Analysis Of Related Factors Affecting Postoperative Metamorphopsia In Patients With Idiopathic Macular Epiretinal Membrane

Objective:To observe the improvement of visual deformation after vitrectomy combined with macular exfoliation in patients with idiopathic anterior macular membrane(iMEM),and to analyze the relationship between visual deformation and macular microstructure.Methods:A total of 20 patients(20 eyes)with iMEM diagnosed in the Ophthalmology Center of the second Hospital of Jilin University from September 2017 to October 2019 were collected.All patients were treated with 25 g or 23 g transconjunctival minimally invasive vitrectomy combined with macular epiretinal membrane exfoliation.All patients were examined by best corrected visual acuity(BCVA),intraocular pressure(IOP),spectral domain optical coherence tomography(SD-OCT)before and after operation,and M-charts table was used to quantitatively examine the visual deformation before and after operation.BCVA,M-charts and SD-OCT related parameters were observed before operation,1 week,1 month,3 months and 6 months after operation.The M-charts table is used to check the vertical metamorphopsia(MV),horizontal metamorphopsia(MH)and mean metamorphopsia score(M-score).Central foveal thickness(CFT),subfoveal choroid thickness(SFCT),inner nuclear layer thickness(INLT)and ganglion cell-inner plexiform layer thickness(GC-IPLT)at 1000 ?m from the nasal and temporal sides of the central fovea were measured by SD-OCT.The average values of INLT and GC-IPLT on the nasal side and the temporal side were recorded respectively.SPSS Statistics 26.0 statistical software was used for statistical analysis.Results:The changes of MV and MH before and after operation were statistically significant(P <0.001).There was no significant difference in MV between 1 week and 1 month after operation(P =0.227>0.05),but there was significant difference in MV between 1 week and 3 months and 6 months after operation(P <0.05).There was no significant difference in MH between 1 week and 1 month after operation(P =0.199>0.05),and between 1 week and 3 months after operation(P =0.069>0.05),but there was significant difference in MH between 1 week and 6 months after operation(P <0.05).The average MV at each time point before and after operation was higher than the average MH,but there was no significant difference between them(P >0.05).The correlation analysis of the best corrected visual acuity(logMAR)and M-score at each time point before and after operation showed that there was no significant relationship between the best corrected visual acuity(logMAR)and M-score(P >0.05).The correlation analysis between M-score and CFT,SFCT,INLT and GC-IPLT before and after operation showed that there was significant correlation between M-score and CFT,INLT and GC-IPLT(r=0.379,P <0.001;r=0.098,P =0.332;r=0.457,P <0.001;r=0.376,P <0.001).Conclusion:1.Vitrectomy combined with anterior macular membrane exfoliation can improve visual acuity and visual distortion in patients with iMEM.2.In patients with iMEM,the deformation of vertical vision entered the plateau earlier than that of horizontal vision.3.In addition to the best corrected visual acuity,visual distortion can be used as an index to evaluate the improvement of visual function in patients treated with iMEM.4.The thicker of the CFT,INLT and GC-IPLT before operation,the more serious the metamorphopsia of the patients.5.The thicker of the postoperative CFT,INLT and GC-IPLT,the less obvious the improvement of metamorphopsia.