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Ophthalmology – Congenital and Infantile Glaucoma
Congenital and infantile glaucoma is a developmental disorder characterized by trabeculodysgenesis, leading to impaired aqueous humor outflow and elevated intraocular pressure (IOP). It presents at birth or within the first 3–4 years of life and must be distinguished from secondary pediatric glaucomas associated with other ocular or systemic conditions.
The condition may be unilateral (25%) or bilateral (75%), and early recognition is critical to prevent permanent visual damage.
Epidemiologically, incidence varies by region. It is more common in certain populations (e.g., parts of the Middle East) and relatively rare in the United States. There is a slight male predominance (3:2), and family history is an important risk factor.
Genetically, about 10% of cases follow an autosomal recessive inheritance pattern. Several loci have been identified, most notably mutations in the CYP1B1 gene. Other genes such as MYOC and LTBP2 may also be involved. Genetic counseling is recommended, especially in familial cases.
Pathophysiologically, abnormal development of the anterior chamber angle structures leads to impaired aqueous drainage. Proposed mechanisms include malformed trabecular meshwork, abnormal insertion of the iris or ciliary body, and abnormalities of Schlemm’s canal. These abnormalities result in increased intraocular pressure, which in infants causes stretching of ocular tissues.
The classic clinical triad includes:
• Epiphora (excessive tearing)
• Photophobia (light sensitivity)
• Blepharospasm (eyelid squeezing)
Additional features include enlarged eyes (buphthalmos), cloudy corneas, and progressive myopia. Corneal enlargement (>12 mm in diameter) and breaks in Descemet’s membrane known as Haab’s striae are characteristic findings.
Examination often requires sedation or anesthesia. Key findings include elevated IOP (typically 25–35 mm Hg), increased axial length, corneal edema, and optic nerve cupping. Unlike adult glaucoma, optic nerve changes in children may be partially reversible if treated early.
Diagnostic evaluation includes tonometry, gonioscopy (to assess angle structures), optic nerve imaging, and sometimes optical coherence tomography. Visual field testing is performed later when the child is developmentally able.
The differential diagnosis includes other causes of tearing (such as nasolacrimal duct obstruction), corneal clouding (e.g., dystrophies, infections), and enlarged cornea (e.g., megalocornea).
Management is primarily surgical, as this is a structural problem. Medical therapy is used only as a temporary or adjunctive measure to lower IOP. First-line medications include topical beta-blockers, carbonic anhydrase inhibitors, and prostaglandin analogues. Alpha-2 agonists (like brimonidine) should be avoided in very young children due to risk of central nervous system depression.
The mainstay of treatment is angle surgery:
• Goniotomy – first-line in clear corneas, with ~80% success
• Trabeculotomy – preferred when the cornea is cloudy
If these fail, further options include tube shunts, trabeculectomy, or cyclophotocoagulation in advanced cases.
Supportive care is equally important. This includes correction of refractive errors, treatment of strabismus, and especially prevention of amblyopia, which is the most common cause of visual loss in these patients. Frequent refraction and visual monitoring are essential.
Lifelong follow-up is required. Infants often need examinations every 3–4 months, including periodic exams under anesthesia. Monitoring focuses on IOP control, corneal clarity, optic nerve status, and visual development.
Prognosis depends on early diagnosis and timely surgical intervention. Approximately 80% of patients achieve adequate IOP control, and about 40% may retain good visual acuity (20/40 or better). Outcomes are generally better when surgery is performed between 2–12 months of age.
Complications include visual field loss, amblyopia, refractive errors (myopia, astigmatism), cataract, corneal scarring, and blindness. In severe or untreated cases, the eye may become painful or progress to phthisis bulbi.
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