Leukocoria (white pupillary reflex) in a 2-year-old child should be urgently evaluated. The most common cause of leukocoria in children under 3 years is:

• A Cataract (congenital or developmental) ✓
• B Retinoblastoma
• C Persistent fetal vasculature (PFV)
• D Coats' disease

Explanation

Congenital or developmental cataract is the most common cause of leukocoria overall in children; however, retinoblastoma is the most common intraocular malignant tumor and the most important diagnosis to exclude. When the question specifies the most common cause (not the most dangerous), cataract leads. Retinoblastoma typically presents before age 3 (60% unilateral, 40% bilateral), and in bilateral cases is almost always hereditary with RB1 gene mutation. PFV and Coats' disease are less common. The key clinical principle: ALL leukocoria requires urgent ophthalmic evaluation to exclude retinoblastoma.

Reference: Khurana Comprehensive Ophthalmology, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.