1.    a.T    b.F    c.T    d.T    e.T
 
        Many drugs have been implicated in optic neuropathy, the following are the better     known:

• anti-tuberculous: ethambutol and isoniazid
• chloramphenicol
• digitalis
• oral hypoglycaemic agents: chlopropamide and tolbutamide
• chloroquine
• disulfirum
• D-penicillamine

2.    a.T    b.T    c.F    d.T    e.F

        Hypotony:

• occurs when the intraocular pressure is sufficient low to compromise the ocular function usually below 6 mmHg
• may be caused by decreased aqueous production or excessive aqueous drainage
• can results in:

    - corneal oedema
    - cataract formation
    - uveal effusion
    - macular oedema
    - disc oedema
    - choroidal folds
    - choroidal detachment

3.    a.T    b.T    c.F    d.F    e.T

        Ankylosing spondylitis:

• inflammatory disorders of spinal joints
• 90% have the HLA-B27 halotype
• systemic features include peripheral arthritis, uveitis, aortic valve incompetence and chronic inflammatory bowel disease
• the condition is commoner and more severe in males than females
• in the spine, the inflammation begins at the site where ligaments are attached to vertebral bone (the entheses), however,  signs may occur before the patients complain of any symptoms.

4.    a.T    b.F    c.T    d.F   e.T

        Scleritis:

• many varieties and some have a higher incidence of systemic association than other. In decreasing order: necrotizing scleritis without inflammation ie. scleromalacia perforans (over >90%), nodular and necrotizing scleritis (50%), diffuse scleritis (30%) and posterior scleritis (10%)
• severe pain is common
• serous retinal detachment is a known complication especially with posterior scleritis
• in mild to moderate scleritis, oral non-steroidal anti-inflammatory agents such as dicoflenac are useful in suppressing the inflammation
• glaucoma occurs in 5% of cases and is related to: steroid use, increased episcleral venous pressure and rarely angle closure glaucoma due to choroidal effusion

5.    a.T    b.F    c.F    d.T    e.F

       Ocular parasites:

• Trichinella spiralis causes trichinosis which is an infestation of striated muscle by the larva. They are acquired through eating undercooked pork. The orbit and the upper lid can become infested leading to inflammation and pain on eye movement.
• Loa loa is acquired through bites from Mango flies . The patients presents with pruritic subcutaneous swelling. Ocular manifestation include migration of worms under the conjunctiva, in the anterior chamber and the vitreous
• Leishmania donovani can cause either cutaneous or / and visceral leishmaniasis. It is transmitted by the bite of sandfly. In cutaneous form, the eyelids may become involved and untreated can lead to interstitial keratitis.

6.    a.T    b.F    c.F    d.T    e.F

        Uveal melanoma:

• occur mainly in the white population
• the incidence shows little difference between the sexes
• unlike retinoblastoma the optic nerves are seldom infiltrated
• epithelioid cell type is associated with poor prognosis
• blood test is more sensitive than CT scanning in revealing hepatic metastasis

7.    a.T    b.F    c.F    e.F    e.F

        Marfan's syndrome:

• autosomal dominant condition
• caused by incorrect expression of a gene product for 350kD glycoprotein known as fibrillin which is responsible for the extracellular microfibrol network. Type I collagen abnormality is seen in osteogenesis imperfecta
• 80% have lens subluxation which is typically displaced up and out
• lenticular myopia with normal axial length is a feature
• unlike homocystinuria, the patient is mentally normal

8.     a.T    b.T    c.T    d.T    e.T

        Measles:

• is a paramyxovirus containing RNA
• causes Koplik's spots on the conjunctiva and caruncle
• causes acute catarrhal conjunctivitis
• causes punctate keratitis which is self-limiting in developed countries but in the presence of malnutrition especially vitamin A deficiency, blinding keratitis can occur
• subacute sclerosing panencephalitis tends to occur in children who acquire measles before one year of age. It is characterized by progressive neurological deficit with dementia, myoclonus and focal signs causing death.

9.    a.T    b.T    c.T    d.F    e.T

        Cyclosporin A:

• is the product of the fungus Tolypocladium inflatum
• inhibits T cell activation by stopping the expression of receptors on T lymphocytes that recognize the DR antigen found on antigen presenting cells
• has poor tissue penetration when applied topically
• is the drug of choice in patients with Behcet's disease
• causes nephrotoxicity as the main side effect which is dose-dependent

other side effects include: hypertension, hypertrichosis, gastrointestinal upset, gingival hyperplasia, anaemia and raised ESR

 

• is a type IV immune response to some sensitized antigen typically bacteria antigen
• tuberculosis is a known cause but it is more often associated with Staphlococcus aureus
• often occurs near the limbus
• commoner in children
• topical steroid is the treatment of choice

11.    a. T    b.F    c.T    d.T    e.F
 
        Thiamine deficiency

• common in chronic alcoholics and in those with long-standing diseases of the upper gastrointestinal tract such as peptic ulcer or gastric carcinoma
• causes Wernicke's encepholopathy with memory impairment, ataxia, peripheral neuropathy. Ocular signs include external ophthalmoplegia and nystagmus
• there is characteristic perivascular haemorrhages in the region of the fourth ventricle and aqueduct and also in the mamillary bodies
• treatment of choice is with intravenous thiamine (vitamin B1)

12.    a.T    b.T    c.T    d.T    e.T

         Tentorial herniation:

• occurs when a mass lesion makes one cerebral hemisphere too large for its compartment and cause the infero-medial part of the cerebral hemisphere to be pushed through the tentorial hiatus ( which separates the cerebrum from the cerebellum)
• the increased pressure causes vomiting
• deterioration of consciousness occurs due to disturbance of the reticular formation
• compression on the third nerve results in dilated pupil, ocular palsy and ptosis
• results in coning with the whole brainstem being pushed downward. This interfere with the vital functions of respiration (controlled by medulla oblongata)

compression of the pyramidal fibres result in hemiparesis

13.    a.T    b.T    c.T    d.T    e.T

          Lawrence-Moon-Biedle's syndrome have the following features:

• mental retardation
• obesity
• hypogenitalism
• polydactyly
• spastic paraplegia
• retinitis pigmentosa

14.    a.F    b.F    c.F    d.T    e.F

          Sarcoidosis:

• a systemic disorder of unknown origin
• tends to affect people in their 20s and 30s
• produces non-caseating granuloma
• bilateral hilar lymphadenopathies are common even in the absence of chest symptoms
• causes reduced number of circulating lymphocytes

15.    a.F    b.F    c.F    d.F    e.F

          Sickle cell disease:

• sickle cell trait occurs in 8% of the population
• although SS disease has the most severe systemic manifestation, retinopathy is most severe with SC and S-thal diseases
• neovascularization typically occurs in the peripheral retina
• salmon patches are the result of pre-retinal or internal lining membrane haemorrhages
• the main cause of visual loss is vitreous haemorrhage and rhegmatogenous retinal detachment.

16.    a.T    b.F    c.F    d.T    e.T

          Alport's syndrome:

• a disease with neurosensory hearing loss and haemorrhagic nephritis
• only 15% have ocular abnormalities and this include anterior lenticonus and peripheral retinal fleck
• inheritance may be dominant (most common),  X-linked and recessive

17.    a.T    b.T    c.T    d.T    e.F

         Corneal deposits:

• the mucopolysaccharadosis is a group of storage disease caused by an error of carbohydrate metabolism. Corneal deposits are seen in all types except in Sanfilippo's (type III) and the majority of Hunter's (type II) syndrome
• myeloma can lead to amyloidosis of cornea

cystinosis is an autosomal recessive condition characterized by widespread cystine crystal deposits including the cornea

18.    a.F    b.T    c.T    d.F    e.F

• rubeosis iridis occurs in about 10% of patients
• rarely retinal neovascularization is seen
• atrial fibrillation is a cause of embolus which may lead to retinal artery occlusion
• delayed hyperfluorescence of choroidal circulation is a feature of ophthalmic artery occlusion
• optic atrophy occurs due to loss of ganglion cell layers and these may take months to develop

         Accommodative esotropia:

• there is overconvergence associated with accommodation
• most patients have a hypermetropia of +2.00 dioptres or more
• age of presentation is between 18 months and 4 years
• binocular fusion is usually good
• unlike infantile esotropia, inferior oblique overaction is not a feature

20.    a.T    b.T    c.T    d.T    e.T

          Phospholine iodide:

• is an acetylcholinesterase inhibitor which is used as a miotic agent
• can help patient with hypermetropic accommodative esotropia and patient with a high AC/A ratio
• causes contraction of ciliary muscle and iris sphincter resulting in an increased accommodation for a given accommodative effort and therefore less convergence
• side effects include: iris cysts (reduced with concurrent treatment with phenylephrine, cataract, retinal detachment and angle closure glaucoma in adults.
• has systemic effect and can prolong the action of succinylcholine. Therefore, patients should not have succinylcholine or have to stop the drops at least six weeks prior to surgery

21.    a.T    b.F    c.F    d.T    e.T

          Infantile esotropia:

• the patients typically present in the first six months of life
• there is a large angle esotropia
• associated features include: inferior oblique overaction (70%), DVD (75%) and latent nystagmus (50%)
• a mild to moderate hypermetropia is common (+2.00 to +3.00 dioptres)
• monocular asymmetrical OKN is seen with poor response when the drum is rotated from the nasal to temporal direction

22.    a.T    b.F    c.T    d.F    e.T

          Congenital nystagmus:

• may be sensory due to abnormality involving the afferent vision or motor
• the nystagmus is worse when one eye is covered
• the nystagmus is reduced on convergence and this may result in nystagmus blockage syndrome with esotropia
• about 2/3 of the patients have paradoxical inversion of the opticokinetic response (the direction of the quick recovery phase is the same as that of the drum rotation instead of in the opposite direction)
• oscillopsia is not a feature
• paradoxical pupillary constriction may occur with the pupil initially constrict when the room light is dimmed

23.    a.T    b.T    c.T    d.F    e.T

          Brown's syndrome:

• caused by a taut superior oblique tendon
• slight downshooting on adduction is common and widening of the palpebral fissure on adduction
• the condition may resolve spontaneously and therefore surgery is not usually indicated

surgery include superior oblique tenotomy with silicone expander or superior oblique tenotomy with ipsilateral inferior oblique recession to prevent post-operative inferior oblique overaction

24.    a.T    b.F    c.F    d.T    e.T

         Unilateral internuclear ophthalmoplegia:

• results from a lesion in the medial longitudinal fasciculus between the sixth nerve and third nerve nuclei
• causes failure of the ipsilateral medial rectus to adduct on horizontal gaze
• there is nystagmus of the contralateral abducting eye (caused by excessive innervation to the normal lateral rectus in accordance with Hering's law)
• diplopia is a feature

due to abnormal saccade the OKN is abnormal

25.     a.F    b.F    c.F    d.F    e.T

          Aberrant regeneration of the third nerve (oculomotor synkinesis):

• features of congenital third nerve palsies and those caused by tumours, aneurysms and trauma but not those due to ischaemic ophthalmoplegia
• known features include: elevation of the upper lid on attempted adduction or depression of the eye, retraction of the globe on attempted depression or elevation of the eye

constriction of the pupil on attempted adduction or depression
 
 

          Angioid streaks occur in many conditions including:

• pseudoxanthoma elasticum
• Ehlers-Danlos syndrome
• sickle cell disease

Paget's disease

28.    a.F    b.T    c.T    d.T    e.T

          Latanaprost:

• is a prostaglandin analogue
• more potent than beta-blocker in reducing the intraocular pressure
• works by increasing the uveal scleral outflow
• side effects include: conjunctival injection, increased iris pigmentation, hypertrichosis and ocular inflammation

29.    a.F    b.F    c.T    d.F    e.T

          Pigmentry glaucoma:

• typically seen in young myopic males
• raised pressure is believed to be due to blockage of the trabecular meshwork by the pigments
• there is radial iris transillumination
• high intraocular pressure following exercise is a feature

 
 

          Benign intracranial hypertension:

• the eye movement is usually normal but there may be sixth nerve palsy
• the CT scan should be normal
• in young women on contraceptive pill, brain scan is important to exclude saggital sinus thrombosis which may presents with similar pictures
• optic nerve fenestration is indicated if there were evidence of optic nerve dysfunction
• the condition can be treated with diuretic and repeated lumbar puncture. Ventricular-peritoneal is rarely required.

31.    a.T    b.T    c.F    d.F    e.F

        Medication and contact lenses:

• contraceptive pill may cause poor tear secretion and interfere with contact lens wear
• rifampicin causes discoloration of secretion including the tear which may stain the contact lens

32.    a.T    b.T    c.T    d.F    e.F

         Gout:

• is the result of purine metabolism
• may be associated with excess alcohol consumption but not a direct link
• causes conjunctivitis and scleritis if the uric crystals were to become deposited in the conjunctiva or sclera
• may cause uric acid crystals deposition in the cornea typically in the interpalpebral fissure but the crystals are typically subepithelial

          Iron deposition in the cornea:

• Fleischer's ring occurs at the base of keratoconus
• Hudson-Stahli's line is a normal ageing change
• Stocker's line is found in front of a pterygium
• Ferry's line is found in front of a bleb
• iron deposition is commonly seen near incisions of radial keratotomy

34.    a.T    b.F    c.F    d.F    e.T

          Corneal grafts:

• zenografts refer to transplant between two different species
• isografts refer to transplant between two identical twins
• lamellar keratoplasty is not suitable for Fuch's dystrophy where the endothelium is non-functioning
• blood transfusion does not appear to affect graft survival. In some transplant like renal, previous transfusion actually has a positive effect
• broken suture can elicit neovascularization leading to increased rejection

 

         Goldenhar's syndrome:

• is a type of hemifacial microsomia
• sporadic occurrence
• facial asymmetry with mandibular hypoplasia
• preauricular appendages, malformation of the ear, hearing loss caused by external ear lesions
• ocular features: epibulbar dermoids, limbal dermoids, eyelid colobomas and subcutaneous dermoids of the lids

36.    a.T    b.F    c.T    d.F    e.T

        Colour defect:

• macular problems usually cause loss of blue/yellow colour discrimination
• optic nerve defects tend to result in red / green colour defect

37.    a.F    b.T    c.T    d.T    e.F

        Cavernous sinus lesion in a patient with unilateral third nerve palsy:

• involvement of other nerves in the cavernous sinus such as fourth nerve, sixth nerve, fifth nerve (causing reduced corneal reflex and decreased facial sensation), and sympathetic nerve (pupil constriction).

          Carotid-cavernous fistula:

• dilated superior ophthalmic vein can be seen on CT scan due to congestion
• blood in the Schlemmn's canal occurs due to raised episcleral pressure
• as the two cavernous sinuses are interconnected, unilateral fistula can cause contralateral proptosis
• there are two types of fistula: the high flow in which there is direct connection between the internal carotid artery and the cavernous sinus this is seen in the traumatic cases. The low flow is the dural fistula which results from a connection between the meningeal branches of the internal carotid or external carotid artery and the cavernous fistula. The low flow is typically seen in post-menopausal women with history of atherosclerosis or hypertension
• high flow fistula rarely close spontaneously whereas the low flow closes spontaneously in about 50% of cases

         X-linked condition:

• Fabry's disease is an X-linked recessive disorder caused by the deficiency of the enzyme galactosidase
• Refsum's disease is an recessive condition in which there is a defect in the fatty acid metabolism and result in increased levels of phytanic acid
• Norrie's disease is an X-linked recessive disorder with ocular dysgenesis with progressive auditory and mental impairment.
• Choroideremia is an X-linked recessive disorder with bilateral progressive degeneration of the choriocapillaris.
• Rod monochromatism (achromatopsia is an autosomal recessive disorder with reduced vision, nystagmus, photophobia

and absent colour vision

40.    a.F    b.F    c.F    d.T    e.T

         Mesodermal dysgenesis:

• Axenfeld's syndrome is associated with posterior embryotoxon and iris strands extending onto the cornea. Iris hypoplasia is a feature of Reiger's anomaly
• Axenfeld's syndrome is an autosomal dominant disorder
• Rieger's anomaly is associated with posterior embryotoxon, prominent iris processes and iris stroma atrophy. Rieger's syndrome is Rieger anomaly plus skeletal, facial, cranial and dental anomalies
• peter's anomaly consists of bilateral central corneal opacity due to defects in the posterior stroma. 50% of cases have glaucoma

41.    a.T    b.F    c.F    d.T    e.T

          Lattice degeneration:

• found in 8% of the population
• causes 25% of the retinal detachment
• has a higher incidence amongst the high myopes
• retinal detachment usually occurs due to tear at the periphery of the degeneration rather than due to the hole within the lattice
• extensive cases are better treated with cryotherapy

42.    a.T    b.T    c.F    d.F    e.T

          Indications for subretinal fluid drainage include:

• bullous detachment making hole or tear identification difficult
• immobilized retina
• raised intraocular pressure
• inferior retinal detachment

43.    a.T    b.T    c.T    d.F    e.F

          Intravitreal gas injection:

• can cause retinal tear and cataract
• C3F8 has a longer half life than SF6 and also more expansile. C3F8 typically expands to 4 times its volume where as SF6 only 2 to 3 times and therefore C3F8 also causes more significant increase in intraocular pressure than SF6

44.    a.T    b.F    c.F    d.F    e.T
 
          In ptosis surgery:

• brow suspension allows the frontalis to perform upper lids elevation and is therefore recommended in severe congenital ptosis
• Fasavella-Servant is reserved for mild ptosis
• previous ptosis results in distortion of the normal lid anatomy making posterior approach unsuitable
• in mitochondrial myopathy poor Bell's phenomenon is often a feature and maximal resection can result in corneal exposure
• assessment of Bell's phenomenon and corneal sensation are essential prior to surgery to avoid exposure keratitis

45.    a.F    b.T    c.F    d.T    e.F

         Fourth nerve palsy can be treated by three surgical approaches:

• strengthening of the ipsilateral superior oblique such as tucking
• weakening of ipsilateral inferior oblique (myectomy or recession)
• weakening of the contralateral inferior rectus (recession)

46.    a.T    b.T    c.T    d.F    e.F
 
          Corneal blood staining:

• seen in 5% of hyphaema
• caused by passage of erythrocyte breakdown product into the stroma
• it is commoner in: recurrent hyphaema, large hyphaema, presence of endothelial dysfunction and elevated intraocular pressure
• clearing of the staining typically begins peripherally and move centrally. This may take months or years

47.    a.F    b.F    c.F    d.F    e.F

          In acute bacterial endophthalmitis:

• Staphylococcus epidermidis is the most common pathogen
• according to the Endophthalmitis Vitrectomy Study, the majority of patients present at 6 days after operation
• the Study also shows systemic antibiotic is of no value and treatment should include intravitreal antibiotics
• the role of steroid is controversial but not contraindicated
• mycotic causes tend to take longer to develop

48.    a.F    b.T    c.F    d.F    e.F

      Laser iridotomy:

• dark colour iris absorbs argon laser well and therefore respond better than light colour iris
• less energy is usually required for YAG than argon laser
• raised intraocular pressure may be reduced with anti-glaucoma treatment such as iodipine
• patient iridotomy is indicated when pigment is seen flowing out of the hole
• cataract may occur but is usually localized and of no visual significant.

49.    a.F    b.F    c.F    d.T    e.F

          Corneal graft donor:

• history of hepatitis B or HIV are contraindicated
• low endothelial cell count contribute to early corneal decompensation

50.    a.F    b.T    c.F    d.F    e.T

          Argon laser trabeculoplasty:

• high power can lead to significant inflammation and anterior synechiae
• is better in those over 50 years of age
• reduced pressure is due to alternation of the aqueous outflow
• produces a drop of pressure of between 5 to 10 mmHg
• is used when the patient is not responsive to maximal medical therapy for glaucoma

51.    a.F    b.F    c.T    d.F    e.F
 

Refractive surgery:
•  radial keratomy is suitable only for myopes with less than 8D of myopia. Long term stability is a problem in between 15 to 30% of patients with hypermetropic shift and there are complications associated with the procedures including loss of best corrected visual acuity, glare, diurnal fluctuation of visual acuity and etc.
• removal of suture along the axis of the largest plus cylinder is useful in reducing astigmatism
• keratomileusis involves removal of the anterior part of the corneal tissue which is then carved on its posterior stromal surface to alter its radius of curvature before replacing it.

 
 

Reduction of post-operative astigmatism:
• reduced by small incision
• reduced by incision far from the centre of the cornea and therefore limbal better than corneal approach and temporal corneal approach better than superior approach (the horizontal diameter of the cornea is greater than the vertical diameter)

 
 

Anterior capsule removal:
• capsulorrhexis is a more difficult technique to master than capsulotomy but produces a stronger edge and causes less displacement of the lens due to more equal distribution of force should the capsule undergoes fibrosis

 
 

Inferior oblique recession:
• a weakening procedure
• is performed in the following situation: primary inferior oblique overaction as in V-pattern esotropia or secondary inferior overaction as in ipsilateral superior oblique palsy or contralateral superior rectus palsy
• is more difficult to perform than myectomy as the muscle needs to be reattached posteriorly

55.    a.F    b.F    c.F    d.T    e.T
 

Unrecovered sixth nerve palsy:
• botulinum toxin injection reduces the problem of medial rectus contracture but does not speed up recovery
• resection/recession of the affected eye can move the eye into the primary position and reduces diplopia in this position
• operation on more than two muscles is associated with anterior segment ischaemia
• Faden's procedure on the contralateral medial rectus produces progressive weakening on adduction which matches the poor abduction of the affected eye

• visually insignificant CMO occurs in about 15% of patients undergoing extracapsular cataract extract as demonstrated by fluorescein angiography. Visually significant CMO only occurs in about 1% of these patients
• the risk of CMO is higher in intracapsular cataract extraction than extracapsular extraction
• other risk factors include: prolapsed vitreous, malpositioned of the intraocular lens and post-operative endophthalmitis.

57.    a.F    b.T    c.T    d.F    e.F

The classification of retinopathy of prematurity is as follow:
• Stage 1: presence of demarcation line
• Stage 2: presence of demarcation line that protrudes into the vitreous
• Stage 3: presence of peripheral retina fibrovascular proliferation
• Stage 4: subtotal retinal detachment
• Stage 5: total retinal detachment
 
 

Pseudoexfoliation syndrome:
• compare with primary open angle glaucoma, the intraocular pressure is more difficult to control with medication and there is greater incidence of asymmetry of glaucoma. Otherwise, the age range is identical and the success rate of trabeculectomy is not different
• there is presence of pigments in the trabecular meshwork called the Sampaolesi's line
 
 

        Radiation therapy:

• the pathology appears similar to diabetic retinopathy with occlusive microangiopathy secondary to loss of endothelial cell and capillary closure
• the lowest report dose is 11 Gy
• the photoreceptors are more resistant than the vascular cells the damage of which is the main cause of radiation therapy
• patients who are on chemotherapy, hypertensive and diabetic are more vulnerable to radiation therapy
• hyperbaric oxygen is of unproven benefit

 
 

        Local anaesthesia:

• peribulbar anaesthesia relies on diffusion of the anaesthetic agents into the muscle cone to achieve anaesthesia whereas with retrobulbar anaesthesia, the anaesthetic agents are injected directly into the muscle cone
• lignocaine works faster than marcaine but the duration of action is shorter
• topical amethocaine can achieve adequate anaesthesia of cornea and conjunctiva but no the iris
• retrobulbar haemorrhage increases the orbital pressure and therefore the risk of expulsive haemorrhage

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