Epiretinal Membrane Eyes Research Articles

Cross-Sectional Imaging Analysis of Epiretinal Membrane Involvement in Unilateral Open-Angle Glaucoma Severity.

To determine the relevance of epiretinal membranes (ERMs) in primary open-angle glaucoma (POAG) and potential risk for glaucoma severity. Sixty eyes of 30 patients with POAG who had a unilateral ERM were analyzed; 60 nonglaucomatous eyes of 30 patients with a unilateral ERM also were recruited in this institutional cross-sectional study. Patients underwent swept-source (SS) optical coherence tomography (OCT) imaging and visual field testing. Intraindividual differences in the SS-OCT retinal nerve fiber layer (RNFL) disc cupping area measurements and visual field outcomes were analyzed in the two groups. In patients with POAG, the mean circumpapillary RNFL thickness in the eyes with an ERM was 75.6 ± 16.5 μm superiorly and 71.8 ± 26.0 inferiorly compared with the fellow eyes without an ERM (87.2 ± 23.6 μm, P = 0.0061 and 81.3 ± 27.7 μm, P = 0.034, respectively). The areas of disc cupping and cup-to-disc ratio seen on OCT horizontal and vertical B-scans were larger in eyes with an ERM than in the fellow eyes without ERM (P = 0.0004 and P = 0.0011, respectively). The average mean deviations were -11.6 ± 7.5 dB in the ERM group and -8.19 ± 6.4 dB in the group with no ERM (P = 0.029). Eyes with an ERM received more antiglaucoma eye drops (P = 0.018). Those differences were not seen between eyes with an ERM or fellow eyes in patients without glaucoma. The presence of an ERM can be a potential risk factor for unilateral severity in eyes with POAG.

Reflectance and Thickness Analysis of Retinal Layers in Patients with Epiretinal Membranes Using Spectral-Domain OCT before and after Vitrectomy with Membrane Peeling

To compare thickness and reflectance of retinal layer findings in patients with idiopathic epiretinal membranes (ERMs) before and after surgery with those of normal controls. Retrospective study. Patients with ERMs before and after surgery and healthy controls. Spectral-domain (SD) OCT imaging of eyes with ERMs before and after surgery and of healthy eyes were analyzed for morphologic appearance and using a customized algorithm to measure retinal layer reflectance and thickness. Findings were correlated with visual acuity outcomes. Retinal layer thickness and reflectance. Thirty-four ERM and 12 healthy eyes were identified. Mean preoperative best-corrected visual acuity (BCVA) improved from 0.53±0.31 logarithm of the minimum angle of resolution (logMAR; Snellen equivalent, 20/68) to 0.41±0.25 logMAR (Snellen equivalent, 20/51) after surgery (P= 0.030). Differences in reflectance and thickness of retinal layers were identified among the preoperative ERM, postoperative ERM, and healthy eyes. High preoperative reflectance of the internal limiting membrane (ILM) to outer plexiform layer (OPL) was correlated with better postoperative BCVA (r= -0.451; P= 0.007). A larger improvement in BCVA was correlated with preoperative thick measurements of the outer nuclear layer (r= 0.514; P= 0.002), high reflectance of the group of layers from the ILM to the OPL (r= 0.426; P= 0.012), and low reflectance of the photoreceptor layer (r=-0.453; P= 0.007). Using linear regression analysis, better postoperative BCVA was associated with better preoperative vision (standardized regression coefficient, 0.553; P= 0.001) and high reflectance of the group of layers from the ILM to OPL (standardized regression coefficient, -0.526; P= 0.001). A larger improvement in BCVA was associated with worse preoperative BCVA (standardized regression coefficient, -0.539; P < 0.001) and high reflectance of the group of layers from the ILM to OPL (standardized regression coefficient, -0.428; P=0.001). Quantitative differences in reflectance and thickness among preoperative, postoperative, and normal SD OCT imaging allow assessment of retina layer changes secondary to ERMs. High reflectance of the ILM to OPL correlated with and was associated with better postoperative BCVA and improvement in BCVA.

Macular microvasculature features before and after vitrectomy in idiopathic macular epiretinal membrane: an OCT angiography analysis.

To evaluate pre-operative and post-operative morphologic characteristics in idiopathic macular epiretinal membrane (ERM) by optical coherence tomography angiography (OCTA). Thirty-three subjects with unilateral idiopathic ERM were enrolled and the contralateral eyes served as controls. Vascular parameters including superficial capillary plexus (SCP), deep capillary plexus (DCP), outer capillary plexus (OCP), and choroidal capillary plexus (CCP) were evaluated by OCTA. The superficial foveal avascular zone (FAZ) was significantly smaller in eyes with ERM (P < 0.0001). The vessel densities (VDs) were significantly increased in the fovea but dramatically decreased in the parafovea in SCP and DCP of ERM eyes (all P < 0.0001), in contrast to those in OCP and CCP. The blood flow was augmented in OCP but declined in choroid compared with the controls. In CCP, the mean foveal VD in ERM was significantly smaller (P = 0.023), whereas parafoveal VD did not significantly change (P = 0.66). At 6 months after surgery, flow area was decreased in OCP (P = 0.0007), and foveal and parafoveal VDs were significantly altered in all layers except the foveal VD in OCP and the choroid (all P < 0.05). The total and inner retinal thickness of the fovea and parafovea were correlated with pre-operative and post-operative visual outcomes, respectively. Smaller FAZ and greater interocular differences between post-operative and fellow eyes in FAZ were associated with worse post-operative visual outcomes. OCTA provides a better display of the vascular network of the retina and choroid to evaluate the severity and surgical prognosis of ERM patients.

Retinal-image quality and contrast sensitivity function in eyes with epiretinal membrane: a cross-sectional observational clinical study

BackgroundTo investigate the effect of idiopathic epiretinal membrane (ERM) on the retinal-image quality and psychophysical contrast sensitivity function (CSF).MethodsForty-four subjects with diagnosis of idiopathic unilateral ERM were enrolled in this cross-sectional observational clinical study. The fellow unaffected eyes were set as the control group. For retinal-image quality assessment, an Optical Quality Analysis System (OQAS) based on double-pass technique was used to evaluate objective scatter index (OSI) and Strehl ratio. For visual performance, the CSF under photopic condition was measured.ResultsFor retinal-image quality, the result of double-pass device revealed a significant lower Strehl ratio and larger OSI in the ERM eyes compared to the fellow eyes (all P < 0.05). For visual performance, the CSF at all spatial frequencies under photopic condition were also significantly degraded in the ERM eyes compared to the fellow eyes (all P < 0.05). For the ERM eyes, the reduction of Strehl ratio and CSF was 29.41 and 54.39%, respectively, and the increase of OSI was 164.10% compared to the fellow eyes. Besides, BCVA significantly correlated to the total CSF (ERM eyes, r = − 0.53, P < 0.001; the fellow eyes, r = − 0.467, P = 0.002) and Strehl ratio (ERM eyes, r = − 0.485, P = 0.001; the fellow eyes, r = − 0.311, P = 0.043) in both of the ERM and the fellow eyes.ConclusionEyes affected with ERM showed poorer retinal-image quality and visual performance than the normal eyes. Retinal-image quality measured by OQAS based on double-pass technique could be useful for assessing the retinal-image quality for ERM-affected eyes, in which retinal scattering was significantly increased.

Vitrectomy for Epiretinal Membranes: Ganglion Cell Features Correlate with Visual Function Outcomes

To evaluate the relationship between retinal microstructure and central visual field sensitivity (CVFS) after vitrectomy with internal limiting membrane (ILM) peeling for epiretinal membrane (ERM) using swept-source (SS) OCT and Humphrey Field Analyzer (HFA) (Zeiss, Dublin, CA) 10-2 program. Retrospective, interventional case series. Forty-five eyes in 45 patients with unilateral ERM who were treated with vitrectomy with ILM peeling using indocyanine green (ICG) or triamcinolone acetonide (TA) staining. We evaluated retinal microstructure (full thickness of the retina, thickness of the retinal ganglion cell complex [GCC], and thickness of the outer retinal layer) with SS-OCT and CVFS using HFA 10-2 before and 3 and 12 months after vitrectomy with ILM peeling. Data were analyzed using a standard Early Treatment of Diabetic Retinopathy Study (ETDRS) grid, with thresholds measured at 68 points corresponding to ETDRS grid locations using HFA 10-2. Retinal microstructure and CVFS in normal contralateral eyes were also measured and used as controls. We also compared the ICG-stained group (27 eyes), TA-stained group (18 eyes), and control group as subgroup analysis on ILM peeling staining dyes. Changes in retinal microstructure and CVFS before and 3 and 12 months after vitrectomy, and the correlation between retinal microstructure and mean CVFS postoperatively. Inner and outer temporal GCC thickness after vitrectomy significantly decreased compared with control eyes (P= 0.019 and P= 0.002, respectively). Mean CVFS in ERM eyes was significantly lower than control eyes at baseline (P < 0.001). Although change in overall CVFS was not significantly different 3 and 12 months postvitrectomy (P= 0.394 and P= 0.337, respectively), outer nasal CVFS was significantly lower 3 months postvitrectomy (P= 0.039). The CVFS on the nasal region and temporal GCC thickness were significantly decreased only in the ICG staining group postoperatively. Postoperatively, mean CVFS significantly correlated with GCC thickness (P < 0.001, r= 0.557). In ERM eyes after vitrectomy with ILM peeling, CVFS was associated with GCC thickness. Combined SS-OCT and HFA 10-2 analysis using the ETDRS grid offers more detailed measurements that effectively evaluate postoperative retinal microstructure and function.

Cataract Surgery Outcomes in Eyes With Primary Epiretinal Membrane

Primary epiretinal membrane (ERM) is a common retinal disorder with a prevalence of 4% to 18.5%. Although ERM and cataracts commonly occur together, to our knowledge, no studies have investigated the outcome of cataract surgery alone in this setting. To analyze the visual outcome and cystoid macular edema risk with cataract surgery in eyes with primary ERM. In this retrospective clinical database study, data were collected from July 2003 to March 2015 from 8 locations in the United Kingdom. Cataract surgery data of 217 557 eyes were extracted from the electronic medical record of the UK National Health Service. After exclusion of 57 561 eyes with combined surgery, prior vitrectomy, copathology, and complications, 812 eyes with primary ERM and 159 184 reference eyes were analyzed. We report on visual acuity (VA), the incidence of cystoid macular edema, and the need for ERM surgery. The mean (SD) age of patients in the ERM group was 73.7 (9.23) years, and 395 of 812 were men (46.8%). The mean (SD) age of patients in the reference group was 74.4 (12.19) years, and 65 265 of 159 184 were men (41%). Epiretinal membrane eyes assessed at 4 to 12 weeks postoperatively gained 0.27 (0.32) logMAR (approximately 3 Snellen lines), with 200 of 448 (44.6%) improving by 0.30 logMAR or more (≥3 Snellen lines) and 32 of 448 (7.1%) worsening by 0.30 logMAR or more. Reference eyes gained a mean (SD) of 0.44 (0.26) logMAR (approximately 4 Snellen lines), with 48 583 of 77 408 (62.8%) improving by 0.30 logMAR or more and 2125 of 77 408 (2.7%) worsening by 0.30 logMAR or more. Although all eyes with preoperative VA of 20/40 or less improved, only reference eyes with preoperative VA of more than 20/40 showed improvement. Cystoid macular edema developed in 57 of 663 ERM eyes (8.6%) (95% CI, 6.69-10.98) and 1731 of 125 435 reference eyes (1.38%) (95% CI, 1.32-1.45) (P < .001). Epiretinal membrane surgery was performed in 43 of 663 (6.5%) ERM eyes. On average, VA improved 0.27 logMAR (approximately 3 Snellen lines) in eyes with ERM. Eyes with ERM and VA of 20/40 or less showed more benefit after cataract surgery than those with better preoperative vision. However, compared with eyes without ERM, higher rates of cystoid macular edema and a lower postoperative VA gain were noted.

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Epiretinal membrane (ERM) is a common retinal fibrotic disorder disease causing visual impairment and metamorphopsia. Recently, increasing attention has been devoted to ERM progression after uncomplicated cataract surgery. Cytokines, which play a role in diverse physiological and pathological activities in eyes, are suggested to be involved in these postoperative changes. However, few studies have investigated the post-cataract surgery cytokine expression changes in ERM eyes and their roles in the postoperative changes. The purpose of this study was to evaluate the aqueous levels of cytokines in eyes with idiopathic epiretinal membrane (iERM) both pre- and post-cataract surgery, and their correlations with postoperative iERM progression. In this study, aqueous humor (AH) samples were collected from iERM eyes (n = 25) and non-iERM eyes (n = 23) from 48 patients (48 eyes) undergoing uncomplicated cataract surgery preoperatively and 20 h postoperatively. Samples were analyzed for 48 cytokines with multiplex bead-based immunoassay. Correlations between cytokine level changes (postoperation vs. preoperation) and three-month postoperative best-corrected visual acuity (BCVA) and optical coherence tomography measure changes were evaluated in iERM eyes. We found that in iERM eyes, the levels of 4 cytokines exhibited significant elevations when compared with those in the controls (all p ≤ 0.0015) preoperatively. Postoperatively, the concentrations of 21 cytokines were higher than the preoperative levels in iERM eyes (all p ≤ 0.0015), among which GRO-α, IL-8, and MCP-3 levels showed more pronounced changes than the controls. Additionally, in iERM eyes, IL-4 level changes showed moderate positive correlations with MV (r = 0.492, p = 0.028) and MT (r = 0.481, p = 0.032) changes. LogMAR changes were positively correlated with IL-1α (r = 0.553, p = 0.011), IL-12(P40) (r = 0.544, p = 0.013), and MCP-3 (r = 0.588, p = 0.006) level changes. No significant cytokine-level-change differences were found between eyes with and without postoperative cystoid macular edema development. In conclusion, cataract surgery will bring great alterations to the specific intraocular cytokine microenvironment inherently in eyes with iERM. Many fibrotic and inflammatory cytokines showing elevated levels or relationships with clinical characteristics are suggested to be involved in the pathogenesis and post-cataract surgery progression of iERM; however, further investigations are needed to discern their real roles.

Assessment of macular function in patients with idiopathic Epiretinal membrane by multifocal Electroretinography: correlation with visual acuity and optical coherence tomography

BackgroundThis study evaluates the macular function changes in patients with idiopathic macular epiretinal membrane (ERM) by multifocal electroretinography (mfERG) and their correlations with visual acuity and central macular thickness (CMT) by optical coherence tomography (OCT).MethodsTwenty eyes of 20 patients with ERM underwent OCT and mfERG examinations. The response amplitude densities and implicit times of mfERG were compared to the control fellow eyes. Correlation analyses among visual acuity, central macular thickness and mfERG values in the central two concentric rings were performed.ResultsThe mfERG P1 response amplitude densities in ring 1–2 and P1 implicit time in ring1 were significantly changed in epiretinal membrane eyes compared with controls (P < 0.05). Multivariate stepwise linear regression analyses showed LogMAR visual acuity was significantly correlated with CMT (P = 0.004), and also with the P1 amplitude density in ring 1 (P = 0.002). CMT showed significant correlation with P1 implicit time in ring 2 (P = 0.013).ConclusionsThe mfERG abnormalities show macular function changes and correlate with visual acuity and central macular thickness in eyes with ERM. In first-order mfERG responses, P1 wave changes may be a sensitive functional measurement for ERM patients.

Correlation of visual acuity and metamorphopsia with foveal morphology before and after vitrectomy with internal limiting membrane peeling in idiopathic macular epiretinal membrane eyes

Objective To analyze the correlation of visual acuity and metamorphopsia with foveal morphology before and after vitrectomy with internal limiting membrane peeling (ILMP) in idiopathic macular epiretinal membrane (IMEM) eyes. Methods This is a retrospective case series of 47 IMEM patients (49 eyes). All the patients underwent 25G pars plana vitrectomy with IMEM removal and ILMP. The best corrected visual acuity (BCVA) was measured using the international standard visual acuity chart, and the results were converted to the logarithm of the minimum angle of resolution (logMAR) visual acuity. The severity of metamorphopsia was measured using M-charts. The central macular thickness (CMT), inner nuclear layer thickness (INT), inner retinal layer thickness (IRT), outer retinal layer thickness (ORT), the status of ellipsoid zone (EZ) were assessed with spectral-domain optical coherence tomography at baseline and each month postoperatively. The differences in BCVA, CMT, INT, IRT, ORT and status of EZ before and after surgery were analyzed, so did the correlations between these indexes at the same time. Results Compared with baseline, the postoperative BCVA was significantly increased (F=6.133, P<0.001), but the M value, CMT, INT, IRT, ORT were significantly decreased (F=12.481, 10.565, 15.739, 6.046, 10.569; P<0.001);the integrity of EZ was improved significantly (χ2=12.309, P<0.001). Preoperative BCVA was positively related to the CMT (r=0.720) and ORT (r=0.720, 0.887; P<0.05), while negatively related to preoperative integrity of EZ (r=−0.295, P<0.05). The postoperative BCVA was positively related to the preoperative BCVA and postoperative CMT, ORT (r=0.774, 0.754, 0.842; P<0.05), while negatively related to postoperative integrity of EZ (r=−0.676, P<0.05). The preoperative M value was positively related to the preoperative CMT, INT, IRT, and ORT (r=0.931, 0.668, 0.840, 0.637; P<0.05). The postoperative M value was positively related to the preoperative M value and postoperative CMT, INT, IRT, and ORT (r=0.723, 0.722, 0.767, 0.825, 0.387; P<0.05). Conclusions Vitrectomy with ILMP for IMEM can improve the visual acuity, metamorphopsia and foveal morphology. Both visual acuity and metamorphopsia correlate with foveal morphology. Key words: Macula lutea; Membranes; Vitrectomy; Tomography, optical coherence

Changes in choroidal thickness after vitrectomy for epiretinal membrane combined with vitreomacular traction.

To compare choroidal thickness after vitrectomy between epiretinal membrane (ERM) with and without vitreomacular traction (VMT). In this retrospective study, 228 consecutive participants with ERM who underwent vitrectomy were categorized into two groups according to the presence of VMT on spectral domain-optical coherence tomography: VMT group (ERM with VMT, n=21) and non-VMT group (ERM without VMT, n=207). The primary outcome was the mean subfoveal choroidal thickness (SFCT) at baseline, and at 3 and 6months postsurgery. At baseline, the prevalence of VMT in eyes with ERM was 9.6% (21/228), and mean SFCT was greater in the VMT than in the non-VMT group (270.3±93.4 vs. 223.7±82.1μm; p=0.015). After surgery, mean SFCT decreased in the VMT group (241.7±92.3μm at 3months and 228.8±86.4μm at 6months; p<0.001), but remained unchanged in the non-VMT group (223.6±78.9μm at 3months and 223.3±82.6μm at 6months; p=0.696). There were no differences in mean SFCT between the groups at 3 and 6months after surgery (p=0.339 and p=0.772, respectively). Choroidal thickness was greater in ERM eyes with than without VMT possibly due to direct anteroposterior traction on the retina and choroid, increased vascular endothelial growth factor associated with stress on retinal pigment epithelial cells and inflammation. After vitrectomy, mean SFCT reduced in the eyes with VMT, but not in those without VMT.

Reflectivity and thickness analysis of epiretinal membranes using spectral-domain optical coherence tomography.

To compare thickness and reflectivity spectral domain optical coherence tomography (SD-OCT) findings in patients with idiopathic epiretinal membranes (ERMs), before and after ERM peeling surgery, with normal controls. A retrospective study analyzed SD-OCTs of eyes with ERMs undergoing ERM peeling surgery by one surgeon from 2008 to 2010 and normal control eyes. SD-OCTs were analyzed using a customized algorithm to measure reflectivity and thickness. The relationship between the SD-OCT findings and best corrected visual acuity (BCVA) outcomes was also studied. Thirty-four ERM eyes and 12 normal eyes were identified. Preoperative eyes had high reflectivity and thickness of the group of layers from the internal limiting membrane (ILM) to the retinal pigment epithelium (RPE) and the group of layers from the ILM to the external limiting membrane (ELM). The values of reflectivity of these two groups of layers decreased postoperatively, but were still higher than normal eyes. In contrast, preoperative eyes had lower reflectivity of two 10×15 pixel regions of interest (ROIs) incorporating: 1) ELM + outer nuclear layer (ONL) and 2) photoreceptor layer (PRL) + RPE, compared to controls. The values of reflectivity of these ROIs increased postoperatively, but were still lower than normal controls. A larger improvement in BCVA postoperatively was correlated with a greater degree of abnormal preoperative reflectivity and thickness findings. Quantitative differences in reflectivity and thickness between preoperative, postoperative, and normal SD-OCTs allow assessment of changes in the retina secondary to ERM. Our study identified hyperreflective inner retina changes and hyporeflective outer retina changes in patients with ERMs. SD-OCT quantitative measures of reflectivity and/or thickness of specific groups of retinal layers and/or ROIs correlate with improvement in BCVA.

Natural History of Idiopathic Epiretinal Membrane in Eyes with Good Vision Assessed by Spectral-Domain Optical Coherence Tomography

Purpose: To investigate the natural history of idiopathic epiretinal membrane (ERM) in eyes with good visual function using optical coherence tomography (OCT). Methods: Sixty-two eyes of 58 patients with idiopathic ERM, visual acuity of 20/40 or better, and no significant metamorphopsia were included. The best corrected visual acuity (BCVA), central macular thickness (CMT), membrane configuration, and ellipsoid zone signal data over 24 months were retrospectively analyzed. Based on OCT findings, ERM configurations were categorized as global attachment (GA), partial attachment (PA), pseudohole, and vitreomacular traction (VMT). Results: The mean BCVA and CMT did not change significantly between baseline and 24 months. GA, PA, pseudohole, and VMT types were observed in 33, 19, 9, and 1 eye at baseline, and in 20, 22, 10, and 1 eye at 24 months, respectively. A membrane configuration change was noted in 24 eyes (38.7%) during follow-up, and the distribution shifted from GA to the other types (p < 0.001). Six eyes had visual loss due to membrane progression, and 4 eyes had spontaneous membrane separation. Of the 10 eyes with progression or separation, 6 were of the PA type. Conclusions: Although the BCVA remains stable over 2 years in most idiopathic ERM eyes with good visual function at baseline, the membrane configuration may change, affecting visual acuity. The GA type would be an early stage, and the PA type is prone to changes in visual acuity.

INTRAOPERATIVE SPECTRAL DOMAIN OPTICAL COHERENCE TOMOGRAPHY IMAGING AFTER INTERNAL LIMITING MEMBRANE PEELING IN IDIOPATHIC EPIRETINAL MEMBRANE WITH CONNECTING STRANDS.

To report the intraoperative optical coherence tomography findings in idiopathic epiretinal membrane (ERM) with connecting strands and to describe the postoperative outcomes. A retrospective, case series study within a prospective observational intraoperative optical coherence tomography imaging study was performed. Epiretinal membranes with connecting strands were characterized on preoperative spectral domain optical coherence tomography images and assessed against corresponding intraoperative (after internal limiting membrane [ILM] peeling) and postoperative spectral domain optical coherence tomography images. Eleven locations of the connecting strands in 7 eyes were studied. The connecting strands had visible connections from the inner retinal surface to the ERM in all locations, and the reflectivity was moderate in 8 locations and high in 3 locations. After ERM and ILM peeling, disconnected strands were identified in all of the intraoperative optical coherence tomography images. The reflectivity of the remaining intraoperative strands was higher than that of the preoperative lesions and appeared as "finger-like" and branching projections. The remaining disconnected lesions were contiguous with the inner retinal layers. Postoperatively, the intraoperative lesions disappeared completely in all locations, and recurrent formation of ERM was not identified in any eyes. In ERM eyes with connecting strands, intraoperative spectral domain optical coherence tomography imaging showed moderately to highly reflective sub-ILM finger-like lesions that persist immediately after membrane and ILM peeling. Postoperatively, the hyperreflective lesions disappeared spontaneously without localized nerve fiber layer loss. The sub-ILM connecting strands may represent glial retinal attachments.

Foveal contour changes following surgery for idiopathic epiretinal membrane.

We evaluated the change in foveal contour in eyes with idiopathic epiretinal membrane (ERM) before and four months following pars plana vitrectomy with internal limiting and epiretinal membrane peeling, and correlated foveal contour with best corrected visual acuity (BCVA) and optical coherence tomography (OCT) parameters. Retrospective chart review of consecutive patients undergoing surgery with pre- and postoperative OCT. Foveal contour grading was devised according to the thickness of the fovea relative to the surrounding macula from OCT radial line scans: Grade 0, foveal depression relative to surrounding macula; Grade 1, relative flatness; and Grade 2, fovea thicker than surrounding macula. Baseline and follow-up grades were compared for change and correlated with BCVA, central retinal thickness (CRT), central subfield thickness (CST), central subfield volume (CSV), and integrity of the ellipsoid zone (EZ). Among 41 eyes of 41 patients, mean follow-up was 125 days. No eyes were Grade 0 at baseline; 7 of 41 eyes were Grade 0 at follow-up. Baseline Grade 1 eyes improved CRT (P < 0.001), CST (P < 0.001), CSV (P = 0.002), and BCVA (P = 0.022). Baseline Grade 2 eyes improved CRT (P < 0.001), CST (P < 0.001), and CSV (P < 0.001), but not BCVA (P = 0.369). We developed a novel foveal contour grading method to assess retinal contour in ERM eyes before and after surgery. In eyes with ERM and no foveal depression, the majority did not regain foveal depression following surgery even though retinal thickness improved.

Retinal nerve fiber layer configuration in eyes with epiretinal membrane.

To characterize configurations of the optic nerve head (ONH) and peripapillary retinal nerve fiber layer (RNFL) eyes with epiretinal membrane (ERM). We reviewed medical records of consecutive patients with ERM who were examined between September 2012 and August 2013. Patients were categorized based on the severity of ERM on fundus imaging; patients with ERM but without retinal distortion were in group 1, and patients with ERM and retinal distortion were in group 2. Optic nerve head and RNFL parameters measured by spectral domain optical coherence tomography were assessed and compared between eyes with ERM and normal fellow eyes. There were no significant differences in ONH and RNFL parameters between ERM eyes and normal fellow eyes in group 1 (n = 12). In group 2 (n = 33), cup volume was smaller (p = 0.020), temporal quadrant RNFL thickness was greater by 18.8 ± 16.6 μm (p < 0.001), and RNFL peak angle was smaller by 18.7 ± 25.3 degrees in ERM eyes compared with fellow eyes (p = 0.001). In the 15 patients in group 2 who underwent ERM removal, temporal quadrant RNFL thickness decreased and the RNFL peak angle increased after the surgery (p = 0.008 and p = 0.001, respectively). The configurations of the ONH and peripapillary RNFL in eyes with ERM were different from those in fellow eyes. The characteristic configurations of RNFL such as small peak angle and temporal quadrant thickening may be considered when evaluating parameters as measured by spectral domain optical coherence tomography.

Changes in anterior chamber depth following vitrectomy

Background Anterior segment morphometry is crucial for ophthalmologists to understand the visual outcomes of cataract surgery, keratorefractive surgery, as well as some other anterior segment disorders. Previous reports in literature have shown that anterior chamber depth (ACD) may shift slightly after vitrectomy. This study aimed to characterize the short-term changes in ACD in eyes after vitrectomy by means of A-scan ultrasound. Methods A prospective case series study was carried out on 29 eyes of 29 patients who underwent vitrectomy as the sole procedure. ACD was measured using A-scan ultrasound biometry shortly before vitrectomy and 1 week, 1 month, and 3 months after the surgery. Postoperative ACDs were compared with baseline. Results Twenty-nine patients (16 males and 13 females) were enrolled in the study, with mean age of (50±11) (25-65) years. Twenty-three eyes of 23 patients were vitrectomized for vitreous hemorrhage (VH) and the other six were operated for idiopathic epiretinal membrane (ERM). The mean preoperative ACD of the VH eyes was (2.98±0.38) mm. No significant difference was found between the ACD of the VH eyes and their fellow eyes (P=0.058). The average preoperative ACD in the ERM eyes was (2.94±0.31) mm, which was statistically deeper than that of their fellow eyes ((2.85±0.28) mm, P=0.008). No statistical difference was found in the postoperative average ACD of the VH eyes compared with baseline. In the ERM group, the postoperative ACD in the surgical eyes was still statistically deeper than the fellow eyes 1 week after surgery (P=0.034). However, such statistical difference disappeared at 1 or 3 months postoperative (P=0.186 and 0.682). Conclusions ERM may induce deepening of the ACD, which can be recovered by uneventful vitrectomy. VH does not cause shift of ACD, neither does vitrectomy.

REPRODUCIBILITY AND REPEATABILITY OF CIRRUS AND SPECTRALIS FOURIER-DOMAIN OPTICAL COHERENCE TOMOGRAPHY OF HEALTHY AND EPIRETINAL MEMBRANE EYES

To evaluate the accuracy and reproducibility of retinal thickness measurements in healthy and epiretinal membranes (ERM) eyes by Cirrus and Spectralis Fourier-domain optical coherence tomography devices. Eighty-seven ERM and 122 healthy subjects underwent 3 macular scans using both optical coherence tomography instruments. Mean thickness measurements in the nine Early Treatment Diabetic Retinopathy Study areas were compared, evaluating the repeatability and the relationship between devices. Macular thickness increase was detected in ERM eyes for all optical coherence tomography parameters (P < 0.001). Mean foveal thickness was 423.5 ± 81.4 and 438.0 ± 54.2 μm for ERM eyes and 267.1 ± 20.2 and 277.5 ± 18.9 μm for healthy eyes using Cirrus and Spectralis, respectively. Macular average thickness in ERM eyes as determined by both optical coherence tomography was correlated (r = 0.812; P < 0.001) but significantly different (P = 0.044). In ERM eyes, measurements showed a mean of the coefficients of variation of 2.95%, 2.2%, and 1.01% using Cirrus, Spectralis, and Spectralis progression feature, respectively. Intraclass correlation coefficients were higher than 0.919 in all cases. Reproducibility of both Cirrus and Spectralis optical coherence tomography was high in healthy and ERM eyes. However, considerable differences were found between macular thickness measurements obtained by both devices despite the high correlation between them.

Macular microstructure and relation with visual prognosis of micro-invasive vitrectomy for diabetic vitreous hemorrhage

Objective To investigate the relationship of macular microstructure and visual prognosis of micro-invasive vitrectomy for diabetic vitreous hemorrhage.Methods Fifty-three patients (53 eyes) with diabetic vitreous hemorrhage who underwent micro-invasive vitrectomy were enrolled in this retrospective study.The preoperative and postoperative best-corrected visual acuities (BCVA) were recorded.The central foveal thicknesses (CFT) were measured after surgery by spectral domain-optical coherence tomography (SD-OCT).The median follow-up time was (12.81-8.22) months,ranging from six to 36 months.According to the results of SD-OCT at last follow-up time,macular edema (ME),epiretinal membrane (ERM),interrupted inside and outside section (IS/OS) and interrupted external limiting membrane (ELM) were macular abnormalities were observed.The preoperative and postoperative BCVA of different macular abnormalities were comparatively analyzed.The correlation between BCVA and macular microstructure were analyzed.Results The CFT was ranged from 103.00 μm to 498.00 μm,with the mean of(251.12 ±90.23) μm.Macular abnormalities were observed in 37 eyes (69.8％),and normal macula in 16 eyes (30.2％).Among 37 eyes with macular abnormalities,there were 20 eyes (37.7％) with ME,12 eyes (22.6％) with ERM,33 eyes (62.3％) with interrupted IS/OS,and 20 eyes (37.7％) with interrupted ELM.The BCVA of ME eyes decreased significantly than that in non-ME eyes (t=-2.09,P＜0.05).The difference of BCVA in ERM and non-ERM eyes was not statistically significant (t=-1.10,P＞0.05).The BCVA of interrupted IS/OS eyes decreased significantly more than that in continuous IS/OS eyes (t=-4.33,P＜0.05).The BCVA of interrupted ELM eyes decreased significantly more than that in continuous ELM eyes (t=-2.58,P＜ 0.05).The postoperative BCVA correlated positively with integrity of the IS/OS junction,CFT,and whether ME or not (r=7.65,8.21,4.99; P＜0.05),but insignificantly associated with integrity of the ELM and whether ERM or not (r=0.01,0.82; P＞0.05).Conclusion The final visual acuity of patients with diabetic vitreous hemorrhage after micro-invasive vitrectomy is related to the CFT,the status of IS/OS junction,whether ME or not,but not related to integrity of the ELM or whether ERM or not. Key words: Diabetic retinopathy/complications; Vitreous hemorrhage/surgery; Tomography,optical coherence

Quantification of Retinal Tangential Movement in Epiretinal Membranes

To describe a technique of quantifying retinal vessel movement in eyes with epiretinal membrane (ERM) and correlate the retinal vessel movement with changes in best-corrected visual acuity (BCVA), central macular thickness (CMT), and patients' subjective reports about experienced symptoms (symptoms). Retrospective, observational, comparative case series. A total of 206 eyes of 113 patients: 142 eyes with ERM and 64 healthy fellow eyes. All patients were examined as part of a screening protocol for a randomized clinical trial on ERM. Heidelberg Spectralis (Heidelberg Engineering Inc, Carlsbad, CA) optical coherence tomography (OCT) scanning had been performed twice or more in all patients. Eyes with ERM and healthy fellow eyes were examined. For each eye, the 2 fundus images were aligned using Heidelberg's AutoRescan feature. The macular area was divided into 9 subfields, and retinal vessel movements were calculated. For each eye, the total length of the 9 vectors was summed to describe the total retinal vessel movement (retinal tangential movement [RTM]). To quantify retinal vessel movements associated with ERM. The secondary outcome was to correlate measured retinal vessel movement with changes in BCVA, CMT, and patients' subjective symptoms. The study found significantly greater RTM in ERM eyes compared with healthy eyes (P<0.001). Among ERM eyes, the RTM was significantly greater in patients with worsening of symptoms compared with ERM eyes with unchanged assessment of symptoms. There were statistically significant correlations between increased RTM and reduction in BCVA (P = 0.024), increased CMT (P<0.001), and time between visits (P<0.001). This study showed that ERM is not a static retinal disease but a dynamic condition in which retinal vessel movement associated with ERM was measureable, even in patients who had stable BCVA and CMT. The retinal vessel movements correlated to worsening of BCVA and increased CMT, and were more pronounced in patients with worsening of symptoms.

Morphologic and functional association of retinal layers beneath the epiretinal membrane with spectral-domain optical coherence tomography in eyes without photoreceptor abnormality

To access the differential thickening of retinal layers in the epiretinal membrane (ERM) and to determine their correlation with visual acuity. Prospective and comparative case series of 22 patients, each of whom has one unilateral ERM eye and one normal eye. The eyes with abnormal photoreceptor layer by OCT images were excluded. Spectral-domain optical coherence tomography (SD-OCT) images were generated with Spectralis OCT (Heidelberg Engineering, Heidelberg, Germany). The thicknesses were obtained by a volume scan program using manual segmentation of the total retina, inner retina, inner nuclear layer (INL), outer plexiform layer (OPL), and outer nuclear layer (ONL) in the fovea (1.0mm diameter) and the parafovea (3.0mm diameter). The thickness and the proportion of each retinal layer and their relationship with visual acuity were analyzed. All retinal layers of ERM eyes were thicker than the patients' normal eyes (P < 0.05). In the fovea, the levels of thickness difference of inner retina (240.38%) and INL (266.26%) were significantly higher than total retina (126.7%). Visual acuity was not correlated with the retinal thickness in both ERM eyes and normal eyes (P > 0.05). However, significant correlations between visual acuity difference with retinal thickness difference were found in the total retina (rho = 0.450, P = 0.046) and the inner retina (rho = 0.602, P = 0.005) of the fovea, as well as in the inner retina (rho = 0.468, P = 0.037) and the INL (rho = 0.466, P = 0.039) of the parafovea. When we convert each retinal thickness into a proportion, in the foveal area, the percentages of thickness of the inner retina and the INL of ERM eye were significantly higher than that of the normal eye (P < 0.05), whereas that of the ONL was significantly lower (P < 0.05). In the parafoveal area, the percentage of thickness of the inner retina of the ERM eye was significantly higher than that of the normal eye (P < 0.05), whereas that of ONL was significantly lower (P < 0.05). Idiopathic ERM affects the volume of all retinal layers. Inner retina had the most variability of thickness and is strongly associated with visual acuity changes in the case of intact photoreceptor layer.