Clinical Presentation: The Classic Triad

The three cardinal signs of congenital glaucoma are:

Epiphora (Watering)

Excessive tearing that may be mistaken for blocked tear ducts. IOP elevation irritates the cornea, triggering excessive tear production.

Photophobia (Light Sensitivity)

Avoidance of light, keeping eyes closed in bright environments. Again, corneal irritation from elevated pressure is the cause.

Blepharospasm (Eye Blinking/Closure)

Frequent blinking, spasm of the eyelid muscles, or constant eye closure. Often parents report the child appears uncomfortable or in pain.

Additional findings include: corneal diameter greater than 11 mm in a newborn or 12 mm in a child under 1 year (normal is 9–10 mm); corneal clouding from oedema (diffuse haze); Haab’s striae (horizontal breaks in Descemet’s membrane appearing as horizontal lines); and buphthalmos (visible globe enlargement).

Diagnosis: Examination Under Anaesthesia (EUA)

In an infant, accurate IOP measurement and comprehensive eye examination require general anaesthesia. During EUA, ophthalmologists measure IOP using Tonopen or rebound tonometry (non-contact pneumotonometry is unreliable in this age group), assess corneal clarity and diameter, examine the optic disc for cupping and pallor, and perform gonioscopy to visualise the trabecular meshwork dysgenesis.

Genetic Basis

The CYP1B1 gene (cytochrome P450 family 1 subfamily B member 1) is responsible for approximately 75% of familial congenital glaucoma cases and 40% of sporadic cases, with autosomal recessive inheritance. Other genes implicated include LTBP2, FOXC1, and PITX2. Genetic counselling and testing are appropriate for familial cases, and all siblings require screening.

Surgical Treatment

Surgery is the definitive treatment for congenital glaucoma. Medical therapy (IOP-lowering drops) is used temporarily to lower IOP before surgery and may manage select mild cases, but long-term control requires surgical intervention.

Goniotomy

The procedure of choice when the cornea is clear enough to visualize the angle. A goniolens is used, and a surgical blade (Goniakntome or fine surgical knife) incises the trabecular meshwork under direct visualisation. Success rate approximately 50% as first procedure; if unsuccessful, repeat goniotomy or trabeculotomy performed.

Trabeculotomy

Performed when cornea is cloudy (precluding gonioscopy). A probe is passed beneath the trabecular meshwork (either through an external approach or internally through Schlemm’s canal), then rotated to open the meshwork. Can be performed externally (trabeculotomy ab externo) or internally (gonioscopy-assisted transluminal trabeculotomy, GATT). Success rate approximately 65% for primary trabeculotomy.

Combined/Staged Surgery

Many infants require more than one procedure. If goniotomy fails, trabeculotomy performed as second stage. If both fail, trabeculectomy with mitomycin C (MMC) or Ahmed glaucoma valve insertion considered, though these have higher complication rates in infants.

Long-Term Visual Outcomes

With early diagnosis (within weeks) and surgical intervention, over 80% of children with primary congenital glaucoma achieve useful vision and eye survival. Amblyopia (lazy eye) is a critical concern — even with perfect IOP control, refractive error, corneal scarring, or the patching required for surgery can cause deprivation amblyopia if not managed aggressively with refraction, glasses, and visual rehabilitation. Lifelong glaucoma monitoring is required, as IOP can rise again in adolescence and adulthood.