What is Glaucoma?
Glaucoma is a group of eye disorders that results in loss of vision and optic nerve damage. These disorders are caused by pressure build up due to the accumulation of eye fluids. This condition is divided into two categories: open-angle and closed-angle. Angle refers to the area between the iris and cornea, where the fluid must flow to escape. Cases classified as closed-angle are often painful and appear suddenly. It is the discomfort brought about by this category of the disorder that often forces patients to seek medical attention before permanent damage occurs. On the other hand, open-angle cases develop at a slower rate and are usually painless. The lack of symptoms somehow makes it more dangerous. More often than not, patients discover the damage when the disorder has developed to a critical stage and more aggressive treatment is necessary.
Among the symptoms that people with closed-angle glaucoma experience include sudden eye pain, vision of halos around lights, red eye, and very high pressure within the eyes, nausea, vomiting, sudden decreased vision, and a mid-dilated pupil. In some cases, the pupil becomes oval in shape. The decreased vision usually affects the sides of the field of vision, as if the sides are surrounded in a black cloud, with clarity of vision converging more in the center. The main cause is always ocular hypertension, or elevated pressure within the eye, however in some places, only 50% of those who have the disorder has ocular hypertension. Caffeine increases intraocular pressure for those who already have the disorder, but does not affect normal individuals.
Risk factors include genetics, sex, ethnicity, and human activities or conditions. The risk is increased two- to four-fold for those who have a sibling with the disorder. It is also associated with mutations in several different genes. In terms of sex, women are more three times more likely to develop the disorder than men due to their shallower anterior chambers. For ethnicity, those of the African descent are also three times more likely to develop the disorder. A human activity that contributes to the increased risk of developing the disorder is prolonged use of steroids; conditions include those that restrict blood flow to the eye, like severe diabetic retinopathy, ocular trauma, and uveitis.
Diagnosis is done by optometrists and ophthalmologists after a standard eye examination. Patients are advised to go for a tonometry to check for inner eye pressure; an ophthalmoscopy to check the shape and color of the optic nerve; a perimetry to test for complete field of vision; a gonioscopy to inspect the angle in the eye where the iris joins with the cornea; a pachymetry to determine the thickness of the cornea; and a nerve fiber analysis to measure the thickness of the nerve fiber layer. Those who are at risk of developing the eye disorder are advised to undergo ophthalmoscopy at least once a year.
Medication includes the use of eye drops to lower intraocular pressure, and in severe cases, surgery is recommended. There are a lot of surgical methods to cope with the disorder, such as canaloplasty, laser surgery, trabeculectomy, and glaucoma drainage implants. Conventional surgery for glaucoma involves making a new opening in the meshwork to help the fluid leave the eye, lowering intraocular pressure