Changes in visual acuity and contrast sensitivity following macular photocoagulation for clinically significant macular edema: Four month outcomes

Threshold severity of diabetic macular edema (DME) at which initiation of laser treatment is justified, was defined as ‘clinically significant macular edema' (CSME) by ETDRS (Early treatment of diabetic retinopathy study). ETDRS showed that macular photocoagulation decreased persistent macular edema and risk of moderate visual loss by 50% in CSME. Benefit of treatment generally observed in 3-4 months. Objectives: To estimate the improvement in visual acuity VA and contrast sensitivity CS at four months following macular photocoagulation, in a single arm of Type 2 diabetes patients diagnosed with CSME in a semi-urban population of South Kerala. Methodology: It was a prospective study (Descriptive). 250 eyes of Type 2 diabetics with CSME were included. Focal/grid pattern macular photocoagulation, using frequency doubled Nd: YAG laser was administered to all participants. Improvement in VA was defined as gain by one line/more and decrease by more than two lines was considered as worsening. Any drop/gain in CS was considered significant. Analysed using SPSS 16.0. Results: 148 eyes (59.2%) received focal and 102 eyes (40.8%) received grid pattern lasers. 242 eyes were included in final analysis. VA in 77 eyes (30.8%) was stable, improved by one line/more in 134 eyes (53.6%), decreased by <2 lines in 22 eyes (8.8%) and decreased by >2 lines in 9 eyes (3.6%). Paired sample t-test to compare VA and CS before and after therapy, showed significant improvement (p<0.001 and p<0.001 respectively). Conclusion: VA as well as CS showed statistically significant improvement at 4 months following focal/ grid pattern of macular photocoagulation in CSME.