Diabetic Eye Disease
Diabetes is a common condition which affects many organs in the body including the eye. Hence anyone with diabetes should have regular eye examinations.
How Does Diabetes affect the eye?
Diabetes affects mainly the small blood vessels of the eye, especially those found in the retina causing a condition known as diabetic retinopathy. The damage is brought about by high and fluctuating levels of blood sugar levels. As a result of this, it can lead to reduced vision and in its later stages, loss of vision.
The process of retinopathy starts from leakage of fluid, protein, fat and blood from the damaged capillaries which in turn accumulate in the retina which can then disrupt its function. It has a particular tendency to occur at the macula which is the part of the retina that is responsible for central vision. Hence one of the early symptoms that a patient may experience is blurred vision. However a significant portion of patients may not experience any visual symptoms until the later, more severe stages of damage, hence the importance of regular eye examinations.
Patients with advanced cases of retinopathy can present with symptoms due to growth of abnormal new vessels in the retina. These often bleed and at times promote formation of scar tissue which can stretch, distort or at times detach the retina. Patients will often experience a sudden increase in floaters or a loss of vision in one or both eyes.
Treatment of Diabetic Retinopathy
The chances of developing diabetic retinopathy increases with the duration of diabetes and how well the diabetic control has been. It also depends on the control of other co-existing medical conditions like hypertension, hypercholesterolaemia, obesity and smoking.
Apart from managing the overall diabetes, diabetic retinopathy can be treated quite effectively as long as it is diagnosed and treated early enough.
A) Laser treatment
The mainstay of treatment is laser. Laser is applied through a special contact lens in an outpatient setting and the patient can go home after having it done. The treatment is usually not uncomfortable.
Areas of the retina are treated with tiny laser burns if there is significant leakage of fluid, especially at or near the macula, or if there are areas where the retina is affected severely by poor circulation causing ischaemia. The aim of treatment is to help prevent further visual loss from further leakage and to promote reabsorption of fluid from the retina and hence reduce the stimulus to new vessel growth.
In cases where new blood vessels are already present, the aim of laser therapy is to cause the new vessels to regress and prevent any further vessels from developing. Repeated treatments are usually needed. If diabetic retinopathy is too advanced before laser treatment is undertaken, it may fail to improve significantly and may continue to progress, even to the point of blindness in both eyes. Once again, this underlines the importance of regular screening to detect diabetic retinopathy early and then start laser treatment as soon as it is needed.
B) Surgical treatment
Surgical treatment may be possible for very advanced cases of the condition where there has been severe bleeding in the eye, scar formation or retinal detachment. Surgery however is normally reserved as an attempt to rescue desperate cases of advanced diabetic retinopathy from blindness.
C) Other treatments
New forms of treatments include injecting drugs into the eye to reduce swelling in the retina and suppress new vessel growth. These are similar drugs to those used in the treatment of wet macular degeneration.