Clinical Study In Risk Factors And Relationship Between Macular Anatomical And Functional Outcomes In Idiopathic Macular Epiretinal Membranes

Objective:To research the risk factors relating to idiopathic macular epiratical membranes (IMEM), the features and correlation of frequency-domain optical coherent tomography (fdOCT) and multifocal electroretinogram (mfERG) in patients with IMEM were investigated, and visual acuity was also included. By objectively evaluating the effect of IMEM on macular structure and function benefited researching its pathogenesis. It was expected to provide clinical evidence for ophthalmologists to prepare for prevention, screen the affect individuals and pertinency treatment.Methods:1.72eyes of60patients who were diagnosed as IMEM and100middle-aged or elderly people (≥50years old) without this disease from March2012to January2013at Tianjin Eye Hospital were recruited. We carried out the detailed ophthalmologic examination and conducted a questionnaire survey for all the people, including ocular histories, the general conditions, systemic diseases and long-term (>3monthes) medications. Then, the correlation of IMEM with the above factors was analyzed;30cases with unilateral IMEM underwent mfERG, who had clear refraction media and took concerted action. The data from the affect eyes was used as the test group and contralateral normal eyes was used as the control group. The features and relationship between the results of macular morphology and function were analyzed, and the effect on visual acuity was also included. The best corrected visual acuity (BCVA), slit-lamp biomicroscropy, ophthalmoscopy, fudus fluorescein angiography and fdOCT were performed for all the patients. All the resualts were input to perform a statistical analysis.2. Statistical method:the data was analyzed by17.0statistical software with methods of multivariate regression models, paired t test, single factor analysis of variance and correlation analysis, P<0.05as the standard of significant difference in statistic.Results: 1. Patients with IMEM:86.7%patients had systemic diseases. Among them, cervical spondylosis, hypertensive disease, cardiovascular and cerebrovascular diseases were the top three diseases associated with IMEM. According to the fundus and FFA imaging outcomes, the diseases were divided into three stages:1stage,18eyes, accounted for25%,2stage,36eyes, accounted for50%,3stage,18eyes, accounted for25%and macular hole including5eyes accounted for6.9%.2. The univariate logistic regression analysis revealed that4research factors were significant difference in statistic (x2=4.220,4.903,5.073,3.979; P=0.040,0.027,0.024,0.046), including gender, age, diabetic mellitus, hyperlipemia. However, multivariate regression models showed that there were no statistic significant difference in diabetic mellitus, hyperlipemia and antidiabetic drugs (P=0.288,0.114,0.963). Gender (P=0.040; OR=2.186; OR95%CI:1.038～4.606) and age (P=0.026; OR=2.259; OR95%CI:1.102～4.62) were the main risk factors for IMEM. Systemic diseases and long-term medications were no found to be involved in the mechanism of IMEM.3. Patients with unilateral IMEM:The features of macular morphology, function and relationship between them were analyzed, the results were as follows:(1) Morphological changes in the macular area:fdOCT revealed that there were significantly statistical differences in the retinal thicknesses ahout macular fovea, parafovea and perifovea between the test group and control group (t=6.275,3.808,3.594; P=0.000,0.001,0.001). These demonstrated that the overall retinal thickness was increased with the biggest in fovea, followed by parafovea and perifovea.(2) Functional changes in the macular area:Posterior retinal responses with varying degrees in patients with IMEM, such as the general declining in the retinal response densities and prolonging in the implicit times obviously in some areas. Compared with the normal fellow eyes, the resualts revealed that there were significant differences in the amplitude densities of P1waves and the implicit times of N1waves at ring1to5(P<0.05). There were no statistical differences in the response densities of every waves at Ⅰ-Ⅳquadrants, up and down fields (P>0.05) except the implicit times of all the waves (P<0.05).(3) The relationships among best-corrected visual acuity, macular structure and function:The visual acuity was negatively correlated with the central retinal thickness (r=-0.449, P=0.013). The visual acuity can be worse with the increase of retinal thickness at fovea. The implicit times of P1,N1waves at ring1had effect on visual acuity (r=-0.493,-0.423; P=0.006,0.020), however, the amplitude densities were not (r=0.184,0.228; P=0.332,0.227). The amplitude densities and implicit times of the mfERGs in fovea were also not significantly correlated with the increased central retinal thickness (r=-0.356,-0.245,-0.038,0.058; P=0.053,0.193,0.843,0.762).Conclusions:Gender and age were the main risk factors for IMEM. Systemic diseases and long-term medications were no found to be involved in the mechanism of IMEM. Patients with IMEM often accompanied by systemic diseases, cervical spondylosis, hypertensive disease, cardiovascular and cerebrovascular diseases were common among them. IMEM could lead to morphological and functional changes in the macular area. The visual acuity can be worse with the increase of central retinal thickness, but it was not consistent with the retinal damage. The combination of fdOCT and mfERG have better evaluation in the effect of IMEM on macular anatomical and functional outcomes. This would be used to choice better clinical treatments.