Short-term results of intravitreal ranibizumab injection in eyes with diabetic macular edema

Purpose The aim of the study was to investigate the 1-week and 1-month effects of intravitreal injection of ranibizumab on central macular thickness (CMT) and visual acuity (VA) in patients with diabetic macular edema (DME). Patients and methods In this nonrandomized clinical study, 71 eyes of 62 patients with DME received intravitreal ranibizumab. VA and macular edema were assessed preoperatively and at 1 week and 1 month after injection. Eyes were subgrouped by spectral domain optical coherence tomography (SD-OCT) findings into spongiform edema, cystoid, serous retinal detachment, and tractional. Results Overall, the mean preinjection CMT was 432.0 ± 144.0 μm (range 202.0-846.0 μm); at 1 week it was 369.0 ± 99.33 μm (range 198.0-656.0 μm) with 11.54% improvement (P < 0.001), and at 1 month it was 341.0 ± 88.66 μm (range 191.0-608.0 μm) with 17.96% improvement (P < 0.001). Thirteen eyes with spongiform edema had a significant decrease in CMT (298-285-272 μm) (P = 0.001), yet had nonsignificant vision improvement. CMT decreased significantly in 42 eyes with cystoid edema (439-358-332 μm) (P < 0.001) and in 14 eyes with serous retinal detachment (476-447-386 μm) (P = 0.002). VA significantly improved in the latter two groups. Two eyes with tractional element showed no significant change in CMT and a significant drop in vision. Conclusion Intravitreal ranibizumab is effective in improving VA and decreasing macular edema after 1 week and 1 month after injection; except in eyes with tractional element, which can worsen. Eyes with cystoid edema or serous detachment exhibit significant improvements in both VA and CMT, whereas those with spongiform thickening show significant decrease in CMT without concomitant visual improvement. Therefore, patients could be counseled about the short-term changes in vision and macular edema depending on their SD-OCT-based subtype of DME.