Controlling DR and avoiding blindness

Diabetes Retinopathy (DR) is a vision threatening complication that can happen in any person with diabetes. Starting with mild vision problems, the condition can worsen and threaten your vision. The damage, according to Consultant Ophthalmologist Dr. M. Nandakumar is quite irreversible and has the potential to cause complete blindness.

DR is caused by high blood sugar levels associated with diabetes. It affects the tiny blood vessels that nourish the retina which is the tissue at the back of the eye that captures light and relays information to the brain.

That diabetes affects the body from head to toe is a well-known fact. In the eyes too, it can affect any part, bringing about an early onset of cataract; optic neuropathy where the nerve from the eye to the brain is affected; and nerve paralysis that affects eye movement, or DR, the latter causing poor vision or blindness - the most serious of them all.

A leading cause of blindness in adults in Western countries, DR accounts for about 12% of new cases of legal blindness in the US. This serious eye complication is fast becoming a common phenomenon, especially in Asian countries with the incidence of diabetes reaching alarming levels in the past 15 years.

Significantly more than 85% of diabetics who have had the disease for over 20 years have some degree of DR. Although it may not occur during the first 4-5 years of developing diabetes, a person is at risk every consecutive year from then.

Dr. Nandakumar clarifies that the kind of retinopathy a person has depends on: duration of diabetes, sugar control, type of diabetes and other factors such as Hypertension, kidney problems, pregnancy or anaemia that can worsen the effect of diabetes in the eyes. However, DR has not been proven as a hereditary condition. The disease invariably affects both eyes almost equally.

Large scale research of the Asian population indicates that 20-24% of diabetics will have some degree of DR. "The best predictor remains the duration of diabetes - the longer you have diabetes, the higher the chances of developing DR," the doctor states.

It is only an ophthalmologist who can discover changes of retinopathy from an early stage, based on which they can be graded into the following:

Non-proliferative Diabetic Retinopathy (NPDR): Diabetes affects the blood supply to different organs in the body including the retina. Starved of oxygen, changes begin to occur in the retina in the form of bleeding, leakage of proteins and fluid from the blood vessels and sluggish blood circulation. These changes may often be asymptomatic or there can be mild blurring of vision.

Proliferative Diabetic Retinopathy (PDR): In the absence of oxygen, the retina produces substances called Angiogenic factors that try to produce new blood vessels to improve circulation. The new vessels grow abnormally, leak protein and/or blood and bleed easily, reducing vision further.

Bleeding in the eye is often indicated by black or red spots in the vision and fall in vision. During either of the above, the central portion of the retina called the Macula that is responsible for sharp vision needed for reading, writing, and recognizing people can get affected in a process called Maculopathy. Once this happens, deterioration in vision is often severe and to a large extent permanent. Unchecked PDR can cause repeated attacks of bleeding in the eye. In the advanced stages the vessels can pull the retina leading to retinal detachment and haemorrhage which can cause total blindness.

Soon after an eye examination that includes a vision check, detecting eye pressure and a dilated retinal exam doctors grade the condition into mild, moderate or severe form of retinopathy. If possible, photographs are taken of the retinal condition for records before deciding on the mode of treatment.

While regular follow-up would suffice for mild and moderate forms of NPDR, doctors may require other investigations such as angiogram of the eye to ascertain the severity of the condition for other forms. Angiogram may not be needed for other cases and one can directly go ahead with treatment.

Traditional treatment options include laser therapy to try and halt the progression of disease. Surgery might be required in more advanced cases.

Newer treatment modalities that can be done in addition to laser include injection of steroids or injection of anti-angiogenic factors also inside the eyes. After treatment, consistent follow-up and/or multiple treatments may be required over the years to keep vision stable.

No warning signs

Notably, DR has no warning signs until significant damage occurs. Ophthalmologists can control DR and prevent further damage. It is important to have the condition diagnosed as early as possible so that normal vision can be maintained. This can be done through regular checks rather than waiting for any symptoms to show.

Recommendations

The American Academy of Ophthalmologists recommends that if you are a young diabetic, it would be pertinent to have the first eye examination in the first 3-5 years of diabetes.

If above 30 years of age, the patient needs to get the test done soon after becoming diabetic. After the first check, a yearly retinal examination is mandatory. The frequency of checks is also determined by the severity of condition. If the first exam shows changes of DR the doctor may see the patient more often than once a year.

Further, ophthalmologists globally recommend that young women with diabetes have a detailed examination prior to conceiving, failing which an exam is done every trimester of pregnancy to detect and if necessary treat DR.

Dr. Nandakumar’s advice to preserve good vision till the end of one's life is to be aware of the risk of DR, have sugar under ontrol through self-monitoring of sugar every few days to ensure that there is no wild fluctuation in levels and to exercise and maintain a healthy lifestyle. A person with diabetes should not let the eye disease start and progress.

Notably, a large proportion of patients with significant DR also have renal complications. Hence sugar, retina, and renal onditions need to be checked and monitored closely.

The threat of blindness is certainly terrifying. But with early detection and treatment, the risk of severe vision loss from DR can be reduced. The good news is that timely therapy has been shown to be 90% effective.