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NBEO TMOD study materials
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NBEO TMOD practice questions

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Question 1Clinical decision-making and diagnostic reasoning

A 62-year-old presents with a painless, gradually enlarging yellowish plaque on the bulbar conjunctiva nasal to the cornea, separated from the limbus by a clear zone. Which diagnosis best fits this finding?

  1. Conjunctival intraepithelial neoplasia
  2. Pinguecula Correct answer.
  3. Subconjunctival hemorrhage
  4. Pterygium

Explanation

A pinguecula is a benign elastotic degeneration of the conjunctival stroma appearing as a yellow-white elevated deposit, typically on the nasal bulbar conjunctiva, and characteristically leaves a clear interval between the lesion and the limbus. Pterygia, by contrast, cross the limbus onto the cornea as a fibrovascular wedge.

Question 2Clinical decision-making and diagnostic reasoning

Which corneal finding is the most reliable slit-lamp sign of keratoconus on direct observation?

  1. A central rust-colored ring
  2. Inferior corneal thinning with apical protrusion Correct answer.
  3. Perilimbal superficial neovascularization
  4. Diffuse punctate epithelial erosions

Explanation

Keratoconus is an ectatic disorder defined by localized corneal thinning and anterior protrusion, usually inferior or inferotemporal to the apex, which is visible on slit-lamp beam sectioning. The other listed findings are nonspecific or indicate different disease processes.

Question 3Clinical decision-making and diagnostic reasoning

A patient reports sudden painless loss of vision in one eye described as a curtain descending over the field, with floaters that appeared just beforehand. Which diagnosis should be prioritized?

  1. Anterior ischemic optic neuropathy
  2. Rhegmatogenous retinal detachment Correct answer.
  3. Central retinal vein occlusion
  4. Acute angle-closure glaucoma

Explanation

Photopsia and a sudden increase in floaters followed by a painless visual field defect that behaves like a curtain are the classic presentation of a rhegmatogenous retinal detachment. Prompt referral is required because the macula may still be attached and vision salvageable.

Question 4Clinical decision-making and diagnostic reasoning

Which systemic condition is most strongly associated with the development of anterior uveitis in a young adult with recurrent episodes?

  1. Type 2 diabetes mellitus
  2. Primary open-angle glaucoma
  3. Human leukocyte antigen B27-related spondyloarthropathy Correct answer.
  4. Age-related macular degeneration

Explanation

HLA-B27-associated spondyloarthropathies, including ankylosing spondylitis, are a leading systemic association of recurrent acute anterior uveitis in young adults. The uveitis tends to be unilateral, sudden, and accompanied by pain, photophobia, and cells in the anterior chamber.

Question 5Clinical decision-making and diagnostic reasoning

An older adult reports gradual, painless, bilateral loss of near vision with difficulty reading in dim light, and the slit lamp shows a yellow-brown nuclear opacity. What is the most likely diagnosis?

  1. Nuclear sclerotic cataract Correct answer.
  2. Posterior subcapsular cataract
  3. Cortical cataract
  4. Corneal endothelial dystrophy

Explanation

Nuclear sclerosis produces a gradual yellowing and hardening of the lens nucleus, causing painless progressive blur and reduced contrast, especially in low light. The yellow-brown appearance on retroillumination is characteristic of nuclear cataract.

Question 6Clinical decision-making and diagnostic reasoning

Which clinical finding most strongly suggests giant cell arteritis in an elderly patient with sudden visual loss?

  1. Scalp tenderness with an elevated erythrocyte sedimentation rate Correct answer.
  2. Unilateral tearing with a purulent discharge
  3. Painless proptosis with resistance to retropulsion
  4. Bilateral ptosis with fatigable weakness

Explanation

Giant cell arteritis should be suspected in any older adult with sudden visual loss accompanied by headache, jaw claudication, scalp tenderness, or polymyalgia symptoms, and an elevated sedimentation rate and C-reactive protein support the diagnosis. Urgent steroid treatment is indicated while biopsy is arranged to protect the fellow eye.

Question 7Clinical decision-making and diagnostic reasoning

A patient with long-standing poorly controlled diabetes reports fluctuating vision that varies through the day. Which mechanism best explains this symptom?

  1. Osmotic lens swelling from fluctuating blood glucose Correct answer.
  2. Progressive nuclear sclerosis
  3. Choroidal neovascularization
  4. Vitreous syneresis

Explanation

Acute hyperglycemia drives osmotic fluid shifts into the lens, changing its refractive index and producing transient myopic shifts that fluctuate with glucose control. Stable refractive correction should therefore be delayed until glycemic control is stable.

Question 8Clinical decision-making and diagnostic reasoning

Which test is the most appropriate initial screening for a patient suspected of having primary open-angle glaucoma?

  1. Electroretinography
  2. Visual evoked potential
  3. Ultrasound biomicroscopy of the ciliary body
  4. Optic disc assessment with intraocular pressure and gonioscopy Correct answer.

Explanation

Primary open-angle glaucoma is diagnosed from a combination of optic nerve head appearance, intraocular pressure, and open anterior chamber angles on gonioscopy, with visual field testing to document functional loss. Structural and pressure assessment together form the initial evaluation.

Question 9Clinical decision-making and diagnostic reasoning

A 45-year-old presents with a painful red eye, photophobia, and a dendritic corneal lesion that stains with fluorescein. Which management step is most appropriate?

  1. Topical antibiotic monotherapy
  2. Topical corticosteroid alone to reduce inflammation
  3. Immediate patching without medication
  4. Topical antiviral therapy with ophthalmology follow-up Correct answer.

Explanation

A dendritic epithelial lesion with pain and photophobia is characteristic of herpes simplex keratitis, and topical antivirals such as ganciclovir gel or trifluridine are first-line for epithelial disease. Corticosteroids alone are contraindicated because they can promote viral replication and worsen the ulcer.

Question 10Clinical decision-making and diagnostic reasoning

Which pattern of visual field loss is most consistent with a lesion at the optic chiasm?

  1. Altitudinal defect
  2. Homonymous hemianopia
  3. Bitemporal hemianopia Correct answer.
  4. Central scotoma

Explanation

At the chiasm, fibers from the nasal retina of each eye decussate, so a chiasmal lesion compressing these crossing fibers produces a bitemporal hemianopia. This pattern points to a pituitary or suprasellar mass and warrants neuroimaging.

Question 11Clinical decision-making and diagnostic reasoning

A patient on chronic topical steroid therapy for allergic conjunctivitis develops a raised intraocular pressure with an open angle. Which mechanism best explains the pressure rise?

  1. Reduced trabecular outflow from steroid-induced extracellular matrix changes Correct answer.
  2. Excess aqueous production from ciliary epithelium stimulation
  3. Pupillary block from iris-lens apposition
  4. Ciliary body shutdown with shallowing of the anterior chamber

Explanation

Steroid responders develop elevated intraocular pressure through increased resistance to aqueous outflow at the trabecular meshwork, driven by accumulation of extracellular matrix material. The angle remains open, distinguishing it from angle-closure mechanisms.

Question 12Clinical decision-making and diagnostic reasoning

A 70-year-old reports distorted central vision with metamorphopsia in one eye, and examination shows drusen with subretinal fluid. Which imaging study best confirms active neovascular disease?

  1. Automated perimetry
  2. Pachymetry
  3. Gonioscopy
  4. Optical coherence tomography with fluorescein angiography Correct answer.

Explanation

Optical coherence tomography detects subretinal and intraretinal fluid and guides treatment, while fluorescein angiography demonstrates the leaking choroidal neovascular membrane. Together they confirm active neovascular age-related macular degeneration.

Question 13Clinical decision-making and diagnostic reasoning

A child presents with an asymmetric red reflex and leukocoria in one eye. Which diagnosis must be excluded first because of its life-threatening potential?

  1. Retinoblastoma Correct answer.
  2. Congenital cataract
  3. Coats disease
  4. Persistent fetal vasculature

Explanation

Leukocoria in a child requires urgent exclusion of retinoblastoma, an intraocular malignancy that can be fatal if untreated and may be bilateral in heritable cases. Any child with an abnormal red reflex should be referred promptly for dilated fundus examination and imaging.

Question 14Clinical decision-making and diagnostic reasoning

In a patient with acute anterior uveitis, which finding on slit-lamp examination confirms active inflammation in the anterior chamber?

  1. Peripheral iris transillumination defects
  2. Cells and flare in the anterior chamber Correct answer.
  3. Posterior subcapsular opacity
  4. Krukenberg spindle on the endothelium

Explanation

Anterior chamber cells represent inflammatory cells in the aqueous, and flare reflects increased protein from breakdown of the blood-aqueous barrier, both hallmark signs of active anterior uveitis. Their quantification guides treatment response.

Question 15Clinical decision-making and diagnostic reasoning

A patient presents with a painful, red eye and a hypopyon two days after cataract surgery. Which action is most appropriate?

  1. Prescribe artificial tears and cool compresses
  2. Reassure the patient that this is expected postoperative inflammation
  3. Prescribe topical steroids alone and recheck in one week
  4. Obtain aqueous and vitreous cultures and start intensive topical and intravitreal antibiotics urgently Correct answer.

Explanation

A hypopyon with pain and redness after intraocular surgery suggests acute postoperative endophthalmitis, a sight-threatening emergency. Aqueous and vitreous sampling for culture followed by prompt intravitreal antibiotic injection is the standard of care.

Question 16Clinical decision-making and diagnostic reasoning

Which clinical feature best distinguishes bacterial from viral conjunctivitis in a primary care setting?

  1. Bilateral itching with seasonal recurrence
  2. Watery discharge with preauricular lymphadenopathy
  3. Follicular reaction of the inferior tarsus
  4. Mucopurulent discharge with glued lashes on waking Correct answer.

Explanation

Bacterial conjunctivitis typically produces thick mucopurulent discharge that causes the lids to stick together on waking, whereas viral conjunctivitis tends to be watery with a follicular response and preauricular node. This distinction guides whether antibiotics are likely to help.

Question 17Clinical decision-making and diagnostic reasoning

A patient with a long-standing history of poorly controlled hypertension presents with sudden painless visual loss and a swollen optic disc with splinter hemorrhages. Which diagnosis is most likely?

  1. Optic neuritis
  2. Central serous chorioretinopathy
  3. Papilledema from raised intracranial pressure
  4. Nonarteritic anterior ischemic optic neuropathy Correct answer.

Explanation

Nonarteritic anterior ischemic optic neuropathy causes sudden painless monocular visual loss with an altitudinal field defect and a swollen, often hyperemic disc, and is associated with vascular risk factors such as hypertension. Papilledema would be bilateral and accompanied by signs of raised intracranial pressure.

Question 18Clinical decision-making and diagnostic reasoning

Which refractive error is most consistent with a patient who has clear distance vision but requires plus lenses for reading and reports asthenopia after prolonged near work?

  1. Astigmatism
  2. Myopia
  3. Anisometropia
  4. Hyperopia Correct answer.

Explanation

Hyperopic patients accommodate to maintain clear distance vision, and that accommodative effort becomes insufficient for sustained near tasks, producing asthenopia and a need for plus reading lenses. Myopes see near clearly without correction but have blurred distance vision.

Question 19Clinical decision-making and diagnostic reasoning

A 30-year-old presents with a unilateral red eye, photophobia, and a history of recurrent episodes that resolve spontaneously. Slit lamp shows fine keratic precipitates and no hypopyon. Which diagnosis is most likely?

  1. Bacterial corneal ulcer
  2. Scleritis
  3. HLA-B27-associated anterior uveitis Correct answer.
  4. Acute conjunctivitis

Explanation

Recurrent unilateral anterior uveitis with photophobia, fine keratic precipitates, and a quiet conjunctiva is typical of HLA-B27-associated disease, which often recurs and may be linked to spondyloarthropathy. The absence of a hypopyon does not exclude it.

Question 20Clinical decision-making and diagnostic reasoning

Which finding on a dilated fundus examination most strongly suggests a retinal tear in a patient with acute floaters?

  1. Tortuous dilated veins with flame hemorrhages
  2. A horseshoe-shaped retinal break with surrounding subretinal fluid Correct answer.
  3. Drusen in the macula
  4. Cotton-wool spots along the arcades

Explanation

A horseshoe tear with adjacent subretinal fluid indicates a symptomatic retinal break that may progress to detachment and generally requires laser retinopexy or cryotherapy. Identifying the break guides urgent treatment to prevent macular involvement.

Question 21Clinical decision-making and diagnostic reasoning

A patient reports intermittent monocular visual loss lasting minutes, described as a shade coming down over one eye, and has a history of carotid disease. Which term best describes this symptom?

  1. Photopsia
  2. Diplopia
  3. Hemianopia
  4. Amaurosis fugax Correct answer.

Explanation

Amaurosis fugax is transient monocular visual loss caused by temporary retinal ischemia, often from an embolus originating in the carotid artery. It is a warning sign of stroke risk and warrants urgent vascular evaluation.

Question 22Clinical decision-making and diagnostic reasoning

A 55-year-old with a history of migraine reports a transient visual disturbance of zigzag lines and shimmering that expands over 20 minutes and is followed by a mild headache. Which diagnosis best fits?

  1. Transient ischemic attack
  2. Acute angle-closure glaucoma
  3. Migraine with aura Correct answer.
  4. Retinal detachment

Explanation

A slowly expanding scintillating scotoma of zigzag lines that resolves within about an hour and is followed by headache is characteristic of migraine with aura, which is benign and distinct from ischemic events. The gradual march of symptoms helps separate it from amaurosis fugax.

Question 23Clinical decision-making and diagnostic reasoning

A patient with known open-angle glaucoma presents with a sudden severe headache, halos around lights, nausea, and a mid-dilated fixed pupil with a hazy cornea. Which mechanism best explains this acute presentation?

  1. Optic nerve head cupping
  2. Pupillary block causing angle closure Correct answer.
  3. Trabecular meshwork sclerosis with open angles
  4. Ciliary body inflammation reducing aqueous production

Explanation

Pupillary block from iris-lens apposition obstructs aqueous flow into the anterior chamber, causing acute angle closure with a shallow peripheral chamber, high intraocular pressure, corneal edema, and a mid-dilated pupil. This is an emergency requiring immediate pressure-lowering therapy.

Question 24Clinical decision-making and diagnostic reasoning

A patient with a suspected orbital cellulitis has proptosis, restricted eye movement, and pain with eye movement. Which feature most reliably distinguishes orbital from preseptal cellulitis?

  1. Restricted extraocular motility with proptosis Correct answer.
  2. Conjunctival injection
  3. Eyelid edema
  4. Fever

Explanation

Orbital cellulitis involves structures posterior to the orbital septum and produces proptosis, ophthalmoplegia, and pain on eye movement, whereas preseptal cellulitis is confined to the lids. Imaging and urgent intravenous antibiotics are indicated for orbital involvement.

Question 25Clinical decision-making and diagnostic reasoning

A patient with a history of herpes zoster ophthalmicus develops a dendritic corneal lesion with reduced corneal sensation. Which management principle best applies?

  1. Reassure the patient that corneal involvement is not expected
  2. Treat with topical antiviral therapy and monitor closely for corneal complications Correct answer.
  3. Prescribe topical corticosteroids without antiviral coverage
  4. Use topical antibiotics as the primary therapy

Explanation

Herpes zoster ophthalmicus can cause pseudodendrites, neurotrophic keratopathy, and reduced corneal sensation, so antiviral therapy with close monitoring for surface breakdown and stromal complications is appropriate. Corticosteroids require antiviral coverage and careful supervision.

Question 26Clinical decision-making and diagnostic reasoning

A 62-year-old reports a sudden painless loss of vision in the superior half of one eye's field, described as a curtain descending. Fundoscopy shows a pale, edematous retina with a cherry-red spot at the macula. Which vascular territory is most likely occluded?

  1. Branch retinal vein
  2. Central retinal artery Correct answer.
  3. Optic nerve head capillary bed
  4. Central retinal vein

Explanation

A cherry-red spot with diffuse retinal whitening reflects infarction of the inner retina supplied by the central retinal artery, with the fovea appearing red because choroidal perfusion persists beneath the thin macula. Central retinal vein occlusion instead produces a blood-and-thunder fundus with hemorrhages, and branch occlusions spare most of the retina.

Question 27Clinical decision-making and diagnostic reasoning

A 6-year-old has had a red, itchy eye with watery discharge for two days after swimming in a public pool. Vision is normal, the conjunctiva is diffusely hyperemic, and there is no corneal uptake of fluorescein. Which management is most appropriate?

  1. Topical corticosteroid drops
  2. Topical antibiotic drops four times daily
  3. Supportive care with cool compresses and hygiene advice Correct answer.
  4. Immediate referral for corneal scraping

Explanation

Watery discharge, itching, bilateral involvement, and normal vision point to viral or irritant conjunctivitis, which is self-limited and managed supportively with hygiene measures. Antibiotics are reserved for suspected bacterial disease with purulent discharge, and steroids are avoided in undiagnosed red eyes because they can worsen herpes simplex keratitis.

Question 28Clinical decision-making and diagnostic reasoning

A 24-year-old contact lens wearer presents with severe pain, photophobia, and a ring-shaped corneal infiltrate with hypopyon. Which organism should be suspected first, and what action is required?

  1. Herpes simplex virus; start oral antivirals and observe
  2. Acanthamoeba; start topical steroids to reduce inflammation
  3. Pseudomonas aeruginosa; obtain corneal scrapings and start fortified antibiotics urgently Correct answer.
  4. Staphylococcus aureus; prescribe a standard fluoroquinolone and review in one week

Explanation

A contact lens wearer with a ring infiltrate, severe pain, and hypopyon raises concern for Pseudomonas keratitis, which can progress to perforation within days. Corneal scrapings for culture and immediate fortified topical antibiotic therapy are the standard of care, with same-day ophthalmology involvement.

Question 29Clinical decision-making and diagnostic reasoning

A 68-year-old with a long-standing esotropia is found to have reduced stereopsis on testing. Which test is most appropriate to detect the presence of any binocular single vision?

  1. Ishihara color plate test
  2. Cover test with prism alternate occlusion
  3. Worth four-dot test Correct answer.
  4. Amsler grid

Explanation

The Worth four-dot test assesses whether images from both eyes are being fused or suppressed by presenting separate targets to each eye through red-green filters. It can distinguish fusion, suppression, and diplopia even when stereoacuity is too poor to measure with fine disparity tests.

Question 30Clinical decision-making and diagnostic reasoning

A 55-year-old with a known optic neuropathy reports that a red object appears duller in one eye. Which bedside test best quantifies this asymmetry between the two eyes?

  1. Confusion color plate testing
  2. Pupillary light-near dissociation testing
  3. Red desaturation comparison Correct answer.
  4. Contrast sensitivity grating testing

Explanation

Comparing the subjective brightness or saturation of a red target between eyes is a quick, sensitive screen for asymmetric optic nerve dysfunction, often preceding measurable acuity loss. The finding is a relative afferent pupillary defect in the same eye in most unilateral optic neuropathies.

Question 31Clinical decision-making and diagnostic reasoning

A patient with an acute red eye is found to have a fixed, mid-dilated pupil, corneal haze, and intraocular pressure of 52 mmHg. Which medication class should be avoided during initial management?

  1. Topical beta-blockers
  2. Systemic carbonic anhydrase inhibitors
  3. Topical pilocarpine in the inflamed eye Correct answer.
  4. Topical prostaglandin analogs

Explanation

Pilocarpine is often ineffective during acute angle closure because the ischemic iris sphincter cannot respond to the drug, and it may worsen the situation by inducing anterior movement of the lens-iris diaphragm. Definitive management prioritizes aqueous suppression and pressure lowering, followed by laser peripheral iridotomy once the cornea clears.

Question 32Clinical decision-making and diagnostic reasoning

A 40-year-old reports gradual painless blurring of near vision over several months, worse in the evening, with normal distance acuity. Which diagnosis is most consistent with these symptoms?

  1. Central serous chorioretinopathy
  2. Incipient nuclear sclerotic cataract Correct answer.
  3. Primary open-angle glaucoma
  4. Acute anterior uveitis

Explanation

Gradual painless decline in near vision with glare and worsening in dim light suggests early nuclear sclerosis, which increases the refractive index of the lens and shifts the eye toward myopia. Slit-lamp examination showing yellowing of the lens nucleus confirms the diagnosis.

Question 33Clinical decision-making and diagnostic reasoning

A 72-year-old with hypertension and diabetes presents with sudden painless loss of vision in one eye. Fundoscopy reveals a swollen, pale optic disc with splinter hemorrhages at the margin. Which additional finding would most strongly support a diagnosis of non-arteritic anterior ischemic optic neuropathy over arteritic disease?

  1. Elevated erythrocyte sedimentation rate above 70 mm/h
  2. A cup-to-disc ratio asymmetry of 0.3
  3. A relative afferent pupillary defect in the affected eye Correct answer.
  4. Jaw claudication and scalp tenderness

Explanation

Both arteritic and non-arteritic anterior ischemic optic neuropathy can produce a pale swollen disc, but a relative afferent pupillary defect is a nonspecific sign of optic nerve dysfunction present in either form. Features such as jaw claudication, scalp tenderness, and markedly elevated inflammatory markers point toward giant cell arteritis and warrant urgent steroids.

Question 34Clinical decision-making and diagnostic reasoning

A 30-year-old presents with sudden onset of a central scotoma and photopsias in one eye. Examination shows a normal macula but a swollen optic disc, and MRI reveals enhancement of the optic nerve with normal brain parenchyma. Which diagnosis is most likely?

  1. Anterior ischemic optic neuropathy
  2. Papilledema from raised intracranial pressure
  3. Optic neuritis Correct answer.
  4. Leber hereditary optic neuropathy

Explanation

Unilateral painful visual loss with a central scotoma, reduced color vision, and optic nerve enhancement on MRI in a young adult is characteristic of demyelinating optic neuritis. Papilledema is bilateral and due to raised intracranial pressure, while ischemic optic neuropathy usually occurs in older patients with vascular risk factors.

Question 35Clinical decision-making and diagnostic reasoning

A 45-year-old presents with a unilateral red eye and a painful vesicular rash on the tip of the nose. Which structure involvement does this finding most strongly suggest?

  1. Long ciliary nerve involvement of the globe Correct answer.
  2. Nasolacrimal duct obstruction
  3. Ciliary body inflammation alone
  4. External auditory canal involvement

Explanation

Vesicles on the tip of the nose indicate involvement of the nasociliary branch of the ophthalmic division of the trigeminal nerve, which supplies the long ciliary nerves to the globe. This Hutchinson sign raises the risk of herpetic keratouveitis and warrants prompt antiviral therapy and ophthalmologic monitoring.

Question 36Clinical decision-making and diagnostic reasoning

A 50-year-old reports seeing a sudden shower of floaters and flashes of light in one eye. Which examination finding would most strongly increase the likelihood of a retinal tear requiring urgent referral?

  1. Posterior vitreous detachment without retinal break
  2. Tobacco dust pigment cells in the anterior vitreous Correct answer.
  3. A single floater with a normal peripheral retina
  4. Mild nuclear sclerosis

Explanation

Pigment cells in the anterior vitreous, sometimes called tobacco dust or Shafer sign, suggest a retinal tear with release of pigment into the vitreous. Combined with acute floaters and photopsias, this finding warrants urgent dilated peripheral retinal examination and possible laser retinopexy.

Question 37Clinical decision-making and diagnostic reasoning

A 35-year-old with a history of recurrent episodes of a red, painful eye with photophobia is found to have a central corneal scar and a positive fluorescein dendritic lesion. Which topical therapy is contraindicated?

  1. Topical corticosteroid without antiviral cover Correct answer.
  2. Topical ganciclovir
  3. Topical antibiotic prophylaxis
  4. Oral acyclovir

Explanation

Topical corticosteroids without antiviral coverage can promote replication of herpes simplex virus and worsen epithelial dendrites, potentially leading to geographic ulceration. Antiviral therapy, either topical or systemic, is the mainstay for active epithelial disease.

Question 38Clinical decision-making and diagnostic reasoning

A 60-year-old with a history of angle-closure glaucoma presents with a sudden severe headache, halos around lights, and nausea. The eye is red with a mid-dilated pupil and a hazy cornea. Which initial pharmacologic step is most appropriate?

  1. Topical beta-blocker and systemic carbonic anhydrase inhibitor Correct answer.
  2. Topical corticosteroid alone
  3. Topical pilocarpine alone
  4. Topical prostaglandin analog

Explanation

Acute angle closure requires rapid lowering of intraocular pressure with aqueous suppressants such as topical beta-blockers and systemic carbonic anhydrase inhibitors, followed by definitive laser peripheral iridotomy. Pilocarpine is often ineffective in the acutely inflamed eye because the ischemic iris sphincter cannot constrict.

Question 39Clinical decision-making and diagnostic reasoning

A 70-year-old with a long-standing history of poorly controlled hypertension presents with sudden painless visual loss and a fundus showing extensive retinal hemorrhages, dilated tortuous veins, and disc edema. Which complication should be monitored most closely?

  1. Retinal detachment from lattice degeneration
  2. Central serous chorioretinopathy
  3. Optic neuritis
  4. Neovascular glaucoma Correct answer.

Explanation

Central retinal vein occlusion can lead to iris and angle neovascularization, particularly when there is extensive retinal ischemia, resulting in neovascular glaucoma. Close monitoring of the anterior segment and prompt panretinal photocoagulation when neovascularization appears are essential.

Question 40Clinical decision-making and diagnostic reasoning

A 25-year-old presents with a unilateral red eye, photophobia, and a history of recurrent episodes that resolve spontaneously. Slit-lamp examination shows fine keratic precipitates and a low-grade anterior chamber reaction. Which underlying condition should be considered?

  1. HLA-B27-associated anterior uveitis Correct answer.
  2. Dry eye disease
  3. Allergic conjunctivitis
  4. Bacterial conjunctivitis

Explanation

Recurrent unilateral anterior uveitis with fine keratic precipitates in a young adult raises suspicion for an HLA-B27-associated spondyloarthropathy. Systemic review for joint, skin, or bowel symptoms helps identify the underlying disorder.

Question 41Clinical decision-making and diagnostic reasoning

A 55-year-old with diabetes reports fluctuating vision that varies through the day. Which finding on dilated fundus examination would most strongly suggest clinically significant macular edema?

  1. Hard exudates within 500 microns of the foveal center Correct answer.
  2. Dot-blot hemorrhages in the midperiphery
  3. Microaneurysms in the temporal periphery
  4. Cotton-wool spots at the disc margin

Explanation

Clinically significant macular edema is defined by retinal thickening or hard exudates within 500 microns of the foveal center, or a zone of thickening at least one disc area in size involving the fovea. These findings warrant consideration of focal laser or anti-VEGF therapy.

Question 42Clinical decision-making and diagnostic reasoning

A 45-year-old presents with a painless, gradually enlarging pigmented lesion on the iris. Which feature most strongly raises concern for iris melanoma rather than a benign nevus?

  1. Uniform brown pigmentation
  2. Presence of a feeder vessel and pupillary distortion Correct answer.
  3. Stable size over five years
  4. Diameter less than 2 mm

Explanation

Iris melanoma is suggested by a prominent vascular supply, distortion of the pupil, and growth over time, whereas iris nevi are typically small, flat, and stable. Documentation with serial photography and anterior segment imaging helps detect progression.

Question 43Clinical decision-making and diagnostic reasoning

A 35-year-old presents with a progressive drooping eyelid and double vision that worsens through the day. Which test is most appropriate to confirm the diagnosis?

  1. Exophthalmometry
  2. Ice pack test Correct answer.
  3. Schirmer test
  4. Tear film breakup time

Explanation

Fatigable ptosis and diplopia that worsen with sustained activity suggest myasthenia gravis. The ice pack test can produce rapid improvement in ptosis and is a useful bedside adjunct, while serologic testing for acetylcholine receptor antibodies provides confirmation.

Question 44Clinical decision-making and diagnostic reasoning

A 60-year-old with a history of thyroid disease presents with proptosis, lid retraction, and restricted eye movement. Which finding on imaging most strongly supports thyroid eye disease?

  1. Enlargement of the extraocular muscles sparing the tendinous insertions Correct answer.
  2. Diffuse enlargement of the lacrimal gland alone
  3. Thickening of the optic nerve sheath
  4. A well-circumscribed orbital mass

Explanation

Thyroid eye disease typically produces enlargement of the extraocular muscle bellies with sparing of the tendinous insertions, most commonly affecting the inferior and medial recti. This pattern helps distinguish it from orbital myositis, which often involves the tendon.

Question 45Clinical decision-making and diagnostic reasoning

A 28-year-old presents with a sudden onset of a curtain-like visual field defect in one eye lasting several minutes, followed by complete recovery. Which evaluation is most appropriate?

  1. Immediate lumbar puncture
  2. Carotid Doppler and echocardiography Correct answer.
  3. Visual evoked potentials
  4. Optical coherence tomography of the macula

Explanation

Transient monocular visual loss, or amaurosis fugax, suggests an embolic or hemodynamic event in the carotid circulation and warrants evaluation for carotid stenosis and cardiac sources of emboli. Prompt assessment is essential because it may herald a stroke.

Question 46Clinical decision-making and diagnostic reasoning

A 30-year-old reports a transient visual disturbance of zigzag lines and shimmering that expands over about 20 minutes and is followed by a mild headache. Which feature most strongly favors migraine aura over a transient ischemic event?

  1. Sudden onset with maximal deficit immediately
  2. Association with carotid bruit
  3. Positive visual phenomena that expand gradually Correct answer.
  4. Monocular loss described as a curtain

Explanation

Migraine visual aura is characterized by positive phenomena such as scintillations and fortification spectra that gradually spread and then resolve, often followed by headache. Transient ischemic events typically produce negative symptoms such as loss of vision with abrupt onset.

Question 47Clinical decision-making and diagnostic reasoning

A 65-year-old with known open-angle glaucoma presents with a sudden severe headache, halos around lights, nausea, and a mid-dilated pupil. Which management step is most definitive after initial medical stabilization?

  1. Selective laser trabeculoplasty
  2. Topical prostaglandin therapy alone
  3. Laser peripheral iridotomy Correct answer.
  4. Trabeculectomy

Explanation

Once the cornea clears and intraocular pressure is controlled, laser peripheral iridotomy relieves pupillary block and is the definitive treatment for acute angle closure. It also protects the fellow eye, which is at high risk.

Question 48Clinical decision-making and diagnostic reasoning

A 4-year-old presents with an asymmetric red reflex and leukocoria in one eye. Which diagnosis must be excluded first because of its potential for metastasis?

  1. Congenital cataract
  2. Retinoblastoma Correct answer.
  3. Coats disease
  4. Persistent fetal vasculature

Explanation

Leukocoria in a young child requires urgent evaluation for retinoblastoma, an intraocular malignancy that can metastasize and is associated with a germline RB1 mutation in some cases. Prompt imaging and referral to a pediatric ocular oncology center are essential.

Question 49Clinical decision-making and diagnostic reasoning

A 50-year-old presents with a painful red eye and a hypopyon two days after cataract surgery. Which action is most appropriate?

  1. Topical corticosteroid drops alone
  2. Immediate vitreous and aqueous tap with intravitreal antibiotic injection Correct answer.
  3. Observation with warm compresses
  4. Topical antibiotic drops alone with review in one week

Explanation

Postoperative endophthalmitis is a sight-threatening emergency requiring immediate aqueous and vitreous sampling for culture followed by intravitreal antibiotic injection. Delay in treatment is associated with poor visual outcomes.

Question 50Clinical decision-making and diagnostic reasoning

A 55-year-old with a history of herpes zoster ophthalmicus develops a dendritic corneal lesion with reduced corneal sensation. Which feature best distinguishes this from herpes simplex keratitis?

  1. Reduced corneal sensation and a history of dermatomal rash Correct answer.
  2. Associated conjunctival hyperemia
  3. Positive fluorescein staining
  4. Presence of a branching dendritic pattern

Explanation

Varicella-zoster virus keratitis often presents with reduced corneal sensation and follows a dermatomal vesicular rash, whereas herpes simplex keratitis typically has a branching dendrite with terminal bulbs and variable sensation. Both stain with fluorescein, so the clinical context is key.