# 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.

| Feature | Primary Congenital Glaucoma | Juvenile Open-Angle Glaucoma |
|---|---|---|
| Onset | Birth to 3 years | 4-35 years |
| Inheritance | Autosomal recessive | Autosomal dominant |
| Gene | CYP1B1 | MYOC (myocilin) |
| Mechanism | Trabeculodysgenesis | TM dysfunction |
| Buphthalmos | Yes (elastic sclera) | No |
| Classic signs | Epiphora, photophobia, Haab striae | Asymptomatic; high IOP |
| Primary treatment | Surgery (goniotomy/trabeculotomy) | Medical +/- surgery |

### 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)

![Clinical photograph showing bilateral buphthalmos and corneal clouding in primary congenital glaucoma](/images/ophthalmology/pcg-buphthalmos-corneal-edema.jpg)

### 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.

![Slit-lamp photograph showing Haab striae (breaks in Descemet membrane) in a child with PCG](/images/ophthalmology/haab-striae-slit-lamp.jpg)

## 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.

![Fundus photograph showing asymmetric optic nerve cupping in pediatric glaucoma](/images/ophthalmology/pediatric-glaucoma-optic-nerve-cupping.jpg)

## 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.