The Cathedral Eye Clinic

Diabetes is very common, affecting approximately 1 in 25 patients in the developed world. In the UK up to 9% of the whole NHS budget is used to treat diabetes and its related complications.

The condition can start in childhood or later in life. It can affect many different parts of the body, but particularly the eye.

How does diabetes affect the eye?

Diabetes can affect the eye in various ways. The most serious effects however are through problems in the retina. This problem is called diabetic retinopathy.

Diabetic retinopathy occurs as a consequence of diabetes and can result in loss of vision either through leaky blood vessels causing swelling of the retina or by causing the production of abnormal blood vessels which result in bleeding within the eye and scaring of the retina.

Screening is essential to detect vision threatening stages prior to loss of vision.

Having diabetes does not mean that a person will have eye problems, but it is important that regular eye examinations are carried out to ensure that any potential problems are diagnosed early. Sight loss from diabetes can usually be prevented if retinopathy is diagnosed and treated early. After diagnosis the condition can be graded by a person’s eye specialist depending on its severity.

Treatment

The most important aspect of management of diabetes is to ensure that good cooperation exists between each patient and the team of health professionals who are involved in managing their care. The general practitioner is key to proper management of all systemic medical factors. However, the ophthalmologist as a diabetic retinopathy screener in addition to directly managing retinal problems should provide support to the GP by helping to communicate the value of good systemic medical management. Strategies for treatment combine optimization of systemic risk factors such as blood glucose control, blood pressure management, reducing blood lipid levels.

Evidence for the value of controlling these factors includes:

Glycaemic Control:- Diabetes Control and Complications Trial (DCCT) demonstrated a 26% reduction in the risk of developing macular oedema where there was intensive insulin treatment

Blood Pressure Control:- UK Prospective Diabetes Study (UKPDS) reported a 47% reduction in loss of vision from macular oedema in Type II diabetics where there was tight blood pressure control

Blood Lipid Control:- The DCCT and the ETDRS studies have demonstrated positive correlations between lipid profiles and the development of macular oedema in patients with type I Diabetes.

Smoking:- This is a well recognized risk factor for diabetic micro- and macrovascular problems. No diabetic should smoke.

Local Ophthalmic Treatment

The Cathedral Eye Clinic follows the Early Treatment of Diabetic Retinopathy Study (ETDRS) guidelines when managing diabetics with laser photocoagulation. This study sponsored by the US National Eye Institute has shown that early laser intervention when clinically significant macular oedema is present can reduce the risk of moderate visual loss by 50%.

In addition to the ETDRS study guidelines the institute advocates using larger spot sizes with longer durations and lower energy profiles. This is in response to more recent studies demonstrating effectiveness of this technique while minimising any side-effects of the laser treatment. (Roider J et al, 2000, BJO 84(1):40-47)