Purpose
To evaluate the effects on contrast sensitivity (CS) measuraments of intravitreal bevacizumab injections associated with standard metabolic control in eyes with diabetic macular edema.
Methods
Prospective, randomized, masked and interventional study. Forty-one eyes of 34 patients with type 2 DM, Glycate hemoglobin (HbA1c) less than 11% and previously treated macular edema three months before were randomized in two groups. The baseline examination consisted of visual acuity (VA), CS using the Pelli-Robson Charts, optical coherence tomography (OCT) and angiofluoresceinography for all eyes. Group 1 ( 21 eyes) was treated with intravitreal bevacizumab injection (1.25mg) at the weeks 0,6,12 and 18. Group 2 (20 eyes) received a sham injection at the weeks 0 and 6; and intravitreal bevacizumab injetion at the weeks 12 and 18. The Mann-Whitney U and Wilcoxon tests were applied to compare the differences between the two groups to categorical and continuous variables, respectively. The null hypothesis were rejected for P-value < 0.05.
Results
Reduction > 0.5% on average HbA1c levels in both groups in the period of 24 weeks. The corresponding data: the baseline was 8.28% ± 1.08 and 8.44% ± 1.20; and at week 24, 7.72% ± 0.99 and 7.66% ± 1.15 for groups 1 and 2 respectively. The mean CS for groups 1 and 2 was at baseline respectively: 1.14±0.37 and 1.00±0.32 logCS (p=0.36). At week 12, respectively 1.30±0.24 and 1.13±0.30 logCS (p=0.11). At week 24, respectively 1.28±0.23 and 1.21±0.22 logCS (p=0.51). No statistically significant difference was found between the two groups for VA, OCT or CS in the period of 6 months. Both groups improved substantially their VA, OCT and CS at week 12 and 24 (p<0.05).
Conclusions
The CS improvement demonstrated in both groups can be attributed to better control of the blood glucose with glycated hemoglobin (HbA1c) associated with intravitreal bevacizumab injections. Two consecutive intravitreal bevacizumab injections associated with standard metabolic control were comparable to two consecutive sham injections associated with standard metabolic control for macular structure and function in diabetic macular edema
Keywords: 499 diabetic retinopathy •
478 contrast sensitivity •
505 edema