Which feature is absent in mature cataracts?

Which feature is absent in mature cataracts?

• A. Capsular wrinkling
• B. Tapetal reflection absent (correct)
• C. Protein aggregates
• D. Tapetal reflection still visible

Answer: (B)

The question hinges on how lens opacity from a mature cataract affects the eye’s reflective signals. A tapetal reflection (the bright glow you see when shining light into the eye in animals with a tapetum) comes from light that passes through the cornea and lens to reach the retina and then reflects back. If the lens is fully opaque, as in a mature cataract, light cannot reach the retina and cannot be reflected back. Therefore the tapetal reflection is absent in a mature cataract. Capsular wrinkling is more characteristic of hypermature stages when the capsule shrinks; protein aggregates are a feature of the cataract itself; and the tapetal reflection still being visible would contradict the complete opacity of a mature cataract.

The question hinges on how lens opacity from a mature cataract affects the eye’s reflective signals. A tapetal reflection (the bright glow you see when shining light into the eye in animals with a tapetum) comes from light that passes through the cornea and lens to reach the retina and then reflects back. If the lens is fully opaque, as in a mature cataract, light cannot reach the retina and cannot be reflected back. Therefore the tapetal reflection is absent in a mature cataract.

Capsular wrinkling is more characteristic of hypermature stages when the capsule shrinks; protein aggregates are a feature of the cataract itself; and the tapetal reflection still being visible would contradict the complete opacity of a mature cataract.