While primary open-angle glaucoma and angle-closure glaucoma are the two most common types, there are several other forms.
Also known as low-tension glaucoma, this form is distinguished by the optic nerve progressively becoming more damaged and progressive loss of vision – yet, the intraocular pressure is within normal limits. It’s thought to be caused by poor blood flow to the optic nerve. Currently, there are no definitive treatments, but there is much research occurring in the field of optic nerve blood flow, with the hope that this will lead to treatments.
With open-angle glaucoma, the intraocular pressure rises slowly, so there are little or no symptoms. With acute glaucoma, sometimes called acute angle closure glaucoma, the pressure rises suddenly, often within a matter of hours. This can be very painful – the eye becomes red, the cornea clouds and occasionally it can cause nausea or vomiting. Occasionally, it may come as a series of ‘small attacks’. Acute glaucoma is an emergency condition and should be treated immediately.
Developed more frequently by men who suffer from myopia (nearsightedness), it often begins in the 20s or 30s. Medication or laser is often the treatment chosen by ophthalmologists, however this can vary.
Most common among people of European descent, this form of glaucoma is the result of tiny white flakes (almost like dandruff) building up on the lens of the eye. Exfoliation material rubs off the lens with eye movement, and at the same time the pigment is rubbed off the iris. These combine to block the trabecular meshwork, causing high intraocular pressure. This can lead to both open-angle glaucoma and angle-closure-glaucoma, although not everyone with exfoliation syndrome develops glaucoma.
An injury or a chemical burn can disrupt the eye’s drainage system, preventing draining of fluid from the eye, which can lead to glaucoma. If you’ve ever had such an injury should have regular checkups for glaucoma.
It is rare for a child to develop glaucoma, but if it happens it is a serious condition. Caused by an abnormal increase in intraocular pressure, it may be associated with other medical diseases. Approximately 10% of cases are present at birth, and 80% are diagnosed within the first 12 months of life. It’s often first noticed as clouding or an enlargement of the cornea, as well as light sensitivity, tearing and blinking often. Most patients require prompt surgery, long-term care and monitoring of visual development.