ABO Cataract and Lens 2 — Questions and Answers
Question 1: A 3-week-old infant has a dense, visually significant unilateral cataract. To minimize the risk of irreversible deprivation amblyopia, surgery is ideally performed by approximately what age?
- 1 week
- 4-6 weeks (Correct answer)
- 4-6 months
- 12 months
Correct answer: 4-6 weeks
Dense unilateral congenital cataracts have the best visual outcomes when removed by about 4-6 weeks of age, before the critical period of deprivation amblyopia sets in.
Question 2: Which morphologic type is the most common form of congenital cataract, appearing as an opacified layer surrounding a clear nucleus, often with 'riders'?
- Posterior lenticonus
- Lamellar (zonular) cataract (Correct answer)
- Anterior polar cataract
- Cerulean cataract
Correct answer: Lamellar (zonular) cataract
Lamellar cataract involves a specific lamella surrounding a clear center, frequently with spoke-like 'riders', and is the most common congenital cataract type.
Question 3: A tall 14-year-old with long fingers and an aortic root dilation has bilateral lens subluxation. In which direction is the lens most typically displaced?
- Inferonasal
- Superotemporal (Correct answer)
- Directly posterior into the vitreous
- Inferotemporal
Correct answer: Superotemporal
In Marfan syndrome the lens is classically displaced superotemporally with zonules often stretched but intact.
Question 4: An infant with failure to thrive, jaundice, and hepatomegaly has bilateral central 'oil droplet' lens opacities. Which condition is most likely?
- Congenital rubella
- Galactosemia (Correct answer)
- Lowe syndrome
- Hypocalcemia
Correct answer: Galactosemia
Galactosemia causes galactitol accumulation in the lens producing oil-droplet cataracts that can regress with a galactose-free diet.
Question 5: According to the Infant Aphakia Treatment Study, how did primary IOL implantation compare with contact lens aphakic correction after unilateral cataract surgery in infants 1-6 months old?
- IOL produced significantly better visual acuity at 4.5 years
- Visual acuity was similar, but IOL eyes had more adverse events and reoperations (Correct answer)
- Contact lens eyes had more glaucoma and reoperations
- IOL eyes had less strabismus and better stereopsis
Correct answer: Visual acuity was similar, but IOL eyes had more adverse events and reoperations
IATS found no significant difference in visual acuity at 4.5 years, but the IOL group had more adverse events and additional intraocular surgeries.
Question 6: A 40-year-old with ptosis, frontal balding, and difficulty releasing his grip has polychromatic iridescent crystals in the lens cortex. What is the most likely diagnosis?
- Myotonic dystrophy (Correct answer)
- Wilson disease
- Fabry disease
- Neurofibromatosis type 2
Correct answer: Myotonic dystrophy
Polychromatic 'Christmas tree' cataracts are characteristic of myotonic dystrophy, which also causes myotonia, ptosis, and frontal balding.
Question 7: A young patient with liver disease and neuropsychiatric symptoms has a central anterior subcapsular lens opacity with petal-like radiations. What does this finding represent?
- Glassblower's cataract
- Sunflower cataract from copper deposition (Correct answer)
- Siderosis lentis from retained iron
- Vossius ring
Correct answer: Sunflower cataract from copper deposition
Sunflower cataract results from copper deposition in the anterior capsule in Wilson disease and is also seen with intraocular copper foreign bodies (chalcosis).
ABO Cataract and Lens 2
A 3-week-old infant has a dense, visually significant unilateral cataract.
To minimize the risk of irreversible deprivation amblyopia, surgery is ideally performed by approximately what age?