[Using asymmetric mixed bivariate modeling for comparing diabetic macular edema treatments according to visual acuity and central macular thickness outcomes]

One of the major causes of visual acuity loss in diabetic patients is diabetic macular edema [DME]. Best-corrected visual acuity and central macular thickness changes are considered as two main outcomes in diabetic macular patients. The goal of this study was to compare the effect of intravitreal bevacizumab injection alone or combined with triamcinolone versus macular photocoagulation as primary treatment for diabetic macular edema according to the clinical trial data sets. A new method was proposed to determine the best treatment for DME; i.e. intravitreal bevacizumab injection alone or combined with triamcinolone versus macular photocoagulation using asymmetric mixed modeling based on the recorded data in 97 diabetic patients. Effect of these treatments was investigated according to simultaneous investigation of visual acuity and central macular thickness as two major outcomes without omitting any outlier. The results of bivariate asymmetric mixed model revealed that intravitreal bevacizumab injection alone or combined with Triamcinolone treatments had more therapeutic effect than the macular photocoagulation in terms of increasing visual acuity and decreasing central macular thickness in patients with DME. Using asymmetric bivariate mixed model, there was a significant difference among the treatment modalities, duration of diabetes and gender in terms of visual acuity and central macular thickness