Question

The 68-year-old female patient has had a diabetic cataract for 3 months. Accumulation of which of the following substances is responsible for this?

• A. Glucose
• B. Fructose
• C. Lactose + Glucose
• D. Sorbitol + Fructose

Hint:

In diabetes, sorbitol accumulation is particularly problematic because it leads to osmotic swelling and lens damage, contributing to cataract formation.

Answer 1

The Correct Option is D

Diabetic cataract is a common complication of diabetes mellitus, where changes in the lens of the eye lead to cloudiness and vision impairment. The primary cause of cataract formation in diabetics is the accumulation of sorbitol in the lens.
Sorbitol is formed from glucose through the action of the enzyme aldose reductase. In a hyperglycemic state, as is often seen in diabetes, glucose levels are high, leading to the increased conversion of glucose to sorbitol. Sorbitol accumulates in tissues such as the lens, where it cannot easily be converted back to fructose due to the limited activity of sorbitol dehydrogenase in the lens.
Additionally, fructose can also accumulate as a result of the sorbitol pathway, leading to osmotic stress and lens opacification, which contributes to cataract formation. Thus, the correct answer is Sorbitol + Fructose, as the accumulation of these substances in the lens contributes to the development of diabetic cataracts.