Not true regarding rubella cataract:
**Core Concept**
Rubella cataract is a congenital cataract that occurs due to intrauterine infection with the rubella virus. It is a result of the virus's effect on the developing lens in the fetus, leading to a characteristic cataract formation.
**Why the Correct Answer is Right**
Rubella cataract is typically associated with a "chicken wire" or "snowflake" appearance on ophthalmological examination. This unique appearance is due to the virus's disruption of lens fiber formation and organization during fetal development. The mechanism involves the virus's interference with the normal lens cell growth and differentiation, resulting in the characteristic cataract morphology.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is often incorrect because rubella cataract is not typically associated with a "sunflower" cataract appearance, which is more commonly seen in galactosemia.
**Option B:** This option is often incorrect because congenital rubella syndrome does not typically present with a "snowflake" cataract appearance in both eyes, although it may occur in one eye.
**Clinical Pearl / High-Yield Fact**
Rubella cataract is a classic example of a congenital cataract that can be prevented through vaccination against rubella. Mothers who are rubella immune before conception are at lower risk of transmitting the virus to their fetus.
**Correct Answer: C.**