Eye diseases do not always have symptoms. Your best defense is to have regular checkups as early detection and treatment may prevent vision loss. See an eye care professional right away if you have a sudden change in vision, everything appears dim or if you see flashes of light. Other symptoms requiring quick attention are eye pain, double vision, fluid coming from the eye and eye inflammation.
Glaucoma is an eye disease caused by an increased pressure in the eye. This can damage the optic nerve, which transmits visual information to the brain, resulting in loss of vision. Glaucoma is the second leading cause of blindness in the U.S. Individuals over the age of 40, individuals with a family history of glaucoma, and African-Americans are at an increased risk of developing glaucoma. Other risk factors for the development of glaucoma include thinner corneas, systemic vascular conditions (e.g. diabetes, hypertension, heart disease), prolonged corticosteriod use, high myopia, chronic ocular inflammation, and ocular trauma.
Macular degeneration (MD) is the leading cause of blindness in Americans over the age of 60. MD causes deterioration and loss of photoreceptors and other cells in the macula, the part of the retina responsible for sharp, clear central vision. Because only central vision is usually affected, people rarely experience total blindness from the disease. However, MD can sometimes make it difficult to read, drive, or perform other daily activities that require fine, central vision. Most people with MD have the dry form, for which there is no known treatment. The less common wet form may respond to laser procedures, if diagnosed and treated early.
The Age-Related Eye Disease Study (AREDS), sponsored by the National Eye Institute, has found that taking high levels of antioxidants and zinc can reduce the risk of developing advanced MD by about 25 percent. The specific daily amounts of nutrients used in the study were 500 milligrams of vitamin C; 400 International Units of vitamin E; 15 milligrams of beta-carotene (often labeled as equivalent to 25,000 International Units of vitamin A); 80 milligrams of zinc as zinc oxide; and two milligrams of copper as cupric oxide. Copper was added to the AREDS formulations containing zinc to prevent copper deficiency anemia, a condition associated with high levels of zinc intake.
The retina is the light-sensitive tissue that lines the inside back wall of the eye. In retinal detachment, the retina is separated from its underlying supportive tissue, depriving it from nutrients and oxygen. The longer the retina is detached, the greater the risk of permanent vision loss. Retinal detachment, thus, is a medical emergency requiring prompt surgical treatment to preserve vision. Warning signs of retinal detachment include: floaters, flashes of light, a sudden decrease in vision, and a shadow or curtain over the vision. Risk factors for retinal detachment include: high myopia, previous severe eye injury/trauma, family history of retinal detachment, and previous history of retinal detachment in the other eye.
Cataract is the clouding of the eye’s natural crystalline lens. This loss of transparency decreases the amount of light that can reach the retina, resulting in overall blurriness of images. Signs and symptoms of cataract include: blurry, hazy vision, reduced intensity of colors, increased sensitivity to glare, increased difficulty with night vision, and changes in the eye’s refractive error. Cataracts are typically due to age-related changes in the natural lens. Other precipitating factors may include: ultraviolet radiation exposure, diabetes, corticosteroid use, smoking, high alcohol consumption, and certain nutrient deficiency. Recent studies have shown that antioxidants (e.g. vitamin C, vitamin E, carotenoids) may decrease cataract formation.