特发性黄斑前膜患眼手术后中心凹无血管区面积变化及其与视物变形的相关性研究

Changes of foveal avascular zone size and correlation between foveal avascular zone size and metamorphopsia before and after idiopathic macular epiretinal membrane surgery

目的观察特发性黄斑前膜(IMEM)患眼玻璃体切割手术(PPV)后中心凹无血管区(FAZ)面积变化及其与视物变形的相关性。方法回顾性系列病例研究。2016年8月至2017年10月于解放军中部战区总医院眼科检查确诊的IMEM患者38例42只眼纳入研究。均行BCVA、视物变形评分表、扫频光源OCT及OCT血管成像(OCTA)检查。患眼平均logMAR BCVA为0.61±0.21;平均视物变形度(M)值为0.66±0.38;平均黄斑中心凹视网膜厚度(CMT)为(337.71±57.63)μm;平均浅层、深层FAZ面积分别为(0.113±0.037)、(0.202±0.03)mm^2。所有患眼均行经睫状体平坦部三切口闭合式25G PPV,同时剥除视网膜前膜(ERM)及内界膜(ILM)。观察手术后12个月FAZ面积、M值及BCVA变化情况;同时分析FAZ面积与M值之间的相关性。手术前后BCVA、M值、CMT、FAZ面积比较采用单因素重复测量资料的方差分析;手术前后BCVA、M值与CMT、FAZ面积的相关性分析均采用Spearman秩相关分析。结果手术后12个月时,浅层、深层FAZ面积分别为(0.146±0.021)、(0.240±0.019)mm^2,较手术前明显扩大(F=8.484、14.346,P<0.001、<0.001);平均M值为0.12±0.22,较手术前明显降低(F=17.763,P<0.001);平均logMAR BCVA为0.47±0.19,较手术前明显改善(F=5.044,P=0.001);平均CMT为(270.60±33.27)μm,较手术前明显下降(F=13.545,P<0.001)。相关性分析结果显示,手术前浅层FAZ面积与M值呈负相关(r=-0.816,P<0.001),与BCVA无相关(r=-0.198,P=0.216);深层FAZ面积与BCVA、M值呈负相关(r=-0.422、-0.882,P=0.005、<0.001)。手术后浅层FAZ面积与手术前后M值呈负相关(r=-0.791、-0.716,P<0.001、<0.001),与手术前后BCVA无相关(r=-0.290、-0.296,P=0.063、0.057);深层FAZ面积与手术前后BCVA、M值呈负相关(r=-0.343、-0.330、-0.732、-0.694,P=0.026、0.033、<0.001、<0.001)。结论PPV联合ERM及ILM剥除能有效恢复IMEM患眼浅层、深层FAZ面积,提高患眼视力、降低视物变形程度;浅层FAZ面积与视物变形度呈负相关,深层FAZ面积与视物变形度、BCVA呈负相关。

Objective To observe the changes of foveal avascular zone(FAZ)size before and after surgery in idiopathic macular epiretinal membrane(IMEM)eyes and analyze the correlation of FAZ with metamorphopsia.Methods A retrospective case series study.From August 2016 to October 2017,42 eyes of 38 patients affected with IMEM diagnosed in Central Theater Command General Hospital of Chinese People's Liberation Army were enrolled in this study.All the patients underwent a 25G pars plana vitrectomy(PPV)with IMEM removal and ininternal limiting membrane(ILM)peeling.The BCVA was measured using the international standard visual acuity chart,and the results were converted to the logMAR visual acuity.The severity of metamorphopsia was measured using M-charts.The FAZ areas were evaluated with OCT angiography in both the superficial and deep capillary plexus layers.The central macular thickness(CMT)were assessed with spectral-domain OCT before and after surgery.The logMAR BCVA was 0.61±0.21.The M-score was 0.66±0.38.The CMT of fovea was 337.71±57.63μm.The FAZ areas in superficial and deep capillary plexus were 0.113±0.037 mm^2 and 0.202±0.03 mm^2,respectively.The differences in BCVA,M-score and FAZ area before and 1,3,6,12 months after surgery were analyzed by ANOVA.The Spearman rank correlation analysis was performed to investigate the relationship between FAZ areas,visual acuity and metamorphopsia.Results At 12 month after surgery,the FAZ areas in superficial and deep capillary plexus were 0.146±0.021 mm^2 and 0.240±0.019 mm^2,respectively.Compared with baseline,the the FAZ areas in superficial and deep capillary plexus after surgery significantly increased(F=8.484,14.346;P<0.001,<0.001).The postoperative logMAR BCVA 0.47±0.19,M-score 0.12±0.22 and CMT 270.60±33.27μm were significantly improved compared with baseline(F=5.044,17.763,13.545;P=0.001,<0.001,<0.001).The preoperative FAZ area in superficial capillary plexus correlated negatively with preoperative M-score(r=-0.816,P<0.001);the preoperative FAZ area in deep capillary plexus correlated negatively with preoperative BCVA and M-score(r=-0.422,-0.882;P=0.005,<0.001).The postoperative FAZ area in superficial capillary plexus correlated negatively with preoperative and postoperative M-score(r=-0.791,-0.716;P<0.001,<0.001).The postoperative FAZ area in deep capillary plexus correlated negatively with BCVA and preoperative and postoperative M-score(r=-0.343,-0.330,-0.732,-0.694;P=0.026,0.033,<0.001,<0.001).Conclusions PPV with ILM peeling can effectively restore the FAZ areas in superficial and deep capillary plexus,improve the visual acuity and metamorphopsia in patients with IMEM.Both superficial and deep plexus FAZ areas correlated negatively with metamorphopsia,and deep plexus FAZ area also correlated negatively with BCVA.