RESUMEN
Objective To compare visual impairment following secondary macular edema between diabetic and non-diabetic patients with branch retinal vein occlusion (BRVO) and assess the potential risk factors.Methods All 92 eyes in 87 patients with BRVO and secondary macular edema were recruited from Shaanxi provincial people's hospital and their clinical data were retrospectively analyzed.The patients were divided into 2 groups based on their blood glucose level:diabetic group including 38 patients (40 eyes) with diabetes mellitus and non-diabetic group including 49 patients (52 eyes) without diabetes.Baseline demographic assessments of vascular risk factors were evaluated at the beginning,including gender,age,medical history,BMI,blood pressure,serum lipid,HbAlc and ischemic heart disease.Visual acuity,axial length,intraocular pressure and central macular thickness (CMT) were observed when patients were admitted and at 1 month,3 months and 6 months during follow-up in the both groups,and logistic regression analysis was used to determine the related risk factors for visual impairment.Results There was no significant difference in the best corrected visual acuity between the two groups before treatment (P ＜ 0.05).The visual acuity of the nondiabetic group improved significantly during 1-month follow-up when compared with the diabetic group (t =2.22,P ＜ 0.05).However,no difference in visual acuity was found between the two groups during 3-month and 6-month follow-up.With " long-distance visual acuity ＞ 0.5 logMAR" as the dependent variable and various risk factors as the independent variable,univariate logistic regression analysis showed that diabetes mellitus (P =0.000),hyperlipidemia (P =0.000) BMI and axial length (P =0.000) were significantly associated with visual impairment following BRVO.According to the logistic regression analysis,hyperglycaemia (OR =8.222,P =0.014),hyperlipidemia (OR =25.247,P =0.002) and overweight (OR =1.388,P =0.014) were associated with the increased risk for final vision impairment,and axial length (OR =O.213,P =0.000) was proved to be a protective factor,which could alleviated the vision impairment.Conclusion Severe vision impairment following BRVO occurs more often in diabetic patients than non-diabetic patients,and controlling weight,glucose and lipid level may be an effective method for preventing vision impairment.