**Question:** Ramnath attends the ophthalmology outpatient clinic in Kanpur, with yellowish white patch on the bulbar conjunctiva, near limbus. Which of the following is false regarding this condition?

A. This condition is not related to the cornea or sclera
B. The condition is always present at birth
C. The condition is caused by a deficiency of vitamin A
D. The condition is caused by a defect in the corneal epithelium

**Correct Answer:** B. **The condition is always present at birth**.

**Core Concept:** The yellowish white patch on the bulbar conjunctiva, known as Leber's congenital amaurosis, is a group of inherited retinal dystrophies characterized by the involvement of both the retina and the cornea.

**Why the Correct Answer is Right:** Leber's congenital amaurosis is typically diagnosed early in life due to its severe visual impairment. This condition is not present at birth but appears during the first year of life, indicating that the symptoms develop after the critical period of retinal development.

**Why Each Wrong Option is Incorrect:**

A. **This condition is not related to the cornea or sclera:** Leber's congenital amaurosis is a retinal dystrophy, not affecting the cornea or sclera. The yellowish white patch is found on the bulbar conjunctiva, near the limbus, indicating the involvement of the retina.

B. **The condition is always present at birth:** As explained above, Leber's congenital amaurosis appears during the first year of life, contradicting this statement.

C. **The condition is caused by a deficiency of vitamin A:** Leber's congenital amaurosis is a genetic disorder, not caused by a deficiency of vitamin A. The condition results from mutations in several genes associated with retinal function, such as RPE65 gene mutations.

D. **The condition is caused by a defect in the corneal epithelium:** Leber's congenital amaurosis affects the retina, not the corneal epithelium. The condition is caused by genetic mutations affecting retinal function.

**Clinical Pearl:**

Leber's congenital amaurosis is a rare disorder affecting retinal development and function. Early diagnosis and intervention can help preserve vision and improve the quality of life for affected individuals and their families. It is essential for healthcare professionals to differentiate between this condition and other corneal dystrophies or neonatal vision problems, which might have different etiologies and treatment options.