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ABPS Ophthalmology study materials
ABPS Ophthalmology study resources

ABPS Ophthalmology practice questions

One question at a time. Build your ABPS Ophthalmology understanding.

First 50 of 200 questions. Each one lists the choices, the correct answer, and an explanation. The checker at the top of this page saves progress in this browser when it is available.

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Question 1Anterior Segment and Cornea

Which corneal layer is primarily responsible for maintaining corneal deturgescence and transparency?

  1. Bowman layer
  2. Endothelium Correct answer.
  3. Corneal epithelium
  4. Stroma

Explanation

The corneal endothelium actively pumps fluid out of the stroma via Na+/K+-ATPase, keeping the cornea relatively dehydrated and clear. Its barrier and pump functions maintain the precise hydration needed for optical transparency.

Question 2Anterior Segment and Cornea

A patient reports a sudden painful red eye with a fluorescein-staining epithelial defect shaped like a dendrite with terminal bulbs. What is the most appropriate initial management?

  1. Topical antibiotic with steroid combination
  2. Topical antiviral therapy Correct answer.
  3. Pressure patching without medication
  4. Topical corticosteroid alone

Explanation

A branching dendritic ulcer with terminal bulbs is characteristic of epithelial herpes simplex keratitis. Topical antivirals such as ganciclovir gel or topical acyclovir are first-line; corticosteroids alone can worsen the infection.

Question 3Anterior Segment and Cornea

Which of the following is the most common cause of microbial keratitis associated with contact lens wear?

  1. Pseudomonas aeruginosa Correct answer.
  2. Streptococcus pneumoniae
  3. Herpes simplex virus
  4. Acanthamoeba

Explanation

Pseudomonas aeruginosa is the most frequent organism in contact lens-related bacterial keratitis, favored by its affinity for hydrogel materials and ability to form biofilms. It typically produces a rapidly progressive suppurative ulcer.

Question 4Anterior Segment and Cornea

Which dystrophy is characterized by bilateral, symmetric, central corneal opacities appearing in the first or second decade, with a 'map-dot-fingerprint' pattern on slit lamp?

  1. Fuchs endothelial dystrophy
  2. Epithelial basement membrane dystrophy Correct answer.
  3. Granular corneal dystrophy
  4. Lattice corneal dystrophy

Explanation

Epithelial basement membrane dystrophy (Cogan dystrophy) shows maps, dots, and fingerprint lines due to aberrant basement membrane. It commonly presents with recurrent erosion symptoms and is bilateral and symmetric.

Question 5Anterior Segment and Cornea

A 65-year-old presents with gradual painless vision loss and slit lamp shows central corneal thinning with iron deposition in a Fleischer ring at the base of the cone. What is the diagnosis?

  1. Mooren ulcer
  2. Terrien marginal degeneration
  3. Keratoconus Correct answer.
  4. Pellucid marginal degeneration

Explanation

Keratoconus is a non-inflammatory ectasia producing a cone-shaped protrusion, Fleischer ring (iron at the cone base), and Vogt striae. It causes progressive myopic astigmatism and painless vision decline.

Question 6Anterior Segment and Cornea

Which of the following best describes the normal corneal refractive power contributed by the anterior surface?

  1. About 20 diopters
  2. About 10 diopters
  3. About 48 diopters Correct answer.
  4. About 60 diopters

Explanation

The anterior corneal surface contributes approximately 48 diopters of refractive power, the largest single refractive component of the eye. The posterior surface contributes a negative power, giving a total corneal power of about 43 diopters.

Question 7Anterior Segment and Cornea

A patient presents with a painful red eye, photophobia, and a hypopyon. Slit lamp reveals a corneal ulcer with feathery margins and satellite lesions. Which organism is most likely?

  1. Herpes simplex virus
  2. Fusarium species Correct answer.
  3. Staphylococcus aureus
  4. Neisseria gonorrhoeae

Explanation

Feathery margins and satellite lesions are classic for filamentous fungal keratitis, with Fusarium being a leading cause, especially after organic trauma. Fungal ulcers progress slowly and may show endothelial plaques and hypopyon.

Question 8Anterior Segment and Cornea

Which clinical finding is most consistent with a diagnosis of Acanthamoeba keratitis?

  1. Nummular anterior stromal scars
  2. Dendritic epithelial ulcer with terminal bulbs
  3. Subepithelial breadcrumb opacities
  4. Ring-shaped stromal infiltrate with severe pain out of proportion to signs Correct answer.

Explanation

Acanthamoeba keratitis often presents with a ring infiltrate and severe pain disproportionate to clinical signs, frequently in contact lens wearers. Perineural involvement can also occur.

Question 9Anterior Segment and Cornea

Which statement about the corneal endothelium is correct?

  1. It has a high mitotic rate throughout life
  2. It is a stratified squamous epithelium
  3. It regenerates readily by mitosis after injury
  4. It cannot regenerate and cell loss is compensated by cell enlargement Correct answer.

Explanation

Human corneal endothelial cells have minimal proliferative capacity in vivo; lost cells are compensated by spreading and migration of remaining cells. This is why endothelial cell density declines with age and after surgery.

Question 10Anterior Segment and Cornea

In a patient with keratoconus, which corneal imaging finding is most characteristic?

  1. Generalized thickening with normal curvature
  2. Central flattening with normal pachymetry
  3. Inferior steepening with a thin thinnest point Correct answer.
  4. Superior steepening with a thick central cornea

Explanation

Keratoconus typically shows inferior steepening on topography and a thinnest point displaced inferiorly on pachymetry. These findings help distinguish it from other ectasias and from normal variation.

Question 11Anterior Segment and Cornea

What is the most appropriate treatment for a corneal abrasion with no retained foreign body and no infection?

  1. Immediate penetrating keratoplasty
  2. Topical anesthetic drops for long-term use
  3. Topical antibiotic ointment with lubrication Correct answer.
  4. Topical steroid and cycloplegic

Explanation

Simple corneal abrasions are managed with lubrication, topical antibiotic prophylaxis, and analgesia; most heal within days. Topical anesthetics are avoided for prolonged use due to corneal toxicity.

Question 12Anterior Segment and Cornea

Which of the following is a recognized risk factor for the development of a corneal ulcer in a contact lens wearer?

  1. Overnight wear of hydrogel lenses Correct answer.
  2. Use of daily disposable lenses
  3. Regular replacement schedules
  4. Daily wear with proper disinfection

Explanation

Extended or overnight wear substantially increases the risk of microbial keratitis because of corneal hypoxia and epithelial compromise. Daily wear with proper hygiene and regular replacement reduces risk.

Question 13Anterior Segment and Cornea

A patient with long-standing rheumatoid arthritis develops a painful peripheral corneal thinning with an overhanging edge. What is the most likely diagnosis?

  1. Peripheral ulcerative keratitis associated with systemic disease Correct answer.
  2. Terrien marginal degeneration
  3. Pellucid marginal degeneration
  4. Mooren ulcer

Explanation

Peripheral ulcerative keratitis is often immune-mediated and associated with systemic diseases such as rheumatoid arthritis. It presents with painful peripheral thinning and can progress to perforation.

Question 14Anterior Segment and Cornea

Which corneal finding is most characteristic of Fuchs endothelial dystrophy?

  1. Inferior conical protrusion
  2. Subepithelial map-dot-fingerprint changes
  3. Branching refractile stromal lines
  4. Central guttae and stromal edema Correct answer.

Explanation

Fuchs endothelial dystrophy is characterized by central corneal guttae (excrescences of Descemet membrane) and progressive stromal edema as endothelial function fails. It is bilateral and often asymmetric.

Question 15Anterior Segment and Cornea

A patient with a history of ocular surface disease has a corneal epithelium that stains with rose bengal but not fluorescein. What does this pattern most suggest?

  1. Healthy epithelium with intact mucin layer
  2. Corneal perforation
  3. Active herpetic dendritic ulcer
  4. Devitalized or unprotected epithelial cells Correct answer.

Explanation

Rose bengal stains devitalized epithelial cells and areas lacking a protective mucin layer, whereas fluorescein stains areas of epithelial loss. This pattern suggests ocular surface disease with compromised mucin.

Question 16Anterior Segment and Cornea

Which of the following is the most appropriate initial therapy for a patient with severe dry eye and punctate epithelial erosions?

  1. Topical antiviral ointment
  2. Preservative-free artificial tears and punctal plugs Correct answer.
  3. Systemic corticosteroids
  4. Topical antibiotic drops

Explanation

Management of dry eye begins with lubrication, preferably preservative-free, and punctal occlusion to increase tear residence time. Anti-inflammatory therapy is added for more severe disease.

Question 17Anterior Segment and Cornea

A patient presents with a corneal foreign body after grinding metal. What is the most important next step after removing the foreign body?

  1. Schedule penetrating keratoplasty
  2. Check for a rust ring and remove it if present Correct answer.
  3. Prescribe topical steroid for 1 month
  4. Apply a tight pressure patch for 1 week

Explanation

Metallic foreign bodies often leave a rust ring that should be removed to reduce inflammation and scarring. Removal is followed by topical antibiotic prophylaxis and appropriate follow-up.

Question 18Anterior Segment and Cornea

Which of the following best describes the role of Bowman layer in the cornea?

  1. It contains the endothelial pump cells
  2. It actively pumps fluid from the stroma
  3. It provides the main refractive power of the cornea
  4. It is an acellular condensation of collagen that helps maintain corneal shape Correct answer.

Explanation

Bowman layer is an acellular condensation of collagen beneath the epithelium that contributes to corneal structural integrity and shape. It does not regenerate after injury and scarring can cause irregular astigmatism.

Question 19Anterior Segment and Cornea

A patient with keratoconus is being fitted with contact lenses. Which lens type is most commonly used to improve vision in mild to moderate disease?

  1. Piggyback soft lens alone
  2. Rigid gas-permeable corneal lens Correct answer.
  3. Soft toric lens
  4. Scleral lens as first-line

Explanation

Rigid gas-permeable lenses create a tear lens that neutralizes irregular corneal astigmatism and are first-line for mild to moderate keratoconus. Scleral lenses are reserved for more advanced or intolerant cases.

Question 20Anterior Segment and Cornea

Which of the following is a contraindication to performing a corneal transplant using donor tissue with positive serology for hepatitis B surface antigen?

  1. The tissue should never be used
  2. Only use with systemic antiviral prophylaxis
  3. Only use if the recipient is immune
  4. No contraindication exists for corneal tissue Correct answer.

Explanation

Corneal tissue is avascular and the risk of transmitting hepatitis B via corneal transplantation is considered negligible, so HBsAg-positive donors are generally acceptable. Eye banks apply specific screening criteria but do not universally exclude such tissue.

Question 21Anterior Segment and Cornea

A patient develops a dense central corneal scar after a chemical burn. Which factor most strongly predicts poor visual outcome?

  1. Mild superficial punctate keratitis
  2. Limbal stem cell deficiency with conjunctivalization Correct answer.
  3. Transient corneal edema
  4. Small peripheral scar

Explanation

Limbal stem cell deficiency after chemical injury leads to conjunctivalization, persistent epithelial defects, and corneal opacity, strongly predicting poor visual prognosis. Preserving or restoring limbal stem cells is critical.

Question 22Anterior Segment and Cornea

Which of the following statements about the corneal wound healing response after photorefractive keratectomy is correct?

  1. Haze is unrelated to epithelial debridement
  2. Haze is caused by endothelial cell loss
  3. Haze is prevented by early steroid discontinuation
  4. Subepithelial haze results from myofibroblast activity and stromal remodeling Correct answer.

Explanation

PRK haze arises from epithelial-stromal interactions, including myofibroblast transformation and new collagen deposition in the anterior stroma. Topical corticosteroids are used to modulate this response.

Question 23Anterior Segment and Cornea

A patient presents with a corneal perforation after a severe bacterial ulcer. Which of the following is the most appropriate immediate management?

  1. Observation with no intervention
  2. Topical steroid intensification
  3. Immediate penetrating keratoplasty in all cases
  4. Cyanoacrylate tissue adhesive with bandage contact lens and antibiotics Correct answer.

Explanation

Small to moderate perforations can be managed acutely with cyanoacrylate glue, a bandage contact lens, and intensive antimicrobial therapy to stabilize the eye. Urgent tectonic keratoplasty is reserved for larger perforations or glue failure.

Question 24Anterior Segment and Cornea

Which of the following best explains why the cornea remains transparent despite being composed largely of collagen?

  1. Continuous epithelial turnover
  2. High lipid content
  3. Presence of melanin in keratocytes
  4. Uniform collagen fibril diameter and regular lattice spacing Correct answer.

Explanation

Corneal transparency depends on the uniform diameter and regular spacing of collagen fibrils, which minimizes light scatter (the lattice theory). Disruption of this order, as in scarring or edema, causes opacity.

Question 25Anterior Segment and Cornea

A patient with a known history of herpes simplex keratitis presents with a central corneal ulcer and stromal thinning after using topical corticosteroids prescribed elsewhere. What is the most likely explanation?

  1. Acanthamoeba infection
  2. Steroid-induced exacerbation of HSV with stromal melting Correct answer.
  3. Fungal superinfection from steroids
  4. Contact lens overwear

Explanation

Topical corticosteroids without antiviral coverage can reactivate HSV and promote stromal necrosis and melting. This is a well-recognized complication requiring antiviral therapy and careful steroid tapering.

Question 26Anterior Segment and Cornea

Which layer of the cornea is the thickest?

  1. Stroma Correct answer.
  2. Descemet membrane
  3. Epithelium
  4. Bowman layer

Explanation

The corneal stroma constitutes approximately 90% of the corneal thickness, making it the thickest layer. It is composed of regularly arranged collagen lamellae and keratocytes.

Question 27Anterior Segment and Cornea

A 45-year-old man presents with a painful red left eye after being poked in the eye with a tree branch. Slit-lamp examination reveals a 2-mm corneal epithelial defect with a positive Seidel test. What is the most appropriate immediate management?

  1. Prescribe topical antibiotics and patching
  2. Apply a bandage contact lens and topical antibiotics
  3. Refer for urgent surgical repair of the corneal laceration Correct answer.
  4. Place a cyanoacrylate tissue adhesive and consider a bandage contact lens

Explanation

A positive Seidel test indicates a full-thickness corneal laceration with aqueous leakage, which requires urgent surgical repair to restore globe integrity and prevent infection. Tissue adhesive or bandage contact lens may be temporizing measures for small perforations but are not definitive for a laceration.

Question 28Anterior Segment and Cornea

Which of the following is the most common cause of infectious keratitis associated with contact lens wear?

  1. Herpes simplex virus
  2. Pseudomonas aeruginosa Correct answer.
  3. Staphylococcus aureus
  4. Fusarium species

Explanation

Pseudomonas aeruginosa is the most frequent pathogen in contact lens-related microbial keratitis, particularly with soft lens wear. It thrives in moist environments and can adhere to lens surfaces.

Question 29Anterior Segment and Cornea

A 30-year-old woman presents with a 3-day history of a red, painful right eye. Slit-lamp examination shows a dendritic corneal ulcer with terminal bulbs. What is the most appropriate initial treatment?

  1. Topical antibiotics
  2. Topical corticosteroids
  3. Topical antivirals Correct answer.
  4. Topical antifungal agents

Explanation

The dendritic ulcer with terminal bulbs is characteristic of herpes simplex keratitis. Topical antivirals such as ganciclovir gel or trifluridine are the first-line therapy for epithelial HSV keratitis.

Question 30Anterior Segment and Cornea

A 65-year-old man with a history of trachoma presents with trichiasis and conjunctival scarring. Which of the following best describes the underlying mechanism of corneal damage in trachoma?

  1. Immune-mediated stromal melting triggered by chlamydial antigens
  2. Direct invasion of corneal epithelium by Chlamydia trachomatis
  3. Repeated mechanical trauma from inturned eyelashes and secondary infection Correct answer.
  4. Ischemic damage from conjunctival scarring and reduced limbal blood flow

Explanation

In trachoma, repeated conjunctival inflammation leads to scarring and trichiasis, causing mechanical abrasion of the cornea. This trauma, along with secondary bacterial infection, results in corneal opacification and ulceration.

Question 31Cataract and Refractive Surgery

Which structure is removed during capsulorhexis in phacoemulsification?

  1. The central portion of the anterior lens capsule Correct answer.
  2. The central portion of the iris
  3. The entire posterior lens capsule
  4. The zonular fibers

Explanation

Capsulorhexis is a continuous circular tear that removes a central disc of the anterior lens capsule, creating a stable opening for phacoemulsification and lens implantation. The posterior capsule is preserved to support the intraocular lens and separate anterior from posterior segments.

Question 32Cataract and Refractive Surgery

A patient reports glare and halos around lights at night after cataract surgery with a multifocal intraocular lens. Which optical property of multifocal lenses most directly explains these symptoms?

  1. Thickening of the posterior lens capsule
  2. Simultaneous projection of multiple focal points onto the retina Correct answer.
  3. Increased axial length of the eye
  4. Reduced corneal endothelial cell density

Explanation

Multifocal lenses split incoming light into several foci, so out-of-focus images overlap with the in-focus image and produce halos and glare, especially with large pupils at night. The other listed changes are unrelated to the optical design of the implant.

Question 33Cataract and Refractive Surgery

Which biometric measurement is most important for calculating intraocular lens power in a highly myopic eye?

  1. Central corneal thickness
  2. Axial length Correct answer.
  3. Anterior chamber angle
  4. Pupil diameter

Explanation

IOL power calculation depends primarily on axial length, which dominates the refractive outcome, particularly in extremes such as high myopia. Corneal power also matters, but the listed alternatives are not primary determinants of implant power.

Question 34Cataract and Refractive Surgery

During phacoemulsification, the surgeon notices the anterior chamber shallowing and the pupil constricting after a sudden loss of red reflex. What is the most likely event?

  1. Retinal detachment
  2. Acute angle-closure glaucoma
  3. Corneal epithelial abrasion
  4. Posterior capsule rupture with vitreous presentation Correct answer.

Explanation

Sudden shallowing, pupil constriction, and loss of red reflex during phacoemulsification are classic signs of posterior capsule rupture with vitreous prolapse. Immediate recognition allows the surgeon to change technique and avoid further vitreous loss.

Question 35Cataract and Refractive Surgery

Which refractive error is corrected by a toric intraocular lens?

  1. Presbyopia
  2. Amblyopia
  3. Regular corneal astigmatism Correct answer.
  4. High myopia without astigmatism

Explanation

Toric IOLs incorporate cylindrical power to neutralize regular corneal astigmatism at the time of cataract surgery. They do not address presbyopia, spherical myopia alone, or amblyopia.

Question 36Cataract and Refractive Surgery

A patient with a history of radial keratotomy is being planned for cataract surgery. Which issue most complicates IOL power calculation?

  1. Chronic anterior uveitis
  2. Unpredictable corneal power from prior incisions Correct answer.
  3. Loss of the red reflex
  4. Reduced axial length measurement accuracy

Explanation

Prior refractive incisions alter corneal shape and make keratometry unstable and unreliable, so standard formulas may misestimate effective corneal power. This is the dominant challenge in post-refractive eyes.

Question 37Cataract and Refractive Surgery

Which finding on slit-lamp examination is most characteristic of posterior capsule opacification?

  1. A ring of pigment on the anterior capsule
  2. Corneal stromal edema
  3. Folds in Descemet membrane
  4. A pearly white opacification behind the intraocular lens Correct answer.

Explanation

Posterior capsule opacification appears as a whitish, fibrotic or pearl-like proliferation on the posterior capsule behind the implant. It is treated with Nd:YAG laser capsulotomy when visually significant.

Question 38Cataract and Refractive Surgery

Which laser is used to treat visually significant posterior capsule opacification?

  1. Nd:YAG laser Correct answer.
  2. Argon laser
  3. Excimer laser
  4. Selective laser trabeculoplasty

Explanation

Nd:YAG laser capsulotomy creates an opening in the opacified posterior capsule by photodisruption. The other lasers serve different ophthalmic purposes such as retinal photocoagulation, corneal surface ablation, or trabecular treatment.

Question 39Cataract and Refractive Surgery

Which factor most increases the risk of suprachoroidal hemorrhage during cataract surgery?

  1. Small incision size
  2. Preoperative pupil dilation
  3. Sudden intraoperative hypotony in an elderly hypertensive patient Correct answer.
  4. Use of topical anesthesia

Explanation

Suprachoroidal hemorrhage is driven by rupture of choroidal vessels when intraocular pressure drops abruptly, especially in older patients with vascular disease. Maintaining intraocular pressure and controlling systemic risk factors reduce the risk.

Question 40Cataract and Refractive Surgery

Which endothelial condition most strongly predisposes to corneal decompensation after cataract surgery?

  1. Keratoconus
  2. Anterior basement membrane dystrophy
  3. Fuchs endothelial corneal dystrophy Correct answer.
  4. Pinguecula

Explanation

Fuchs dystrophy reduces endothelial reserve, so the stress of surgery can precipitate persistent corneal edema and decompensation. Preoperative assessment of endothelial health guides surgical planning.

Question 41Cataract and Refractive Surgery

What is the primary goal of femtosecond laser-assisted cataract surgery compared with conventional phacoemulsification?

  1. Eliminating the need for intraocular lens implantation
  2. Automating capsulotomy and lens fragmentation with greater precision Correct answer.
  3. Preventing all posterior capsule opacification
  4. Replacing the need for corneal incisions

Explanation

Femtosecond lasers automate anterior capsulotomy, lens fragmentation, and some incisions with high geometric precision. They do not remove the need for an implant, eliminate opacification, or avoid incisions entirely.

Question 42Cataract and Refractive Surgery

A patient desires freedom from glasses for both distance and near vision after cataract surgery and has healthy eyes with regular astigmatism. Which implant design best matches this goal?

  1. Toric monofocal intraocular lens
  2. Anterior chamber phakic intraocular lens
  3. Monofocal spherical intraocular lens
  4. Multifocal or extended-depth-of-focus intraocular lens Correct answer.

Explanation

Multifocal and extended-depth-of-focus designs provide a range of focus to reduce spectacle dependence for distance and near. Monofocal designs correct only one distance, and phakic lenses are not used after cataract extraction.

Question 43Cataract and Refractive Surgery

Which preoperative measurement is essential before implanting a toric intraocular lens?

  1. Intraocular pressure
  2. Corneal astigmatism magnitude and axis Correct answer.
  3. Visual field testing
  4. Tear film breakup time

Explanation

Toric IOL selection and alignment require accurate keratometric astigmatism magnitude and axis, often with corneal topography or tomography. The other tests do not guide cylinder correction.

Question 44Cataract and Refractive Surgery

A patient develops persistent corneal edema two weeks after uncomplicated cataract surgery with a clear incision. Which mechanism is most likely?

  1. Retained lens cortex inducing glaucoma
  2. Excessive capsule opacification
  3. Endothelial cell loss exceeding functional reserve Correct answer.
  4. Wound leak with shallow anterior chamber

Explanation

Persistent edema with an intact wound usually reflects inadequate endothelial pump function after surgical trauma. Assessing endothelial status and ruling out other causes guides management.

Question 45Cataract and Refractive Surgery

Which refractive procedure removes corneal tissue to flatten the central cornea in a myopic eye?

  1. Radial keratotomy
  2. Conductive keratoplasty
  3. Photorefractive keratectomy for hyperopia
  4. Myopic laser in situ keratomileusis Correct answer.

Explanation

Myopic LASIK uses an excimer laser to ablate central corneal tissue, flattening the cornea and reducing myopic refractive error. Radial keratotomy uses incisions, and the other options treat hyperopia or use thermal energy.

Question 46Cataract and Refractive Surgery

Which patient characteristic is a relative contraindication to laser refractive surgery?

  1. Stable myopia for five years
  2. Progressive keratoconus with unstable topography Correct answer.
  3. Age over 21 with stable refraction
  4. Normal corneal thickness

Explanation

Progressive ectasia such as keratoconus is a relative contraindication because surgery can further weaken the cornea and worsen ectasia. Stability of refraction and adequate corneal thickness are favorable features.

Question 47Cataract and Refractive Surgery

What is the main advantage of phakic intraocular lenses for high myopia compared with corneal laser ablation?

  1. Elimination of the need for any follow-up
  2. Preservation of corneal tissue and optical quality in high corrections Correct answer.
  3. Complete reversibility with no surgical risk
  4. Ability to treat concurrent cataract

Explanation

Phakic lenses correct high refractive errors without removing corneal tissue, which can preserve corneal biomechanics and optical quality when ablation would be excessive. They still carry surgical risks and require monitoring.

Question 48Cataract and Refractive Surgery

Which complication is most specifically associated with an anterior chamber intraocular lens?

  1. Posterior capsule opacification
  2. Cystoid macular edema
  3. Zonular dialysis
  4. Corneal endothelial damage Correct answer.

Explanation

Anterior chamber lenses sit close to the corneal endothelium and can cause progressive endothelial cell loss and damage. This proximity is the defining risk of this implant location.

Question 49Cataract and Refractive Surgery

A patient reports a sudden onset of floaters and a curtain over the visual field one month after cataract surgery. Which diagnosis should be considered first?

  1. Posterior capsule opacification
  2. Retinal detachment Correct answer.
  3. Corneal abrasion
  4. Angle-closure glaucoma

Explanation

Photopsia, floaters, and a visual field curtain suggest retinal detachment, a known complication after cataract surgery, especially with posterior capsule rupture. Urgent dilated fundus examination is required.

Question 50Cataract and Refractive Surgery

Which formula parameter most affects IOL power prediction error in eyes with very short axial length?

  1. Tear film osmolarity
  2. Corneal diameter
  3. Pupil size
  4. Effective lens position estimation Correct answer.

Explanation

In short eyes, small errors in predicted effective lens position translate into large refractive errors, so formula choice and lens position estimation are critical. The other parameters are not primary inputs to IOL power calculation.