Residency · Residency · Ophthalmology

Pediatric Glaucoma: Primary Congenital and Juvenile Forms

Introduction

Pediatric glaucoma encompasses a spectrum of conditions characterized by elevated intraocular pressure (IOP) and optic nerve damage in children. Unlike adult glaucoma, the elastic pediatric eye responds to elevated IOP with globe enlargement (buphthalmos), corneal changes, and rapid optic nerve cupping that may be reversible with IOP reduction.

Classification

Primary Pediatric Glaucoma

Primary congenital glaucoma (PCG) -- onset birth to 3 years; isolated trabeculodysgenesis. Juvenile open-angle glaucoma (JOAG) -- onset 4-35 years; resembles adult POAG.

Secondary Pediatric Glaucoma

Associated with ocular anomalies: aniridia, Axenfeld-Rieger syndrome, Peters anomaly, Sturge-Weber syndrome. Associated with systemic disease: neurofibromatosis, Lowe syndrome, homocystinuria. Acquired: aphakic/pseudophakic glaucoma (after congenital cataract surgery), steroid-induced, traumatic, uveitic.

Primary Congenital Glaucoma

Epidemiology and Genetics

Incidence: 1 in 10,000-20,000 births (higher in consanguineous populations) Autosomal recessive inheritance. CYP1B1 gene mutations -- most common cause; chromosome 2p22. LTBP2 gene mutations -- second identified gene. Male predominance (65%); bilateral in 70%.

Pathophysiology

Trabeculodysgenesis -- developmental abnormality of the trabecular meshwork and anterior chamber angle. Barkan membrane theory: imperforate membrane over trabecular meshwork (historically proposed but debated) Elevated IOP causes globe expansion (buphthalmos) due to scleral elasticity in infants.

Clinical Features

Classic triad: epiphora, photophobia, blepharospasm. Corneal edema and enlargement -- horizontal corneal diameter >11 mm at birth or >12 mm before age 1 year. Haab striae -- horizontal or curvilinear breaks in Descemet membrane (pathognomonic); distinguish from vertical breaks of forceps injury. Buphthalmos -- enlarged globe; irreversible after IOP normalization. Optic nerve cupping -- may reverse with IOP reduction in young children (unlike adults) Elevated IOP (>21 mmHg; measured under anesthesia, noting anesthetic effects)

Examination Under Anesthesia (EUA)

IOP measurement -- Tono-Pen or Perkins tonometry (chloral hydrate/sevoflurane lowers IOP; ketamine may raise it) Corneal diameter -- calipers; horizontal measurement. Gonioscopy -- high iris insertion, flat iris plane, absent angle recess. Optic nerve evaluation -- direct ophthalmoscopy or RetCam. Cycloplegic refraction -- progressive myopia suggests globe expansion. Axial length -- A-scan ultrasonography; asymmetry >1 mm is significant.

Treatment

Primary surgical management -- medical therapy is temporizing only. Goniotomy -- ab interno incision of trabecular meshwork; requires clear cornea; 80-90% success with 1-2 procedures. Trabeculotomy -- ab externo approach; can be performed with hazy cornea; similar success rate. 360-degree trabeculotomy (circumferential) -- Visco360, TRAK, or suture technique; improved single-procedure success. Combined trabeculotomy-trabeculectomy -- for refractory cases. Glaucoma drainage devices (Ahmed, Baerveldt) -- for failed angle surgery.

Cyclodestructive procedures -- diode transscleral cyclophotocoagulation; reserved for refractory cases.

Juvenile Open-Angle Glaucoma

Features

Onset 4-35 years; often presents with advanced disease due to asymptomatic progression. Autosomal dominant inheritance with high penetrance. MYOC (myocilin) gene mutations -- chromosome 1q24; most common identified gene. No buphthalmos (sclera no longer elastic) Often very high IOP (>30 mmHg) Gonioscopically open angle.

Treatment

Medical therapy -- may be effective initially but often insufficient long-term. Surgery -- trabeculectomy with mitomycin C, goniotomy (emerging evidence), glaucoma drainage devices. Higher surgical success rates than adult POAG due to less episcleral scarring.

Secondary Pediatric Glaucoma

Aphakic/Pseudophakic Glaucoma

Occurs in 10-25% of eyes after pediatric cataract surgery. Risk factors: surgery before age 9 months, microphthalmos, PFV. Lifelong risk; may present years after cataract surgery. Treatment: medical therapy, goniotomy, drainage devices.

Sturge-Weber Syndrome

Choroidal hemangioma increases episcleral venous pressure. Ipsilateral glaucoma in 30-70% with upper eyelid port-wine stain. Combined mechanism: angle anomaly + elevated episcleral venous pressure. Treatment: angle surgery, medical therapy, drainage devices.

Follow-Up and Prognosis

Frequent EUAs during infancy; transition to office-based exams as child cooperates. Monitor corneal diameter, IOP, axial length, optic nerve, and refraction. Aggressive amblyopia management is essential -- anisometropia and strabismus are common. PCG presenting at birth to 3 months has best surgical prognosis. Late-presenting or secondary glaucoma carries worse prognosis.

Key Clinical Pearls

The classic triad of epiphora, photophobia, and blepharospasm in an infant should prompt urgent evaluation for congenital glaucoma. Haab striae are horizontal/curvilinear (PCG) vs. vertical (forceps injury) Optic nerve cupping in children can reverse with IOP normalization -- a unique feature of the pediatric optic nerve. PCG is a surgical disease -- medical therapy is a bridge to surgery, not definitive treatment. Aphakic glaucoma risk persists lifelong after pediatric cataract surgery.

References

1. Papadopoulos M, et al. The British Infantile and Childhood Glaucoma (BIG) Eye Study. Invest Ophthalmol Vis Sci. 2007;48(10):4100-4106.
2. Mandal AK, Chakrabarti D. Update on congenital glaucoma. Indian J Ophthalmol. 2011;59(Suppl 1):S148-S157.
3. Chen TC, Chen PP, Francis BA, et al. Pediatric glaucoma surgery: a report by the AAO. Ophthalmology. 2014;121(11):2107-2115.
4. American Academy of Ophthalmology. Glaucoma. BCSC Section 10. 2023-2024.

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