The medical term glaucoma refers to a group of ocular (visual) disorders. Glaucoma is the leading cause of irreversible blindness worldwide. Glaucoma risk factors include a family history of glaucoma, myopia, diabetes, and high intraocular pressure.
Causes of glaucoma
The most common cause of Glaucoma is an increase in the pressure of the fluid, which normally flows into and out of the eye. For reasons that are not fully understood, this flow of this fluid, aqueous humor, can become partially blocked and the resulting increase of pressure within the eye will then cause damage to the optic nerve. This, in turn, leads to glaucoma. While people who have elevated intraocular pressure are more at risk for developing the disease, not everyone with this condition goes on to develop glaucoma.
Symptoms of the most common types of glaucoma
While there are a number of different types of glaucoma the majority of cases that are diagnosed fall into two main categories, which are characterized by different rates of vision loss progression. Left untreated, the types of glaucoma in both categories will end in blindness. The two most common categories of glaucoma are:
Open-angle glaucoma also called wide-angle glaucoma, is the most common type of glaucoma. The structures of the eye appear normal, but fluid in the eye does not flow properly through the drain of the eye, called the trabecular meshwork.
- Visual loss progresses slowly over time
- Peripheral vision loss that is gradual
- Usually affects both eyes
- Because the loss of vision is gradual it may not be noticed until damage is profound
- Tunnel vision in the later stages
Angle-closure glaucoma, also called closed-angle glaucoma, occurs when the iris bulges forward to narrow or block the drainage angle formed by the cornea and the iris. As a result, fluid can’t adequately flow through and exit your eye, and your eye pressure may increase abruptly. Angle-closure glaucoma usually occurs suddenly (acute angle-closure glaucoma), but it can also occur gradually (chronic angle-closure glaucoma).
- Often appears suddenly
- Discomfort can be pronounced (eye pain)
- Blurry vision
- Eyes can become irritated and red
- Halo can seem to surround lights
- Visual loss can happen quickly
Glaucoma cannot currently be prevented, but if diagnosed and treated early it can usually be controlled. Glaucoma is diagnosed through a comprehensive eye examination. Testing includes patient history, visual acuity measurements, tonometry, pachymetry, visual field testing, evaluation of the retina of the eye, supplemental testing (gonioscopy, serial tonometry).
Treatments for Glaucoma are mostly focused on decreasing the fluid pressure within the eye. A variety of prescription oral medications and eye drops are available. Generally, this is the first line of treatment, with surgery being reserved for cases where the less invasive solutions are not effective. Glaucoma can be treated surgically using special instruments designed specifically for this type of surgery. Glaucoma instruments include tiny drains that can be implanted within the eye to assist the draining of fluid.