Choroidal macrovascular and capillary alterations in eyes with idiopathic epiretinal membranes

ABSTRACT Purpose: To evaluate the choroidal vascular alterations and effect of surgical treatment in the setting of idiopathic epiretinal membranes. Methods: The structure of the choroid was studied in 33 patients with unilateral idiopathic epiretinal membrane using optical coherence tomography with enhanced depth imaging and optical coherence tomography angiography. Eyes with epiretinal membrane underwent 25-gauge vitrectomy with epiretinal membrane and internal limiting membrane peeling. The choroidal vascularity index, Haller layer/choroidal thickness ratio, and choriocapillaris flow density were used to evaluate changes in choroidal structure after surgery and compare with the healthy fellow eyes. Results: The choroidal vascularity index and Haller layer/choroidal thickness ratio of the eyes with epiretinal membrane were higher than those of the fellow eyes at baseline (p=0.009 and p=0.04, respectively) and decreased postoperatively compared with preoperative values (p=0.009 and p=0.001, respectively). The choriocapillaris flow of eyes with epiretinal membrane was lower than that of the fellow eyes at baseline (p=0.001) and increased after surgery compared with the preoperative value (p=0.04). The choroidal vascularity index, Haller layer/choroidal thickness ratio, and choriocapillaris flow values of the healthy fellow eyes were comparable at baseline and final visit. In eyes with epiretinal membrane, the final choroidal vascularity index correlated with the final choriocapillaris flow (r=-0.749, p=0.008) in the multivariate analysis. Conclusion: Idiopathic epiretinal membrane appears to affect the choroidal structure with increased choroidal vascularity index and Haller layer/choroidal thickness ratio and decreased choriocapillaris flow. These macrovascular (choroidal vascularity index and Haller layer/choroidal thickness) and microvascular (choriocapillaris flow) alterations appear to be relieved by surgical treatment of the epiretinal membranes.

Metamorphopsia change and influence factors before and after idiopathic epiretinal membrane surgery / 中华实验眼科杂志

Objective To investigate the changes of metamorphopsia between before and after surgery in the patients with idiopathic epiretinal membrane and its influence factors.Methods A series cases observitional study included 39 eyes of 39 patients with idiopathic epiretinal membrane.Follow-up was carried out at 1 week before surgery and 3,6 months after surgery respectively.M-chart was used to quantify the severity of metamorphopsia (M-score).EDTRS visual chart was used to quantify best corrected visual acuity (BCVA) (converted to LogMAR).Central subfield thickness (CST),central foveal volumn (CV),cube average thickness (CAT),central foveal thichness (CFT),ganglion cell layer (GCL) thickness,inner nuclear layer (INL) thickness,outer nuclear layer (ONL) and outer plexiform layer (OPL) thickness,the integrity of external limiting membrane,ellipsoid zone and interdigitation zone were analyzed by using spectral domain-optical coherence tomography (OCT).This study protocol was approved by Ethic Committee of Beijing Tongren Hospital (No.TRECKY-012).Written informed consent was obtained from each subject before surgery.Results Mean M-score was significantly decreased from 0.8 (0.3,1.1) before surgery to 0.5 (0.2,0.8) at 3 months after surgery,with a significant difference between the two time points (Z=-2.013,P=0.044).Mean M-score was 0.6(0.2,0.8) at 6 months after surgery,which was not significantly different in comparison with before surgery and 3 months after surgery (Z =-1.873,P =0.061;Z =-0.288,P =0.773).Compared with before surgery,the horizontal M-score was significantly decreased 3 months and 6 months after surgery (Z =-2.329,P =0.020;Z =-2.858,P =0.004).No significant difference was found in vertical M-score among before surgery and 3,6 months after surgery (all at P＞0.05).The BCVA was improved from 0.40 (0.30,0.66) before surgery to 0.20 (0.06,0.42) 3 months after surgery and declined to 0.30 (0.10,0.52) at 6 months after surgery,and significant differences were obtained between 3 months after surgery and before surgery or 6 months after surgery (Z =-4.087,P＜0.001;Z =-2.235,P =0.025).Compared with before surgery,the BCVA in cataract combined with vitrectomy operative group was significantly improved in 3 months and 6 months after surgery (Z=-2.613,P=0.009;Z=-2.466,P=0.014) and the BCVA in only vitrectomy group was significantly improved at 3 months after surgery but decreased 6 months after surgery,showing significant differences between 3 months after surgery and before surgery or 6 months after surgery (Z =-3.104,P =0.002;Z =-3.464,P =0.001).Preoperative M-score was positively correlated with preoperative BCVA,preoperative CST or preoperative CFT (rs =0.384,P =0.016;rs =0.585,P＜0.001;rs =0.601,P＜0.001).No correlation was found between BCVA with GCL,INL or ONL + OPL thickness.Horizontal M-score was positively correlated with CST,postoperative CV and postoperative CAT (rs=0.322,P=0.045;rs=0.340,P=0.034;rs =0.336,P=0.036),and no correlation was found between horizontal M-score and BCVA,CFT,GCL thickness,INL thickness,ONL+OPL thickness in 6 months after surgery.The vertical M-score and mean M-score were not correlated with OCT parameters in 6 months after surgery.The mean M-score was positively correlated with preoperative mean M-score,preoperative CST,preoperative CV,preoperative CAT in 6 months after surgery (rs =0.589,P＜0.001;rs =0.330,P =0.040;rs =0.404,P =0.011;rs =0.410,P =0.009).In addition,and no significant correlation between mean M-score and preoperative BCVA,CFT,GCL thickness,INL thickness,ONL+OPL thickness.Multivariate stepwise linear regression showed that preoperative M-score was a predictor of postoperative M-values (adjusted R2 =0.211,P =0.002).Conclusions Most metamorphopsia can be alleviated after idiopathic epiretinal membrane surgery.The residue metamorphopsia after surgery probably is correlated with preoperative metamorphopsia and CFT.

Recurrent myopic foveoschisis: resolution after internal limiting membrane removal / Isquise miópica recorrente: resolução após remoção da membrana limitante interna

We report a case of a 66-year-old man with a history of high myopia and who was referred for acute decreased visual acuity of the right eye. Fundus examination and optical coherence tomography (OCT) showed a mild epiretinal membrane (ERM) and splitting of retinal layers. Pars plana vitrectomy was performed with intravitreous triamcinolone injection, posterior hyaloid and ERM peeling, and 12% perfluoropropane (C3F8) gas tamponade. After remaining asymptomatic for 17 months, the patient reported a new episode of sudden decreased visual acuity in his right eye, and OCT showed recurrent myopic foveoschisis (MF). He underwent vitrectomy and internal limiting membrane (ILM) peeling. Six months later, the patient’s best corrected visual acuity had improved to 20/25. Optical coherence tomography showed a remarkably improved macular anatomy, with residual traction along the inferotemporal arcade, which was attributed to the vessel stiffness itself. We conclude that removing the internal limiting membrane is a challenging maneuver in myopic foveoschisis, even with staining approaches. Although myopic foveoschisis may be resolved without peeling the internal limiting membrane, its removal should be considered if the condition recurs.

Relatamos caso de um homem de 66 anos, com antecedente de alta miopia, que referiu baixa de acuidade visual aguda no olho direito. O mapeamento de retina e o exame de tomografia de coerência óptica (OCT) mostraram discreta membrana epirretiniana (ERM) e isquise retiniana. Foi realizada vitrectomia via pars plana com injeção intravítrea de triancinolona, retirada da hialóide posterior, peeling da membrana epirretiniana e tamponamento com gás perfluorpropano (C3F8) a 12%. O paciente permaneceu assintomático por 17 meses, quando queixou-se de novo episódio de baixa de acuidade visual súbita no olho direito e o tomografia de coerência óptica mostrou recorrência da isquise miópica. Ele foi submetido a nova vitrectomia com peeling da membrana limitante interna (ILM). Após 6 meses, a acuidade visual corrigida era de 20/25. A tomografia de coerência óptica mostrou melhora importante da anatomia macular, com área de tração residual observada na arcada inferotemporal, que foi atribuída à rigidez do próprio vaso. A retirada da membrana limitante interna é uma manobra desafiadora em olhos alto míopes, mesmo estando corada. A resolução da isquise miópica pode ser atingida sem o peeling da membrana limitante interna, mas sua remoção deve ser considerada em casos de recorrência.

Refractive shift following the combination of phacoemulsification, intraocular lens implantation and vitrectomy in the eyes with idiopathic macular epiretinal membrane / 中华实验眼科杂志

Background Idiopathic macular epiretinal membrane (IMEM) combined with age-related cataract (ARC)is a common eye disease and the primary managing approach is the combination of phacoemulsification,intraocular lens (IOL) implantation and vitrectomy.However,whether the ocular length measured by IOL Master is accurate for the calculation of IOL refraction in the eye with IMEM remains unclear.Objective The aim of this study was to evaluate the refractive outcomes of combination surgery of phacoemulsification,IOL implantation and vitrectomy in IMEM eyes.Methods A prospective cohort study was designed.Forty-two eyes of 42 patients with IMEM combined with ARC (IMEM+ARC group) were enrolled in Peking University People's Hospital and the combination of phacoemulsification,IOL implantation and vitrectomy was performed from September 2010 to August 2011,and 47 eyes of 47 patients with ARC were included for the phacoemulsification combined with IOL implantation in the corresponding period (ARC group) under the approval of Ethic Committee of Peking University People's Hospital and informed consent of the patients.Ocular length and corneal curvature were measured using IOL Master,and the expected IOL diopter was calculated with SRK-T formula.Regular eye examination and medical optometry were performed 1 month and 3 months after operation to obtain the actual diopter and the refractive error.The outcomes were compared between the two groups.The correlations of refractive error with change of fovea thickness were evaluated after operation in the IMEM+ARC group.Results There were no statistically significant differences in the age,ocular length and corneal curvature between the two groups before operation (P =0.863,0.704,0.770).The visual acuity was improved 3 months after operation in comparison with before operation in both groups (P=0.001,0.000).The negative diopters were obviously higher 1 month and 3 months after operation than those before operation in both groups (all at P＜0.001),but no significant difference was seen between the IMEM+ ARC group and ARC group (Fgroup =0.417,P =0.520).The diopter deviations 1 month and 3 months after operation were (-0.727±0.666)D and (-0.628±0.627)D in the IMEM+ARC group,and those in the ARC group were (-0.664±0.644) D and (-0.642±0.550) D,showing insignificant differences between the two groups (Fgroup =0.036,P =0.849 ; Ftime =1.523,P =0.221).In IMEM + ARC group,the macular fovea thickness was (474.89 ± 135.76)μm in preoperation,and the shift values of macular fovea thickness were (-83.84 ±91.12)μm and (-158.53±113.03) μm in postoperative 1 month and 3 months.No positive correlations were presented between the diopter deviations and change of fovea thickness 1 month and 3 months after operation in the IMEM+ARC group (r=0.200,P =0.229 ; r =0.065,P =0.698).Conclusions Myopia shift after operation is similar in the IMEM combined with ARC patients to the only ARC patients,suggesting that the ocular length and corneal curvature measured by IOL Master is not affected by epiretinal membrane.