Using Mixed Models with Flexible Random Effects for Determining the Best Diabetic Macular Edema Treatment

Diabetic macular edema is one of the most prevalent outcomes between diabetic patients. According to high prevalence of this disorder and its related outcomes between diabetic patients, the goal of this study is determining the efficacy of a single intravitreal injection of bevacizumab (IVB) alone or in combination with triamcinolone versus macular laser photocoagulation (MPC) as primary treatment for diabetic macular edema (DME) using updated statistical modelling. This modeling was performed on 102 diabetic patients in three above-mentioned groups who had diabetic macular edema and did not get any treatment before the beginning of clinical trials. A mixed model with non-normal random effects has been proposed to compare the effects of treatment on diabetic macular edema by omitting the effects of confounders. Effect of these treatments has been investigated according to variation of best-corrected Visual Acuity and central macular thickness, as two major outcomes. The results of mixed modelling with non-normal random effects according to omitting the effects of confounders in the period of study, show that the Intravitreal Bevacizumab injection alone or combined with Triamcinolone treatments have more Therapeutic effect than the Macular Photocoagulation treatment on Diabetic Macular Edema patients. According to this investigation, patients with more diabetic duration who had more central macular tickness and less best-corrected visual acuity in the beginning of the study had better response to interventions. More investigations showed using different treatments lead to different results on diabetic macular edema.