A Concise Guide to Glaucoma--Symptoms, Causes and Treatments
Glaucoma damages your optic nerve the way high blood pressure damages your cardiovascular system. When fluid pressure increases significantly inside your eye, this pressure progressively impairs the ability of your optic nerve to transmit visual signals to your brain. Scientists aren't sure how intraocular pressure damages the optic nerve but know abnormally high intraocular pressure can lead to blindness if not treated with medications or surgery.
Facts about Glaucoma
Open-angle and Closed-angle Glaucoma
Glaucoma is not a single disease but an umbrella term for over a dozen different eye conditions affecting the optic nerve and causing loss of vision. Open-angle glaucoma is the most commonly diagnosed type of glaucoma resulting from clogged drainage canals and an open, wide angle between the cornea and iris. Symptoms of open-angle glaucoma may not be noticeable for decades following its onset, which makes receiving regular eye exams even more important, especially for people over 40.
Angle-closure glaucoma is less common than open-angle glaucoma and happens quickly when drainage canals become blocked and increase intraocular pressure. Open-angle glaucoma requires immediate attention as vision loss, head pain and sometimes nausea/vomiting occurs rapidly, usually within hours, days or weeks of intraocular pressure rising.
Normal-tension glaucoma is glaucoma not caused by high eye pressure, although the optic nerve is damaged. Other variations of glaucoma include secondary glaucoma, traumatic glaucoma, pigmentary glaucoma and neovascular glaucoma. All glaucoma types cause progressively worsening vision, reduced functioning of the optic nerve and potentially, blindness.
Symptoms of open-angle glaucoma are not readily apparent. It may take 20 years before someone with glaucoma notices their vision becoming blurry or their peripheral vision narrowing in scope. For people who do not get their eyes examined at least once a year, an unexpected diagnosis of advanced glaucoma will demand aggressive treatment to help delay progression of vision loss.
Diagnosis of Glaucoma
Diagnosing glaucoma involves one or more eye tests that are painless and noninvasive. These include a tonometry (evaluates intraocular pressure); ophthalmoscopy (dilation of eyes to observe the optic nerve); perimetry (field of vision); gonioscopy (checks angle where cornea meets iris) and pachymetry (measures corneal thickness).
Treatment for Glaucoma
The initial treatment for open-angle glaucoma is usually prostaglandin eye drops to increase the flow of fluid out of the eye, which decreases pressure. Beta blocker eye drops are also prescribed to decrease fluid production. For glaucoma patients allergic to certain ingredients in prostaglandin and beta blocker eye drops , or whom those drugs are not effective, alpha agonist eye drops may be prescribed as an alternative medication to decrease fluid production and help increase drainage. When eye drops do not reduce intraocular pressure, surgery, such as a trabeculectomy may be necessary to reduce the pressure inside the eye.
If it is time to have your eyes checked or if you haven't had your eyes checked in several years, please schedule an appointment for a comprehensive eye examination and glaucoma test today by calling the University Vision Centre: 915-533-1811.