Efficacy of single intravitreal injection of Ranibizumab for diabetic macular edema

AIM: To observe the efficacy of single time intravitreal injection of ranibizumab(IVR)in patients with diabetic macular edema(DME).<p>METHODS: Twenty-nine cases of DME patients who complied with diagnostic criteria for clinically significant macular edema were enrolled in this retrospective study. All the patients receive single dose IVR(0.05mL, 10mg/mL), and no other eye treatments were performed before this operation. All data were recorded before and after injection of 4, 8, and 16wk. Best corrected visual acuity(BCVA), central foveal thickness(CFT), the integrity of the foveal photoreceptor layer on optical coherence tomography were analyzed. The data of photoreceptor integrity and photoreceptor defect group also were recorded and analyzed.<p>RESULTS: BCVA was significantly improved at 4 and 8wk after IVR(<i>P</i>=0.009,0.003), macular edema was relieved, and CFT was significantly lower in the same time(<i>P</i><0.01,<i>P</i>=0.001). But the drug action was weakened in 16wk, BCVA was poorer than that in 4 and 8wk(<i>P</i>=0.043,0.019), macular edema recurred CFT increased(<i>P</i><0.01,<i>P</i>=0.005). BCVA and CFT value were not statistically significant different between 4 and 8wk(<i>P</i>=0.074,0.420). There was no significant change in BCVA before and after surgery in photoreceptor complete group(<i>P</i>=0.076), but CFT was lower obviously(<i>P</i>=0.001). BCVA and CFT value were better in photoreceptor defect group after IVR in 4wk(<i>P</i><0.01,<i>P</i><0.01). There was significant correlation between visual acuity and photoreceptor integrity before and after treatment in 4wk(<i>P</i>=0.015, 0.024).<p> CONCLUSION: Patients with DME treated with ranibizumab obtained great improvements in vision and macular edema in the short term. Macular photoreceptor integrity was closely related to the vision. IVR may also repair the macular photoreceptor damage