Retinopathy
Diabetic retinopathy is the commonest cause of visual loss amongst working age people in the UK. However, it is almost completely preventable with good glycaemic control and regular retinal screening. Diagnosis is usually made on retinal screening. Management is by laser photocoagulation, good glycaemic control and there is also some role for ACE inhibition and possibly fibrate therapy.
How long has the patient had diabetes?
If the diagnosis is T1DM or gestational diabetes then diabetic retinopathy is extremely unusual at presentation and in the case of T1DM, is relatively unusual within ten years of diagnosis.
However, approximately 10% of patients with newly diagnosed T2DM will already have some retinopathy. The risks of retinopathy generally go up the longer the patient has had diabetes.
Does the patient have other microvascular complications such as nephropathy or neuropathy?
The presence of other microvascular complications increases probability that the patient will develop further ones.
What has the HbA1c been like?
The higher the average HbA1c over the years since diagnosis, the greater the risks of developing retinopathy (and other microvascualr complications).
Is there a history of hypertension?
Hypertension is also a significant risk factor for retinopathy.
When did the patient last have digital retinal photography?
All people with diabetes (except gestational diabetes) in the UK should undergo annual digital retinal screening photography. An interval since last screening of over a year increases the risks that significant retinopathy has developed.
Is the patient pregnant?
Pregnancy with pre-existing T1DM and T2DM is an important risk factor for worsening of retinopathy and, traditionally, retinal screening is performed three times during pregnancy - once in each trimester.
More recently, NICE have recommended that retinal screening is performed at booking and again at 28 weeks. If pre-exisitng retinopathy is present, an additional screen should be performed at 16-20 weeks gestation.
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