Eye care for diabetics is more urgent than ever
Posted on 24 November 2020
When was the last time you had your eyes checked? People with diabetes are at significantly higher risk of developing serious, sight-threatening eye health conditions. Dr Nicholas Davey, an ophthalmologist from Mediclinic Pietermaritzburg, explains what can be done.
“If you have diabetes, you will need to have your eyes routinely examined once or twice a year. But if you experience any changes in your eyesight, don’t wait. See an optometrist immediately who will refer you to a doctor should you need further medical intervention.”
Insulin plays a crucial role in the normal functioning of the body, helping move glucose from your blood into your cells, where it’s used for energy. But if you have Type 2 diabetes, your cells aren’t able to respond to insulin as well as required. This is known as insulin resistance, and it can have disastrous consequences throughout the body, including the eyes.
Over time, the accumulation of too much glucose in the blood damages blood vessels, and if untreated, this can affect the health of your eyes in a variety of ways, says Dr Nicholas Davey, an ophthalmologist from Mediclinic Pietermaritzburg.
“Cataracts, glaucoma, diabetic macular edema and diabetic retinopathy develop in different ways,” he explains. “When diabetes is not well managed, the blood vessels in the eye leak fluid, swell and cause pressure – all of which can put your eyesight at risk.”
Alarmingly, the Centre for Diabetes and Endocrinology (CDE) estimates that most patients are only diagnosed seven to 10 years after the onset of the disease. The result: your eyes could be damaged without you even knowing it.
“We see a lot of patients who have developing eye health conditions as a result of their diabetes,” he explains. “For example, many of the surgeries we perform are lens replacements to treat cataracts, as on average, these patients will develop cataracts five to 15 years earlier than usual.”
While the lenses in the eye tend to become cloudy as we age, chronic high blood glucose can cause the buildup of deposits, clouding the eye prematurely and necessitating cataract surgery. Diabetes also doubles the risk of glaucoma, which can lead to severe vision loss if not caught and treated early on.
Diabetic retinopathy is another major risk, Dr Davey says. “When blood vessels weaken, bulge or leak at the back of the eye they can damage the retina. Eventually, this can cause new or abnormal blood vessels to grow, or proliferate, on the surface of the retina.”
High blood glucose causes damage all over your body as it affects the blood vessels. In your eyes, the glucose imbalance effectively blocks the vessels that feed your retina. As a result, new vessels then form in their place – but are unable to operate as effectively.
This is extremely dangerous, Dr Davey says, as it is difficult to notice at first without expert help, yet develops rapidly and can lead to permanent blindness. “There are different grades of diabetic retinopathy, and ideally we want to prevent it from reaching the proliferative stage, as that can cause a range of lasting and very damaging complications.”
While diabetic retinopathy progresses naturally as a result of diabetes, that process is much slower if the disease is well controlled, he says. “Managing your blood glucose carefully, with the help of a multidisciplinary team of experts – endocrinologists, dietitians and others – will help a great deal. But because these complications present only as minor vision impairments, regular eye check-ups are essential.”
The effects of diabetic retinopathy can only be managed with the help of regular, expert surgical interventions from an ophthalmologist. “We can inject a number of effective medications directly into the eye, in our rooms, which helps to slow or prevent the progression of the symptoms. We also use photocoagulation, or focal laser treatment.”
Photocoagulation can also be performed in the doctor’s rooms, and involves using a fine, focused laser to cauterise and destroy or fuse ocular blood vessels in the retina. “This is a quick and relatively simple procedure that helps us manage the condition in the very early stages, so we can ensure it progresses at the slowest possible rate. The goal is to keep your eyesight clear for the duration of your life.”