Question

Leucoria is seen in all of the following EXCEPT

• A. Retinoblastoma
• B. Congenital glaucoma
• C. Persistent hyperplastic primary vitreous
• D. Fungal endophthalmitis

Hint:

Leucoria is a white mass or membrane behind the lens; congenital glaucoma instead clouds the cornea itself.

Answer 1

The Correct Option is B

Step 1: Recall what leucoria means.
Leucoria is a white reflex seen in the pupil instead of the normal red reflex. It happens when something white or opaque sits behind the lens, such as a tumour, a fibrous membrane, an exudate or a detached retina, and reflects light back as white.

Step 2: Check retinoblastoma.
Retinoblastoma is the classic and most dangerous cause of leucoria in a child, sometimes called cat's eye reflex. The white tumour mass behind the lens reflects light white. So this does cause leucoria.

Step 3: Check persistent hyperplastic primary vitreous (PHPV).
PHPV is a failure of the fetal hyaloid vascular system to regress, leaving a fibrovascular membrane behind the lens. This white membrane also produces leucoria, usually in a small eye (microphthalmos). So this does cause leucoria.

Step 4: Check fungal endophthalmitis.
Fungal endophthalmitis fills the vitreous cavity with white inflammatory exudate, which also shows up as a white pupillary reflex. So this does cause leucoria too.

Step 5: Check congenital glaucoma.
Congenital glaucoma raises pressure inside the eye and causes corneal edema, an enlarged hazy cornea (buphthalmos), watering and light sensitivity. The clouding is in the cornea itself, not a white mass behind the lens, so it does not produce a true leucoria (white pupillary reflex). This is the odd one out.

Step 6: Final answer.
Congenital glaucoma is not a cause of leucoria.
\[ \boxed{\text{Congenital glaucoma}} \]