Board Certified Ophthalmologist Lens and Cataract Questions and Answers — Questions and Answers
Question 1: A 58-year-old patient with a history of severe rheumatoid arthritis, managed for over a decade with oral prednisone, presents with a chief complaint of disabling glare when driving at night and difficulty reading, which has worsened over the last year. Visual acuity is 20/50 in the right eye and 20/40 in the left. Slit-lamp examination is most likely to reveal which type of cataract?
- Nuclear sclerotic
- Cortical spoking
- Posterior subcapsular (Correct answer)
- Traumatic rosette
Correct answer: Posterior subcapsular
Long-term systemic corticosteroid use is a well-established and significant risk factor for the development of posterior subcapsular cataracts (PSC). The symptoms of glare and difficulty with near vision are classic for PSCs because the opacity is located at the nodal point of the eye's optical system.
Question 2: An 82-year-old man presents with a dense, white, mature cataract in his left eye, reducing vision to hand motion. The posterior segment cannot be visualized. Which of the following is the most critical ancillary test to perform to assess for co-existing posterior segment pathology before proceeding with cataract surgery?
- Corneal topography
- B-scan ultrasonography (Correct answer)
- Specular microscopy
- Macular OCT
Correct answer: B-scan ultrasonography
When a cataract is so dense that it prevents visualization of the retina and optic nerve, B-scan ultrasonography is essential. It allows the surgeon to rule out significant posterior segment pathologies such as retinal detachment, large tumors, or dense vitreous hemorrhage, which would dramatically alter the surgical plan and visual prognosis.
Question 3: The remarkable transparency and high refractive index of the human crystalline lens are primarily maintained by a high concentration of which family of water-soluble structural proteins?
- Collagens
- Albumins
- Globulins
- Crystallins (Correct answer)
Correct answer: Crystallins
The crystalline lens is composed of approximately 60% protein, and 90% of these water-soluble proteins are crystallins (alpha, beta, and gamma). These proteins are arranged in a highly ordered, short-range structure that minimizes light scatter, thereby ensuring lens transparency.
Question 4: A patient is evaluated on postoperative day 1 after uneventful phacoemulsification. They report minimal pain but significant blurriness. Examination reveals 20/200 vision, diffuse limbus-to-limbus corneal edema, and a deep, quiet anterior chamber with 1+ cell and no fibrin or hypopyon. What is the most likely diagnosis?
- Infectious endophthalmitis
- Toxic Anterior Segment Syndrome (TASS) (Correct answer)
- Retained cortical fragment
- UGH (Uveitis-Glaucoma-Hyphema) Syndrome
Correct answer: Toxic Anterior Segment Syndrome (TASS)
Toxic Anterior Segment Syndrome (TASS) is a sterile inflammatory reaction that typically presents within 12-24 hours of surgery. The hallmark signs are diffuse, limbus-to-limbus corneal edema and a significant anterior chamber reaction that is out of proportion to any pain and lacks the classic signs of infection like a hypopyon or significant vitritis. Infectious endophthalmitis usually presents later (3-7 days), with more severe pain, and often involves the vitreous.
Question 5: Which of the following is the LEAST established independent risk factor for the development of age-related cataracts?
- Systemic hypertension (Correct answer)
- Diabetes mellitus
- Chronic ultraviolet light exposure
- Myopia
Correct answer: Systemic hypertension
While diabetes, chronic UV exposure, and myopia are all well-established independent risk factors for cataract formation, the association with systemic hypertension is less direct and not as strongly supported as an independent risk factor in many large-scale studies. Often, its association is confounded by other co-existing conditions like diabetes.
Question 6: A pediatrician refers a 2-month-old infant for evaluation of bilateral leukocoria. Examination under anesthesia confirms the presence of bilateral, dense, visually significant cataracts. Based on morphology, which type of congenital cataract is most commonly associated with the need for early surgical intervention?
- Sutural
- Lamellar (zonular) (Correct answer)
- Anterior polar
- Cerulean (blue-dot)
Correct answer: Lamellar (zonular)
While many morphologies exist, lamellar (or zonular) cataracts, which affect a specific layer of lens fibers surrounding the fetal nucleus, are a common form of visually significant congenital cataract that often requires early surgical removal to prevent amblyopia. Sutural and cerulean cataracts are often not visually significant, and small anterior polar cataracts may also be observed without intervention.
