Search for a rare disease
Other search option(s)
Congenital glaucoma (CG) is a developmental glaucoma that results from the abnormal development of the aqueous drainage structure, characterized by an elevated intra-ocular pressure, enlargement of globe (buphthalmos), corneal edema and optic nerve cupping, and presenting clinically with the characteristic triad of epiphora, photophobia and blepharospasm.
- Primary congenital glaucoma
- Prevalence: 1-9 / 100 000
- Inheritance: Autosomal recessive or Not applicable or Autosomal dominant
- Age of onset: Infancy, Neonatal
- ICD-10: Q15.0
- OMIM: 231300 600975 613085 613086 617272
- UMLS: C0020302
- MeSH: -
- GARD: -
- MedDRA: -
CG is the most common glaucoma of infancy. The birth prevalence is estimated at around 1/27,800 live births in Europe. Males are more commonly affected than females and the disease is bilateral in 70 to 80% cases.
Diagnosis is made in the first year of life in about 80% of cases. Age of onset can be delayed up to early adulthood. The classic triad includes epiphora, blepharospasm and photophobia. Affected children are noted as having red watery eyes, cloudy corneas and ocular enlargement, caused by stretching of the immature eye due to elevated intraocular pressure. Children older than 3 years develop progressive myopia and insidious field loss. Untreated CG invariably leads to blindness.
Etiology is poorly understood but the obstruction to the aqueous outflow seems to occur at the iridocorneal angle and at the level of the trabeculum. Gene mapping of affected families has identified three chromosomal loci, GLC3A in 2p22.2, GLC3B in 1p36 and GLC3C in 14q24.3-q31.1 of which, the CYP1B1 gene (2p22.2) on GLC3A harbors mutations. Mutations in LTBP2 (14q24.3) and MYOC (1q23-q24) genes have also been identified.
Diagnosis is made by a complete ophthalmologic examination which reveals a hazy cornea of increased size and presence of Haab's striae, increased intraocular pressure (IOP) (more than 20 mm Hg or asymmetry of more than 5 mm Hg is of concern), deep anterior chamber, abnormally high insertion of iris, poorly developed scleral spur (with gonioscopy), increased cup to disc ratio of the optic nerve head and refraction testing showing myopia and astigmatism. Examination under anesthesia is done if necessary.
The differential diagnoses for red watery eyes include nasolacrimal duct obstruction, conjunctivitis, corneal abrasion and uveitis while those for corneal enlargement include high axial myopia and megalocornea. The differential diagnoses for corneal clouding and edema include congenital corneal dystrophies, birth trauma, keratitis, congenital ocular anomalies or storage diseases while those for optic nerve cupping include physiologic cupping, coloboma of optic papilla, genetic optic atrophy and optic nerve hypoplasia.
Prenatal diagnosis can determine the risk of the disease in families with known mutations.
Most cases are sporadic, in about 10% of cases autosomal recessive inheritance is seen with variable penetrance.
Management and treatment
Congenital glaucoma is primarily managed surgically, with medical therapy playing only an adjunctive role. Traditionally, goniotomy is recommended for children younger than 2 to 3 years of age if cornea is clear. Trabeculotomy is offered to children in whom the angle is inadequately visible and to older children. Trabeculectomy and glaucoma drainage devices are used in refractory cases. Amblyopia, corneal scarring and cataract are late complications. Early visual rehabilitation is important to prevent amblyopia. Patients may need regular life-long follow up to monitor IOP.
Prognosis is largely related to the timing of presentation; early diagnosis and prompt surgical treatment significantly influences the visual outcome. Most patients successfully treated in infancy maintain good pressure control with stable optic nerves and fully functional visual fields into adulthood.