Written by Mr Hemal Mehta for Doctify
Diabetic retinopathy is no longer the leading cause of blind registration in the working age population in the UK – a success of screening
There is a global epidemic of diabetes, with the International Diabetes Federation reporting that 1 in 11 adults have diabetes. One complication of diabetes known as diabetic retinopathy can cause worsening vision due to leakage of fluid at the centre of the retina (macula) or bleeding within the eye. Diabetic retinopathy remains the leading cause of blindness in the working age population worldwide. However, in the UK this is no longer the case because of the success of diabetic retinopathy screening programmes. These identify disease at an early stage and can mean more effective treatments.
If you’re diagnosed with diabetes, your doctor should arrange a dilated fundus examination. You’ll then be screened annually for potentially treatable diseases. This gives you the best opportunity to maintain your driving license, ability to work and independence.
New treatments for diabetic macular oedema are not available to all patients on the NHS
A Cochrane Review has shown that visual outcomes are better with a type of injection called intravitreal (into the eye) anti-VEGF. This is more effective when compared with the previous standard of care, which was macular laser therapy.
Most clinical trials in this review had an entry requirement of greater than 300µm central macular thickness (CMT). If you are a patient with a CMT of less than 400µm, this treatment won’t be available to you on the NHS on grounds of cost-effectiveness. Patients in this situation should be informed of alternate routes to access gold-standard therapy.
An alternative to laser treatment for proliferative diabetic retinopathy
The current standard of care for people with proliferative diabetic retinopathy is a laser treatment known as panretinal photocoagulation (PRP). However, a large American clinical trial showed that regular intravitreal injections with ranibizumab offered similar visual acuity outcomes.
The advantage of these injections is they don’t impair the peripheral visual field. This is in contrast to PRP laser treatment, which can often lead people to lose their driving license. The disadvantage of injections is the small risk of infection within the eye, their cost and need for regular follow-up. I discuss these treatment options with patients and tailor management according to their needs.
Fenofibrate may reduce diabetic macular oedema and diabetic retinopathy progression in people with type 2 diabetes
Two large clinical trials have examined the effect of fenofibrate on diabetic retinopathy in type 2 diabetes. The FIELD Study reported that patients receiving fenofibrate had a 31% lower relative risk of needing retinal laser treatment compared with placebo. The ACCORD-Eye Study reported that patients receiving fenofibrate in combination with a statin had a 79% lower relative risk of diabetic retinopathy progression over 4 years compared with patients who received only a statin. These ocular benefits appear to be independent of its cholesterol lowering effects.
Therefore, Fenofibrate 145mg once daily is licensed in Australia for patients with type 2 diabetes and any diabetic retinopathy to reduce the progression of their condition. In the UK where the license is currently more restricted, it would be reasonable to consider fenofibrate in patients with type 2 diabetes, diabetic retinopathy and abnormal lipid profile.
If fenofibrate is prescribed, kidney function should be monitored and patients should be advised of the early warning symptoms of the rare complication of myopathy: muscle pain, tenderness and weakness. Fenofibrate should not be given in pregnancy.
Cataract surgery in diabetic retinopathy poses unique challenges
Cataract surgery can lead to significant worsening of diabetic retinopathy and diabetic macula oedema. Ideally diabetic eye disease should be treated and stabilised prior to cataract surgery. At times, cataract surgery has to proceed without diabetic retinopathy being completely controlled and perioperative intravitreal anti-VEGF or intravitreal steroid agents may be needed.
The UK National Dataset of over 55,000 cataract surgery cases identified higher complication rates and lower visual acuity improvement in patients with diabetes compared with the general population. Hence, the need for specialist management from a cataract surgeon with expertise dealing with retinal disease.