Abstract
Purpose: :
To elucidate values of optical coherence tomography (OCT) based macular thickness assessment methods in definition of correlations between visual acuity and macular thickness values in different treatment methods of diabetic macular edema.
Methods: :
Sixty-three patients treated with intravitreal triamcinolone (IVTA) (group 1), intravitreal bevacizumab (IVB) (group 2), and modified grid/focal laser photocoagulation (GLP) (group 3) for treatment-naive, chronic, center-involving, nonischemic diffuse diabetic macular edema (DDME) were included. In each group, correlation between changes in best corected visual acuity (BCVA) and central macular thickness (CMT) values recorded during 12 months follow-up were defined, regarding four CMT assessment methods including absolute change in retinal thickness (ACRT), relative change in retinal thickness (RCRT), relative change in retinal thickening (RCRTing), and logaritmic changes in retinal thickness (LCRT).
Results: :
Baseline BCVA (logMAR) and CMT were, 0.95±0.4 and 491.8±163.9 µ for the IVTA group; 0.79±0.4 and 426.1±116.5 µ for the IVB group; 0.44±0.1 and 391.7±100 for the GLP group, respectively. After the treatment, at 12 months BCVA had improved by 0.09±0.2 logMAR in the IVTA group, 0.10±0.2 in the IVB group and decreased by 0.03±0.2 in GLP group. ACRT, RCRT, RCRTing, and LCRT were, respectively 174±164, 29.4±29, 0.87±0.9 and 0.18±0.1 in the IVTA group; 93±161, 16.9±32, 0.3±0.6 and 0.11±0.17 in the IVB group; 19.3±87.2, 2.6±23.2, 0.01±0.67 and 0.02±0.09 in GLP group. When comparing these CMT assessments, a remarkable difference was observed among the groups (p<0.01, p=0.01, p<0.01 and p=0.01 respectively) and the IVTA group had significantly better results. When comparing the logMAR improvements between groups, no significant difference was found (p=0.47). Correlations between logMAR improvements and all CMT assessments were significant only in GLP group (p<0.01). The most correlated OCT parameters with the logMAR improvements were RCRTing in GLP group (r=-0.61) and IVTA group (r=0.11); LCRT (r=0.33) and RCRT(r=-0.33) in IVB group.
Conclusions: :
RCRTing in eyes treated with GLP and IVTA; LCRT and RCRT in IVB seem to be the method of choice to analyse correlation between BCVA and CMT values.
Keywords: diabetic retinopathy • visual acuity • vascular endothelial growth factor