Diabetic Retinopathy
Diabetes and the Eye
An increasing incidence of diabetes mellitus poses a major health problem in India. The contributing factors are:
- an inappropriate diet, high in fat and carbohydrates
- sedentary lifestyle
Diabetes may affect both the young (type I) and the old (type II). The latter type is far more common.
Regardless of the type of diabetes, many diabetics develop a complication called diabetic retinopathy, a change in the retinal blood vessels that leads to loss of vision.
Diabetic Retinopathy: A silent presence
- Diabetics are twice as likely as non-diabetics to develop eye problems . The most common eye complication in diabetes is diabetic retinopathy; other complications are cataract and glaucoma.
- Fifty percent of diabetics develop some degree of diabetic eye disease.
- The risk of blindness is 25 times higher in diabetics than in non-diabetics.
- Early detection and timely treatment of diabetic eye disease significantly reduces the risk of vision loss.
- Diabetic retinopathy is often symptomless in the early stages. Since only an ophthalmologist can detect early signs of diabetic retinopathy, all diabetics should have their eyes examined at least once every year.
How does diabetes affect the eye?
Diabetes causes weakening of the blood vessels in the body. The tiny, delicate retinal blood vessels are particularly susceptible. This deterioration of retinal blood vessels, accompanied by structural changes in the retina, is termed diabetic retinopathy and will lead to loss of vision. Diabetic retinopathy is gradual in onset and is related to the duration of diabetes. High blood glucose levels, high blood pressure and genetics influence the development and progression of diabetic retinopathy.
There are two main stages of diabetic retinopathy:
Non-proliferative: When the blood vessels leak, macular edema may occur, thereby reducing vision.
Proliferative: When new, weak blood vessels grow or proliferate, bleeding into the vitreous may occur and cause severe visual loss.
Eye examination in diabetic retinopathyEvery diabetic is a potential candidate for diabetic retinopathy. There are no symptoms at the initial stages. Periodic eye examination with dilated pupils is the only way to detect early disease and prevent further deterioration of vision.
Diagnosis
Diagnostic tools such as a slit lamp, ultrasound and procedures such as fluorescein angiography are used in addition to an ophthalmoscope to assess whether the patient has diabetic retinopathy or other eye problems.
Fluorescein Angiography
This is a magnified photography of the retina using an injectable dye. It helps classify the condition, record changes in the retinal blood vessels, decide on the mode of treatment and evaluate the treatment.
Treatment
Lasers are widely used in treating diabetic retinopathy. Lasers are formed by an intense and highly energetic beam of light. They can slow down or stop the progression of diabetic retinopathy and stabilise vision.
The laser experience
Laser treatment is usually performed as an outpatient procedure. The patient is given topical anaesthesia to prevent any discomfort and is then positioned before a slit lamp. The ophthalmologist directs the laser beam precisely on the target with the aid of the slit lamp and a special contact lens. Absorption by the diseased tissue either seals or destroys the tissue. Additional treatment may be required according to the patient's condition.
Side effects
Some patients may experience side effects after laser treatment. These are usually temporary. Possible side effects include watering eyes, mild headache, double vision, glare or blurred vision. In the event of sudden pain or vision loss, the ophthalmologist must be contacted immediately.
Vitrectomy
In some patients, there may be bleeding into the vitreous or the vitreous may pull the retina, reducing vision severely. In such instances a surgical procedure called vitrectomy (replacing the vitreous by a clear artificial solution) is performed. Vitrectomy is done only after other forms of treatment have been unsuccessful.
Age Related Macular Degeneration (ARMD)
Macular degeneration is a condition of the eye that is often related to aging. It is commonly referred to as age-related macular degeneration, and is often abbreviated as AMD. Age related macular degeneration is the most common cause of legal blindness in the geriatric population in the west and is probably more common in India than believed.
