A 2-month-old infant was brought by this mother's complaints of inability to open the eyes in light and excessive watering. The clinical picture is given below. What is the most probable diagnosis? La d

Correct Answer: A. Congenital glaucoma

Congenital glaucoma (primary congenital glaucoma, PCG) presents classically in infants aged 0–3 months with the triad of photophobia, epiphora (excessive tearing), and blepharospasm—exactly as described in this 2-month-old. The condition results from maldevelopment of the trabecular meshwork and Schlemm's canal, leading to elevated intraocular pressure (IOP) from birth or early infancy. The photophobia and inability to open eyes in light occur due to corneal irritation from raised IOP and secondary corneal edema. Epiphora is a reflex response to corneal irritation. The clinical picture likely shows the characteristic signs: buphthalmos (enlargement of the globe due to elasticity of infant eyes), Haab's striae (horizontal lines on Descemet's membrane from stretching), and a hazy/cloudy cornea from edema. PCG is the most common cause of blindness in children in India and requires urgent gonioscopy and IOP measurement (normal infant IOP ~10–12 mmHg; PCG typically shows IOP >21 mmHg). Early diagnosis and treatment (topical agents, laser gonioplasty, or surgery) are critical to prevent permanent vision loss. The age of presentation (2 months) and symptom triad are pathognomonic for PCG.

Why the other options are wrong

B. Ophthalmia neonatorum — Ophthalmia neonatorum (neonatal conjunctivitis) presents with purulent discharge, conjunctival injection, and eyelid edema, typically appearing within 1–2 weeks of birth. It does not cause photophobia or the classic triad of PCG. The absence of discharge and the specific presentation of inability to open eyes in light (not from discharge but from corneal irritation) rules this out. Additionally, ophthalmia neonatorum is a conjunctival infection, not a glaucoma. C. Mucopolysaccharidosis — Mucopolysaccharidosis (MPS) causes corneal clouding and cataracts, but these develop gradually over months to years, not acutely in a 2-month-old. MPS does not present with the acute triad of photophobia, epiphora, and blepharospasm. While corneal involvement occurs in MPS, it is due to glycosaminoglycan deposition, not raised IOP. The acute presentation and specific symptom triad are inconsistent with MPS. D. Cataract — Congenital cataracts cause visual impairment and may present with leukocoria (white pupil), but they do not cause photophobia or epiphora as primary symptoms. Cataracts do not elevate IOP and do not produce the acute distress and inability to open eyes in light characteristic of PCG. The clinical picture in PCG (buphthalmos, corneal haze, Haab's striae) is distinct from cataract presentation.

High-Yield Facts

Mnemonics

**PEB for Congenital Glaucoma Triad Photophobia, Epiphora, Blepharospasm — the classic triad of primary congenital glaucoma in infants 0–3 months old. BIG HAAB for PCG Signs Buphthalmos, Increased IOP, Gonial abnormality; Haab's striae, Acute presentation, Age <3 months, B**lurred cornea (edema).

NBE Trap

NBE pairs photophobia with infectious causes (ophthalmia neonatorum) to trap students who confuse reflex photophobia from corneal irritation (due to raised IOP) with photophobia from conjunctival inflammation. The key discriminator is the absence of discharge and the acute triad in a 2-month-old, which points to PCG, not infection.

Clinical Pearl

In Indian pediatric practice, any infant presenting with the triad of photophobia, epiphora, and blepharospasm should be treated as a glaucoma emergency until proven otherwise. Delayed diagnosis of PCG is a leading cause of preventable blindness in Indian children; urgent referral to a pediatric ophthalmologist for IOP measurement and gonioscopy is lifesaving.

_Reference: Bailey & Love Ch. 35 (Ophthalmology); Robbins Ch. 29 (Eye pathology); Harrison Ch. 229 (Glaucoma)_