Development of proliferative retinopathy in patients with long-standing insulin-dependent diabetes mellitus

Some patients with long-standing insulin-dependent diabetes mellitus (IDDM) develop little or no retinopathy. Using a clinic-based questionnaire and examination, we investigated a group of patients with over 40 years or more of IDDM who had been followed up at the King's Diabetes Centre for an average of 40 years. We compared those who had developed proliferative diabetic retinopathy during their disease with those with minimal or no retinopathy.

The study did not find any statistically significant differences between the two groups to suggest why some long-term insulin-dependent diabetics develop little retinopathy. Those who developed sight-threatening retinal complications did so at an average of 35 years after diagnosis and it resulted in little visual disablement. Very few patients in either group had developed other significant complications.

This study details an interesting group of patients with long-term IDDM mellitus with a mean follow-up period of 40 years. Some patients with long-standing IDDM develop little or no retinopathy. With the advent of community ophthalmic screening, these patients are now rarely seen in the eye clinic. Those who did develop retinal complications and required treatment have remarkably little visual disablement. However, these complications developed late in the history of their disease, emphasising the need for continued screening.