The study focused on type 2 diabetes patients who had nonproliferative diabetic retinopathy (DR). There were 105 patients in the study.
Each patient had a complete ophthalmic examination. Additionally, researchers obtained a plasma determination of oxidative (malonyldialdehyde [MDA]) and antioxidant parameters (total antioxidant status [TAS]) at baseline.
Then one part of the patient population was randomly assigned to take oral antioxidant supplementation (at nutritional doses).
There were 97 patients who completed the 5-year follow-up period, and the same examinations (complete ophthalmic, MDA, and TAS) were done on those patients.
The following were compared for the beginning of the study and the end of follow-up:
The study found that supplementation with an oral antioxidant did not change best-corrected visual acuity. The retinopathy stage, though, did who a slowing of progression for those taking the supplement; for those were not taking the antioxidant supplement, retinopathy stage worsened.
Additionally, those taking the supplement maintained antioxidant plasma status levels.
The study concludes that oral antioxidant supplementation may be a useful adjunct long-term therapy for patients with type 2 diabetes who have nonproliferative diabetic retinopathy.