What is childhood glaucoma?
Glaucoma is a condition in which the normal fluid pressure inside the eyes (known as intraocular pressure, or IOP) slowly rises. This occurs as a result of the fluid aqueous humor — which normally flows in and out of the eye — not being able to drain properly.
In cases of glaucoma, the fluid collects and causes pressure damage to the optic nerve (a bundle of more than 1 million nerve fibers that connects the retina with the brain) and, eventually, loss of vision.
Glaucoma is classified according to the age of onset. If it begins before the child is 3 years old, it is called infantile or congenital (present at birth) glaucoma. If it occurs in a child older than 3 years old, it is called childhood glaucoma.
What causes childhood glaucoma?
Glaucoma occurs when the fluid drainage from the eye is blocked by abnormal development or injury to the drainage tissues, thus resulting in an increase in the intraocular pressure, damage to the optic nerve and loss of vision.
There are many causes of childhood glaucoma. It can be hereditary or it can be associated with other eye disorders. If glaucoma cannot be attributed to any other cause, it’s classified as primary. If glaucoma is a result of another eye disorder, eye injury or other disease, it is classified as secondary.
In about one-third of cases, congenital glaucoma is inherited by an autosomal recessive gene, meaning that both males and females are equally affected and that two genes are required to have the condition — one inherited from each parent, who act as carriers.
- Carrier parents have a one in four, or 25 percent, chance with each pregnancy to have a child with congenital glaucoma. The remaining two-thirds of congenital glaucoma cases occur sporadically, or by chance.