The Comparison of Contrast Sensitivity after Three Different Treatment Modalities for Clinically Significant Macular Edema

Purpose: The aim of this study was to evaluate the effect of adjuvant treatments on contrast sensitivity in patients with clinically significant macular edema (CSME) treated with macular photocoagulation (MPC). Methods: Forty eight eyes from 30 patients with non-proliferative diabetic retinopathy (NPDR) and CSME were included in a prospective randomized clinical trial between August 2008 and October 2009. They randomly assigned in sham injection, intravitreal bevacizumab (IVB) injection (1.25 mg/0.05 cc) and intravitreal triamcinolone (IVT) injection (2 mg/0.05 cc) groups. MPC was done within 1 month for them. Detailed fundus examination, ocular coherence tomography, and determination of best corrected visual acuity (BCVA) and contrast sensitivity which were repeated after 3 and 6 months are reported. Results: A total of 48 eyes from 30 patients were enrolled. CSME resolved in 32 (66.6%) of 48 eyes 3 months after MPC. Despite no statistical significant difference in visual acuity (VA) among groups, contrast sensitivity in IVB group was significantly higher than sham group in 4.8 cycles per degree (cpd) (P=0.03). Also contrast sensitivity in IVT group was significantly higher than sham group in 4.8 cpd (P=0.03) and 12 cpd (P=0.03). Six months after MPC, 37 eyes (77.08%) had resolved CSME. There was no significant difference in VA among groups but contrast sensitivity at 4.8 cpd in IVT group was significantly higher than sham group (P=0.005). There was no significant difference between the other groups. Conclusion: Three months after MPC, IVT combined with MPC and IVB combined with MPC had better effect on contrast sensitivity comparing MPC alone. Six months after MPC, IVT combined with MPC was associated with greater beneficial effects on contrast sensitivity than MPC alone.