Macular Degeneration and Diabetes

In the recently released EUREYE study, it was shown that there is a postive association between neovascular macular degeneration and diabetes mellitus.  The majority of risk factors associated with macular degeneration have been age, smoking, cholesterol, weight and hypertension.  Until now, only smoking has been consistently associated with macular degeneration.  Diabetes has never been consistently associated with macular degeneration.

In the EUREYE study, participants aged 65 and over underwent an eye examination that included digital retinal photography.  These images were graded at a single centre and a structured questionnaire was administered, examining the risk factors for macular degeneration, including diabetes.

After the data was collected, models were used to examine the association between macular degeneration and diabetes, including the various stages of the eye disease.  The models accounted for demographic, behavioural, dietary and medical factors as well.

The photographic images were graded according to an international classification system for macular degeneration.  Classification consisted of no signs of macular degeneration (stage 0), early macular degeneration (stage 1 – 3) and late macular degeneration (stage 4).  Late stage macular degeneration was further subdivided into neovascular macular degeneration and geographic atrophy.

Data on diabetes history were available in 2117 control subjects without macular degeneration, 2182 participants with early stage macular degeneration, 49 with geographic atrophy and 101 with neovascular macular degeneration.  After adjusting the data, subjects with neovascular macular degeneration compared with controls had increased the odds for diabetes.  Those participants with early macular degeneration had no increased odds for diabetes when compared with those without the eye disease.

In the EUREYE study as postive association of diabetes and neovascular macular degeneration was found.  This has led to the hypothesis that diabetes associated with neovascular macular degeneration and not geographic atrophy may suggest a different pahtogenesis in the two for the eye disease and this may require further study.

Finding an association between diabetes and macular degeneration in the EUREYE study is not consistent with other published studies.