The study, published in the June issue of Archives of Ophthalmology, also found that diabetes patients using the drug were less likely to have reductions in visual acuity.
Proliferative diabetic retinopathy occurs when a mass of new blood vessels develop on the retina, decreasing visual acuity and eventually causing serious vision loss. So far there are no medications that are known to specifically prevent this from occuring.
These findings come from a study conducted by Lucy Shen(Jules Stein Eye Institute, University of California-Los Angeles) and colleagues, who focused on the relationship between eye health and the drug rosiglitazone. The researchers collected data from medical records of 124 patients from the Joslin Diabetes Center in Boston. The patients were treated with rosiglitazone and were receiving medical and eye care at the center between May 2002 and May 2003. The rosiglitazone sample was then compared to 158 diabetes patients who were not being treated with rosiglitazone or a similar medication.
The initial analysis of the data revealed that 14 eyes (6.4%) in the rosiglitazone group and 24 eyes (9.3%) in the comparison group had an early stage of the disease called non-proliferative diabetic retinopathy (the new blood vessels had not yet formed). After one year, several of these eyes had progressed to proliferative diabetic retinopathy - 7.7% of the rosiglitazone group and 29.2% of the comparison group. Shen and colleagues calculated a 59.5% relative reduction in risk of progressing from the non-proliferative to the proliferative form of the disease for patients being treated with rosiglitazone. Only 19.2% of the rosiglitazone group, compared to 47.4% of the comparison group had progressed after three years.
The researchers also noted that during an average of 2.8 years of follow-up, eyes in the rosiglitazone group were less likely than the eyes in the comparison group to experience a loss in visual acuity of three or more lines on the vision chart - 0.5% to 14.5%, respectively.
They conclude that, "Determination of the full efficacy and clinical role of rosiglitazone in the treatment of proliferative diabetic retinopathy and other angiogenic conditions awaits confirmation of risks and benefits and possibly large-scale definitive studies."
