Ophthalmology Prometric exam questions with answers

1. Question 1Optics, Refraction and Visual Functioneasy

   An uncorrected myopic patient, with accommodation fully relaxed, has a far point 50 cm in front of the eye. Ignoring vertex distance, what spectacle lens power will correct distance vision?

   1. A-0.50 D
   2. B-2.00 D
   3. C-5.00 D
   4. D+2.00 D
   Show answer and explanation▾

   Answer: B. -2.00 D

   The far point of a myopic eye lies at a distance equal to the reciprocal of the refractive error, so a far point of 0.5 m corresponds to 2.00 D of myopia, corrected with a -2.00 D lens whose focal point coincides with the far point. A plus lens would increase the myopic blur. Values of -0.50 D and -5.00 D result from inverting the calculation or confusing centimetres with metres.

2. Question 2Optics, Refraction and Visual Functionmedium

   A patient wearing -4.00 D spherical spectacles has the optical centre of the right lens decentred 5 mm horizontally from the visual axis. Using Prentice's rule, what prismatic effect is induced at the visual axis?

   1. A0.8 prism dioptres
   2. B1.25 prism dioptres
   3. C20 prism dioptres
   4. D2 prism dioptres
   Show answer and explanation▾

   Answer: D. 2 prism dioptres

   Prentice's rule states that prismatic effect in prism dioptres equals decentration in centimetres multiplied by lens power in dioptres: 0.5 cm x 4 D = 2 prism dioptres. Using millimetres instead of centimetres gives the erroneous value of 20. Induced prism from decentration is a common cause of asthenopia and diplopia with higher-power spectacles.

3. Question 3Cornea, External Disease and Ocular Surfacemedium

   A 27-year-old soft contact lens wearer who rinses her lenses in tap water has 3 weeks of severe pain out of proportion to the signs despite topical fluoroquinolone. There is a paracentral ring-shaped stromal infiltrate and radial infiltrates along the corneal nerves. What is the most likely diagnosis?

   1. AAcanthamoeba keratitis
   2. BPseudomonas keratitis
   3. CHerpes simplex stromal keratitis
   4. DFusarium keratitis
   Show answer and explanation▾

   Answer: A. Acanthamoeba keratitis

   Acanthamoeba keratitis is strongly associated with contact lens exposure to tap or swimming water and typically causes pain disproportionate to the signs, radial perineuritis and later a ring infiltrate; it does not respond to standard antibacterials. Diagnosis is by corneal scraping for culture or PCR, or in vivo confocal microscopy, and treatment uses biguanides such as PHMB or chlorhexidine. Pseudomonas causes a rapidly progressive suppurative ulcer with copious discharge over days, without radial keratoneuritis.

4. Question 4Cornea, External Disease and Ocular Surfaceeasy

   A 36-year-old man with a red, watery eye was started on topical dexamethasone by a walk-in clinic 4 days ago and is now worse. Fluorescein shows a branching epithelial ulcer with terminal bulbs and reduced corneal sensation. What is the most appropriate management?

   1. AIncrease the dexamethasone frequency to control inflammation
   2. BAdd topical chloramphenicol and continue dexamethasone
   3. CStop the steroid and start topical ganciclovir or oral aciclovir
   4. DBandage contact lens and lubricants only
   Show answer and explanation▾

   Answer: C. Stop the steroid and start topical ganciclovir or oral aciclovir

   A dendritic ulcer with terminal bulbs and reduced corneal sensation is herpes simplex epithelial keratitis, which topical corticosteroids worsen and can convert into a large geographic ulcer. The steroid should be stopped and an antiviral started, such as topical ganciclovir gel or oral aciclovir, with ophthalmology follow-up. Antibacterials do not treat herpes simplex, and lubricants alone allow viral replication to continue.

5. Question 5Cataract and Lens Surgerymedium

   Six weeks after uncomplicated phacoemulsification, a 70-year-old woman reports blurred central vision, now 6/18, after initially seeing well. The eye is quiet. OCT shows cystoid spaces in the outer plexiform and inner nuclear layers with increased central thickness. What is the most appropriate initial treatment?

   1. APars plana vitrectomy
   2. BTopical NSAID with topical corticosteroid
   3. CIntravitreal anti-VEGF injection
   4. DObservation without treatment for 6 months
   Show answer and explanation▾

   Answer: B. Topical NSAID with topical corticosteroid

   Pseudophakic cystoid macular oedema (Irvine-Gass syndrome) typically peaks 4 to 12 weeks after surgery, and first-line treatment is a topical NSAID combined with a topical corticosteroid. Periocular or intravitreal steroid is reserved for refractory cases, and vitrectomy is considered only with vitreous incarceration or persistent disease. Anti-VEGF is not first-line for pseudophakic oedema, and treatment usually speeds recovery compared with observation.

6. Question 6Glaucomamedium

   A 64-year-old hypermetropic woman presented with acute primary angle closure in the right eye. Intraocular pressure has been lowered medically to 18 mmHg and the cornea has cleared. Gonioscopy of the left eye shows an appositionally closable angle. What is the most appropriate definitive management?

   1. ALaser peripheral iridotomy in the right eye only
   2. BLong-term topical pilocarpine in both eyes
   3. CTrabeculectomy in the right eye
   4. DLaser peripheral iridotomy in both eyes
   Show answer and explanation▾

   Answer: D. Laser peripheral iridotomy in both eyes

   After an acute attack is controlled, laser peripheral iridotomy relieves pupil block in the affected eye, and the fellow eye should also be treated prophylactically because a large proportion of untreated fellow eyes develop acute angle closure within a few years. Long-term pilocarpine does not reliably prevent attacks and causes side effects. Filtration surgery is reserved for persistently raised pressure after iridotomy, and lens extraction is an alternative definitive option in selected patients.

7. Question 7Glaucomahard

   An 18-month-old child with primary congenital glaucoma has persistently raised intraocular pressure while awaiting further surgery. Which topical medication should be avoided?

   1. ABrimonidine
   2. BTimolol 0.25%
   3. CDorzolamide
   4. DLatanoprost
   Show answer and explanation▾

   Answer: A. Brimonidine

   Brimonidine crosses the immature blood-brain barrier and can cause severe central nervous system depression, bradycardia, hypotension and apnoea in infants and young children, so it is contraindicated under 2 years of age. Topical carbonic anhydrase inhibitors and prostaglandin analogues are generally well tolerated in children, and low-concentration timolol can be used with monitoring for bronchospasm and bradycardia. Surgery remains the definitive treatment for primary congenital glaucoma.

8. Question 8Medical and Surgical Retina, Vitreousmedium

   A 58-year-old myopic man has had new floaters and flashes for 2 days. Slit-lamp examination shows pigment granules in the anterior vitreous. Undilated fundoscopy by the referring doctor was reported as normal. What is the most appropriate management?

   1. AReassure and review in 6 weeks if symptoms persist
   2. BArrange OCT of the macula only
   3. CSame-day dilated fundus examination with scleral indentation
   4. DPrescribe topical steroid for vitritis
   Show answer and explanation▾

   Answer: C. Same-day dilated fundus examination with scleral indentation

   Pigment granules in the anterior vitreous (Shafer sign, or tobacco dust) with acute posterior vitreous detachment symptoms are strongly associated with a retinal tear that may progress to detachment. Urgent dilated examination of the peripheral retina with indirect ophthalmoscopy and scleral indentation is required, with laser retinopexy if a tear is found. An undilated view cannot exclude a peripheral tear, and macular OCT does not image the periphery.

9. Question 9Uveitis, Ocular Immunology and Ocular Infectionmedium

   A 26-year-old immunocompetent woman has floaters and reduced vision. Fundoscopy shows dense vitritis with a fluffy white focus of retinochoroiditis adjacent to an old pigmented chorioretinal scar, giving a headlight in the fog appearance. What is the most likely diagnosis?

   1. ACytomegalovirus retinitis
   2. BToxoplasma retinochoroiditis
   3. CAcute retinal necrosis
   4. DCandida endophthalmitis
   Show answer and explanation▾

   Answer: B. Toxoplasma retinochoroiditis

   Active focal necrotising retinochoroiditis next to a pigmented scar with overlying vitritis is the classic appearance of reactivated ocular toxoplasmosis, the commonest cause of infectious posterior uveitis in immunocompetent adults. CMV retinitis occurs in severe immunosuppression, with granular haemorrhagic retinitis and minimal vitritis. Acute retinal necrosis causes peripheral confluent necrosis with occlusive vasculitis, and Candida typically affects intravenous drug users or hospitalised patients with fluffy lesions and no pigmented scar.

10. Question 10Neuro-Ophthalmologyeasy

    A 52-year-old woman has sudden headache and diplopia. The left eye has complete ptosis and is deviated down and out, with a dilated, poorly reactive pupil. What is the most appropriate next step?

    1. AOutpatient review in 3 months, as most microvascular palsies resolve
    2. BCheck blood glucose and blood pressure and review in 1 week
    3. COrthoptic assessment and a Fresnel prism
    4. DEmergency CT or MR angiography
    Show answer and explanation▾

    Answer: D. Emergency CT or MR angiography

    A painful, pupil-involving third nerve palsy is caused by a compressive lesion, classically a posterior communicating artery aneurysm, until proved otherwise, and needs emergency vascular imaging because rupture carries high mortality. Microvascular ischaemic palsies usually spare the pupil and recover over about 3 months, but this cannot be assumed when the pupil is involved. Prisms and vascular risk factor checks do not address the life-threatening cause.

11. Question 11Oculoplastics, Orbit and Lacrimal Systemhard

    A 58-year-old smoker with Graves disease has 3 weeks of reduced vision in the right eye to 6/24, desaturated colour vision, a right relative afferent pupillary defect and marked restriction of eye movements. CT shows enlarged extraocular muscles crowding the orbital apex. What is the most appropriate immediate treatment?

    1. AIntravenous pulsed methylprednisolone, with urgent decompression if response is poor
    2. BOral selenium and smoking cessation alone
    3. COrbital radiotherapy as monotherapy
    4. DEyelid lowering surgery to protect the cornea
    Show answer and explanation▾

    Answer: A. Intravenous pulsed methylprednisolone, with urgent decompression if response is poor

    Dysthyroid optic neuropathy is a sight-threatening emergency caused by apical compression from enlarged muscles. Very high-dose intravenous methylprednisolone is first-line, and urgent surgical orbital decompression is performed if visual function does not respond within about 1 to 2 weeks. Selenium is used only for mild disease, radiotherapy is too slow to be used alone for optic neuropathy, and eyelid surgery is a late rehabilitative step once the disease is inactive.

12. Question 12Paediatric Ophthalmology and Strabismushard

    A preterm infant born at 26 weeks' gestation is examined at 35 weeks postmenstrual age. There is stage 3 retinopathy of prematurity in zone II with plus disease in both eyes. What is the most appropriate management?

    1. ARe-examine in 1 week and treat if stage 4 develops
    2. BRe-examine in 2 weeks, as regression is expected
    3. CLaser photocoagulation or intravitreal anti-VEGF within 72 hours
    4. DVitrectomy within 1 week
    Show answer and explanation▾

    Answer: C. Laser photocoagulation or intravitreal anti-VEGF within 72 hours

    Zone II stage 2 or 3 ROP with plus disease is type 1 ROP under the ETROP criteria, which requires treatment, ideally within 48 to 72 hours, with peripheral retinal laser or intravitreal anti-VEGF therapy. Observation is appropriate only for type 2 ROP, such as zone II stage 3 without plus disease. Vitrectomy is reserved for retinal detachment in stage 4 or 5 disease.

13. Question 13Ocular Trauma and Ophthalmic Emergencieshard

    A 10-year-old boy is kicked in the right eye. He has nausea, vomiting and a heart rate of 48/min, with marked restriction and pain on upgaze. The eye is white with minimal periorbital bruising. CT shows a small orbital floor fracture with the inferior rectus trapped in it. What is the most appropriate management?

    1. AOral steroids and review in 2 weeks when swelling settles
    2. BUrgent surgical release of the entrapped muscle and fracture repair
    3. CObservation, as diplopia in children usually resolves
    4. DElective repair only if enophthalmos exceeds 2 mm
    Show answer and explanation▾

    Answer: B. Urgent surgical release of the entrapped muscle and fracture repair

    This is a white-eyed trapdoor blowout fracture, common in children because elastic bone springs back and traps the inferior rectus or its surrounding tissue, and the oculocardiac reflex causes bradycardia, nausea and vomiting. Urgent surgical release, ideally within 24 to 48 hours, is needed to prevent muscle ischaemia and permanent restrictive strabismus. The delayed repair used for adult fractures with enophthalmos or persistent diplopia is inappropriate here.

14. Question 14Ocular Oncology, Pathology and Systemic Diseasemedium

    An 18-month-old boy is referred because his mother noticed a white reflex in his left eye on flash photographs. Red reflex testing confirms leukocoria and there is a left esotropia. Retinoblastoma is suspected. Which investigation strategy is most appropriate?

    1. AExamination under anaesthesia by an ocular oncology team, with MRI of orbits and brain
    2. BFine-needle aspiration biopsy of the intraocular mass for cytology
    3. CCT of the orbits to detect intraocular calcification
    4. DRepeat red reflex testing in 3 months
    Show answer and explanation▾

    Answer: A. Examination under anaesthesia by an ocular oncology team, with MRI of orbits and brain

    Suspected retinoblastoma needs urgent referral for examination under anaesthesia with ocular ultrasound, which shows the characteristic calcification, and MRI to assess optic nerve and pineal involvement. CT is avoided because ionising radiation increases the risk of second malignancies in children with germline RB1 mutations. Intraocular biopsy is contraindicated because of the risk of tumour seeding along the needle track.

15. Question 15Patient Safety, Professionalism, Ethics and Practice in the GCCeasy

    A cataract unit reviews its endophthalmitis prevention protocol. Which preoperative measure has the strongest evidence for reducing post-cataract endophthalmitis?

    1. ATopical antibiotic drops for 3 days before surgery
    2. BTrimming the eyelashes before surgery
    3. CRoutine conjunctival swabs for culture
    4. DPovidone-iodine 5% instilled into the conjunctival sac
    Show answer and explanation▾

    Answer: D. Povidone-iodine 5% instilled into the conjunctival sac

    Povidone-iodine 5% applied to the conjunctival sac and periocular skin immediately before surgery is the preoperative measure with the strongest evidence for reducing endophthalmitis, with aqueous chlorhexidine as an alternative when povidone-iodine cannot be used. Intracameral antibiotic at the end of surgery provides additional protection. Preoperative topical antibiotics, lash trimming and conjunctival cultures have not been shown to reduce endophthalmitis.

Last reviewed September 2026. Questions are original and written to the published exam blueprint; they are not taken from any real paper.