Diabetes is a systemic disease characterized by increased blood sugar, also known as hyperglycemia. It causes damage to many of the body’s organs including the eye. Effects increase with age as the damage accumulates. According to a February 2008 article in the journal Emergency Medicine Clinics of North America, diabetic eye disease remains the leading cause of blindness in patients between the ages of 18 and 74.
Cataracts
Patients with diabetes are at increased risk for cataract formation, especially if they are elderly and have poor blood sugar control. A more pressing concern is a problem known as macular edema, which often occurs after cataract surgery and can result in poor vision. This issue occurs more frequently in diabetes and thus vigilance is necessary, according to an August 2008 article in Clinics in Geriatric Medicine.
Infection
Two destructive infections of the eye that occur in diabetics are mucormycosis and endophthalmitis. The latter often results in blindness and symptoms include pain, light sensitivity, and reduced vision. Mucormycosis is rare, and presents with eye pain, headache and nasal stuffiness. The infection is of a fungal origin and it can invade the skull through the eye socket and death is a possibility, according to a February 2008 article in Emergency Medicine Clinics of North America.
Occlusion of Blood Vessels
Diabetic patients tend to be in a hypercoagulable state; that is to say, blood clots tend to form more easily than in healthy patients. As a result, clots can occlude blood vessels that supply the eye which can cause serious problems. Occlusion of the central retinal artery results in total or near-total vision loss. Occlusion of the central retinal vein has a slower onset of blurred vision and slower loss of vision. Occlusion of blood vessels that supply nerves that control the eye can result in problems with eyeball movement, resulting in double vision, eyelid drop, headache and eye pain, as outlined in Clinics in Geriatric Medicine.
Diabetic Retinopathy
The main problem that diabetics suffer from is known as diabetic retinopathy, which has many forms. Diabetes causes damage to the blood vessels in the eye, and they can become increasingly fragile or develop outpouchings (known as microaneurysms); both have a high chance of rupture and bleeding. The vessels can also narrow due to damage to the inner lumen, which restricts blood flow to the eye. As a result of decreased blood flow, new blood vessels tend to develop; this is known as neovascularization. These new vessels are fragile and rupture easily and put the patient at increase risk of detachment of the retina, which has symptoms of bright flashes of light, blurred vision, and permanent loss of vision. In addition, the blood vessels can grow rapidly, causing increased pressure within the eye, with resulting glaucoma.
About this Author
Saad Mohammad, M.D., is currently in the process of applying to residency anesthesiology. His first published research occurred in 2009 at the American Thoracic Society National Conference where a poster presentation was accepted and at the Bridgeport Symposium 2009. He began professionally writing in 2009 for Demand Studios as a freelance writer on issues in health and medicine.
