As an ophthalmologist preparing for post doctoral fellowship exam test my knowledge by asking 50 good quality with moderate or high level difficulty mcqs on general ophthalmology

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I have the textbook context. Now I'll generate 50 high-quality MCQs from my knowledge of Kanski's Clinical Ophthalmology and the Wills Eye Manual, drawing on fellowship-level topics across all major areas of ophthalmology.

50 Fellowship-Level MCQs in General Ophthalmology

Format: Question → Options → Answer with explanation

CORNEA & EXTERNAL DISEASE (Q1-10)

Q1. A 35-year-old contact lens wearer presents with a central corneal ulcer, severe pain disproportionate to clinical findings, and a ring infiltrate. Confocal microscopy shows double-walled cysts. The MOST appropriate initial treatment is:

A. Topical natamycin 5% B. Topical polyhexamethylene biguanide (PHMB) + propamidine isethionate (Brolene) C. Topical voriconazole + oral fluconazole D. Corneal scraping + topical moxifloxacin

Answer: B The clinical picture describes Acanthamoeba keratitis - contact lens use, ring infiltrate, pain disproportionate to signs, confocal showing double-walled cysts. First-line treatment is dual biguanide therapy: PHMB 0.02% + propamidine (Brolene) or hexamidine. Natamycin is for fungal keratitis. (Kanski's 10th)

Q2. Regarding Fuchs endothelial corneal dystrophy (FECD), which statement is MOST accurate?

A. It is caused by mutation in the COL8A2 gene in late-onset disease B. Guttae are most prominent at the corneal periphery initially C. CTG18.1 trinucleotide repeat expansion in TCF4 is the most common genetic cause of late-onset FECD D. The characteristic histological finding is Bowman layer thickening

Answer: C Late-onset FECD (the common form, >40 years) is associated with a CTG18.1 trinucleotide repeat expansion in TCF4 in ~70% of cases. Early-onset FECD is linked to COL8A2 mutations. Guttae begin centrally (not peripherally). The histological hallmark is endothelial cell loss with Descemet membrane thickening and excrescences (guttae), not Bowman layer changes.

Q3. A patient undergoes DALK (Deep Anterior Lamellar Keratoplasty) for keratoconus. Intraoperatively, a type 1 "big bubble" is achieved. This bubble forms:

A. Between stroma and Bowman layer B. Between posterior stroma and Dua's layer (pre-Descemet layer) C. Between Dua's layer and Descemet membrane D. Within the mid-stroma

Answer: C In the Anwar big bubble technique, a Type 1 big bubble forms between Dua's layer (pre-Descemet layer) and Descemet membrane, leaving Dua's layer with the graft. Type 2 bubble forms between Descemet and stroma. Dua's layer is a distinct, acellular, collagen-rich layer ~10 µm thick identified by Harminder Dua in 2013.

Q4. Which finding on corneal topography is MOST specific for ectasia risk in a candidate for LASIK?

A. Simulated K > 45 D B. Inferior-superior (I-S) asymmetry > 1.4 D C. Posterior corneal elevation > 16 µm above best-fit sphere on Scheimpflug tomography D. Central corneal thickness < 500 µm

Answer: C Posterior corneal elevation on Scheimpflug tomography (Pentacam) is the MOST sensitive and specific marker for subclinical ectasia. A posterior elevation >16 µm above the best-fit sphere is a significant risk marker. While I-S asymmetry, steep K, and thin cornea are all risk factors, posterior elevation detects subclinical ectasia before anterior changes become apparent.

Q5. A child presents with bilateral limbal lesions, a shield ulcer, and giant papillae under the upper tarsal conjunctiva. Trantas dots are noted. The MOST useful pharmacological agent to reduce corneal complications long-term is:

A. Topical prednisolone 1% B. Topical olopatadine C. Topical ciclosporin 0.05% D. Oral cetirizine

Answer: C This is vernal keratoconjunctivitis (VKC). Topical ciclosporin reduces the inflammatory cytokine cascade (IL-5, eosinophil activation) and has proven efficacy in reducing shield ulcer recurrence and long-term corneal complications, with a better safety profile than prolonged steroids. Steroids are effective short-term but carry IOP elevation and cataract risk. Olopatadine helps mild symptoms.

Q6. In Stevens-Johnson syndrome (SJS) involving the eye, which intervention in the ACUTE phase has the strongest evidence for preventing long-term sequelae?

A. Topical lubricants alone B. Topical corticosteroids C. Amniotic membrane transplantation (AMT) within first 2 weeks D. Systemic cyclosporine

Answer: C Amniotic membrane transplantation in the acute phase (within the first 7-14 days) has strong evidence for reducing symblepharon formation, fornix shortening, limbal stem cell loss, and corneal vascularization. The anti-inflammatory and anti-fibrotic properties of amniotic membrane address the acute immune-mediated conjunctival destruction.

Q7. A patient with granular corneal dystrophy type 1 (GCD1) undergoes PTK. Which mutation is responsible, and what is the expected recurrence behaviour after keratoplasty?

A. TGFBI gene R555W mutation; recurs only in host stroma B. TGFBI gene R124H mutation; recurs rapidly in graft C. TGFBI gene R555W mutation; recurs in grafts due to keratocyte migration from host D. TGFBI gene R124C mutation; does not recur after PK

Answer: C GCD1 is caused by the R555W mutation in TGFBI (transforming growth factor beta-induced). After penetrating keratoplasty, it classically recurs in the graft because host keratocytes migrate into donor stroma and deposit the abnormal TGFBI protein. PTK is effective for superficial recurrences. R124H causes lattice dystrophy; R124C causes Reis-Bücklers dystrophy.

Q8. The MOST common cause of unilateral limbal stem cell deficiency (LSCD) in a young adult in South Asia is:

A. Aniridia B. Chemical burn (alkali) C. Ocular cicatricial pemphigoid D. Contact lens overwear

Answer: B Alkali chemical burns are the most common cause of unilateral LSCD in young adults in South Asia (often occupational or acid attack-related, but alkali is more destructive). Alkali penetrates more deeply due to liquefactive necrosis, causing limbal ischemia. Aniridia causes bilateral LSCD. OCP causes bilateral disease. Contact lens-related LSCD is emerging but less severe.

Q9. In a patient with Thygeson's superficial punctate keratitis, which statement is TRUE?

A. It is associated with Chlamydia trachomatis infection B. HLA-DR3 is strongly associated C. Topical corticosteroids worsen the condition D. Cyclosporin A 0.05% is effective and avoids steroid complications

Answer: D Thygeson's SPK has an unknown etiology (possibly viral/immune-mediated). It responds to topical ciclosporin 0.05%, which is effective for controlling exacerbations without the risks of long-term topical steroids (glaucoma, cataract). Low-dose steroids also work short-term, but ciclosporin is preferred for maintenance. It is NOT associated with Chlamydia.

Q10. A corneal graft failure occurs 18 months post-penetrating keratoplasty. The MOST common cause at this time point is:

A. Primary graft failure B. Endothelial rejection C. Raised intraocular pressure D. Herpes simplex recurrence

Answer: B Endothelial rejection is the most common cause of corneal graft failure occurring months to years post-PK, with peak incidence at 12-18 months. It presents with Khodadoust line (endothelial rejection line), keratic precipitates, corneal oedema. Primary graft failure occurs within the first week. HSV recurrence is possible but less common as a cause.

GLAUCOMA (Q11-20)

Q11. A 60-year-old with POAG has IOP of 22 mmHg on maximum tolerated medical therapy (latanoprost + timolol + brimonidine). Visual fields show progressive loss. You perform trabeculectomy. Which antimetabolite produces the LOWEST bleb-related infection risk?

A. Intraoperative 5-FU (50 mg/mL × 5 min) B. Intraoperative MMC (0.4 mg/mL × 2 min) C. Intraoperative MMC (0.2 mg/mL × 2 min) + needling D. Subconjunctival 5-FU injections (5 mg) postoperatively

Answer: A - but best answer is D in context of infection risk specifics

Revised: The HIGHEST infection risk is with MMC (thin, avascular, ischaemic blebs). Between the options, 5-FU produces less avascular blebs than MMC, hence lower bleb-related endophthalmitis risk. Subconjunctival 5-FU post-op (option D) is associated with more diffuse blebs and lower infection risk compared to high-dose intraoperative MMC. In clinical practice, MMC 0.4 mg/mL carries the greatest late bleb infection risk.

Answer: A (intraoperative 5-FU carries lower long-term infection risk than MMC-based regimens due to less avascular bleb formation)

Q12. In the Ocular Hypertension Treatment Study (OHTS), which factor was MOST predictive of conversion from ocular hypertension to POAG?

A. Older age B. Larger cup-to-disc ratio C. Thinner central corneal thickness (CCT) D. Higher IOP at baseline

Answer: C The OHTS identified thinner CCT as the strongest independent predictor of POAG conversion. A CCT < 555 µm conferred a 3× greater risk than CCT > 588 µm. While higher IOP, larger C/D ratio, age, and vertical C/D asymmetry were also predictors, CCT was the most significant finding that changed clinical practice.

Q13. Regarding the mechanism of action of netarsudil (Rhopressa), which is CORRECT?

A. Rho kinase (ROCK) inhibition decreases aqueous production B. ROCK inhibition increases uveoscleral outflow C. ROCK inhibition increases trabecular meshwork outflow by relaxing myosin light chain D. Net adrenergic transporter inhibitor effect decreases episcleral venous pressure

Answer: C Netarsudil is a ROCK inhibitor + norepinephrine transport (NET) inhibitor. Its primary IOP-lowering mechanism is through ROCK inhibition, which relaxes trabecular meshwork cells and Schlemm's canal cells, increasing conventional (trabecular) outflow facility. The NET inhibition reduces episcleral venous pressure. It does NOT increase uveoscleral outflow (that's the mechanism of prostaglandin analogues).

Q14. A patient with narrow angles undergoes laser peripheral iridotomy (LPI). Post-procedure, she reports monocular diplopia and a vertical line/arc of light (dysphotopsia). This is MOST likely due to:

A. Malpositioning of LPI in the nasal quadrant B. LPI placed too inferiorly, not covered by lid C. LPI located superiorly but exposed due to high upper lid position D. Corneal astigmatism induced by laser energy

Answer: C LPI dysphotopsia (streaks, arcs, ghost images) occurs when the iridotomy is NOT covered by the upper eyelid - classically when placed superiorly but the patient has a high-riding upper lid. Placing LPI at 11 or 1 o'clock positions usually ensures lid coverage. Inferior placement is incorrect (inferior LPI is generally avoided). The mechanism is light entering through the iridotomy causing prismatic effects.

Q15. In normal tension glaucoma (NTG), which vascular parameter has the STRONGEST association with disease progression?

A. Systemic hypertension B. Nocturnal hypotension (dipping) C. Elevated endothelin-1 levels D. Increased ophthalmic artery resistivity index

Answer: B Nocturnal hypotension ("dippers") - excessive drop in BP during sleep - is strongly associated with NTG progression by reducing ocular perfusion pressure during sleep when IOP is already at its nadir. The Collaborative Normal-Tension Glaucoma Study showed IOP reduction alone was less impactful in some NTG patients, implicating vascular factors. Elevated endothelin-1 is found but is a secondary association.

Q16. A 45-year-old patient presents with acute angle closure. After laser iridotomy resolves the attack, the fellow eye shows an occludable angle. Gonioscopy of the FELLOW eye demonstrates the plateau iris configuration. The MOST appropriate management of the fellow eye is:

A. Laser iridotomy alone B. Laser iridotomy + argon laser peripheral iridoplasty (ALPI) C. Phacoemulsification alone D. Goniosynechialysis

Answer: B Plateau iris syndrome is characterized by a flat iris plane with anteriorly positioned ciliary processes keeping the peripheral iris against the trabecular meshwork even after a patent iridotomy. Management requires LPI first (to rule out pupil block component) + ALPI, which contracts peripheral iris, pulling it away from the angle. Lens extraction is also effective but is more invasive.

Q17. The MOST likely mechanism of IOP elevation in exfoliative glaucoma (pseudoexfoliation glaucoma) is:

A. Increased aqueous production from ciliary body B. Trabecular meshwork clogging with exfoliative material C. Angle closure from lens zonule laxity D. Schlemm canal fibrosis

Answer: B In pseudoexfoliation (PXF) glaucoma, the primary mechanism is obstruction of the trabecular meshwork by exfoliative material and pigment, reducing conventional outflow. Additionally, trabecular endothelial cell damage occurs. IOP elevation tends to be more severe and asymmetric than POAG. Zonule laxity causes lens subluxation but not angle closure. Schlemm canal fibrosis is not the primary mechanism.

Q18. A patient is taking topical timolol 0.5% twice daily for glaucoma. They are scheduled for cardiac surgery. The MOST important interaction to counsel about is:

A. Potentiation of hypotensive effects of general anaesthetic B. Interaction with suxamethonium causing prolonged neuromuscular blockade C. Systemic beta-blockade masking signs of hypoglycemia in diabetic patients D. Both A and C

Answer: D Topical timolol has significant systemic absorption (up to 80% via nasolacrimal drainage). Beta-blockade effects include: (1) potentiation of hypotension with volatile anaesthetic agents, (2) masking tachycardia response to hypoglycemia in insulin-dependent diabetics, (3) exacerbation of reactive airway disease. Patients should use nasolacrimal occlusion after drops.

Q19. In a patient with glaucomatous visual field loss, which Humphrey visual field pattern is MOST specific for early glaucoma?

A. Inferior nasal step with arcuate defect B. Superior temporal wedge defect C. Central scotoma D. Generalised depression

Answer: A The inferior nasal step and arcuate (Bjerrum) scotoma following the course of arcuate retinal nerve fibres is the MOST characteristic and SPECIFIC pattern for glaucoma. It respects the horizontal midline (nasal step). Superior arcuate defects correspond to inferior disc damage. Central scotomas suggest macular disease; generalised depression is nonspecific.

Q20. Regarding the Ahmed glaucoma valve, which statement about the Molteno double-plate vs Ahmed FP7 is CORRECT?

A. Molteno has a flow restrictor valve; Ahmed does not B. Ahmed FP7 (184 mm² plate) shows lower failure rates than BGI (250 mm²) at 5 years per ABC trial C. In the TVT (Tube vs Trabeculectomy) study, tube was superior to trabeculectomy for IOP control at 5 years D. The Baerveldt 350 plate is smaller than the Ahmed FP7

Answer: C The TVT study (Tube vs Trabeculectomy) showed that at 5 years, Baerveldt tube surgery had significantly fewer failures than trabeculectomy with MMC (15.1% vs 30.7%). IOP control was similar but tube had fewer complications requiring reoperation. Ahmed does NOT have a pressure-dependent Starling resistor - it has a polypropylene valve with a pressure-relief mechanism that opens at 8-12 mmHg.

RETINA & VITREOUS (Q21-30)

Q21. A 55-year-old diabetic patient with proliferative diabetic retinopathy (PDR) and vitreous haemorrhage undergoes vitrectomy. The LANDMARK trial supporting early vitrectomy (within 6 months vs 1-year deferral) in type 1 DM with severe vitreous haemorrhage was:

A. DRCR.net Protocol S B. DRVS (Diabetic Retinopathy Vitrectomy Study) C. ETDRS (Early Treatment Diabetic Retinopathy Study) D. WESDR (Wisconsin Epidemiologic Study of Diabetic Retinopathy)

Answer: B The DRVS (Diabetic Retinopathy Vitrectomy Study) demonstrated that early vitrectomy (1-3 months) in type 1 DM with severe vitreous haemorrhage yielded better visual outcomes. Protocol S (DRCR.net) showed ranibizumab non-inferiority to PRP for PDR. ETDRS established when to start laser treatment. WESDR is an epidemiological study.

Q22. In branch retinal vein occlusion (BRVO), the MOST common site of occlusion is:

A. Arteriovenous crossing at the optic disc margin B. Superotemporal arcade AV crossing C. Inferotemporal arcade AV crossing D. Nasal AV crossing

Answer: B BRVO occurs preferentially at arteriovenous crossings where the artery and vein share a common adventitial sheath. The superotemporal arcade is the most commonly affected site (~60-70% of cases), likely because it has the most AV crossings and the artery overlies the vein at this location. The superotemporal territory also produces the most visually significant macular oedema.

Q23. A patient presents with sudden visual loss, cherry-red spot at the macula, and a relative afferent pupillary defect (RAPD). Fundus shows diffuse retinal pallor. The MOST appropriate immediate management is:

A. Intravenous methylprednisolone B. Ocular massage, anterior chamber paracentesis, and IOP-lowering agents C. IV heparin infusion D. Nd:YAG laser to the optic disc

Answer: B This is central retinal artery occlusion (CRAO). Immediate measures aim to restore perfusion: ocular massage (dislodge embolus), anterior chamber paracentesis (lower IOP to increase perfusion pressure), IOP-lowering agents (acetazolamide IV), and carbogen (95% O₂/5% CO₂) inhalation. The therapeutic window is very narrow (90 minutes). IV thrombolysis (tPA) is used in select cases within 4.5 hours.

Q24. In the CATT trial and subsequent studies comparing bevacizumab vs ranibizumab for neovascular AMD, which statement is MOST accurate?

A. Ranibizumab showed significantly superior visual outcomes at 2 years B. Bevacizumab showed equivalent visual outcomes but higher rates of serious systemic adverse events C. Monthly dosing was superior to PRN (pro re nata) dosing for both drugs D. Aflibercept showed superiority over both ranibizumab and bevacizumab in the VIEW studies

Answer: D The VIEW 1 and VIEW 2 studies showed aflibercept (2q8 after loading doses) was non-inferior to monthly ranibizumab. The CATT trial showed bevacizumab and ranibizumab had equivalent visual outcomes, but bevacizumab had marginally higher rates of serious systemic adverse events (though this may reflect differences in patient populations). Monthly dosing was superior to PRN for ranibizumab at 1 year but not at 2 years. Option D is correct about aflibercept's equivalent efficacy.

Q25. Which retinal dystrophy is characterized by nyctalopia (night blindness) as the FIRST symptom, pigmentary changes in a "bone spicule" pattern, arteriolar attenuation, and waxy disc pallor - with ERG showing rod-cone dysfunction?

A. Stargardt disease B. Best vitelliform macular dystrophy C. Retinitis pigmentosa (RP) D. Choroideremia

Answer: C This classical description is retinitis pigmentosa (RP). The sequence is: rod dysfunction first (nyctalopia, peripheral field loss), followed by cone involvement. ERG shows reduced/absent rod response first, then cone involvement. RP is associated with many genetic mutations (most commonly RHO, RPGR, RP2). Choroideremia affects males and shows choroidal atrophy; Stargardt and Best affect the macula primarily.

Q26. In a patient with Stargardt disease, the hallmark finding on fundus autofluorescence (FAF) is:

A. Hyperfluorescent flecks at the level of Bruch membrane B. Hypofluorescent macula with perifoveal hyperfluorescent ring C. Absent choroidal fluorescence on FA ("dark choroid" sign) D. Hyperfluorescent macular lesion with surrounding hypofluorescence

Answer: C - but the FAF answer is B; Dark choroid is FA

To clarify: The question asks about FAF. On FAF: Stargardt shows a hypofluorescent central macular atrophy with surrounding hyperfluorescent flecks (lipofuscin-laden RPE). The "dark choroid" sign (absence of background choroidal fluorescence due to lipofuscin blocking in RPE) is seen on fluorescein angiography (FA), not FAF.

Answer: B (On FAF - central hypoAF [atrophy] surrounded by hyperAF flecks; Option C describes the FA finding)

Q27. A patient presents with sudden onset of floaters and photopsia. Dilated fundal exam shows a horseshoe tear in the superotemporal periphery with surrounding subretinal fluid extending to the ora serrata but NOT involving the macula. The MOST appropriate management is:

A. Observation with review in 24 hours B. Immediate scleral buckling surgery C. Urgent barrier laser (360° prophylactic) D. Urgent pneumatic retinopexy or pars plana vitrectomy (PPV)

Answer: D This is a rhegmatogenous retinal detachment (RRD) with subretinal fluid present - even though the macula is attached, this is a surgical emergency. With SRF extending from a superotemporal horseshoe tear, there is high risk of macular involvement within hours. Urgent surgery (PPV or scleral buckling or pneumatic retinopexy) is indicated. The macula-on status means excellent visual prognosis if operated immediately. Laser alone is insufficient once SRF is present.

Q28. In central serous chorioretinopathy (CSCR), which finding on OCT-A is MOST characteristic of the chronic form?

A. Subretinal fluid with dome-shaped elevation B. Type 1 choroidal neovascularisation (CNV) under the RPE C. Outer retinal atrophy with sparing of Henle fibre layer D. Ellipsoid zone disruption without CNV

Answer: B Chronic CSCR (>3-4 months of symptoms) is associated with development of Type 1 (occult) CNV in up to 25-30% of cases on OCT-A, even when conventional FA/ICGA may not show it. This represents a secondary neovascular complication. OCT-A has significantly improved detection of this. Chronic CSCR also shows RPE atrophy, outer retinal changes, and loss of the ellipsoid zone.

Q29. The MOST common intraocular tumour in adults is:

A. Primary intraocular lymphoma (PIOL) B. Uveal melanoma C. Metastatic carcinoma to the choroid D. Retinoblastoma

Answer: C Metastatic carcinoma is the MOST common intraocular tumour in adults overall. Breast cancer (women) and lung cancer (men) are the most common primaries. Uveal melanoma is the MOST common primary intraocular malignancy in adults. This distinction - metastatic > primary malignancy - is a classic exam point.

Q30. In choroidal melanoma, which factor has the STRONGEST prognostic significance for metastatic disease?

A. Tumour diameter B. Tumour cell type (spindle vs epithelioid) C. Monosomy 3 / chromosome 3 loss D. Tumour location (ciliary body vs choroid)

Answer: C Monosomy 3 (loss of one copy of chromosome 3) is the STRONGEST molecular prognostic marker for metastatic uveal melanoma, conferring ~50% 10-year metastatic risk vs <5% for disomy 3 tumours. This has replaced histological cell type as the primary prognostic factor. Gene expression profiling (Class 1 vs Class 2) based on chromosome 3 status guides surveillance intensity. (Kanski's 10th)

NEURO-OPHTHALMOLOGY (Q31-38)

Q31. A 35-year-old woman presents with progressive visual loss, dyschromatopsia, and a cecocentral scotoma on visual field testing. MRI shows a lesion at the optic chiasm. Which of the following field defects would you MOST expect on perimetry?

A. Bitemporal superior quadrantanopia B. Binasal hemianopia C. Left homonymous hemianopia D. Junctional scotoma (left eye cecocentral + right superior temporal defect)

Answer: D A lesion at the anterior angle of the chiasm (junction of optic nerve and chiasm) causes a junctional scotoma (Traquair's junctional scotoma): central/cecocentral scotoma in the ipsilateral eye (due to nerve involvement) + superior temporal defect in the contralateral eye (due to involvement of Wilbrand's knee - crossing inferior nasal fibres looping briefly into the contralateral optic nerve). Bitemporal defects are seen with central chiasmal lesions.

Q32. A patient presents with complete third nerve palsy with pupil involvement. The MOST important investigation to exclude a life-threatening cause is:

A. MRI brain with gadolinium B. CT angiography (CTA) of the circle of Willis C. Lumbar puncture D. Carotid Doppler ultrasound

Answer: B A complete 3rd nerve palsy with pupil involvement (dilated, fixed pupil) is a posterior communicating artery (PCoA) aneurysm until proven otherwise. CTA or MR angiography of the circle of Willis is mandatory urgently. CT angiography has >95% sensitivity for aneurysms >3 mm. While MRI with gadolinium is useful, CTA is faster and equally sensitive for aneurysm detection in the acute setting. LP is used if subarachnoid haemorrhage is suspected.

Q33. Regarding Horner syndrome, ptosis in Horner syndrome is DIFFERENT from ptosis in a 3rd nerve palsy in that:

A. Horner ptosis involves the levator palpebrae superioris B. Horner ptosis is due to superior tarsal muscle (Muller's muscle) paresis and is milder (1-2 mm) C. Horner ptosis is associated with a larger pupil on the affected side D. Horner ptosis is typically 4-5 mm of lid drop

Answer: B In Horner syndrome, the ptosis is due to loss of sympathetic innervation to Müller's muscle (superior tarsal muscle), producing only 1-2 mm of ptosis. There is also inverse ptosis (0.5 mm elevation of lower lid) due to inferior tarsal muscle involvement. The pupil is miotic (not dilated) and shows dilation lag. A 3rd nerve palsy causes severe ptosis (4-5 mm) via levator paresis.

Q34. A patient with multiple sclerosis presents with painful visual loss in one eye with an RAPD. OCT shows a normal retinal nerve fibre layer (RNFL). VEP shows prolonged P100 latency with normal amplitude. This picture is MOST consistent with:

A. Anterior ischaemic optic neuropathy (AION) B. Retrobulbar optic neuritis C. Papilloedema D. Leber hereditary optic neuropathy (LHON)

Answer: B Retrobulbar optic neuritis: the optic nerve head appears NORMAL (no swelling) - "the patient sees nothing and the doctor sees nothing." VEP shows prolonged P100 latency (demyelination slows conduction), RAPD is present, RNFL is normal acutely (thinning develops later due to retrograde degeneration). AION causes disc swelling; papilloedema causes bilateral disc swelling; LHON typically lacks pain.

Q35. In a patient with giant cell arteritis (GCA) and visual loss, the INITIAL investigation that most rapidly guides treatment is:

A. ESR and CRP B. Temporal artery biopsy C. Colour Doppler ultrasound of the temporal artery (halo sign) D. PET-CT scan

Answer: A ESR and CRP are the FIRST investigations - they are available within hours and if strongly elevated in the context of a convincing clinical picture, high-dose IV methylprednisolone should be started IMMEDIATELY (do not delay for biopsy). Temporal artery biopsy (gold standard, within 2 weeks of starting steroids) CONFIRMS the diagnosis retrospectively. The halo sign on Doppler ultrasound has high specificity but is operator-dependent.

Q36. A 28-year-old obese woman presents with headache and visual obscurations. Papilloedema is noted bilaterally. LP opening pressure is 32 cmH₂O and CSF is normal. MRI/MRV shows empty sella. The FIRST-LINE treatment is:

A. Acetazolamide + weight loss B. Topiramate C. Lumboperitoneal shunt D. Optic nerve sheath fenestration (ONSF)

Answer: A Idiopathic intracranial hypertension (IIH): First-line treatment is acetazolamide (up to 4g/day) + supervised weight loss (the IIH Weight Trial showed 25 lbs weight loss produced significant IOP reduction and visual improvement). Topiramate is second-line (also aids weight loss). ONSF is for rapidly progressive visual loss; shunting is for refractory headache. The IIH Treatment Trial confirmed acetazolamide efficacy.

Q37. Which statement about Foster Kennedy syndrome is CORRECT?

A. Unilateral optic atrophy with contralateral papilloedema due to a compressive lesion B. Both optic discs show papilloedema C. It is caused by raised intracranial pressure alone D. It is most commonly caused by glioblastoma multiforme

Answer: A Foster Kennedy syndrome: ipsilateral optic atrophy (direct compression of optic nerve by tumour) + contralateral papilloedema (raised ICP). Most commonly caused by olfactory groove or sphenoid wing meningioma. "Pseudo-Foster Kennedy syndrome" refers to sequential non-arteritic AION producing a similar picture (more common than true FK syndrome).

Q38. A patient with internuclear ophthalmoplegia (INO) demonstrates adduction failure of the right eye with abducting nystagmus in the left eye on leftward gaze. The lesion is located at:

A. Right medial longitudinal fasciculus (MLF) B. Left MLF C. Right abducens nucleus D. Left PPRF (paramedian pontine reticular formation)

Answer: A In INO, the MLF lesion is on the SAME side as the adduction failure. Leftward gaze requires: left CN VI nucleus activating left LR (works fine - abducting nystagmus seen) + right MLF carrying signal to right medial rectus (fails - no adduction). Therefore the right MLF is damaged. The rule: "INO - the lesion is on the side of the weak eye (adduction failure)."

OCULOPLASTICS & ORBIT (Q39-44)

Q39. A 65-year-old man presents with unilateral upper lid ptosis, enophthalmos, and ipsilateral miosis. He also reports anhidrosis of the ipsilateral face. Pharmacological testing with cocaine 4% drops CONFIRMS Horner syndrome. The NEXT step to localise the lesion is:

A. Hydroxyamphetamine (Paredrine) 1% test B. Apraclonidine 0.5% test C. Phenylephrine 10% test D. Pilocarpine 0.1% test

Answer: A Hydroxyamphetamine (Paredrine) 1% test localises Horner syndrome to 3rd-order neuron vs 1st/2nd-order: Hydroxyamphetamine causes NE release from presynaptic terminals. If the 3rd-order neuron is intact (1st or 2nd order lesion), the pupil dilates. If the 3rd-order neuron is damaged, NE stores are depleted and the pupil FAILS to dilate. Apraclonidine confirms Horner but doesn't localise. Note: Hydroxyamphetamine is no longer widely available; imaging (MRI from hypothalamus to superior cervical ganglion, CXR for Pancoast tumour) is now used.

Q40. In thyroid eye disease (Graves orbitopathy), the extraocular muscle MOST commonly involved, causing diplopia on upgaze, is:

A. Superior rectus B. Medial rectus C. Inferior rectus D. Lateral rectus

Answer: C The inferior rectus is most commonly involved in Graves orbitopathy (followed by medial rectus, superior rectus, lateral rectus - mnemonic: "I'M SLow"). The enlarged, fibrosed inferior rectus causes restriction of upgaze (not weakness of superior rectus). The diplopia is in upgaze, most noticeable when reading (upgaze). Forced duction test is positive (restrictive pattern).

Q41. The MOST common benign orbital tumour in adults is:

A. Dermoid cyst B. Capillary haemangioma C. Cavernous venous malformation (cavernous haemangioma) D. Neurofibroma

Answer: C Cavernous venous malformation (historically called cavernous haemangioma) is the MOST common benign orbital tumour in adults, presenting with slowly progressive, painless proptosis in middle-aged women. It is intraconal, well-encapsulated, and shows characteristic "progressive fill" on dynamic CT. Dermoid cysts are the most common in children/young adults.

Q42. In dacryocystorhinostomy (DCR), the osteotomy is made between which two bones?

A. Maxilla and ethmoid bone B. Lacrimal bone and inferior turbinate C. Lacrimal bone and frontal process of the maxilla D. Palatine bone and maxilla

Answer: C The DCR osteotomy is made between the lacrimal bone (thin, posterior portion) and the frontal process of the maxilla (thicker, anterior portion). The anterior lacrimal crest is on the maxillary process; the posterior lacrimal crest is on the lacrimal bone. The fossa for the lacrimal sac lies between these. A good DCR flap includes both the thin lacrimal bone and part of the thicker maxillary process.

Q43. A patient presents with rapid-onset proptosis, chemosis, pain, and fever after a sinus infection. CT orbit shows an extraconal collection medial to the medial rectus. According to Chandler classification, this is:

A. Stage I (preseptal cellulitis) B. Stage II (orbital cellulitis) C. Stage III (subperiosteal abscess) D. Stage IV (orbital abscess)

Answer: C Chandler classification of orbital cellulitis:

I: Preseptal (periorbital) cellulitis
II: Orbital cellulitis (post-septal, no abscess)
III: Subperiosteal abscess (collection between periorbita and orbital wall)
IV: Orbital abscess (intraorbital collection within fat)
V: Cavernous sinus thrombosis

A medial subperiosteal collection = Stage III. Management: IV antibiotics; surgical drainage if abscess >10 mm, age >9 years, or no improvement in 24-48 hours.

Q44. Which type of basal cell carcinoma of the eyelid carries the WORST prognosis and is most likely to recur after excision?

A. Nodular BCC B. Morphoeic (sclerosing) BCC C. Superficial multicentric BCC D. Pigmented BCC

Answer: B Morphoeic (sclerosing) BCC has ill-defined, infiltrative margins, making complete excision difficult. It has the highest recurrence rate and worst prognosis because its subclinical extension is much greater than the clinically visible lesion. It may extend to orbital fat and deeper structures. Mohs micrographic surgery is the treatment of choice. Nodular BCC has the best prognosis with clear margins.

LENS & CATARACT (Q45-47)

Q45. A patient develops posterior capsule opacification (PCO) 2 years after phacoemulsification with an AcrySof IOL. The mechanism is BEST described as:

A. Epithelial-mesenchymal transformation (EMT) of residual lens epithelial cells (LECs) B. Proliferation of cortical lens fibres from the equatorial region C. Deposition of inflammatory fibrin on the posterior capsule D. Migration of anterior capsule LECs across the visual axis

Answer: A PCO ("after-cataract") is caused by epithelial-mesenchymal transition (EMT) of residual equatorial lens epithelial cells (E-cells and A-cells), which proliferate and migrate onto the posterior capsule, secreting extracellular matrix. They form Elschnig pearls (clusters) or Soemmerring's ring. AcrySof IOLs have a square-edge design that creates a mechanical barrier against LEC migration, reducing PCO rates. Sharp-edged IOLs reduce PCO.

Q46. During phacoemulsification, a posterior capsule rupture occurs. There is no vitreous prolapse, and the nucleus is largely removed. The BEST next step is:

A. Convert to ECCE immediately B. Triamcinolone injection to identify vitreous, then anterior vitrectomy and in-the-bag IOL placement C. Inject viscoelastic, assess PC tear, perform dry vitrectomy if needed, place IOL in sulcus D. Abandon surgery, close, and bring back in 6 weeks

Answer: C Management of posterior capsule rupture (PCR) without vitreous prolapse:

Inject viscoelastic into anterior chamber to tamponade vitreous
Assess tear size - if small and inferior, may still place IOL in bag
If vitreous present: anterior vitrectomy (dry technique or with triamcinolone to visualise vitreous)
Sulcus IOL placement (3-piece lens preferred for sulcus fixation) if anterior capsule intact
Conversion to ECCE is a last resort. Never abandon if manageable.

Q47. In a patient with Marfan syndrome undergoing cataract surgery for subluxated lens, the MAIN intraoperative risk is:

A. Expulsive suprachoroidal haemorrhage B. Zonular dialysis and posterior lens dislocation C. Corneal decompensation D. Pupil block glaucoma

Answer: B In Marfan syndrome, fibrillin-1 gene mutation causes weak zonules, predisposing to intraoperative zonular dialysis and posterior dislocation of the lens/nucleus into the vitreous. Management requires use of capsular tension rings (CTR) or capsular tension segments (CTS) to stabilise the capsular bag before any phaco energy is used. Hydrodissection should be minimal. PPV may be needed if nucleus drops posteriorly.

PAEDIATRIC OPHTHALMOLOGY (Q48-50)

Q48. A 3-month-old infant is noted to have an absent red reflex in the left eye on screening. Examination under anaesthesia confirms a white retrolental mass. B-scan ultrasound shows calcification. The MOST likely diagnosis and the GENE implicated are:

A. Persistent fetal vasculature - NORRIE gene B. Retinoblastoma - RB1 gene (chromosome 13q14) C. Congenital cataract - GJA8 gene D. Coats disease - NDP gene

Answer: B Retinoblastoma is the most common intraocular malignancy in children. The classic features are: leukocoria (absent red reflex), calcification on B-scan/CT, RB1 mutation (chromosome 13q14). The Knudson "two-hit hypothesis" applies: hereditary (bilateral, 40%) requires only one somatic mutation; sporadic (unilateral, 60%) requires two somatic mutations. Calcification on imaging is highly characteristic.

Q49. A child with esotropia undergoes the Krimsky test and the modified Krimsky/Hirschberg test. The Krimsky test is performed by:

A. Placing prism before the FIXING eye until corneal reflexes are symmetric B. Placing prism before the DEVIATING eye until corneal reflexes are symmetric C. Estimating angle from position of corneal light reflex (1 mm = 7 prism diopters) D. Using the synoptophore to determine angle of deviation

Answer: A The Krimsky test: prisms are placed before the FIXATING eye (neutralising the prism reflex) until the corneal light reflex in the deviating eye is centred. This is useful in non-cooperative children. Modified Krimsky places the prism before the deviating eye. The Hirschberg test estimates deviation from corneal light reflex position (1 mm ≈ 7 prism diopters, or 15° ≈ 25 PD). The Cover test is the gold standard for cooperative patients.

Q50. A premature infant born at 26 weeks gestation and weighing 750 g develops retinopathy of prematurity. Zone II, Stage 3 disease with PLUS signs is found in 6 clock hours. According to ETROP trial criteria, the treatment of choice is:

A. Observation and re-examine in 1 week B. Cryotherapy to the avascular retina C. Laser photocoagulation to the avascular retina D. Intravitreal bevacizumab (IVB)

Answer: C - or D depending on zone

This is Type 1 ROP (Zone II, Stage 3 with plus disease): treatment is indicated. Per the ETROP trial, laser photocoagulation to the avascular retina is the standard treatment, showing superior outcomes to cryotherapy (less myopia, better visual acuity). Intravitreal anti-VEGF (bevacizumab or ranibizumab) is increasingly preferred especially for Zone I disease and posterior ROP, but for Zone II Stage 3+, laser remains the standard. The key ETROP finding: early treatment of Type 1 ROP reduces unfavourable outcomes.

Answer: C (laser - standard per ETROP for Zone II Stage 3+; IVB increasingly used but not yet the ETROP-established standard for Zone II)

SUMMARY TABLE

Q#	Topic	Answer
1	Acanthamoeba keratitis treatment	B
2	FECD genetics - TCF4	C
3	DALK big bubble anatomy	C
4	LASIK ectasia risk marker	C
5	VKC long-term management	C
6	SJS acute management	C
7	GCD1 gene and recurrence	C
8	LSCD most common cause (South Asia)	B
9	Thygeson's SPK treatment	D
10	Corneal graft failure at 18 months	B
11	Trabeculectomy antimetabolite	A
12	OHTS strongest predictor	C
13	Netarsudil mechanism	C
14	LPI dysphotopsia	C
15	NTG vascular factor	B
16	Plateau iris management	B
17	PXF glaucoma mechanism	B
18	Timolol cardiac surgery interaction	D
19	HVF pattern in glaucoma	A
20	TVT study finding	C
21	Early vitrectomy in PDR	B
22	BRVO most common site	B
23	CRAO immediate management	B
24	Anti-VEGF for AMD - VIEW study	D
25	RP description	C
26	Stargardt on FAF	B
27	RRD with SRF management	D
28	Chronic CSCR on OCT-A	B
29	Most common intraocular tumour	C
30	Uveal melanoma prognosis	C
31	Junctional scotoma	D
32	3rd nerve palsy investigation	B
33	Horner ptosis vs 3rd nerve	B
34	Retrobulbar optic neuritis VEP	B
35	GCA initial investigation	A
36	IIH first-line treatment	A
37	Foster Kennedy syndrome	A
38	INO lesion localisation	A
39	Horner localisation test	A
40	Graves orbitopathy EOM	C
41	Most common benign orbital tumour	C
42	DCR osteotomy bones	C
43	Chandler classification	C
44	Worst prognosis BCC	B
45	PCO mechanism	A
46	PCR intraoperative management	C
47	Marfan cataract surgery risk	B
48	Retinoblastoma gene	B
49	Krimsky test	A
50	ROP Type 1 treatment	C

Topics covered: Cornea (10), Glaucoma (10), Retina/Vitreous (10), Neuro-ophthalmology (8), Oculoplastics/Orbit (6), Lens/Cataract (3), Paediatric Ophthalmology (3)

Sources: Kanski's Clinical Ophthalmology 10th Ed, Wills Eye Manual, OHTS, ETROP, CATT, VIEW, TVT, and DRVS trial data.

Another test of same level

Here is your second fellowship-level test — all new questions, no repeats from Test 1.

Test 2: 50 Fellowship-Level MCQs — General Ophthalmology

CORNEA & EXTERNAL DISEASE (Q1–10)

Q1. A 25-year-old presents with recurrent corneal erosions, worse on waking. Slit-lamp shows map-dot-fingerprint changes in the epithelium. Confocal microscopy shows subepithelial fibrogranular deposits. The MOST likely underlying dystrophy and its chromosomal locus are:

A. Meesmann dystrophy — KRT3/KRT12, chromosome 12q13 B. Epithelial basement membrane dystrophy (EBMD) — TGFBI, chromosome 5q31 C. Lisch epithelial corneal dystrophy — LISCH gene, Xp22.3 D. Subepithelial mucinous corneal dystrophy — SMCD gene, chromosome 1p

Answer: B EBMD (map-dot-fingerprint dystrophy / Cogan microcystic dystrophy) is caused by mutations in TGFBI (chromosome 5q31). Despite being classified as a primary epithelial dystrophy, up to 90% of cases are sporadic (acquired). The abnormal basement membrane fails to anchor hemidesmosomes, causing recurrent erosions. Meesmann dystrophy affects keratins (KRT3/KRT12). Treatment: hypertonic saline, lubricants, PTK for recurrent erosions.

Q2. During slit-lamp examination for corneal disease, a patient demonstrates a positive Munson sign and Rizzuti sign. These findings are pathognomonic for:

A. Pellucid marginal degeneration B. Keratoconus C. Terrien marginal degeneration D. Keratoglobus

Answer: B

Munson sign: bulging of the lower eyelid on downgaze due to the ectatic cone
Rizzuti sign: a conical beam of light on the nasal limbus when a penlight is shone from the temporal side - both are pathognomonic for keratoconus. Fleischer ring (iron deposition at cone base), Vogt's striae (deep stromal stress lines), and Bowman layer breaks are other classic signs. Pellucid shows inferior thinning and "crab-claw" topography without a classic cone.

Q3. A 40-year-old patient with a history of atopy and HSV keratitis undergoes penetrating keratoplasty. Which combination of factors places him at HIGHEST risk for corneal graft rejection?

A. Large graft diameter + young recipient + inferior limbal vessels B. Regraft + deep stromal vessels + prior graft rejection episode C. Small graft + older recipient + no pre-existing vascularisation D. Superior corneal position + no prior ocular surgery

Answer: B The most significant risk factors for corneal allograft rejection (Collaborative Corneal Transplantation Studies — CCTS):

Previous graft rejection (strongest)
Corneal vascularisation (especially deep stromal, >2 quadrants)
Regraft status
Large graft size, anterior synechiae, glaucoma, and young age are additional risks. Option B contains the three highest-risk factors. Prophylactic systemic immunosuppression (ciclosporin) may be used in high-risk cases.

Q4. A patient presents with interstitial keratitis (IK) - diffuse stromal oedema, ghost vessels, and reduced corneal sensation. The MOST common infectious cause in developed nations and the MOST common in developing nations are, respectively:

A. Herpes simplex virus (HSV) / Herpes zoster; Treponema pallidum / Mycobacterium tuberculosis B. HSV; Treponema pallidum (congenital syphilis) C. Treponema pallidum (congenital syphilis); HSV D. CMV; Treponema pallidum

Answer: A → Best answer: B Globally, HSV is the most common cause of IK in developed nations. In developing nations, congenital syphilis (Treponema pallidum - Hutchinson triad: IK + deafness + notched teeth) was historically dominant. TB-related IK is also common in developing regions. Answer: A captures the correct developed/developing split more precisely, though HSV-HSZ distinction matters. The classic examination answer pairs HSV (developed) with syphilis (developing countries).

Answer: A

Q5. In the Collaborative Longitudinal Evaluation of Keratoconus (CLEK) study, which clinical variable had the STRONGEST correlation with reduced visual acuity?

A. Steepest keratometry reading B. Corneal scarring C. Pachymetry at thinnest point D. Cone location (central vs. paracentral)

Answer: B The CLEK study found that corneal scarring had the strongest correlation with reduced high-contrast visual acuity in keratoconus, even after controlling for other variables. Steep K was associated with rigid contact lens tolerance. Corneal scarring occurs at Bowman layer rupture sites and is a marker of disease severity.

Q6. Regarding corneal collagen cross-linking (CXL) in keratoconus, the Dresden protocol uses:

A. Riboflavin 0.1% + UV-A 3 mW/cm² for 30 minutes (total energy 5.4 J/cm²) B. Riboflavin 0.1% + UV-A 9 mW/cm² for 10 minutes (total energy 5.4 J/cm²) C. Riboflavin 0.25% + UV-A 30 mW/cm² for 3 minutes (accelerated) D. Riboflavin 0.1% + UV-A 3 mW/cm² for 60 minutes (total energy 10.8 J/cm²)

Answer: A The Dresden protocol (Wollensak et al. 2003): epithelial debridement, riboflavin 0.1% instillation for 30 min, then UV-A 370 nm at 3 mW/cm² for 30 minutes = total energy 5.4 J/cm². This produces cross-links between collagen fibrils (pyridinium bonds), stiffening the stroma to depth of ~300 µm. Minimum corneal thickness before CXL: 400 µm (to protect endothelium from UV damage - Bunsen-Roscoe law).

Q7. A patient with ocular cicatricial pemphigoid (OCP) presents with Stage III disease (Mondino classification). The MOST appropriate systemic treatment is:

A. Oral dapsone 100 mg/day B. Oral prednisolone alone C. IV cyclophosphamide pulse therapy D. Subcutaneous methotrexate

Answer: C OCP staging (Mondino): Stage I - subepithelial fibrosis; Stage II - fornix foreshortening; Stage III - symblepharon; Stage IV - ankyloblepharon. For Stage III-IV (severe, progressive) disease, IV cyclophosphamide pulse therapy is the most effective immunosuppressive. Dapsone is used for mild-moderate disease (Stage I-II). Mycophenolate mofetil and rituximab are alternatives for refractory cases.

Q8. On slit-lamp examination of a patient with iritis, you notice keratic precipitates (KPs) distributed in the inferior corneal endothelium in a triangular pattern. These are called:

A. Mutton-fat KPs — granulomatous uveitis B. Fine stellate KPs — Fuchs heterochromic uveitis C. Arlt's triangle KPs — non-granulomatous uveitis D. Pigmented KPs — old inactive uveitis

Answer: C Arlt's triangle: fine, stellate or round KPs distributed in the inferior endothelium in a triangular pattern (base inferiorly) due to convection currents in the aqueous. This pattern is seen in non-granulomatous anterior uveitis (HLA-B27-associated, JIA, etc.). Large "mutton-fat" KPs indicate granulomatous uveitis (sarcoid, TB, VKH). Fine stellate KPs distributed over the entire endothelium suggest Fuchs heterochromic cyclitis.

Q9. In a patient with band keratopathy, EDTA chelation therapy is the standard treatment. Which systemic condition is MOST commonly associated with calcium band keratopathy in adults?

A. Hyperparathyroidism B. Vitamin D toxicity C. Chronic anterior uveitis (e.g., juvenile idiopathic arthritis) D. Hypophosphataemia

Answer: C In children, JIA-associated chronic uveitis is the most common cause. In adults, chronic anterior uveitis of any cause (including JIA continuing into adulthood, sarcoidosis, HSV keratouveitis) is the most common systemic association. Hypercalcaemia (hyperparathyroidism, Vit D toxicity, sarcoidosis, milk-alkali syndrome) also causes band keratopathy. The calcium precipitates as calcium hydroxyapatite in Bowman layer at the inter-palpebral zone (pH higher here due to CO₂ loss).

Q10. A 60-year-old presents with a white, gelatinous, limbal lesion with feeder vessels. Impression cytology shows cells with high N:C ratio, dyskeratosis, and loss of polarity. The MOST important prognostic factor for recurrence after excision is:

A. Tumour thickness B. Surgical margin status C. Presence of intraepithelial (CIN) vs invasive component D. Tumour size >5 mm

Answer: B This is Ocular Surface Squamous Neoplasia (OSSN). The single MOST important prognostic factor for recurrence after surgical excision is positive surgical margins. The "no touch" technique with wide margins (2-3 mm) + double freeze-thaw cryotherapy to margins is the surgical gold standard. Adjuvant topical chemotherapy (interferon α-2b, 5-FU, MMC) reduces recurrence, especially when margins are uncertain.

GLAUCOMA (Q11–20)

Q11. A patient with POAG on latanoprost develops conjunctival hyperaemia and iris colour change after 8 months. Regarding prostaglandin analogue (PGA) side effects, which is INCORRECT?

A. Increased iris pigmentation is permanent and due to melanogenesis in existing melanocytes B. Eyelash hypertrichosis is reversible on stopping the drug C. Periocular fat atrophy (POLA/PARA) is irreversible after long-term use D. PGAs increase uveoscleral outflow via FP receptor activation

Answer: C PARA (prostaglandin-associated periorbitopathy/POLA) - including periocular fat atrophy, upper lid ptosis, deepening of the superior sulcus, and enophthalmos - was previously thought to be reversible on stopping, but long-term evidence shows it may be partially reversible or permanent with prolonged use. The other statements are correct: iris pigmentation IS permanent (melanin production in melanocytes, not new melanocytes); eyelash changes ARE reversible; FP receptor activation increases matrix metalloproteinase production, remodelling ciliary muscle and increasing uveoscleral outflow.

Answer: C (partially or irreversible - making it the "most incorrect" among the choices as it states definitively "irreversible" — exam answer is C is the INCORRECT statement, as PARA can partially reverse with cessation)

Q12. In the Advanced Glaucoma Intervention Study (AGIS), which finding regarding IOP and visual field progression was LANDMARK?

A. Patients with mean IOP < 14 mmHg showed no visual field progression over 8 years B. African-Americans fared better with trabeculectomy first, then ALT C. Eyes with mean IOP consistently < 18 mmHg showed less progression D. Target IOP should be < 21 mmHg for all glaucoma patients

Answer: A The AGIS landmark finding: eyes with EVERY visit IOP < 18 mmHg showed the least visual field deterioration, and specifically, in the subgroup analysis, mean IOP < 14 mmHg over follow-up was associated with NO visual field progression at 8 years. This established the concept of a "target IOP" below 14 mmHg in advanced glaucoma. The study also showed ALT → Trab sequencing was better for White patients; Trab → ALT was better for African-American patients.

Q13. Which type of glaucoma drainage device does NOT use a valve mechanism and relies on bleb encapsulation for IOP regulation after an initial hypotony phase?

A. Ahmed FP7 B. Ahmed S2 C. Baerveldt 350 D. OptiMed

Answer: C The Baerveldt 350 (and 250) is a non-valved device - it has no flow restrictor. After implantation, the tube is temporarily occluded (ligature suture or Sherwood slit) for 4-6 weeks to allow bleb capsule formation, which provides resistance to outflow. This prevents early hypotony. The Ahmed FP7 and S2 have a valve mechanism (polypropylene leaflets opening at ~8 mmHg). The Molteno also has no valve.

Q14. A patient with primary angle-closure glaucoma (PACG) has undergone LPI but the angle remains partially closed on gonioscopy with elevated IOP. The MOST effective next intervention for IOP control and angle opening is:

A. Argon laser peripheral iridoplasty (ALPI) B. Phacoemulsification and IOL implantation C. Trabeculectomy with MMC D. Cyclodiode laser

Answer: B Clear lens extraction / phacoemulsification in angle-closure is increasingly the preferred definitive treatment. The EAGLE trial (2016) showed that clear lens extraction was more cost-effective than LPI and produced better IOP control and quality of life in newly diagnosed PACG and primary angle closure (PAC) patients. By removing the bulky crystalline lens, the anterior chamber deepens significantly, the angle opens, and IOP drops by ~4 mmHg even in eyes without cataracts.

Q15. In congenital/infantile glaucoma (primary congenital glaucoma, PCG), the underlying developmental abnormality is:

A. Absence of Schlemm canal B. Abnormal differentiation of trabecular meshwork from neural crest cells (trabeculodysgenesis) C. Iris hypoplasia with goniosynechiae D. Ciliary muscle hypertrophy obstructing trabecular meshwork

Answer: B PCG is caused by trabeculodysgenesis - failure of normal differentiation of neural crest-derived trabecular meshwork and anterior chamber angle structures. Barkan membrane (an impermeable membrane over the trabecular meshwork) was hypothesised but not consistently found. CYP1B1 is the most common gene implicated. Surgery (goniotomy or trabeculotomy) is the treatment of choice - not drops. Goniotomy requires a clear cornea.

Q16. Which visual field defect is characteristic of a lesion at the level of the lateral geniculate nucleus (LGN)?

A. Congruous homonymous hemianopia B. Incongruous homonymous hemianopia C. Sectoranopia (wedge-shaped homonymous defect) D. Bitemporal hemianopia

Answer: C LGN lesions produce a characteristic "sectoranopia" - a wedge-shaped or sector-shaped homonymous visual field defect. This is because the LGN receives blood from two separate arterial supplies:

Anterior choroidal artery (supplies the hilum)
Lateral choroidal artery (supplies the peripheral regions) Infarcts produce characteristic double sectoranopias (horizontal sectoranopias sparing the horizontal meridian, or wedge defects). This pattern is UNIQUE to LGN lesions.

Q17. A patient presents with an IOP of 55 mmHg, corneal microcystic oedema, fixed mid-dilated pupil, and a shallow anterior chamber. B-scan shows posterior globe flattening. The MOST likely diagnosis is:

A. Primary acute angle-closure glaucoma B. Aqueous misdirection syndrome (malignant glaucoma) C. Suprachoroidal haemorrhage D. Choroidal detachment with anterior rotation

Answer: B Aqueous misdirection (malignant glaucoma): The hallmarks are:

High IOP despite patent iridotomy
Flat anterior chamber (both central and peripheral)
No response to miotics (worsened by miotics)
Posterior globe flattening on B-scan (aqueous trapped posteriorly in vitreous) Treatment: cycloplegics (atropine) to relax ciliary body, aqueous suppressants, Nd:YAG hyaloidotomy, vitrectomy. Unlike acute ACG, the iridotomy is patent and the AC is flat CENTRALLY.

Q18. Regarding selective laser trabeculoplasty (SLT), which statement is MOST accurate?

A. SLT uses 532 nm Nd:YAG laser with 400 µm spot size B. SLT is not repeatable after initial treatment C. The LiGHT trial showed SLT was non-inferior to medication as first-line therapy D. SLT works by thermally coagulating trabecular endothelial cells

Answer: C The LiGHT trial (2019, Lancet) was the landmark RCT showing SLT as first-line therapy was non-inferior to topical medication for IOP control in OHT and POAG, with higher quality of life, lower medication burden, and lower cost at 3 years. 74% of SLT eyes required no drops. SLT uses 532 nm frequency-doubled Nd:YAG, 400 µm spot size, short pulse (3 ns) that selectively targets melanin-containing trabecular cells without thermal damage to surrounding tissue (hence "selective"). It IS repeatable.

Q19. Which glaucoma medication is CONTRAINDICATED in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency?

A. Brimonidine B. Brinzolamide C. Metipranolol D. None of the above — all are safe

Answer: A Brimonidine (alpha-2 agonist) causes haemolytic anaemia in patients with G6PD deficiency, and is therefore contraindicated. This is a well-documented but frequently missed interaction. Brimonidine is also contraindicated in infants/neonates (apnoea, CNS depression), patients on MAO inhibitors, and those with severe cardiovascular disease. Note: brimonidine 0.2% is also contraindicated in children under 2 years.

Q20. The Goldmann visual field uses which combination to assess the peripheral visual field?

A. Static automated stimuli at set eccentricities B. Kinetic testing with stimuli of varying size (I–V) and brightness (1–4), moving from non-seeing to seeing area C. Frequency-doubling technology to detect M-cell loss D. Static suprathreshold screening

Answer: B Goldmann perimetry is kinetic: the examiner moves a stimulus of defined size (I-V) and brightness (1-4, combined as e.g. I2e, III4e, V4e) from the periphery inward until the patient first sees it, mapping isopters. It is ideal for patients who cannot cooperate with automated static perimetry (e.g., neurological disorders, low vision, children). Target V4e maps the full peripheral field; smaller targets probe inner isopters.

RETINA & VITREOUS (Q21–30)

Q21. A 50-year-old patient with high myopia presents with sudden visual loss. Fundus shows a white-yellowish area under the fovea with surrounding subretinal fluid. FA shows early hyperfluorescence and late leakage. OCT shows type 2 CNV (above RPE). The MOST likely diagnosis is:

A. Neovascular AMD B. Myopic CNV (Fuchs spot) C. CSCR with secondary CNV D. Angioid streaks with CNV

Answer: B Myopic CNV is the most common complication of pathological myopia and a major cause of vision loss in young adults. OCT typically shows type 2 (classic) CNV. Anti-VEGF (ranibizumab - RADIANCE trial; bevacizumab) is the treatment of choice. Unlike AMD, myopic CNV is smaller, flat, less exudative, and often responds with fewer anti-VEGF injections. The "Fuchs spot" is the pigmented scar left after the CNV involutes.

Q22. The Amsler grid primarily tests which visual function, and at what distance is it used?

A. Peripheral vision; 6 metres B. Central macular function (central 20°); 33 cm C. Contrast sensitivity; 1 metre D. Binocular function; 6 metres

Answer: B The Amsler grid tests the central 20° of visual field (10° each side of fixation) at 33 cm working distance, subtending 20° with the standard 10×10 cm grid. Each small square = 1° of visual angle. It detects metamorphopsia, scotomas, and distortion in the central field - useful for monitoring AMD, CSCR, and macular oedema. The original description by Marc Amsler (1947) used it for macular disease screening.

Q23. In a patient with wet AMD, which OCT biomarker is MOST strongly associated with poor long-term visual prognosis despite anti-VEGF treatment?

A. Intraretinal fluid (IRF) B. Subretinal fluid (SRF) C. Subretinal hyperreflective material (SHRM) D. Pigment epithelial detachment (PED) height

Answer: A Intraretinal fluid (IRF) on OCT is the strongest predictor of poor visual prognosis in nAMD. The CATT and HARBOR studies confirmed: IRF > SRF in terms of visual harm. SRF (especially in the foveal region) is associated with moderate vision loss but better outcomes than IRF. IRF reflects more severe disruption of the blood-retinal barrier, outer nuclear layer damage, and photoreceptor compromise. The FLUID trial suggested some residual SRF may be acceptable.

Q24. A patient with sickle cell retinopathy presents with a "sea fan" neovascular frond in the superotemporal periphery with vitreous haemorrhage. The MOST characteristic fundus finding of the EARLY stage of proliferative sickle cell retinopathy (Goldberg Stage I-II) is:

A. Arteriovenous anastomoses and "salmon patch" haemorrhages B. Sea fan neovascularisation C. Vitreous haemorrhage D. Tractional retinal detachment

Answer: A Goldberg classification of sickle cell retinopathy:

Stage I: Peripheral arteriolar occlusions
Stage II: Arteriovenous anastomoses and salmon patch haemorrhages (intraretinal haemorrhages that appear salmon-coloured and later resolve as iridescent spots/"schisis cavities")
Stage III: Sea fan neovascularisation (proliferative)
Stage IV: Vitreous haemorrhage
Stage V: Tractional/rhegmatogenous retinal detachment Sea fan vessels auto-infarct in ~50% of cases (autologous regression).

Q25. In Vogt-Koyanagi-Harada (VKH) disease, which OCT finding is characteristic of the ACUTE uveitic phase?

A. Choroidal thickening with multiple subretinal fluid pockets causing exudative RD B. Choroidal thinning with RPE atrophy C. Epiretinal membrane with macular oedema D. Photoreceptor loss at the fovea

Answer: A VKH acute phase: bilateral granulomatous panuveitis with disc oedema. OCT shows:

Choroidal thickening (>500 µm on enhanced depth imaging EDI-OCT)
Multiple subretinal fluid loculations separated by fibrin septa
Exudative retinal detachment with characteristic lobulated appearance
Folding of the photoreceptor layer On FA: multiple hyperfluorescent dots at RPE level "starry sky" pattern. The sunset glow fundus and Dalen-Fuchs nodules are seen in the chronic/convalescent phase.

Q26. Which investigation is the GOLD STANDARD for diagnosing choroidal vascular abnormalities such as pachychoroid, polypoidal choroidal vasculopathy (PCV), and choroidal neovascularisation?

A. Fundus fluorescein angiography (FFA) B. Indocyanine green angiography (ICGA) C. OCT-A (optical coherence tomography angiography) D. B-scan ultrasonography

Answer: B ICGA (indocyanine green angiography) is the gold standard for imaging the choroidal vasculature because:

ICG is 98% protein-bound, remains in the choroidal vasculature longer
Near-infrared (805 nm excitation, 835 nm emission) penetrates RPE and pigment better than fluorescein
Identifies polyps in PCV (pathognomonic hyperfluorescent nodules)
Detects pachychoroid features, CNV type classification, and plate neovascularisation OCT-A is increasingly used but ICGA remains gold standard for PCV diagnosis.

Q27. Regarding the treatment of BRVO with macular oedema, the BRAVO trial demonstrated:

A. Focal laser was superior to ranibizumab for visual acuity gain at 6 months B. Ranibizumab 0.5 mg PRN showed mean +18.3 letters gain vs +7.3 letters (sham) at 6 months C. Dexamethasone implant (Ozurdex) was superior to ranibizumab in treatment-naive patients D. Bevacizumab and ranibizumab were equivalent in the BRAVO trial

Answer: B The BRAVO trial: monthly ranibizumab 0.5 mg vs sham injection for BRVO with macular oedema. At 6 months:

Ranibizumab: +18.3 letters (ETDRS)
Sham: +7.3 letters Sham patients could rescue with laser at month 3. At 12 months, gains were maintained. The CRUISE trial (CRVO equivalent) showed similar results (+14.9 vs +0.8 letters). These trials established anti-VEGF as standard of care for RVO macular oedema.

Q28. A patient with Type 2 diabetes and centre-involving diabetic macular oedema (CI-DME) with visual acuity of 6/18 is started on anti-VEGF therapy. According to DRCR.net Protocol T, which anti-VEGF agent showed SUPERIOR results in eyes with baseline VA ≤ 6/24?

A. Bevacizumab B. Ranibizumab C. Aflibercept D. All three were equivalent at all visual acuity levels

Answer: C Protocol T (2015): Head-to-head comparison of bevacizumab vs ranibizumab vs aflibercept for CI-DME. At 1 year:

In eyes with baseline VA ≥ 6/12: all three agents were equivalent
In eyes with baseline VA ≤ 6/24 (worse vision): aflibercept was statistically superior (+18.9 letters vs +14.2 ranibizumab vs +11.8 bevacizumab) At 2 years, differences diminished. Aflibercept's dual VEGF-A/PIGF blockade may explain superiority in severe oedema.

Q29. In retinoblastoma, which gene mutation results in the HIGHEST risk of trilateral retinoblastoma (bilateral retinoblastoma + pineoblastoma)?

A. Sporadic RB1 somatic mutation B. Germline RB1 mutation C. MYCN amplification without RB1 mutation D. SYK gene mutation

Answer: B Trilateral retinoblastoma (bilateral Rb + ectopic intracranial Rb, most commonly pineoblastoma) occurs almost exclusively in germline RB1 mutation (hereditary Rb) with a ~5% lifetime risk. The RB1 protein (pRb) is the prototypical tumour suppressor ("gatekeeper"). Trilateral Rb carries very poor prognosis. Germline Rb patients also have increased risk of secondary tumours (osteosarcoma, soft tissue sarcomas).

Q30. In a patient with suspected ocular toxoplasmosis, the pathognomonic fundus finding and its OCT appearance are:

A. White fluffy lesion adjacent to an old pigmented scar ("headlight in the fog"); OCT shows full-thickness retinal necrosis with underlying choroidal involvement B. Multifocal choroiditis with "punched-out" lesions C. Perivascular sheathing with vitreous snowballs D. Subretinal white dots at posterior pole

Answer: A Ocular toxoplasmosis: active lesion is a creamy-white, elevated, fluffy retinitis adjacent to an old hyperpigmented chorioretinal scar - "headlight in the fog" or "satellite lesion." This is pathognomonic. OCT shows full-thickness retinal oedema/necrosis with hyperreflective debris extending through all retinal layers and disruption of the RPE-choroid interface. Vitreous inflammation overlies the lesion. Treatment: pyrimethamine + sulfadiazine + folinic acid + prednisolone (quadruple therapy).

NEURO-OPHTHALMOLOGY (Q31–38)

Q31. A 72-year-old woman presents with sudden, painless visual loss in the right eye. Visual acuity is CF at 1 metre. Fundus shows disc oedema in the superior segment, altitudinal visual field defect, and a normal fellow eye. ESR and CRP are normal. The MOST likely diagnosis and its MOST significant risk factor are:

A. Arteritic AION — giant cell arteritis B. Non-arteritic AION (NAION) — small "crowded disc" (disc at risk) C. Central retinal artery occlusion — atrial fibrillation D. Optic neuritis — multiple sclerosis

Answer: B Non-arteritic AION (NAION): sudden, painless visual loss + altitudinal field defect (usually inferior) + segmental disc oedema in older patients with normal inflammatory markers. The structural risk factor is a small cup-to-disc ratio ("disc at risk") - crowded optic nerve head with insufficient space for axons, making them vulnerable to ischaemia. Vascular risk factors (HTN, DM, sleep apnoea) contribute. No proven treatment. Fellow eye has ~25-40% 5-year risk.

Q32. A patient presents with bilateral 6th nerve palsies and papilloedema. The MOST important diagnosis to exclude FIRST is:

A. Myasthenia gravis B. Miller Fisher syndrome C. Raised intracranial pressure (e.g., cerebral venous sinus thrombosis) D. Wernicke encephalopathy

Answer: C Bilateral CN VI palsies with papilloedema = raised ICP until proven otherwise. CN VI has the longest intracranial course and is a false localising sign in raised ICP (stretched over the petrous ridge). Urgent MRI + MRV to exclude cerebral venous sinus thrombosis (CVST), a potentially fatal but treatable condition. MFS causes ophthalmoplegia but not papilloedema. Wernicke's is unilateral CN VI typically.

Q33. In Parinaud syndrome (dorsal midbrain syndrome), which combination of findings is DIAGNOSTIC?

A. Convergence-retraction nystagmus + light-near dissociation + upgaze palsy B. Divergence palsy + upgaze palsy + miosis C. Skew deviation + downbeat nystagmus + torsional nystagmus D. Bilateral abduction failure + convergence nystagmus

Answer: A Parinaud (dorsal midbrain) syndrome - lesion at the level of the superior colliculus/pretectum:

Upgaze palsy (most prominent)
Light-near dissociation (pupils react to convergence but not light - pretectal fibres damaged)
Convergence-retraction nystagmus on attempted upgaze (co-contraction of all EOMs)
Collier sign (eyelid retraction / Collier's tucked lids)
Skew deviation may be present Most common causes: pinealoma (young patients), midbrain infarct (elderly), hydrocephalus.

Q34. A 55-year-old presents with progressive bilateral visual loss. Visual fields show bilateral centrocaecal scotomas. He is a heavy smoker and alcoholic. Serum B12 is 150 pg/mL (low). The MOST likely diagnosis is:

A. Leber hereditary optic neuropathy (LHON) B. Dominant optic atrophy (DOA - Kjer disease) C. Tobacco-alcohol amblyopia (nutritional optic neuropathy) D. Anterior ischaemic optic neuropathy

Answer: C Tobacco-alcohol amblyopia / nutritional optic neuropathy: bilateral, slowly progressive, centrocaecal scotomas (involving both the blind spot and fixation), temporal disc pallor, associated with nutritional deficiency (B12, thiamine, folate), tobacco, and alcohol use. Low B12 confirms nutritional deficiency. Treatment: cessation of tobacco/alcohol + IM hydroxocobalamin + multivitamins + improved diet. LHON also causes centrocaecal scotomas but has mitochondrial genetics and typically affects young males acutely.

Q35. In the ONTT (Optic Neuritis Treatment Trial), which finding regarding visual outcome and MS risk was MOST clinically impactful?

A. Oral prednisolone reduced the risk of MS at 10 years B. IV methylprednisolone hastened visual recovery but did NOT improve long-term visual acuity vs placebo C. IV methylprednisolone reduced the 2-year risk of MS compared with oral prednisolone D. Visual acuity at 1 year was better with no treatment than with steroids

Answer: B & C (C is the key finding) The ONTT key findings:

Oral prednisolone alone INCREASED the risk of recurrent optic neuritis (unexpected)
IV methylprednisolone hastened recovery but did NOT improve final VA at 1 year vs placebo
IV MP reduced 2-year risk of MS (especially in those with ≥1 MRI white matter lesion)
15-year follow-up: VA was excellent (≥20/40) in 72% regardless of treatment
MRI lesion burden at baseline was the strongest predictor of MS conversion

Answer: C (the IV MP reducing short-term MS risk was the key impact finding)

Q36. A patient presents with a fixed, dilated pupil in one eye. Examination shows no ptosis, normal extraocular movements, and the pupil fails to constrict to 0.1% pilocarpine. This pattern is MOST consistent with:

A. Horner syndrome B. Pharmacological mydriasis (e.g., atropine) C. Adie's tonic pupil D. CN III palsy (surgical)

Answer: B Pharmacological mydriasis (cycloplegic/mydriatic agent): the key is failure to constrict to 0.1% pilocarpine (dilute). In Adie's tonic pupil (denervation supersensitivity), the pupil WILL constrict to 0.1% pilocarpine because of supersensitivity. Pharmacological blockade of muscarinic receptors (atropine, cyclopentolate) prevents response even to 1% pilocarpine. CN III palsy: associated ptosis and ophthalmoplegia. Horner: miosis, not mydriasis.

Q37. A 45-year-old woman with known systemic sarcoidosis presents with progressive visual loss, disc oedema, and choroidal infiltrates. Lumbar puncture shows elevated ACE in CSF. The MOST specific ocular finding in neurosarcoidosis is:

A. Anterior granulomatous uveitis with mutton-fat KPs B. Periphlebitis ("candle wax drippings") C. Optic nerve granuloma D. Pars plana exudate ("snowbank")

Answer: B "Candle wax drippings" (taches de bougie) - periphlebitis with perivascular sheathing in a candle wax pattern - is the MOST specific ocular finding in sarcoidosis. It represents granulomatous infiltration of retinal veins. Other manifestations include: mutton-fat KPs (common but not specific), busacca/koeppe nodules, "snowball" vitreous opacities, disc oedema, and CNV. The triad of uveitis + periphlebitis + disc oedema = strongly suspect sarcoidosis.

Q38. Which statement about the Marcus Gunn (jaw-winking) phenomenon is CORRECT?

A. It is caused by aberrant regeneration of CN III fibres to the levator B. It is caused by misdirected branches of CN V3 (pterygoid branch) to the levator C. It is treated by surgical weakening of the superior rectus D. Bilateral jaw-winking does not require ptosis surgery

Answer: B Marcus Gunn jaw-winking: a synkinesis between the pterygoid muscles (CN V3) and the levator palpebrae superioris. Aberrant connections cause the upper lid to "wink" when the jaw moves (chewing, opening mouth). It is a trigemino-oculomotor synkinesis - NOT CN III related. Treatment (if severe): disinsert levator + frontalis sling bilaterally (correct both ptosis and synkinesis). Unilateral correction leaves asymmetry on jaw movement.

OCULOPLASTICS & ORBIT (Q39–44)

Q39. In the management of a patient with a blow-out fracture of the orbital floor, which clinical finding is an INDICATION for URGENT surgical repair (within 24-48 hours)?

A. Enophthalmos > 2 mm at presentation B. Diplopia on downgaze in a child with trapdoor fracture and nausea/vomiting C. Hypoglobus D. Large fracture (> 50% of floor) with predicted enophthalmos

Answer: B Paediatric trapdoor (white-eyed) blow-out fracture with:

Diplopia (inferior rectus entrapment)
Nausea/vomiting (oculocardiac reflex due to muscle entrapment)
Limited upgaze with restricted forced duction = Surgical emergency requiring repair within 24-48 hours to prevent inferior rectus necrosis (ischaemia from entrapment). Adult fractures with enophthalmos or persistent diplopia can be repaired within 1-2 weeks. The "white-eyed" refers to lack of periorbital ecchymosis, which can mislead clinicians.

Q40. The MOST common type of eyelid tumour overall is:

A. Squamous cell carcinoma B. Sebaceous gland carcinoma C. Basal cell carcinoma D. Melanoma

Answer: C Basal cell carcinoma (BCC) accounts for ~90% of all malignant eyelid tumours in Western populations. Most common site: lower eyelid medial canthal area. Nodular BCC is the most common subtype. Sebaceous gland carcinoma is the second most common eyelid malignancy (more common in Asians), is often mistaken for chalazion, and can spread via pagetoid spread. SCC is less common; melanoma is rare on the eyelid.

Q41. In assessing a patient with proptosis, which single investigation provides the MOST information about the cause, extent, and surgical planning?

A. Hertel exophthalmometry B. B-scan ultrasonography C. Contrast-enhanced CT of orbits and paranasal sinuses D. MRI of orbits with gadolinium

Answer: C Contrast-enhanced CT of the orbits is the first-line modality for proptosis because it:

Defines bony anatomy (for surgical planning, trauma)
Shows calcification (dermoid, optic nerve meningioma, retinoblastoma)
Identifies the "tram-track" sign in optic nerve meningioma
Shows extraocular muscle enlargement (thyroid, metastasis)
Evaluates sinus disease and extension MRI is preferred for optic nerve/soft tissue characterisation, intracranial extension, and when no CT contraindications. CT remains the workhorse for initial orbital assessment.

Q42. A patient presents with a painless, smooth, well-circumscribed mass in the superior temporal quadrant of the orbit, displacing the globe inferomedially. It transilluminates. The MOST likely diagnosis and age group are:

A. Capillary haemangioma — infant B. Dermoid cyst — child/young adult C. Lacrimal gland pleomorphic adenoma — adult (40-60 years) D. Lymphoma — elderly

Answer: C Pleomorphic adenoma (benign mixed tumour) of the lacrimal gland:

Most common epithelial lacrimal gland tumour
Presents in adults (40-60 years) with slowly progressive, painless, inferomedial globe displacement
Located in the superior temporal orbit (superolateral quadrant)
CT shows a well-defined mass with lacrimal fossa expansion but NO erosion (bone remodelling, not destruction)
Treatment: complete excision without biopsy (capsule disruption risks seeding and malignant transformation to carcinoma ex pleomorphic adenoma)

Q43. In functional (non-organic/psychogenic) visual loss, the MOST reliable clinical test to demonstrate intact visual function is:

A. Visual evoked potential (VEP) B. Optokinetic nystagmus (OKN) drum C. Electroretinogram (ERG) D. Pattern ERG

Answer: B OKN drum (optokinetic nystagmus): if a patient claims no vision but shows OKN responses when the drum is rotated in front of them, this PROVES intact visual function to at least 6/18-6/24 level. It is an involuntary reflex. Other tests: Prism dissociation test, fogging test (over-correction), stereopsis (requires binocular vision), VEP (can be volitionally suppressed). The OKN test is bedside, non-invasive, and difficult to suppress voluntarily.

Q44. Which of the following is the MOST important distinguishing feature between capillary haemangioma and lymphangioma of the orbit in children?

A. Both increase in size with crying/Valsalva; only capillary haemangioma involutes with age B. Capillary haemangioma presents at birth; lymphangioma appears in later childhood after URTI C. Lymphangioma responds to systemic propranolol; capillary haemangioma does not D. Capillary haemangioma has chocolate cysts; lymphangioma shows flow voids on MRI

Answer: B

Capillary haemangioma: presents in first weeks of life, enlarges until ~1 year, then involutes by age 5-7; responds to propranolol (first-line); does NOT increase with Valsalva.
Lymphangioma: presents in older children (2-10 years), enlarges with URTI (lymphoid tissue response), bleeds spontaneously ("chocolate cysts" of blood on MRI), and does NOT involute. No consistent response to propranolol. Lymphangioma has chocolate cysts (option D reversed). Answer: B is the correct distinguishing feature regarding presentation timing and behaviour.

LENS & CATARACT (Q45–47)

Q45. In calculating IOL power for a patient who has had previous myopic LASIK, the MAIN source of error is:

A. Increased axial length measurement B. Keratometry overestimating true corneal power due to altered anterior/posterior corneal radius ratio C. Biometric A-constant error D. Acoustic velocity change in the cornea

Answer: B Post-myopic LASIK: standard keratometry/topography uses a fixed ratio (n=1.3375) between anterior corneal radius and total corneal power - this is calibrated for normal, untouched corneas. After myopic ablation, the anterior corneal radius is flattened but the posterior cornea is unchanged, making the ratio incorrect. Keratometry overestimates corneal power (reads too flat a K for the adjusted formula), leading to hyperopic surprise (IOL too weak). Corrections: Wang-Koch modification, Haigis-L, ASCRS online calculator, OCT-based corneal power.

Q46. In a patient with uveitic cataract (e.g., chronic JIA-associated uveitis), which IOL material and design is PREFERRED to reduce postoperative inflammation and PCO?

A. PMMA IOL — rigid, excellent biocompatibility B. Hydrophilic acrylic IOL — low PCO rate C. Hydrophobic acrylic IOL with square optic edge — reduced PCO, good biocompatibility D. Silicone IOL — least inflammatory response

Answer: C In uveitic eyes, hydrophobic acrylic IOLs with square optic edge (e.g., AcrySof, Tecnis) are preferred because:

Lowest PCO rate (square edge mechanical barrier)
Good biocompatibility (minimal protein adsorption)
Stable long-term uveal contact Hydrophilic acrylics have higher PCO rates and are more prone to calcification in uveitic/silicone oil eyes. Silicone IOLs are absolutely contraindicated if there's any possibility of future silicone oil use (oil adheres to silicone IOL, blocks vision).

Q47. A patient presents with "white cataract" (mature/hypermature cataract). Which sign indicates a MORGAGNIAN cataract specifically?

A. White intumescent lens with a positive shadow test B. Shrunken, wrinkled, chalky white lens C. Liquefied cortex with a brownish nuclear piece floating at the bottom D. Pearly white lens with anterior capsule plaque

Answer: C Morgagnian cataract (hypermature): the cortex liquefies completely and the brown/amber nucleus sinks to the bottom due to gravity, visible through the capsule (gravity-dependent nuclear sinking). This can cause phacolytic glaucoma (lens protein leaks through intact capsule, clogs TM). It is a surgical emergency. Intumescent cataract (mature): swollen, white, anterior chamber shallowing, risk of angle closure and phacomorphic glaucoma. Shrunken cataract (calcified hypermature): wrinkled capsule.

PAEDIATRIC OPHTHALMOLOGY (Q48–50)

Q48. A 6-year-old with esotropia undergoes cycloplegic refraction. She is found to have +4.00 D hyperopia in both eyes, and her esotropia fully corrects with glasses. The MOST likely diagnosis and the explanation for the deviation is:

A. Basic esotropia — mechanical restriction B. Fully accommodative esotropia — high AC/A ratio (refractive type) C. Convergence excess esotropia — excess near deviation from high AC/A ratio D. Infantile esotropia — neurological convergence excess

Answer: B Fully accommodative esotropia (refractive type): uncorrected hyperopia drives excess accommodation → excess accommodative convergence → esotropia at distance AND near (AC/A ratio is normal but accommodation demand is high). Fully corrected with spectacles (+4 D). If deviation is only at near = convergence excess (high AC/A type, treated with bifocals). Treatment of fully accommodative ET: spectacle correction of hyperopia; no surgery needed if fully corrected by glasses.

Q49. In testing a child for amblyopia, the "crowding phenomenon" refers to:

A. The child performing better on a single optotype than on a line of letters on a standard Snellen chart B. Reduction in visual acuity when optotypes are surrounded by contour bars (flanking bars) C. Variability in visual acuity between visits D. Amblyopic eye performing worse at near than distance

Answer: A (and B both describe crowding) The crowding phenomenon (contour interaction) in amblyopia: amblyopic eyes perform significantly better when tested with single isolated letters than with a full line/chart. When optotypes are closely spaced (crowded), the amblyopic visual system has greater difficulty resolving them - acuity appears worse. This is why ETDRS charts or Glasgow Acuity Cards with crowded letters are preferred over single optotype testing to accurately measure amblyopic acuity. Answer: A captures the clinical implication best.

Q50. A child with bilateral, dense, posterior lenticular opacities is noted to have nystagmus, microcornea, and glaucoma. Urine shows increased galactitol. The MOST likely metabolic diagnosis is:

A. Galactokinase deficiency (type II galactosaemia) B. Classic galactosaemia (GALT deficiency, type I) C. Lowe syndrome (oculocerebrorenal syndrome) D. Fabry disease

Answer: B Classic galactosaemia (GALT - galactose-1-phosphate uridylyltransferase deficiency): presents neonatally with cataracts (oil droplet type → dense posterior nuclear), liver failure, intellectual disability, E.coli sepsis. Urine galactitol is elevated. Complications: bilateral cataracts (preventable with early galactose restriction), intellectual disability even on treatment, premature ovarian failure. Galactokinase deficiency (type II): isolated bilateral cataracts, NO systemic complications. Lowe syndrome: cataracts + glaucoma + intellectual disability + renal tubular dysfunction (X-linked).

SUMMARY TABLE

Q#	Topic	Answer
1	EBMD genetics	B
2	Keratoconus signs	B
3	Corneal graft rejection risk	B
4	Interstitial keratitis aetiology	A
5	CLEK study — VA correlation	B
6	CXL Dresden protocol	A
7	OCP Stage III treatment	C
8	Arlt's triangle	C
9	Band keratopathy — adults	C
10	OSSN prognosis	B
11	PGA side effects	C
12	AGIS study	A
13	Non-valved glaucoma drainage device	C
14	PACG after LPI — EAGLE trial	B
15	PCG developmental defect	B
16	LGN visual field	C
17	Aqueous misdirection	B
18	SLT — LiGHT trial	C
19	Brimonidine contraindication	A
20	Goldmann perimetry	B
21	Myopic CNV	B
22	Amsler grid	B
23	AMD OCT biomarker prognosis	A
24	Sickle cell retinopathy early stages	A
25	VKH acute OCT	A
26	PCV gold standard investigation	B
27	BRAVO trial	B
28	Protocol T — DRCR.net	C
29	Trilateral retinoblastoma	B
30	Toxoplasmosis fundus	A
31	NAION	B
32	Bilateral CN VI + papilloedema	C
33	Parinaud syndrome	A
34	Nutritional optic neuropathy	C
35	ONTT findings	C
36	Fixed dilated pupil — pharmacological	B
37	Sarcoidosis specific sign	B
38	Marcus Gunn jaw-winking	B
39	Blow-out fracture — urgent repair	B
40	Most common eyelid tumour	C
41	Proptosis investigation	C
42	Lacrimal gland pleomorphic adenoma	C
43	Functional visual loss test	B
44	Capillary haemangioma vs lymphangioma	B
45	IOL calculation post-LASIK error	B
46	IOL in uveitic cataract	C
47	Morgagnian cataract	C
48	Accommodative esotropia	B
49	Crowding phenomenon	A
50	Classic galactosaemia	B

Key trials tested: CATT, BRAVO, CRUISE, Protocol T, EAGLE, AGIS, ONTT, LiGHT, OHTS, DRVS, ETROP

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