Congenital Glaucoma

Affects: 1 in 10,000 newborns in industrialised countries
Affects both eyes in over 66% of cases

What is congenital glaucoma?

Congenital glaucoma is a rare condition where the optic nerve, which connects the retina to the brain, is damaged due to increased intraocular pressure. Glaucoma generally causes progressive damage to the optic nerve and can lead to a reduced visual field or even total vision loss if untreated. While common in adulthood, congenital glaucoma occurs in childhood and can cause severe and irreversible vision loss in affected children.

What causes congenital glaucoma?

In the eye, the anterior chamber is filled with aqueous humour, a fluid that maintains the eye's optical properties. This fluid flows in and out of the anterior chamber, draining through the angle formed by the cornea and iris. The drainage system is essential to maintaining intraocular pressure.

In congenital glaucoma, the drainage system (the angle of the eye) does not develop properly, leading to impaired outflow of aqueous humour and increased intraocular pressure. This causes optic nerve damage.

How is it diagnosed?

Congenital glaucoma is usually diagnosed through a full eye examination, which may require sedation in children under three years of age. The examination includes:

Examination of the front part of the eye: Assesses the condition of the cornea and the angle to determine the most appropriate surgical approach.
Examination of the fundus: After dilating the pupils with eye drops, the ophthalmologist uses a magnifying lens to inspect the retina and optic nerve for damage.
Tonometry: Measures intraocular pressure to check for elevated pressure. Normal pressure ranges from 10 to 20 mm Hg.

Symptoms

Congenital glaucoma typically manifests between birth and three years of age. Parents may notice the following signs:

Photophobia (sensitivity to light)
Watery eyes (epiphora)
Eye discomfort, leading the child to keep their eyes closed (blepharospasm)

As the condition progresses, the appearance of the eyes may change, especially with increased intraocular pressure:

Opacity of the cornea due to damage from high pressure
Enlarged eyes due to tissue distension

Associated treatments

Early treatment is crucial to slowing the progression of congenital glaucoma and preserving vision. The primary treatment is surgery to correct the angle defect. The initial treatment often includes eye drops and medications to stabilize intraocular pressure before surgery.

Common surgical procedures include:

Goniotomy: Performed if the cornea is transparent and the angle is visible.
Trabeculectomy: Performed if the cornea is opaque. This surgery removes a small amount of tissue to create a new drainage channel.
Valve implants: A plastic tube inserted to connect the interior of the eye to the exterior, allowing fluid to drain.

Surgery may need to be repeated to maintain proper intraocular pressure.

Visual prognosis for children affected by congenital glaucoma

The prognosis depends on:

Timing of diagnosis: Early diagnosis and treatment generally lead to better outcomes. Delayed diagnosis worsens the prognosis, especially if high pressure goes untreated for months.
Corneal involvement: If the cornea is damaged, a corneal transplant may be needed in addition to glaucoma surgery.

With early intervention, children may achieve good control over the condition into adulthood.

Congenital Glaucoma