If you’ve had diabetes for 15 years or longer, chances are high that you already have some form of blood vessel damage in your eyes. And without regular screening, you are even at risk of going blind.

Consider the startling figures: Singapore has one of the highest rates of diabetes in the world, with about 10 per cent of the population aged between 18 and 69 suffering from the condition, according to the Diabetic Society of Singapore. The disease is also one of the top six killers here.

Fifteen years ago, only about 20 per cent of diabetic patients screened had damage to the blood vessels in the retina, a condition known as diabetic retinopathy. Today, the percentage of affected patients is around 60 per cent, with many of them at risk of going blind, said doctors.

Diabetic retinopathy

Diabetes is a silent, chronic condition which does not have many obvious signs. The main indicator for diabetes is persistently high blood glucose levels. This can lead to various health complications, including heart disease, kidney failure, amputations and blindness if not properly controlled. Diabetic retinopathy, the most common form of diabetic eye disease, is the leading cause of blindness in Asia. It often does not have any symptoms or early warning signs. Some may experience rapid vision deterioration over a short period of time, while others may experience a gradual blurring of vision, where they see halos around certain objects.

Symptoms indicative of the advanced stage of the condition include floaters (small black specks moving in your field of vision), a potential sign of a vitreous haemorrhage, which is bleeding within the eye, or visual loss from detached retinas, said Adjunct Associate Professor Lee Shu Yen, an ophthalmologist at the Singapore National Eye Centre (SNEC).

Catch it early, save your sight

Given that diabetic retinopathy often has no warning signs, regular checks are particularly important. Doctors recommend that patients get their eyes examined at least once a year. As vision is affected only when the condition is more advanced, it is best to catch it early through a routine check before permanent damage occurs.

During the test, eyedrops are used to enlarge the pupils. This allows doctors to see more of the inside of the eyes to check for signs of the disease.

SNEC has a special photographic process that helps to detect early effects of diabetic retinopathy. It involves the injection of a special dye through the arm into the blood stream. Pictures are taken as the dye passes through the blood vessels in the retina. This allows doctors to check for leakage or poor blood flow, which can lead to loss of vision. The best way to prevent diabetic retinopathy from progressing, doctors say, is to control blood sugar levels, blood pressure and blood cholesterol.

Treatment types

The aim of treatment is to prevent further damage to the retina and blurring of vision. Options include surgery and laser treatment. 

There are two types of laser treatment available: Panretinal photo coagulation (PRP) is used to treat the peripheral retina to prevent or stop the growth of abnormal blood vessels, while a focal laser is used to reduce swelling in the case of macular oedema, caused by blocked or broken blood vessels. These treatments are carried out as simple outpatient procedures at SNEC.

For very advanced cases, surgery or vitrectomy is required, Prof Lee said. This involves removing scar tissue and cloudy fluid from inside the eye. The earlier the operation is done, the more likely it will be successful. Vitrectomies are more expensive than focal laser and PRP, and cost $1,630 – $7,380, depending on whether the treatment is private or subsidised.

Ultimately, even though diabetic retinopathy is not entirely preventable, long-term control of diabetes helps to reduce the risk. Attention should be paid to risk factors for heart disease as well, said doctors, as they also affect the likelihood of developing diabetic retinopathy.