By Christine Gonzales, M.D., Retinal Consultant and Surgeon, Retina & Vitreous Center
As a retina specialist, I often see patients who delay seeking medical attention with new visual symptoms, assuming the symptoms will resolve spontaneously or new glasses will correct the problem. Some patients have been told they have cataracts (cloudy lenses), and they "self-diagnose" increasing blurriness as an increase in their cataract. Cataracts cause visual loss that is usually completely reversible with cataract surgery; however, the decreased vision could be due to a number of retinal conditions which can often be treated successfully if treatment is initiated early enough. Some of these conditions include macular degeneration, diabetic retinopathy, retinal vein occlusions, and retinal detachments.
Macular degeneration is a degenerative condition in the elderly that leads to decreased function in the central retina, the macula. The retina lines the inner back surface of the eye and consists of nerve fiber layers that sense light and images and transmit this neurological information to the brain through the optic nerve. The retina is a very metabolically active organ that produces byproducts, such as free radicals. As we age our ability to remove these harmful byproducts is reduced. Progressive damage occurs in the macula which then decreases vision, initially as dry macular degeneration. In some cases, abnormal blood vessels develop under the retina as with wet macular degeneration. These vessels leak fluid and blood which damage the sensitive retinal cells in the macula, resulting in decreased vision. Early treatment for wet macular degeneration with injections into the eye and/or laser can often reverse visual loss. Antioxidant vitamins and alpha 3 omega fatty acids have been shown to decrease the rate of progression of macular degeneration.
Chronically elevated blood sugar in diabetes can damage retinal capillaries leading to edema in the macula (central retina), growth of abnormal blood vessels, bleeding in the eye, and in more advanced cases, retinal detachment. Early recognition and treatment of diabetic retinopathy usually with a combination of intraocular injections and laser can significantly slow this process and maintain vision. When treatment is delayed however, permanent damage to the retina occurs.
Retinal vascular occlusions (blockages) affect the artery or vein and can cause diminished vision from swelling in the macula and/or damage to the sensitive nerve tissue of the retina from lack of adequate blood flow. These conditions can be associated with serious systemic conditions which can increase one's risk of stroke. Your retinal specialist will work in concert with your primary care doctor in determining the necessary work-up to identify systemic risk factors. Like macular degeneration and diabetic eye disease, intraocular injections and/or laser are used to treat the retinal manifestations of the disease.
Retinal detachment occurs when intraocular fluid flows behind the retina through a retinal tear. Fluid behind the retina causes immediate loss of vision and, if untreated, permanent damage to the retina. The visual loss may begin in one quadrant of the visual field and progress to involve the entire visual field. The initial symptoms of a retinal tear include flashing lights and floaters. These symptoms should be taken seriously and medical attention sought immediately. Diagnosis of a retinal tear before it leads to a retinal detachment is desirable as it can usually be treated in the office; whereas, a retinal detachment requires more extensive surgery in the operating room. Furthermore, if retinal detachment repair is not performed early on, permanent visual loss may result.
There are many other retinal conditions that affect vision, but these are some of the more common conditions. The critical point is to seek medical attention as soon as visual loss is noted to avoid permanent visual loss.