Visual Acuity Outcome in Diabetic Retinopathy after Diode Laser Therapy

Background and Objective: Diabetic retinopathy as an important complication of diabetic mellitus is a common cause of blindness in diabetic people. The purpose of this study is to investigate the efficacy of the diode laser on visual acuity in patients with diabetic retinopathy.

Methods and Materials: In this cross-sectional study, patients with diabetic retinopathy who had clinically significant macular edema were candidates for laser therapy. High-risk diabetic patients with retinopathy that had also clinically significant macular edema were treated by a diode laser with wavelength of 810 nm. The visual acuity was evaluated 3, 6 and 12 months after the intervention and compared with the patient data before intervention. The data were collected with SPSS-15 and the distribution of descriptive data was indeed analyzed by the use of non-parametric test. Furthermore Wilcoxon and Mann-Whitney compared the mean log MAR before and after laser photocoagulation on visual acuity.

Results: This study was done on 50 patients (64 eyes) with diabetic retinopathy. Twenty seven (54%) of patients were males and 23 (46%) were females. The results of this trial showed clinically significant improvement on visual acuity from 1.21 log MAR before laser therapy to 0.83 log MAR 3 months after intervention (p＝0.02). But this improvement was halted after 12 months of intervention and this does not show any statistically significant relation (p＝0.07). Moreover, the different levels of visual acuity before intervention and at 12 months after, showed no significant relation to gender (P=0.23).

Conclusion: According to these results, the patients’ visual acuity recover at 3 and 6 months after intervention but it did not show any significant difference 12 months later. Retinal photocoagulations in patients with diabetic retinopathy have not led to a worsening of patients’ visual acuity in the long run.