Short-term Effects On Intravitreal Ranibizumab Treatment For Different Optical Coherence Tomographic Patterns Of Diabetic Macular Edema

Objective: To evaluate the effect of intravitreal ranibizumab injection on different morphologic patterns of diabetic macular edema(DME)determined by optical coherence tomography(OCT).Methods: The diagnosed DME patients who were treated with intravitreal ranibizumab injection from March 2015 to December 2015 in the First Affiliated Hospital of Dalian Medical University were included in the study.Gender,age,duration of diabetics before treatment were recorded.The eyes were categorized into 3 groups according to the morphology upon OCT: spong-like diffuse retinal thickening(DRT),cystoid macular edema(CME)and serous retinal detachment(SRD).All patients received intravitreal ranibizumab injection 0.05mg/0.5ml.Intraocular pressure(IOP),best corrected viaual acuity(BCVA)were evaluated before and after therapy,shifts in morphology of the macular edema and central macular thickness(CMT)were assessed by OCT in each subgroup.All analyses were computed by using SPSS software.For all statistical tests,P<0.05 was considered significant.Results: A total of 38 eyes(mean age was 57.68±10.04 years old)from 30 patients were collected in this study,including 18 eyes of DRT group,12 eyes of CME group and 8 eyes of SRD group.In DRT group,mean BCVA(Log MAR)were improved from 0.73±0.33 to 0.56±0.31,the improvement had significant difference(P=0.000);mean CMT were decreased from(331.22±82.01)mm to(264.28±69.40)mm after 1 month follow-up,the reduction in CMT was statistically significant(P=0.000).In CME group,mean BCVA(Log MAR)did not show significant difference after 1 month's treatment(P=0.277),which were from 0.71±0.31 to 0.63±0.34;mean CMT were decreased from(455.42±136.39)mm to(286.50±116.52)mm,showed significant difference(P=0.007).In SRD group,mean BCVA(Log MAR)were improved from 0.85±0.44 to 0.76±0.32,but the difference was not statistically significant(P=0.150);mean CMT decreased from(525.50±203.81)mm to(300.13±142.37)mm,the reduction was statistically significant(P=0.031).No statistically significant difference was found among three groups regarding the change in BCVA(P=0.443).The CME and SDR groups were associated with a greater reduction in the CMT than DRT group,and the amount of reduction among three groups showed statistically significant difference(P=0.037).However,there was no statistically significant variation among three groups in terms of percentage of change in CMT(P=0.157).Conclusions: First,intravitreal ranibizumab injection was effective for DME and could improve patients' visual acuity.Second,patients showing DRT upon OCT achieved greater improvements in visual acuity,and showed better visual improvement in proportion to the decrease in CMT.Third,the type of macular edema shown by OCT may provide an objective guideline in predicting the response of DME to IVR injection.