Affiliations : Saint-Georges Hospital, Beirut, Lebanon
Journal reference: doi: 10.1016/j.jfo.2015.04.018.Epub 2015 Oct 29.
Summary: Glaucoma is characterized by an abnormally high pressure in the eye which damages the optical nerve. In this article Dr. Fakhoury explains what glaucoma is and details different treatments and signs to look out for.
Glaucoma is caused by an abnormally high pressure in the eye that damages the optic nerve, potentially leading to irreversible blindness. It occurs mostly in adults and the elderly but can also be present at birth; it is then called congenital glaucoma.
The eye must have a certain pressure to maintain its spherical appearance. This pressure is due to the presence of a transparent liquid/gel that fills the contents of the eye. While a balance between secretion and filtration of this liquid maintains a constant pressure of the eye, the pressure increases when this liquid can no longer be filtered out of the eye through its special channels. This increase leads to a mechanical destruction of the optic nerve, the noblest and most fragile part of the eye.
Large eyes at birth should always bring up the question of whether the child has primary congenital glaucoma. The increase in the size of the eyes is the major symptom of the disorder. The white shell of the eye being very elastic at birth, the increase in pressure directly leads to an increase in the size of the eyes. Other symptoms of primary congenital glaucoma include tearing and discomfort when the child is exposed to strong light. Both eyes are affected more than 90% of the time and there is a family history of congenital glaucoma in 30% of the cases with no gender difference.
When primary congenital glaucoma is suspected, it is urgent to run an eye examination. The examination is usually done under general anesthesia in order to avoid the child’s uncooperative behavior to harm their eye. During the examination the doctor measures:
- The diameter of the cornea: the cornea being the transparent part of the eye that is often larger if the eye increases in size.
- The tension of the eye: measured with an external tool that comes into contact with the cornea and detects the potential high pressure of the internal eye.
The doctor also examines the fundus by looking inside of the eye with a special lens to see the retina and detect potential hollowing of the head of the optic nerve.
Treating glaucoma in adults is relatively easy when using eye drops that reduce the pressure in the eye by decreasing the amount of fluid secretion in the eye. Unfortunately these drops are not efficient in children and filtering surgery is the only way to reduce the pressure in primary congenital glaucoma. Surgery is done under general anesthesia and consists in creating a new canal that will connect the inside to the outside of the eye and will filter the excess liquid secreted throughout life.
If the disease goes unnoticed, the child becomes completely blind within a few months, hence the importance of early diagnosis. It is crucial for pediatricians and parents to be vigilant and to immediately suspect congenital glaucoma in the case of large eyes, excessive tearing and discomfort when exposed to light.