Original scientific paper
The Role of Oxidative Stress after Retinal Laser Photocoagulation in Nonproliferative Diabetic Retinopathy
Davor Galetović
Lovro Bojić
Kajo Bućan
Dobrila Karlica
Mladen Lešin
Ljubo Znaor
Abstract
Diabetic retinopathy (DR) represents the most common chronic complication of diabetes, and it is the leading cause of
new cases of blindness in patients between 20–74 years old in developed countries. Laser photocoagulation (LF) represents
an efficacious approach to the treatment of DR. Oxidative factors, such as free radicals (FR), are continuously generated
in aerobic organisms as a result of different metabolic processes. It is well known that oxidative stress plays a role
in the development of DR. The aim of this study was to evaluate the thermal effects of the scatter retinal laser photocoagulation
technique on the production of FR. A total of 90 patients were enrolled in this study. They were divided in 3
groups: 30 diabetic patients with DR, 30 diabetic patients without DR, and 30 control individuals without diabetes
mellitus (DM). Full scatter retinal LF was performed in all patients with DR. We measured the concentrations of superoxide
dismutase (SOD), glutathione peroxidase (GPOD), catalase, and total antioxidative status (TAS). Of the 30 DR patients,
13 showed the appearance or worsening of macular edema after LF, whereas the other 17 patients showed no
change. Thirty days after LF, improvement in visual acuity was observed, but this change was not statistically significant.
The mean plasma or erythrocyte lysate concentrations of various antioxidants were significantly lower in the diabetic
patients without DR compared to the individuals without DM and in the diabetic patients with DR compared to the
individuals without DM; the diabetic patients with DR did not show lower concentrations of the antioxidants compared
to the diabetic patients without DR. The concentrations of SOD, GPOD, catalase, and TAS were significantly lower in
the diabetic patients with DR after retinal scatter LF, which could be the consequence of retinal oxidative stress caused by
the LF thermal effect.
Keywords
oxidative stress; diabetes mellitus; light coagulation; retina; Croatia
Hrčak ID:
72182
URI
Publication date:
30.9.2011.
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