Diabetic retinopathy in patients who do not meet the diagnostic criteria for cystic fibrosis related diabetes

The UK Cystic Fibrosis (CF) Trust guidelines state that the diagnosis of CF related diabetes (CFRD) should only be made after an oral glucose tolerance test in the diabetic range and hyperglycaemia on serial monitoring. We report three patients with CF who were known to have abnormal glucose tolerance but did not meet the diagnostic criteria for CFRD. As the patients were commenced on insulin they were referred for annual diabetic complication screening and all were diagnosed with diabetic retinopathy. As these patients developed complications without being diagnosed with the causative disease, it questions the current diagnostic criteria for CFRD. This patient group also disproves the hypothesis that CFRD patients without fasting hyperglycaemia do not develop microvascular complications and suggests that, in some patients, such complications may develop earlier than previously thought. Copyright (C) 2015 John Wiley & Sons.