hollenhorst's plaques) (ii) Fibrinoplatelet (iii) Calcific. Heart disease which may give rise to four types of emboli: (i) calcific from calcified valves (ii) Valve vegetations in SBE (sub acute bacterial endocarditis) (iii) Thrombus from the left atrium (iv) From an atrial myxoma. c. The ischemic retina appears white due to cloudy swelling involving the retinal nerve fiber and ganglion cell layers. Because the fovea itself is devoid of these layers the orange reflex from the intact choroidal vessels beneath the fovea stands out in contrast to the surrounding opaque retina. 25) a. Congenital hypertrophy of the retinal pigment epithelium. b. Hereditary polyposis coli which may be associated with one of the following: Gardner's syndrome—osteomas and soft tissue /abnormalities Turcot's syndrome—neuroepithelial brain tumors. c. Autosomal dominant. d. The patient should have a colonoscopy and, if found to have polyposis, prophylactic colectomy should be performed because of the very high risk of adenocarcinoma of the colon. 26) a. Fundus albipunctatus. b. Inheritance is autosomal recessive. c. The long-term visual prognosis is excellent because the macula remains unaffected. d. The main conditions that should be considered in the differential diagnosis of a flecked retina are: Familial dominant drusen—most common by far. Fundus flavimaculatus. Retinitis punctata albescens. Flecked retina of Kandori. 27) a. Malignant melanoma of the iris. b. The differential diagnosis of iris melanoma includes:  Other tumors (i) Large iris naevus (ii) Leiomyoma. (iii) Juvenile xanthogranuloma (iv) Metastasis. Iris cysts (i) Primary (ii) Secondary to intraocular surgery. Large inflammatory granuloma. c. The prognosis is excellent because the predominant cell type is usually spindle-B. d. The treatment options are: Broad iridectomy for localized tumors such as this Iridocyclectomy or iridotrabeculectomy for larger tumors involving the angle Enucleation rarely required for diffusely growing tumors. 28) a. Ectopia lentis is a displacement of the lens from its normal anatomical position. b. Luxation is a complete displacement of the lens from the pupillary space. Subluxation is a partial displacement in which a part of the lens still remains within the pupillary space. c. Syndromes associated with ectopia lentis are: Marfan's syndrome—subluxation is typically up Weill-Marchesani syndrome—lens is small and spherical (microspherophakia) and subluxation is down Stickler's syndrome—10% have lens subluxation Ehlers-Danlos syndrome—subluxation is uncommon. d. Metabolic disorders associated with ectopia lentis are: Homocystinuria—subluxation is down Hyperlysinaemia Sulphite oxidase deficiency. 29) a. Lisch nodules. b. The nodules are melanocytic naevi composed of proliferations of spindle cells of neural crest origin. c. Neurofibromatosis type-1. d. The most likely cause of the proptosis and optic atrophy is an optic nerve glioma which develops in about 15% of patients. e. Other ophthalmic lesions in neurofibromatosis-1 are: Eyelid neurofibromata Other orbital lesions (i) Neural orbital tumors (neurilemmoma, plexiform neurofibroma, meningioma) (ii) spheno-orbital encephalocele. Intraocular lesions (i) Prominent corneal nerves (ii) Congenital glaucoma (iii) Congenital ectropion uveae (iv) Choroidal hamartomas (v) Optociliary shunt vessels in eyes with optic nerve tumors. 30) a. Iris coloboma. b. The condition is usually not hereditary. c. The pathogenesis is failure of fusion of the apex of the embryonic fissure. d. Possible associated ocular anomalies are: Colobomas of the ciliary body, lens, choroid and optic nerve Microcornea. e. Potential systemic associations are: Goldenhar's syndrome Treacher Collins syndrome Cat's eye syndrome Rubenstein-Taybi syndrome CHARGE syndrome (Colobomatous microphthalmia, Heart anomaly, Atresia choanal. Retarded growth, Genital and Ear anomalies). 31) a. A non-filtering flat vascularized bleb. b. Potential causes of failure of filtration are: Subconjunctival fibrosis Accelerated wound healing associated with intraocular inflammation Inadequate sclerostomy. Blockage of the sclerostomy by blood, Descemet's membrane, uveal tissue, or vitreous. c. The success rate of filtration may be enhanced by: Corticosteroids which suppress postoperative inflammation Antimetabolites such as 5-fluorouracil and Mitomycin which prevent fibroblast proliferation Excision of Tenon's capsule. 32) a. Commotio retinae (Berlin's edema) involving the posterior pole. b. The natural course of commotio retinae is either: complete resolution—most common. Development of microcystoid degeneration of the outer retinal layers. Development of retinoschisis from breakdown of the septa in the micro cysts. c. Other posterior segment complications of blunt trauma are: Avulsion of the vitreous base and tearing of the non-pigmented epithelium of the pars plana Retinal dialysis Peripheral retinal holes Macular hole Choroidal rupture. 33) a. Clinically the severity of ptosis is graded by measuring the marginal reflex distance, bearing in mind that the upper eyelid covers between 1.5-2 mm of the cornea. Mild ptosis = 2 mm or less Moderate ptosis = 3 mm (as in this patient) Severe ptosis = 4 mm or more. b. Levator function is assessed by measuring the upper lid excursion. It is graded as follows: Good =12 mm or more Fair =6-11 mm (as in this patient) Poor = 5 mm or less. c. The ideal time to operate is between the ages of 3 and 4. d. Treatment is by levator resection assuming there is simple congenital ptosis not associated with the jaw-winking phenomenon. 34) a. The fundus shows cicatricial retinopathy of prematurity characterized by dragging of the blood vessels and macular heterotopia. b. Threshold disease includes: Stage 3 retinopathy of prematurity Involvement of zone 1 or 2 Evidence of 'plus' disease Involving 5 or more continuous clock hours or 8 cumulative clock hours. c. Screening schedule: Initial, between 4-7 weeks postnatally. Follow-up (i) If normal fundi, every 2 weeks until 36 weeks (ii) If zone 1 or 2 disease present, weekly. 35) a. Partial aniridia. b. The four phenotypes of aniridia are: With normal vision Associated with poor vision due to foveal hypoplasia (as in this case) Associated with Wilm's tumor of the kidney Associated with mental retardation. c. The inheritance pattern may be: Autosomal dominant associated with the first two phenotypes Autosomal recessive associated with mental retardation Sporadic, associated with Wilm's tumor with deletion of the short arm of chromosome 11. d. Other possible ocular defects in aniridia. Glaucoma develops from the second decade of life in 50% of cases. Cornea—opacity, microcornea, sclerocornea, keratolenticular adhesions Lens—cataract, subluxation, congenital absence, persistent pupillary membranes Posterior segment—foveal hypoplasia, choroidal coloboma, hypoplastic discs. 36) a. Crouzon's syndrome is a craniofacial synostosis characterized by proptosis due to shallow orbits. b. The two main causes of poor vision in Crouzon's syndrome are: Optic atrophy caused by bony compression of the optic nerves in the optic canal Exposure keratopathy. c. Other ocular defects include: Hypertelorism and exotropia Luxation of the globe Nystagmus, either primary or secondary to poor vision. d. No; mental retardation is uncommon. 37) a. Left Homer's syndrome—ptosis and miosis. b. The main congenital causes of heterochromia are: Idiopathic Homer's syndrome Waardenburg's syndrome Sturge-Weber syndrome. c. The main acquired causes of heterochromia are:  Fuch's heterochromic cyclitis Diffuse iris tumors (naevi, melanoma, juvenile xanthogranuloma) Pigment dispersion syndrome Siderosis Severe rubeosis iridis Progressive facial hemiatrophy. 38) a. Amaurosis fugax which is a retinal transient ischemic attack. b. Arcus lipoides (often mistakenly referred to as arcus senilis in patients under the age of 60). Both conditions are caused by deposition of non crystalline cholesterol although the former is associated with type II and III hyperlipidemias and the latter is a change associated with age. Type I—hyperchylomicronaemia Type IIa—familial hypercholesterolemia Type lIb—mixed hyperlipidaemia Type III—broad beta disease Type IV—familial hypertriglyceridaemia Type V—hyperchylomicronaemia and familial hypertriglyceridaemia. d. Directly: xanthelasma (II & III); lipaemia retinalis (I, III, IV &V) Indirectly: accelerated atherosclerosis leads to atheromatous carotid artery disease, which predisposes to retinal artery occlusion, homonymous hemianopia due to a cerebrovascular accident and ocular ischemia. 39) a. Lattice degeneration. b. Rare systemic associations are: Stickler's syndrome Marian's syndrome Ehlers-Danlos syndrome. c. The main indications for prophylactic treatment are: Retinal detachment in the fellow eye Extensive lattice in a highly myopic eye Strong family history of retinal detachment The three systemic conditions mentioned above. d. Macular pucker (preretinal gliosis). 40) a. Herpes zoster ophthalmicus. Treatment is as follows: Oral acyclovir, 800 mg 5 times daily for 7 days An antibiotic-steroid preparation (e.g. Neo-Cortef ointment or Terra-Cortil spray) applied directly to the skin lesions. b. The main early acute ocular lesions that may impair vision are: Iritis which may be associated with secondary glaucoma Punctate epithelial keratitis Microdendriric ulceration Nummular keratitis Optic neuritis (rare). c. Apart from optic neuritis, uncommon neurological complications are: Cranial nerve palsies Encephalitis Contralateral hemiplegia. 41) a. Traumatic hyphema. b. Other anterior segment injuries of blunt trauma are: rupture of the iris sphincter Scleral rupture Laceration of the anterior face of the ciliary body (angle-recession), which may be associated with subsequent secondary glaucoma Lens subluxation or dislocation. c. The main current vision-threatening complications are: Secondary glaucoma Blood staining of the cornea, which may occur if the intraocular pressure is over 25 mm Hg for more than 6 days. d. Management is as follows: Admission to hospital for strict bed rest and regular monitoring of intraocular pressure Treatment of secondary glaucoma, if present Topical steroids; the role of mydriatics is controversial. Surgical evacuation of the blood clot if corneal blood staining threatens. 42) a. Type 1 lattice corneal dystrophy. b. Autosomal dominant. c. The material is amyloid. d. The material stains with Congo red. e. This patient has type 1 lattice dystrophy which is not associated systemic disease. However, patients with type 2 lattice dystrophy, which does not present with recurrent corneal erosions, have systemic amyloidosis. 43) a. Pseudoexfoliative glaucoma (glaucoma capsulare). b. About 20% of initially normal fellow eyes develop glaucoma within 10 years. c. Pseudoexfoliative material is thought to be derived from the iris. d. Sampaolesi's line is a scalloped band of pigment running onto or anterior to Schwalbe's line which is virtually pathognomonic of pseudoexfoliation. e. The zonules may rupture during cataract surgery & poor pupillary dilation. 44) a. Squamous cell papilloma. b. Removal is by simple surgical excision with cauterization to the base to prevent recurrence. C. The salient histological features are: Finger-like projections of vascularized connective tissue Acanthotic epidermis with elongated rete ridges Areas of hyperkeratosis and focal parakeratosis within the epidermis. d. Other benign eyelid tumors are: Seborrheic keratosis—basal cell papilloma Molluscum contagiosum Strawberry naevus port wine stain keratoacanthoma pigmented naevi: -intradermal -junctional -compound inverted follicular keratosis. 45) a. A post-traumatic subconjunctival hemorrhage such as this suggests the possibility of a fracture involving the anterior cranial fossa. b. The Battle sign is localized bruising over the mastoid process which occurs in basal skull fractures. c. A right afferent pupillary conduction defect is probably present because the CT scan shows a bony fragment impinging the right optic nerve. 46) a. Angioid streaks. b. Causes of visual impairment in eyes with angioid streaks are: Maculopathy secondary to choroidal neovascularization Traumatic choroidal rupture causing a subfoveal hemorrhage. Foveal involvement by an angioid streak. c. Pseudoxanthoma elasticum, although it is possible that the hemorrhage is incidental. d. About 50% of patients have no systemic disease. Systemic associations in order of importance include: Pseudoxanthoma elasticum (Gronblad-Strandberg syndrome). Paget's disease. Hematological disorders (i) Homozygous sickle cell disease (ii) Thalassaemia (iii) Thrombocytopenic purpura. Miscellaneous: (i) Acromegaly (ii) Senile elastosis (iii) Facial angiomatosis (iv) Lead poisoning. 47) a. Incontinentia pigmenti (Bloch-Sulzberger syndrome)—a mesodermal and ectodermal dysplasia affecting girls. b. X-linked dominant. c. Systemic manifestations are: Vesiculobullous dermatitis that resolves spontaneously leaving irregular patches or whorls of hyperpigmentation (shown here) Variable malformations of teeth, hair, nails, bones and central nervous system. d, Leukocoria is due to fibrovascular proliferation leading to cicatricial retinal detachment. 48) a. Blow-out fracture of the orbital floor. b. Associated clinical signs include: Periocular ecchymosis, edema and occasionally emphysema. Enophthalmos. Infraorbital nerve anaesthesia. Diplopia which typically occurs in both downgaze and upgaze Ocular damage—uncommon. c. Initial management involves: Administration of systemic antibiotics to prevent spread of infection from the maxillary sinus to the orbit. Baseline Hess test to assess muscle restriction Baseline exophthalmometry to assess degree of enophthalmos. d. The main indications for surgery are large fractures involving half or more of the orbital floor, particularly if associated with severe enophthalmos and persistent significant diplopia in the primary position. 49) a. Limbal dermoid. b. Goldenhar's (oculoauricular vertebral) syndrome: Deafness Multiple vertebral anomalies Depressed lateral orbital rims, maxillary and mandibular hypoplasia Wide mouth Microtia and preauricular skin tags. c. Other ocular lesions in Goldenhar's syndrome are: Upper eyelid and iris colobomas Microcornea, microphthalmos and anophthalmos Tilted disc and optic nerve hypoplasia Macular hypoplasia. Strabismus. 50) a. Central retinal artery occlusion. b. Immediate management is: Lie patient flat. Give intravenous Acetazolamide 500 mg. Apply firm ocular massage intermittently for at least 15 minutes. Other measures include: (i) Inhalation of a mixture of 5% carbon dioxide and 95% oxygen (ii) Anterior chamber paracentesis. c. Despite immediate treatment the visual prognosis in the majority of cases is extremely poor. d. Other vascular causes are: Retinal vein occlusion Anterior ischemic optic neuropathy Vitreous hemorrhage Premacular or macular hemorrhage. 51) a. Entropion of the lower eyelid. b. Classification of entropion: Involutional—due to age-related atrophy Acute spastic—secondary to irritation of the cornea Cicatricial—due to scarring of the conjunctiva or eyelid Congenital. c. Depending on the cause, procedures to correct entropion include: Simple taping of the eyelid to the cheek Use of hisroacryl Cautery Transverse lid everting suture Weis procedure Fox procedure strengthening of lower lid retractors Tarsal fracture—for cicatricial entropion. 52) a. Blepharophimosis syndrome. b. The main signs are: Congenital ptosis Epicanthus inversus Telecanthus—a lateral soft tissue displacement of the medial canthi Mild ectropion of the lower lids. c. Where appropriate, initial treatment involves correction of the epicanthus and telecanthus followed later by correction of ptosis with a frontalis suspension procedure. 53) a. Bell's phenomenon. b. It is absent in 10% of normal eyes. c. Exposure keratopathy. d. Prevention of exposure keratopathy. Temporary measures: (i) Frequent instillation of lubricating agents (ii) Taping of eyelids at night (iii) Temporary tarsorrhaphy. Permanent measures: (i) Medial canthoplasty (ii) Graded levator recession (iii) Prosthetic devices. 54) a. The meanings of the histological terms are as follows: Hyperkeratosis is increased keratinization within the skin. Acanthosis is an increase in the prickle cell layer due to increase in mitotic activity of the basal cells. Papillomatosis is a pattern of growth where sheets of cells cover a surface. b. Seborrhoeic keratosis—also referred to as basal cell papilloma, seborrhoeic wart and senile verruca. c. Because it is not a premalignant condition removal is purely on cosmetic grounds. d. Four premalignant eyelid lesions are: Actinic keratosis Bowen's disease Lentigo maligna Cutaneous horn which may be associated with an underlying actinic keratosis or squamous cell carcinoma. 55) a. The most likely diagnosis (taking into account the appearance of the lesion and its slow growth rate) is basal cell carcinoma. b. The risk of metastasis in a basal cell carcinoma is extremely small. c. A basal-cell carcinoma occurring in a young person demands careful follow-up to ensure it is not the first sign of the Gorlin Goltz syndrome (basal cell naevus syndrome). This is an autosomal dominant disorder in which there are, multiple basal cell carcinomas associated with cysts of the jaw, skeletal anomalies, neurological abnormalities and endocrine disorders. 56) a. Keratoacanthoma. b. Indirectly; because keratoacanthoma occurs with increased frequency in immunosuppressed individuals. c. Spontaneous resolution is common but may take up to a year. d. Surgical excision is advised because occasionally keratoacanthoma shows histological evidence of invasive squamous cell carcinoma at deeper levels of section. 57) a. Xanthelasma, which is a xanthoma occurring on the eyelid. b. Nil. c. About one-third of patients with xanthelasma have either primary or secondary hyperlipidaemia. d. Xanthomata may also occur on the skin of buttocks (eruptive type), on extensor surfaces (tuberous type), in palmar creases and on tendons. 58) a. Central tarsorrhaphy (suturing together of the lids). b. The main indications are severe exposure keratopathy or intractable corneal ulcer (usually neuropathic). c. Botulinum toxin A may be injected under electromyographic control into the levator palpebrae superioris. 59) a. Endophthalmitis due to bleb infection. b. The thin-walled cystic bleb with a positive Siedel test is particularly vulnerable because it drains transconjunctivally. c. Management: admit to hospital take aqueous and vitreous cultures Intraocular injection of vancomycin and amikacin Topical cefuroxime and fortified vancomycin or Gentamicin Systemic ceftazidime and/or ciprofloxacin Topical steroids. 60) a. Capillary Hemangioma. b. Removal is only indicated if there is a threat of amblyopia, either by the tumor obstructing the visual axis or by inducing severe astigmatism. c. The Kasabach-Merritt syndrome is the association of hemangioma with thrombocytopaenic purpura. The syndrome usually occurs in infants and the onset of purpura is accompanied by rapid enlargement of the tumor. Its pathogenesis is believed to be linked to sequestration of platelets within the tumor and associated visceral angiomas. 61) a. Acute anterior uveitis. b. In anterior uveitis there is an intense mononuclear cell infiltration of the iris, ciliary body and ciliary muscle. Exposure to bright light induces ciliary muscle spasm. c. Provided the patient is appropriately treated the visual prognosis is very good. The main vision threatening complication is the formation of posterior synechiae which may lead to secondary pupil block glaucoma. In a small proportion of patients the uveitis becomes chronic. 62) a. An inflammatory arthropathy affecting mainly young males, 70% of whom are HLA B27 positive. The classic triad is of urethritis, conjunctivitis and arthritis. Patients may also get balanitis or buccal ulceration. Other features are plantar fasciitis, keratoderma blenorrhagia and nail dystrophy. About 20% of patients develop recurrent attacks of acute anterior uveitis. b. Because of the very severe anterior chamber reaction the patient should be given an anterior sub-Tenon's injection of steroid. The pupil should be dilated with intensive mydriatics. Topical steroid drops should also be prescribed at very frequent intervals. c. Calcification within the Achilles' tendon near its insertion, the so-called calcaneal spur. 63) a. Mutton fat keratic precipitates. b. A fusiform distribution of keratic precipitates in the lower half of the cornea. c. Granulomatous. d. Koeppe and Busacca nodules. e. Causes of granulomatous uveitis: Sarcoidosis Tuberculosis Sympathetic ophthalmitis Vogi-Koyanagi-Harada syndrome Toxoplasmosis Syphilis Lens induced uveitis Late onset postoperative endophthalmitis due to Proprionibacterium acnes. 64) a. Rieger's-anomaly. b. Autosomal dominant. c. About 50% of patients develop glaucoma, usually during early childhood. d. Some patients with Rieger's anomaly have Rieger's syndrome which is associated with the following systemic lesions: Dental anomalies—small teeth (microdontia) and a decrease in number of teeth (hypodontia). Facial malformations—hypoplasia of maxilla, telecanthus, flat nasal bridge and hypertelorism. 65) a. Filamentary keratitis. b. Corneal filaments are composed of mucus threads attached at one end to abnormal corneal epithelium. c. Causes of filamentary keratitis are: Keratoconjunctivitis sicca Superior limbic keratoconjunctivitis Herpes zoster ophthalmicus Essential blepharospasm Midbrain strokes. 66) a. Bacterial, Chlamydia and viral. b. Treatment of bacterial conjunctivitis: Norfloxacin (Noroxin) has a broad spectrum with low toxicity and a prolonged effect so that four times daily use is sufficient. Ofloxacin (Exocin) has similar properties. Fucidic acid (Fucithalmic) is useful for staphylococcal infection. Other drugs include: Gentamicin, framycetin, tobramycin and chloramphenicol. c. Systemic associations: Hay fever Atopic dermatitis Reiter's disease Ocular cicatricial pemphigoid Stevens-Johnson syndrome Epidermolysis bullosa Thyroid dysfunction—superior limbic keratoconjunctivitis. 67) a. There is a white superior corneal infiltrate which is separated from the limbus by a clear zone. b. Marginal keratitis. c. Probably, because in patients with staph. blepharitis the keratitis is thought to be caused by a hypersensitivity reaction to Staphylococcal exotoxins. d. Treatment is with a short course of a weak steroid such as fluorometholone or clobetasone provided the possibility of herpes simplex infection has been excluded. 68) a. Optic atrophy. b. The main hereditary optic atrophies are: Leber's hereditary optic neuropathy which typically affects young males. Autosomal dominant optic atrophy (Kjer type)—onset 4-8 years. Autosomal recessive optic atrophies: (i) Simple—onset 2-3 years (ii) Complicated (Behr's syndrome)—onset 1-9 years and associated with neurological abnormalities (iii) Associated with other defects such as diabetes mellitus, diabetes insipidus, deafness and ataxia. c. The Foster-Kennedy syndrome consists of unilateral optic atrophy and contralateral papilledema. It is classically caused by a sub frontal tumor which causes ipsilateral optic atrophy by direct compression and contralateral papilledema cine to raised intracranial pressure. 69) a. Cytomegalovirus retinitis. b. The cytomegalovirus is an opportunistic infection which only affects immunocompromised individuals, especially those with AIDS. c. The treatment of cytomegalovirus retinitis is with either intravenous gancyclovir or foscarnet. The former can also be administered intravitreally by injections or slow-release devices. d. Other fundus lesions in immunocompromised individuals are: Pneumocystis carinii choroidopathy. Cryptococcus choroiditis. Severe toxoplasma retinochoroiditis Varicella-zoster retinitis. Large cell intraocular lymphoma. 70) a. Optic nerve hypoplasia. b. The condition is not inherited. c. His ataxia may be caused by one of the following: Neurological malformations—basal encephalocele, hypoplasia of the cerebellar  vermis, cystic dilatation of the fourth ventricle, posterior fossa cysts and anterior visual pathway space-occupying lesions. De Morsier's syndrome (septo-optic-dysplasia): short stature and midline developmental anomalies (absence of septum pellucidum, agenesis of corpus callosum, and dysplasia of the anterior third ventricle). d. Other ocular anomalies in eyes with optic nerve hypoplasia are: Microphthalmos Absence of the foveal reflex Aniridia. 71) a. Steroid induced geographic (amoeboid) herpes simplex ulceration. In this patient the inadvertent use of topical steroids has prevented the host response from combating the viral infection so that it has become rampant with the formation of a large ulcer. b. The steroids should be stopped and the patient treated with topical acyclovir ointment five times a day until the ulcer has healed. c. The continued use of topical steroids in this eye could have led to severe complications in the form of stromal necrotic keratitis with subsequent vascularization, scarring and even perforation. 72) a. Treatment of acute glaucoma is as follows: Prophylactic pilocarpine 1% q.i.d. to the fellow eye. Administration of systemic pressure-lowering therapy such as intravenous Acetazolamide or an oral (isosorbide, glycerol) or intravenous (mannitol) hyperosmotic agent. Topical therapy with: (i) Pilocarpine 2% (ii) Beta blockers. (iii) Steroids. Peripheral laser iridotomy once the cornea has cleared. Prophylactic laser iridotomy to the fellow eye. b. The classification of primary angle-closure glaucoma is as follows: Latent Intermittent (sub acute) Acute—congestive and post-congestive Chronic Absolute. c. The three main mechanisms of chronic angle-closure glaucoma are: Gradual and progressive (creeping) synechial angle-closure Following several intermittent attacks A combination of primary open-angle glaucoma with narrow angles. 73) a. Pterygium. b. There is no racial predisposition but pterygia typically occur in people living in hot climates. c. Indications for removal are: Cosmetic Recurrent inflammation and irritation Progressive growth towards the visual axis. d. The methods of preventing recurrences are: Operative use of Mitomycin-C  Postoperative P-irradiation Treatment of early recurrences with the argon laser. e. A true pterygium should be differentiated from a pseudopterygium which is caused by adhesion of a fold of conjunctiva to a peripheral corneal ulcer. 74) a. Superior limbic keratoconjunctivitis of Theodore. b. Thyroid function tests would be appropriate because between 20 and 50% of patients have associated thyroid dysfunction. c. Treatment options are: Correction of thyroid dysfunction, if present. Topical therapy with— (i) Adrenaline 1 % for symptomatic relief (ii) Acetylcysteine 5% to reduce filamentary keratitis (iii) Tear substitutes for associated dry eyes. Soft bandage contact lenses. Thermo cauterization of the superior bulbar conjunctiva. Superior limbal conjunctival resection. 75) a. Corneal abrasion. b. Because fluorescein has been used. The dye remains extra cellular and because it stains the tear film it shows up epithelial corneal defects as bright green when examined under cobalt blue light. c. This patient may subsequently develop the recurrent erosion syndrome due to improper hemidesmosome formation between the basement membrane and epithelium. Diabetics are at increased risk of developing this condition. 76) a. He may be right because topical adrenaline derivatives may result in adrenochrome deposits in the conjunctiva. b. No. c. Yes, because adrenaline is a phenol that is oxidized to adrenochrome by naturally occurring oxidases and then finally to melanin. 77) a. The differential diagnosis is: Herpes simplex stromal keratitis Bacterial keratitis Fungal keratitis Acanthamoeba keratitis. b. The most likely diagnosis is stromal necrotic herpes simplex keratitis because: Corneal sensation is reduced in herpetic infection. There is no apparent predisposing factor to bacterial keratitis. There is no past history of trauma with organic matter which may precede a fungal infection. Acanthamoeba keratitis is unlikely because it typically occurs in contact lens wearers. c. Treatment consists of: healing of any associated epithelial defect Judicious use of topical steroids with antiviral and antibiotic cover. 78) a. Herpes simplex dendritic ulcer. b. The drugs currently available to treat active herpetic epithelial disease are: Acycloguanosine (Acyclovir, Zovirax) 3% ointment 5 times a day Trifluorothymidine 1 % drops 2-houriy Atenine arabinose 3% ointment or 0.1% drops Idoxuridine 0.5% ointment or 0.1% drops Bromovinyldeoxyuridine 1% ointment and 0.1% drops. c. Causes of pseudodendritic ulceration are: Herpes zoster keratitis healing corneal abrasion. Toxic keratopathy from excessive drop administration Contact lens wear. 79) a. Cotton-wool spot. b. Cotton-wool spot formation is caused by occlusion of precapillary arterioles in the retinal nerve fiber layer. The ischemia interrupts axoplasmic flow and results in the build-up of transported material within the nerve axon which is responsible for the white appearance of these lesions. c. The main clinical causes of cotton-wool spots are: Retinal vein occlusion Preproliferative diabetic retinopathy Hypertensive retinopathy Papilledema Collagen vascular disorders such as dermatomyositis, systemic lupus erythematosus and polyarteritis nodosa Human immunodeficiency virus retinopathy Hematological disorders such as anemia, leukemia and hyperviscosity states. 80) a. Idiopathic (age-related) macular hole. b. There is a 1:10 risk to the fellow eye. c. There is no risk of retinal detachment. d. Other causes of macular hole formation are: Blunt ocular trauma. High myopia—may give rise to retinal detachment Solar retinopathy may cause a very small lamellar hole or cyst. 81) a. There is central corneal haze and thickening together with fine keratic precipitates (KP) on the endothelial surface. b. The above findings, together with corneal anaesthesia, point to the likely diagnosis of herpetic disciform keratitis (a hypersensitivity reaction to viral antigen). c. This is a ring around a disciform keratitis that forms as a result of immune complex deposition due to antigen diffusing radially away from the site of the keratitis and reacting with antibodies. 82) a. Left internuclear ophthalmoplegia. b. Other ocular motility defects in demyelination are: Ataxic nystagmus on abduction of the contralateral eye to the internuclear ophthalmoplegia.  Cerebellar nystagmus conjugate gaze paresis skew deviation Isolated ocular motor nerve palsies. Bright areas of abnormal signal in the brain stem and periventricular area. In patients with retrobulbar neuritis MR with special coils may also demonstrate a plaque within the optic nerve. 83) a. Meibomian cyst (chalazion). b. Predispositions are: Acne rosacea Seborrhoeic dermatitis. c. The differential diagnosis: External hordeolum (stye)—staphylococcal infection of a lash follicle Internal hordeolum—staphylococcal infection of a chalazion. d. Treatment options include: Conservative—awaiting spontaneous resolution Incision and curettage Injection of steroid into the lesion Systemic antibiotics for recurrent cases associated with acne rosacea or seborrhoeic dermatitis. 84) a. Cyst of Moll. b. There are no known predispositions. c. The differential diagnosis: Cyst of Zeis—less translucent Sebaceous cyst—has central punctum. Molluscum contagiosum—typically umbilicated. d. Treatment: Simple puncture with a needle Cauterization. 85) a. A retinal detachment is a separation of the sensory retina from the retinal pigment epithelium by subretinal fluid. b. The main types of retinal detachment are: Rhegmatogenous, caused by a retinal break (i) Spontaneous. (ii) Traumatic. Tractional, due to contracting vitreoretinal membranes (i) Proliferative retinopathies (ii) Penetrating trauma. Exudative, due to an abnormality in the retinal pigment epithelium (i) Harada's disease. (ii) Choroidal tumors. (iii) Toxemia of pregnancy. c. Long-standing rhegmatogenous retinal detachment: Retinal tinning. Secondary intraretinal cysts. Pigment demarcation (high-water) marks. Subretinal fibrosis is occasionally present. 86) a. This is either a sub epithelial or a compound conjunctival naevus because it is slightly elevated. Junctional naevi are usually flat. b. Virtually nil, it is common for naevi to grow and become more pigmented at puberty. c. The two main indications for excision are: Cosmetic—by far the most common Enlargement of the lesion during adult life. d. Other benign conjunctival tumors are: Papilloma Dermoid Lipodermoid Hemangioma. 87) a. Symblepharon. b. Other ocular complications of ocular cicatricial pemphigoid are: Keratoconjunctivitis sicca Eyelid deformities (i) Ankyloblepharon (ii) Entropion (iii) Trichiasis (iv) Metaplastic lashes Keratopathy. c. Other causes of symblepharon are: Other bullous skin diseases: (i) Stevens Johnson syndrome (ii) Epidermolysis bullosa. Trauma: (i) Chemical (ii) Irradiation. Membranous conductivities, if inappropriately treated, may rarely give rise to symblepharon. 88) a. Predisposing factors: Contact lens wear Trauma Bullous keratopathy Keratoconjunctivitis sicca Exposure keratopathy Neurotrophic keratopathy Postherapietic disease Chronic dacryocystitis. b. N. gonorrhoeae, C. diphtheriae, Listeria sp., and Haemophilus sp. c. Immediate management: Take scrapings for Gram stain and culture. Until results of cultures are known, treat with a combination of a topical fortified aminoglycoside (Gentamicin or tobramycin) and cefuroxime or ciprofloxacin at half- hourly intervals around the clock. 89) a. Keratoconus (conical cornea). b. The-initial form of treatment of this patient would be the fitting of contact lenses. Corneal grafting is indicated only in patients with advanced progressive disease, especially with significant corneal scarring. c. Associated disorders may be: Ocular (i) Vernal disease (ii) Leber's congenital Amaurosis (iii) Retinitis pigmentosa (iv) Aniridia (v) Ectopia lentis. Systemic (i) Atopic dermatitis (ii) Down's syndrome (iii) Turner's syndrome (iv) Ehlers-Danlos syndrome (v) Marfan's syndrome (vi) Osteogenesis imperfecta (vii) Mitral valve prolapse. 90) a. To aid in the diagnosis of possible keratoconjunctivitis sicca as it has an affinity for mucus as well as dead and devitalized cells. b. 5 mm or less in 5 minutes. c. 10 seconds or less. d. Secondary Sjogren's syndrome comprises dry eyes, dry mouth and one of the following: Seropositive rheumatoid arthritis Systemic lupus erythematosus Systemic sclerosis Psoriatic arthritis Juvenile chronic arthritis Hashimoto's thyroiditis Primary biliary cirrhosis. 91) a. Metamorphopsia is a visual symptom describing distortion of shapes. b. the angiogram shows a choroidal neovascular membrane. c. Neovascular age-related macular degeneration. d. Other important causes of choroidal neovascularization are: Idiopathic High myopia Presumed ocular histoplasmosis syndrome Angioid streaks Optic disc drusen Choroidal naevus Choroidal rupture Excessive laser photocoagulation Best's disease. 92) a. Drusen (colloid bodies). b. The five main types of drusen are: Hard—small Soft—large Mixed—semisolid  Basal laminar—nodular calcified. c. Histological drusen consist of deposits of abnormal material in the inner portion of Bruch's membrane between the basement membrane of the retinal pigment epithelium and the inner collagenous layer. d. This patient's visual prognosis is guarded because she has soft drusen which are associated with diffuse dysfunction of the retinal pigment epithelium and an increased risk of subsequently developing exudative age-related macular degeneration. 93) a. Macular pucker (premacular gliosis). b. Idiopathic. c. The condition is bilateral in only 5% of cases. d. Other causes of premacular gliosis are: Retinal procedures: -retinal detachment surgery -laser photocoagulation -cryotherapy Retinal vascular disease Intraocular inflammation Ocular trauma. 94) a. Bull's-eye maculopathy. b. Long-term chloroquine medication. c. Other causes of a bull's-eye maculopathy are: Cone dystrophy Batten's disease Benign concentric annular macular dystrophy. Bardet-Biedl syndrome Leber's congenital Amaurosis (rarely). d. Fluorescein angiography in bull's-eye maculopathy shows a round area of hyper fluorescence around the fovea due to a window defect corresponding to the area of atrophy of the retinal pigment epithelium. 95) a. Choroidal folds. b. Idiopathic—frequently associated with hypermetropia. c. Other causes of choroidal folds are: Orbital disease including thyroid Choroidal tumor Posterior scleritis Ocular hypotony. d. The hyper fluorescence corresponding to the crests is due to a window defect associated with thinning of the retinal pigment epithelium. In contrast the retinal pigment epithelium is thicker-over the troughs and therefore obscures background fluorescence. 96) a. Morning glory anomaly. b. The condition is not hereditary. c. Most cases are unilateral. Possible systemic associations are: Basal encephalocele Absence of the corpus callosum  Hare lip and cleft palate. 97) a. Juvenile chronic arthritis is an idiopathic, seronegative, inflammatory arthritis of at least 3 months duration occurring before age 16 years. b. The main types, according to onset, are: Pauciarticular—four or fewer joints Polyarticular—five or more joints Systemic—fever, rash, lymphadenopathy, hepatosplenomegaly etc. c. Risk factors for uveitis are: Early-onset pauciarticular Serum antinuclear antibodies Female gender HLA-DW5 and HLA-DPw2. d. Juvenile 'rheumatoid' arthritis is the counterpart of adult seropositive rheumatoid arthritis starting before the age of 16 years. 98) a. Essential iris atrophy. b. The condition is not hereditary. c. Gonioscopy will show superior synechial angle closure. d. The condition is invariably unilateral. e. Differential diagnosis: Iris naevus syndrome of Cogan-Reese Chandler's syndrome. 99) a. A slightly avascular diffuse functioning bleb. b. Trabeculectomy and Scheie's procedure. c. Causes of shallow anterior chamber: wound leak Excessive drainage Ciliary shut-down Ciliary block (malignant) glaucoma. d. Late complications. Bleb infection and endophthalmitis A slight risk of cataract formation. 100) a. The visual field defect (scotoma) in each eye has an arcuate shape. This can be explained by loss of nerve fibers supplying the inferior retina due to glaucomatous damage consistent with thinning of the inferior retinal rim. However, such symmetrical field loss is extremely rare in primary open-angle glaucoma and other possible causes are: Excessive skin (dermatochalasia) on upper eyelids causing obstruction of upper visual field Very thick horn-rimmed spectacles Retinal degenerations such as Sectorial retinitis pigmentosa. b. A paracentral scotoma that lies between 10° and 20° off fixation (Bjerrum's area). 101) a. The vertical cup disc ratio is 0.7. b. 10-21 mmHg. c. Ocular hypertension (i.e. raised intraocular pressure without optic nerve damage). Regular intraocular pressure check with visual Held analysis is required. 102) a. Chronic staphylococcal blepharitis. b. Other signs: Mild papillary conjunctivitis Inferior punctate epitheliopathy Marginal keratitis Dry eyes Styes Phlyctenulosis (rarely). c. Treatment: Regular lid hygiene Topical antibiotic ointment Artificial tear substitutes Weak steroids—when appropriate. d. Atopic dermatitis. 103) a. Posterior blepharitis. b. Classification: Meibomian seborrhea Primary meibomitis Meibomitis with secondary blepharitis. c. Treatment: systemic antibiotics—tetracycline, Doxycycline, or erythromycin Warm compresses Artificial tear substitutes Topical steroids, when appropriate. d. Systemic associations: Acne rosacea Seborrhoeic dermatitis. 104) a. The upper eyelid and lateral canthus drain into the preauricular nodes and the lower eyelid and medial canthus into the submandibular nodes. b. Lesions predisposing to squamous cell carcinoma: Actinic keratosis Bowen's disease Xeroderma pigmentosa Irradiation. c. Malignant eyelid tumors: Basal cell carcinoma Squamous cell carcinoma Sebaceous gland carcinoma Malignant melanoma Merkel cell tumor Kaposi's sarcoma. 105) a. Molluscum contagiosum. b. The causative agent is one of the pox viruses. c. Chronic follicular conjunctivitis. d. The lesions are destroyed by expression, cauterization, shave excision or cryotherapy. e. Corneal micropannus. 106) a. The main indications are intractable secondary glaucomas which have either failed or are very likely to fail with conventional filtering procedures. Currently used shunts: Molteno tube Schocket tube and gutter (shown here) White pump shunt Krupin-Denver valve. c. Complications: Blockage of shunt by blood or fibrovascular tissue Over drainage Corneal endothelial damage implant erosion. 107) a. The tumor may originate from: Meibomian glands Glands of Zeis Sebaceous glands in caruncle Eyebrow. b. Clinical types: Nodular (as shown here)—may masquerade as a 'chalazion'. Spreading—may masquerade as 'chronic blepharitis'. c. Pagetoid spread is extension of the tumor within the epithelium of the conjunctiva. d. Her prognosis is poor because: The upper eyelid is involved. There is maximal diameter of over 10 mm. Duration is over 6 months. 108) a. Clinical signs: Moderate to severe bilateral ptosis Absent upper lid crease Very deep upper sulci Entropion of both lower eyelids. b. Involutional aponeurotic ptosis. c. Other types of ptosis in this age group: Myogenic, e.g. myasthenia gravis Neurogenic, e.g. Homer's syndrome Mechanical, e.g. plexiform neurofibroma d. Operations: Levator resection Fasanella-Servat procedure Brow suspension Aponeurosis strengthening. 109) a. Main clinical types: Ocular Relapsing Progressive. b. Investigations: Tensilon test—may be combined with a Hess test Electromyography to confirm fatigue. Antibodies to acetylcholine receptors and striated muscle CT or MR of the anterior mediastinum to rule out thymoma. c. Other systemic causes of ptosis: Myotonic dystrophy Ocular myopathies (i) Primary (ii) Oculopharyngeal (iii) Kearns-Sayre syndrome. 110) a. There is a fleshy lesion with increased capillarity on the superior bulbar conjunctiva. b. Differential diagnosis: Conjunctival lymphoma—most likely because of the characteristic salmon-patch appearance Conjunctival intraepithelial Neoplasia (Bowen's disease) Invasive Squamous cell carcinoma Pagetoid spread of a sebaceous gland carcinoma. c. Biopsy. 111) a. Severe papillary (cobblestone) conjunctivitis involving the upper tarsus associated with a strand of mucus. b. Vernal Keratoconjunctivitis. c. About 75% of patients have associated atopy and 66% have a close family history of atopy. d. Corneal complications: Superior punctate epitheliopathy Epithelial macroerosions Plaque Subepithelial scarring Pseudogerontoxon. 112) a. Adenoviruses types 8 and 19. b. 80% of patients with conjunctivitis. c. Sequence of corneal changes: Diffuse punctate epithelial keratitis—may clear within 2 weeks. Focal white subepithelial keratitis. Anterior stromal infiltrates—may persist for months. d. Steroids are indicated for anterior stromal infiltrates impairing visual acuity. 113) a. Herbert's pits. b. They are limbal depressions due to cicatrization of follicles and are pathognomonic of trachoma. c. Grading of trachoma: TF = trachomatous follicular inflammation TI = trachomatous intense inflammation. TS = trachomatous conjunctival scarring TT == trachomatous trichiasis  CO = corneal opacity. d. Other chlamydial infections: Adult inclusion conjunctivitis Ophthalmia neonatorum. 114) a. There is extensive subretinal yellowish exudate associated with overlying vascular anomalies. b. The condition is not hereditary. During the first decade with unilateral: Visual loss Strabismus Leukocoria. Other retinal telangiectasias: Idiopathic Juxtafoveolar Telangiectasis Leber's miliary aneurysms. 115) a. Reis-Bucklers' corneal dystrophy. b. Autosomal dominant. c. There is no associated enzyme defect. d. The long-term prognosis is reasonably good although some patients eventually require either lamellar or penetrating keratoplasty. Recurrence of the dystrophy on the graft is common. 116) a. A conjunctival pseudomembrane consisting of coagulated exudate adherent to inflamed conjunctival epithelium. b. Causes: Adenoviral conjunctivitis Vernal disease Ligneous conjunctivitis Gonococcal conjunctivitis Ocular cicatricial pemphigoid Stevens-Johnson syndrome. c. A true conjunctival membrane forms when there is necrosis of the conjunctival epithelium and the formation of a fibrovascular adhesion between the conjunctival stroma and the coagulum. Attempted peeling leaves a raw bleeding area. Causes are p- Hemolytic streptococcus and diphtheria. 117) a. Granular corneal dystrophy type 1. b. Autosomal dominant. c. there are no systemic associations. d. Staining is bringt red with Masson trichrome. e. Between 6/12 and 6/60 118) a. Two types: limited form—unilateral affecting the elderly Progressive type—bilateral affecting the young. b. Treatment: Topical steroids Systemic immunosuppressive agents Conjunctival excision in resistant cases. c. Systemic disease:  Acne rosacea rheumatoid arthritis Systemic lupus erythematosus Wegener's granulomatosis Polyarteritis nodosa. 119) a. Defective depression of the right eye. b. Right third nerve palsy. c. Common causes: Vascular—pupil usually spared Posterior communicating aneurysm—pupil usually involved Idiopathic Trauma. d. Uncommon causes: Tumors Vasculitis associated with collagen vascular disorders Syphilis. 120) a. Sturge-Weber syndrome. b. The condition is not hereditary. c. Mechanism of glaucoma: Congenital angle anomaly raised episcleral venous pressure due to an episcleral hemangioma. d. Other ocular lesions: diffuse choroidal hemangioma Heterochromia iridis Haemangiomas of the iris and ciliary body. 121) a. Coronal plane. b. There is a fracture of the medial wall of the left orbit with soft tissue and/or blood in the left ethmoid complex. c. Patients with a medial orbital wall fracture often present one or two days after trauma when they blow their nose and the periorbital soft tissue fills with air. d. The management is: Examination of the globe to exclude any ocular damage Examination of extra ocular movements to exclude medial rectus entrapment A 10-day course of oral antibiotics If there is evidence of air in the soft tissues surrounding the eye the patient is advised to avoid blowing his nose. 122) a. Axial plane. b. There is an enlarged left medial rectus muscle. c. Yes; this explains her diplopia and decreased vision (if the muscle is compressing the optic nerve at the orbital apex). d. Thyroid-related eye disease; the patient should have thyroid function tests including auto antibodies. 123) a. Since ocular examination was not possible, the diagnosis is orbital cellulitis until proved otherwise. b. Cavernous sinus thrombosis. c. The management here is: Admit the patient. Start intravenous benzyl penicillin, flucloxacillin and metronidazole. Perform a CT scan of the orbits, brain and sinuses. In cases where ocular examination is possible, extraocular movements, pupil reactions, color vision and fundoscopy are used to exclude orbital involvement. If at any stage there is suspicion of cavernous sinus thrombosis (sudden onset proptosis which may be bilateral), urgent neurosurgical intervention is needed. 124) a. Sagittal plane. b. T1 and T2 refer to two methods of measuring the relaxation times of the excited protons after the magnetic field is switched off. Different tissues have different relaxation times and a certain tissue may be Tl or T2 weighted, implying that it is best visualized on a Tl and T2 image. For normal anatomy Tl weighted images are better while pathological findings are usually better seen on T2 weighted images. c. This is a Tl weighted image. d. There is an enlarged mass in the region of the pituitary fossa, most likely a pituitary adenoma. 125) a. There is a dome-shaped vascular bleb which is consistent with an encapsulated bleb or a Tenon's cyst. b. A cyst-like space has formed from Tenon's capsule over the filtering bleb and this is trapping aqueous. As it enlarges it prevents aqueous from entering the subconjunctival space causing the intraocular pressure to rise. c. Treatment options are: Using aqueous suppressants to prevent the cyst getting any bigger Regular ocular massage and topical steroid drops Needling the cyst Surgical revision of the Trabeculectomy A combination of the above. 126) a. A circinate hard exudate. b. If this circinate was nasal to the disc you would just observe. If it were temporal to the disc and within the arcades, you would consider focal laser treatment. Remember that hard exudates may resorbe spontaneously but, if they lie near the macula, they may cause maculopathy and a decrease in vision. c. There is an easy way to remember these by the mnemonic HAVOX: Hemorrhages—'dot and blot' and flame-shaped Aneurysms Venous dilatation Oedema of the retina due to 'leaky' vessels eXudates, hard. 127) a. A large frond of new vessels at the disc. b. HLA DR3 and DR4. c. Vitreous or preretinal hemorrhage. New vessels. Location of new vessels on or near the disc. Severity of new vessels. d. Pan retinal photocoagulation. 128) a. Arteriovenous nipping. b. A thickening of the arteriole vessel wall as a result of intimal hyalinization, medial hypertrophy and endothelial hyperplasia. The two causes are age-related (involutional) and hypertension. c. Grade I—mild generalized arteriolar narrowing Grade II—severe narrowing and focal narrowing of arterioles Grade III—grade II plus hemorrhages, cotton-wool spots and exudates Grade IV—grade III plus disc swelling. 129) a. Grade 4. b. Malignant hypertension. c. Other fundus changes: Retinal vein occlusion Retinal artery occlusion Slow flow retinopathy due to carotid disease Anterior ischemic optic neuropathy Retinal artery microaneurysm Ischemic choroidal infarcts Adverse effects on diabetic retinopathy. d. Indirect effects: Vascular cranial nerve palsies Homonymous hemianopia due to CVA. 130) a. Retinal branch vein occlusion. b. Secondary neovascularization which can lead to vitreous hemorrhage Chronic macular edema. c. The location of the occlusion is usually at an arteriovenous crossing; there appears to be a common adventitia at these points which allows the artery to impinge on the vein and cause thrombosis under certain circumstances, i.e. arterial disease most commonly secondary to systemic hypertension, diabetes mellitus and age-related arteriosclerosis. 131) a. Bilateral ectropion. b. The eyes are watering because the lower lid margin is rolled away from the globe so that the inferior puncta are not in apposition to the tear film. c. Ectropion may be congenital or acquired. Acquired causes are: (i) Involutional—due to age-related atrophy (ii) Neuroparalytic—due to facial nerve palsy (iii) Cicatricial—due to trauma, tumors or burns.  Congenital causes are rare and may be associated with the Blepharophimosis syndrome. 132) a. Ocular toxocara granuloma. b. When toxocariasis presents as a systemic infection it is called visceral larva migrans characterized by pyrexia, jaundice, hepatosplenomegaly, pneumonia and occasionally convulsions. c. The two other common modes of ocular presentation are endophthalmitis and a peripheral granuloma. Other unusual presentations are anterior uveitis with hypopyon, papillitis and vitreous abscess. 133) a. An old chorioretinal scar adjacent to active chorioretinitis ('satellite' lesion). This is probably an active recurrence of congenital toxoplasmosis. b. The blurred vision may be explained by vitreous cells and haze caused by the active retinochoroiditis. This inflammation has probably also spilled into the anterior chamber and caused an anterior uveitis which would explain the photophobia. c. Yes; at times of decreased immunity it is thought that parasitic cysts rupture, releasing proliferating active parasites that destroy tissue and induce an immune reaction. 134) a. A chorioretinal scar probably caused by congenital toxoplasmosis. b. The cat. c. Congenital toxoplasmosis may be active or inactive at birth. If it is active the two main features are hydrocephalus and necrotizing encephalitis. The latter leads to cerebral calcification, convulsions, jaundice, microcephaly and microphthalmos. The only sign of inactive congenital toxoplasmosis may be chorioretinal scars in the fundus. 135) a. Infantile esotropia is characterized by the following: A fairly large and stable angle of squint Alternating fixation in the primary position and cross fixation on side gaze Normal refractive error for the age of the child Nystagmus in some cases. b. Management is as follows: Cycloplegic refraction and fundoscopy. Treatment of amblyopia which occasionally may be present. Surgery at about the age of 12 months. c. Potential long-term problems are: Under correction requiring further surgery Inferior oblique overaction dissociated vertical deviation Accommodative element requiring spectacle correction amblyopia. 136) a. Birdshot retinochoroidopathy. b. There is no underlying metabolic defect. c. The main vision-threatening complications are: Cystoid macular edema Retinal neovascularization and vitreous hemorrhage Retinal atrophy  Optic atrophy. d. Treatment is with periocular or systemic steroids. 137) a. Retinal edema is recognized clinically as thickening of the retina which obscures visualization of the underlying retinal pigment epithelium and choroid. b. Macular edema is defined as retinal thickening or hard exudates within one disc diameter (1500 µm) of the centre of the fovea. c. Clinically significant macular edema is defined as Retinal thickening within 500 (µm of the centre of the fovea Hard exudates within 500 (µm of the centre of the fovea if associated with adjacent retinal thickening (which may be outside the 500 um limit) Retinal edema 1 disc area (1500 µm) or larger, any part of which is within 1 disc diameter of the centre of the fovea. 138) a. There is a very large subhyaloid hemorrhage overlying the posterior pole as well as several flame-shaped hemorrhages. b. Strict diabetic control may delay the onset of but will not prevent retinopathy. In some patients aggressive efforts to normalize blood glucose levels with insulin pumps may worsen the retinopathy during the first few months of treatment. c. Adverse factors are: Systemic hypertension Pregnancy Renal disease Anemia. 139) a. There is severe fibrovascular proliferation with an inferior extra macular tractional retinal detachment. b. The aims of vitrectomy are: Restoration of vision by removing vitreous hemorrhage Prevention of future fibrovascular proliferation by excising vitreous gel Repair of retinal detachment by excising anteroposterior and bridging tractional membranes. c. The main indications for vitrectomy are: Dense persistent vitreous hemorrhage. Dense persistent premacular subhyaloid hemorrhage. Tractional retinal detachment threatening or involving the macula. Combined tractional and rhegmatogenous retinal detachment. Severe and relentlessly progressive fibrovascular proliferation. 140) a. Melanocytoma of optic nerve head. b. Some Melanocytomas grow very slowly. c. The lesion is benign. d. Some deep-seated tumors may cause visual impairment by compressing the nerve fibers and their blood supply. e. There is no treatment. 141) a. Ocular reticulum cell sarcoma characterized by vitritis and multifocal subretinal infiltrates. b. Involvement of the central nervous system by the tumor. c. Both eyes are eventually affected in 80% of cases. d. Treatment of the eyes and central nervous system is with radiotherapy. 142) a. Breast. b. Bronchus. c. prostate d. Treatment is palliative with chemotherapy in conjunction with external beam radiotherapy. e. Other choroidal tumors: Choroidal naevus circumscribed choroidal hemangioma diffuse choroidal hemangioma—in Sturge-Weber syndrome Osteoma Reticulum cell sarcoma. 143) a. Other presentations: Pressure on the lens—displacement, astigmatism and cataract Extension through the iris root Posterior extension—retinal detachment Anterior uveitis due to necrosis diffuse circumferential growth—poor prognosis due to late diagnosis. b. Tests: Gonioscopy Transillumination Ultrasonography Incision wedge biopsy—in atypical cases. c. Other tumors: Medulloepithelioma Hemangioma Leiomyoma Cystic adenoma of pigmented ciliary epithelium. 144) a. Treatment options: Nil, if only eye in elderly patient Enucleation. Radioactive plaque therapy Cyclotron generated charged particle irradiation Photocoagulation—only if small Partial lamellar sclerouveectomy in selected cases Exenteration, if extrascleral extension Palliative therapy, if distant metastases. b. Adverse factors. Remember the mnemonic SPECS-BAD as follows: Size—large Pigmentation Extrascleral extension Cell type—epithelioid Site—anterior to equator Bruch's membrane broken Age—over 65 years  Diffuse growth. 145) a. Three types: Melanoma arising from primary acquired melanosis Primary melanoma Melanoma arising from a pre-existing naevus—very rare. b. Overall mortality is 25%. c. Tumors arising from the palpebral conjunctiva—50% mortality rate. d. Treatment: Local surgical excision Exenteration, if spread to the lids Palliation for Metastatic spread. 146) a. Subepithelial b. There is no risk of malignant transformation. c. Other lesions: Hyperpigmentation of facial skin and mucus membranes (naevus of Ota is very common) Hyperpigmentation 'of ipsilateral uveal tract (common) Hyperpigmentation of the trabecular meshwork and glaucoma (uncommon) Hyperpigmentation of the cornea, lens and optic nerve (rare) Malignant melanomas of the uvea, skin, orbit and CNS (rare) Hyperpigmentation of orbit, meninges and brain (very rare). 147) a. clinical features suggestive of malignancy: Presence of symptoms Evidence of growth Surface lipofuscin pigment Subretinal fluid Overlying retina showing cystoid changes dilated vessels within the tumor Location of posterior margin within 3 mm of the optic disc. b. Special investigations: Ultrasonography to measure thickness Fluorescein angiography Serial photography. 148) a. Classification: Infantile Accommodative (i) Refractive (ii) Non-refractive (iii) Mixed. Non-accommodative (i) Stress-induced (ii) Sensory deprivation (iii) Consecutive (iv) Spasm of near reflex (v) Sixth nerve palsy. b. Types of amblyopia: Strabismic Anisometropic—different refractive errors Isoametropic—equal large refractive errors Sensory deprivation. c. Amblyopia therapy: Occlusion. Atropinization. Manipulation of spectacles. Pleoptics. 149) a. The vertical cup: disc ratio is 0.9. (The cup is the pale area within the total disc diameter which is devoid of any neural disc tissue). The normal ratio is 0.3-0.5. b. One million nerve fibers. c. Systemic conditions: -increasing age -diabetes -hypertension -systemic vascular disease. Ocular conditions: -myopia -Fuchs' endothelial dystrophy -retinitis pigmentosa. d. The diagnosis of primary open angle glaucoma depends on the following: Normal anterior chamber angles raised intraocular pressures Pathologically cupped discs Visual field loss. Given the fact that there is raised intraocular pressure with the above appearance of the disc, the diagnosis of primary open-angle glaucoma can be made, though ideally documented field loss should be present. 150) a. retinal artery macroaneurysm. b. Causes of visual loss: Retinal hemorrhage Retinal edema Hard exudate formation Retinal branch vein occlusion Vitreous hemorrhage. c. Early laser treatment of macular edema and exudation may be beneficial. 151) a. Peters' anomaly. b. Autosomal dominant. c. Other ocular anomalies: Glaucoma—in 50%. Anterior cataract. Miscellaneous uncommon associations: (i) Cornea plana (ii) Sclerocornea  (iii) Microphthalmos (iv) Corectopia (v) Iris hypoplasia. d. There are no systemic associations. 152) a- Opacification types: Elschnig's pearls due to proliferation of lens epithelium Opacification associated with residual subcapsular plaque Capsular fibrosis. b. Indications for capsulotomy: diminished visual acuity Severe glare or monocular diplopia impaired visualization of the fundus for diagnostic or therapeutic purposes. c. Six months or more after the initial cataract extraction. d. Potential complications: Damage to the implant Elevation of intraocular pressure Cystoid macular edema Retinal detachment. 153) a. Lid signs: Lid retraction in primary gaze—Dalrymple's sign (shown here) Lid lag in downgaze—von Graefe's sign Staring and frightened appearance—Kocher's sign Infrequent blinking Fine tremor on lid closure Jerky spasmodic movements on lid opening. b. Surgical procedures: Inferior rectus recession Excision of Muller's muscle Recession of levator aponeurosis Recession of lower lid retractors. c. Other causes: Congenital (very rare). Neurological (i) Marcus—Gunn jaw-winking (ii) Aberrant regeneration of the third nerve (iii) Collier's sign of the dorsal midbrain (Parinaud's syndrome). Mechanical (i) Post-traumatic. (ii) Surgical over-correction (iii) Unilateral ptosis with contralateral levator over action. Metabolic (i) Cirrhosis (ii) Uremia. 154) a. Other features: associated anterior scleritis in 80% Disc edema. Vitritis. Choroidal folds. Retinal changes: -Macular edema -Exudative detachment -Subretinal exudation and subretinal mass -Intra retinal white deposits. b. Differential diagnosis: Choroidal tumor Orbital inflammatory disease Uveal effusion syndrome Harada's disease. c. Differences from retinal detachment: Absence of photopsia and floaters Frequently very low intraocular pressure—anterior chamber may be shallow. Appearance: -convex, smooth, immobile, brown elevations -does not involve posterior pole -peripheral retina and ora serrata easily seen. 155) a. Foville's syndrome characterized by ipsilateral: Sixth nerve palsy combined with gaze palsy. Facial palsy and analgesia. Homer's syndrome. diminished hearing. b. Millard-Gubler syndrome: Ipsilateral sixth nerve palsy Contralateral hemiplegia Variable signs of a dorsal pontine lesion. c. Basilar lesions: raised intracranial pressure Fractures Acoustic neuroma Nasopharyngeal tumors. 156) a. Hyperpigmentation: Pigment dispersion syndrome Pseudoexfoliation syndrome following blunt trauma following acute angle-closure glaucoma Anterior uveitis Diabetes Naevus of Ota. b. Main types of gonioscopes: Direct—provide direct view of angle (i) Diagnostic—Koeppe (ii) Surgical—Swan-Jacob, Barkan, Thorpe etc. Indirect diagnostic—Goldmann, Zeiss. c. Shaffer grade 2: a moderately narrow angle in which only the trabeculum can be identified. 157) a. There are fine keratic precipitates scattered throughout the corneal endothelium. b. Fuchs' heterochromic cyclitis. c. Other signs: Mild aqueous flare and cells Iris atrophy and heterochromia Koeppe nodules Mild rubeosis iridis Absence of posterior synechiae Mild vitritis Fine blood vessels in the chamber angle. d. Management: There is no effective treatment for the uveitis. There is no contraindication to standard cataract surgery. Long-term follow-up is required because of the risk of subsequent development of glaucoma. 158) a- Drainage complications: Choroidal hemorrhage Retinal incarceration Iatrogenic tear formation Vitreous prolapse Postoperative endophthalmitis. b. Early failure: Immobile retina due to proliferative vitreoretinopathy buckle failure—inadequate height, inadequate size, incorrect position Fish mouthing of break Complications of drainage of subretinal fluid missed break. c. Late failure: Proliferative vitreoretinopathy Re-opening of break due to inadequate buckle Re-opening of break due to insufficient cryotherapy New break formation. 159) a. Ocular motility is restricted by edema during the active infiltrative phase and by fibrotic contracture during the fibrotic stage. b. Motility defects: Defective elevation—fibrotic inferior rectus (shown here) Defective abduction—fibrotic medial rectus Defective depression—fibrotic superior rectus Defective adduction—fibrotic lateral rectus. c. Indications for decompression: Cosmetic Optic neuropathy unresponsive to other measures Exposure keratopathy due to severe proptosis. d. Types of decompression: Two wall—antral-ethmoidal Three wall—antral-ethmoidal plus lateral wall  Four wall—three wall plus part of sphenoid and roof. 160) a. Treatment: Systemic steroids in the first instance. Immunosuppressive agents (cyclophosphamide, azathioprine, cyclosporin) in steroid resistant cases. Combined immunosuppressives and pulsed intravenous methylprednisolone as a last resort. b. Causes: Rheumatoid arthritis—most common Wegener's granulomatosis Polyarteritis nodosa Systemic lupus erythematosus Systemic arteritis Relapsing polychondritis. c. Treatment of non-necrotizing scleritis: Topical steroids for associated episcleritis Oral fluriprofen or indomethacin Systemic steroids as last resort. 161) a. Direct carotid-cavernous fistula. b. Causes: Basal skull fracture—most common cause Intracavernous rupture of an aneurysm or an arteriosclerotic artery. c. Other signs: Pulsatile proptosis associated with a bruit abolished by ipsilateral carotid compression raised intraocular pressure Rubeosis iridis Ophthalmoplegia Retinal vascular engorgement or central retinal vein occlusion. d. Dynamic proptosis: Pulsatile with a bruit (i) carotid-cavernous fistula (ii) Orbital arteriovenous malformation. Pulsatile without a bruit (1) Congenital defect in sphenoid bone, neurofibromatosis type 1 (ii) Defect in orbital roof (iii) Indirect carotid-cavernous fistula. Intermittent but not pulsatile (i) Orbital varices (ii) Orbital capillary haemangiomas. 162) a. Conjunctival phlyctenulosis. b. A non-specific delayed hypersensitivity reaction to staphylococcal or other bacterial agents. c. May involve the cornea and cause scarring, ulceration and rarely perforation. d. Topical steroids and, rarely, systemic tetracycline. e. Differential diagnosis: Nodular episcleritis  Inflamed pinguecula. 163) a. Cornea verticillata (vortex dystrophy). b. Systemic diseases: Rheumatoid arthritis or a collagen vascular disease treated with choloroquine Gout treated with indomethacin Cardiac arrhythmia treated with amiodarone Carcinoma of the breast treated with tamoxifen Schizophrenia on long-term chlorpromazine Fabry's disease. c. The following drugs may cause retinal changes: Chloroquine—maculopathy Tamoxifen—minute, superficial, crystalline ring-like deposits at the macula. 164) a. Band keratopathy. b. Chronic anterior uveitis associated with juvenile chronic arthritis. c. Other causes: Idiopathic in the elderly Chronic anterior uveitis in adults Phthisis bulbi Increased serum calcium or phosphorus levels (rare). d. Treatment: Chelation with sodium versenate Excimer laser keratectomy. 165) a. Cafe-au-lait spot. b. Neurofibromatosis type 1 (NF I). c. Classification: NF-I = von Recklinghausen's disease (i) Cafe-au-lait spots (ii) Lisch nodules (iii) Neurofibromas NF-II = bilateral acoustic neuromas NF-III = segmental neurofibromatosis NF-IV == multiple cafe-au-lait spots only. d. Differential diagnosis of congenital iris nodules: Brushfield spots (Trisomy 21) Juvenile xanthogranuloma Lisch nodules Naevi Cysts. 166) a. Hering's law of equal innervations. b. There is right lateral rectus palsy. The more restricted chart is that of the eye with the paretic muscle; the restriction will be greatest in the direction of action of the affected muscle. (The chart is labeled as 'field of eye' and 'fixing eye'; the former annotation indicates which eye's muscles are being examined). c. No; the patient must have normal retinal correspondence for this test to be accurate. 167) a. There is restriction of upgaze and to a lesser extent downgaze in the left eye. b. A rule of thumb to differentiate between innervational defects and mechanical ones is to compare the shape of the inner and outer fields: in innervational defects the two are asymmetrically distorted while in mechanical ones the two are unchanged or symmetrically distorted. c. Left blow out fracture with tethering of the inferior rectus muscle. 168) a. There is restriction of abduction and upgaze in the left eye with corresponding overactions in the right eye. b. This is probably a mechanical defect because: Innervational defect would involve VI nerve palsy with a partial III nerve palsy which is very unlikely The inner and outer fields of the Hess chart are fairly symmetrical. c. Thyroid-related ophthalmopathy. 169) a. This is a V pattern deviation. b. No; inferior oblique palsies are associated with 'A' pattern horizontal deviations. c. This is the typical 'dog ears' Hess chart seen in Brown's syndrome. d. Etiology is: Congenital—abnormality of the superior oblique tendon distal to the trochlear. Acquired (i) Trochlear inflammation, e.g. rheumatoid arthritis (ii) Iatrogenic, such as post superior oblique tendon tuck (iii) Trauma. 170) a. This means that each point in the visual field is presented with a stimulus known to be brighter than the expected normal value for that point. This is used as a quick screening test; if a stimulus is not seen, a defect is noted but its extent is not determined. b. Enlarged blind spots. c. Causes are: Chronic papilledema High myopia Myelinated nerve fibers Optic disc drusen Glaucoma Peripapillary choroiditis. 171) a. There are crystal-like deposits in the cornea. Possible causes are: Corneal dystrophy (i) Schnyder's crystalline dystrophy (ii) Bietti's marginal crystalline dystrophy. Metabolic disorders (i) Cystinosis (ii) Tyrosinosis (iii) Gout (iv) Tangier disease (v) LCAT (lecithin-cholesterol acyltransferase) deficiency. Hematological disorders  (i) Multiple myeloma (ii) Other monoclonalgammopathies. Infection—infectious crystalline keratopathy (most commonly reported with Staphylococcus aureus infections). Others—secondary lipid keratopathy. 172) a. There is hyperostosis involving the sphenoid bone on the left side. b. A similar sign may be seen in: Sphenoid ridge meningioma—most likely diagnosis in this case Fibrous dysplasia—patients are usually much younger Paget's disease of bone—much more widespread Osteoma. 173) a. A child may present because: Parents notice (i) Leukocoria (ii) An opacity 'in the pupil' (usually only if anterior polar cataract and very observant parents) (iii) that the child 'does not follow them' with his eyes (iv) That the child has a squint. (v) That the child has photophobia (due to glare with certain cataracts). A pediatrician (i) Is screening the child for failure to thrive (ii) Has diagnosed a syndrome which is associated with congenital cataracts. b. Etiology of congenital cataracts is: Idiopathic Genetic (i) Simple (ii) Chromosomal disorders, e.g. trisomy 18. Intrauterine infection (i) Rubella (ii) Varicella (iii) Toxoplasmosis. Metabolic (i) With an unwell child, e.g. galactosaemia, Lowe's syndrome, Refsum's disease. (ii) With a healthy child, e.g. galactokinase deficiency. Associated with Ocular anomalies e.g. aniridia, posterior lenticonus, persistent hyperplasic primary vitreous. Associated with Systemic syndromes, e.g. Incontinentia pigmenti, congenital ichthyosis. 174) a. Frontal bossing/saddle nose/poorly developed maxilla/rhagades (linear scars at the angles of the mouth). Her teeth, if visible, would probably have shown peg-like features (Hutchinson's teeth). b. Hutchinson's triad (interstitial keratitis, deafness and Hutchinson's teeth) is suggestive of congenital syphilis. c. Ocular manifestations of congenital syphilis: Interstitial keratitis (IK) Retinopathy, either of a 'salt and pepper' variety or of a type that resembles retinitis pigmentosa Optic atrophy Corneal opacities (usually scars from old IK). 175 a. Chronic papilledema. b. The finding of papilledema with a normal MR scan is suggestive of idiopathic intracranial hypertension. c. Apart from headaches and intracranial noises (which are the commonest) other symptoms include transient visual obscurations, sparkles, visual loss and diplopia (due to sixth nerve palsy). d. A lumbar puncture to show raised cerebrospinal fluid opening pressure. 176) a. This is a left exotropia (manifest divergent squint). b. There are three types: Monocular cover-uncover test: to differentiate between a tropia (manifest) and a phoria (latent) deviation, e.g. if the right eye is covered and then uncovered and the left eye moves there is a tropia; if the right eye moves while it is being uncovered there is a phoria. Alternate cover test: measures the total deviation (latent and manifest); the eyes are covered and uncovered quickly and alternately, thereby causing dissociation of the eyes. Prism and cover test: measures the amount of deviation in prism diopters while both eyes are uncovered, e.g. if the right eye is fixing on an object, it is covered while at the same time a prism (appropriately orientated) is placed in front of the left eye; larger prisms are used until there is no movement by the left eye to take up fixation when the fixing right eye is covered. 177) a. The picture shows Leukocoria (white reflex from the left eye); this is retinoblastoma until proven otherwise. b. The differential diagnosis of Leukocoria in a child is a chestnut of a question; if you fail to impress upon the examiner that you know this and understand its implications, you're struggling! Here is one method of remembering the list: Conditions that involve the pupil/lens (i) Congenital cataract (ii) Cyclitic membrane. Conditions that involve the vitreous (i) Toxocara endophthalmitis (also involves retina) (ii) Persistent hyperplastic primary vitreous (iii) Organized vitreous hemorrhage (iv) Vitreous abscess. Conditions that involve the retina (i) Tumors, e.g. retinoblastoma, retinal astrocytoma (ii) Retinopathy of prematurity (ii) Vascular anomalies, e.g. Coats' disease, angiomatosis retinae (iv) Congenital, e.g. retinal dysplasia, retinochoroidal coloboma, extensive myelinated nerve fibers. (v) Total retinal detachment, e.g. Incontinentia pigmenti, Norrie's disease. 178) a. Retinal astrocytoma. b. Astrocytic hamartoma of the brain in association with tuberous sclerosis. c. Autosomal dominant. d. Skin lesions: Angiofibromas (adenoma sebaceum) Ash-leaf hypopigmented patches which fluoresce with ultraviolet light Skin tags (molluscum fibrosum pendulum) Forehead fibrous plaques Shagreen patches. 179) a. A space-occupying lesion arising from the medial third of the sphenoidal ridge. The diagnosis is a sphenoidal ridge meningioma. b. No; meningiomas arising from the medial third of the sphenoidal ridge tend to cause visual loss and optic atrophy much earlier than proptosis, in complete contrast to those arising from the middle and lateral thirds. c. Meningiomas