FUNCTIONAL AND ANATOMICAL SIGNIFICANCE OF THE ECTOPIC INNER FOVEAL LAYERS IN EYES WITH IDIOPATHIC EPIRETINAL MEMBRANES: Surgical Results at 12 Months

Efficacy of Combined Vitrectomy with Intravitreal Corticosteroid Injection for Idiopathic Epiretinal Membrane Removal on Anatomical and Functional Outcomes: A Meta-analysis

BACKGROUND

Macular edema can be a cause of visual loss in eyes undergoing vitrectomy with epiretinal membrane(ERM) peeling.

OBJECTIVE

To evaluate the efficacy of combined vitrectomy with intravitreal corticosteroid injection for ERM.

METHODS

We conducted a systematic literature review by searching PubMed, Embase, and Medline up to December 2020 for studies that evaluated the effect of intravitreal corticosteroid injection during vitrectomy for ERM. Follow-up data on postoperative best-corrected visual acuity (BCVA) and central macular thickness (CMT) were collected and pooled using the standard mean deviation (SMD) with the corresponding 95% confidence interval (CI). Heterogeneity was statistically quantified using I2 statistics, and a meta-analysis was performed using a random-effects model.

RESULTS

Eight studies provided data on a total sample of 443 eyes. The meta-analysis revealed that concomitant intravitreal corticosteroid administration during vitrectomy contributed to a significant reduction in CMT than vitrectomy alone at 3 months after operation (pooled SMD = -0.353; 95% CI, -0.594 to -0.111; p = 0.004). However, between the two groups, no significant difference was found in CMT reduction at 1 and 6 months after operation and in postoperative BCVA improvement at 1, 3, and 6 months after operation.

CONCLUSION

Combined treatment with vitrectomy and intravitreal corticosteroid injection may accelerate CMT reduction 3 months after ERM surgery. However, it did not result in a significant change in CMT and BCVA compared with vitrectomy alone at the end of follow-up.

A prospective randomized clinical trial comparing nepafenac, intravitreal triamcinolone and no adjuvant therapy for epiretinal membrane

PURPOSE

To compare the efficacy of topical nepafenac 0.1% versus intravitreal triamcinolone acetonide (IVTA) at the conclusion of vitrectomy surgery versus no adjuvant therapy (NAT) in improving macular morphology post-operatively in patients undergoing vitrectomy for epiretinal membrane (ERM), as measured by optical coherence tomography (OCT) imaging and best-corrected visual acuity (BCVA).

METHODS

Design: Prospective randomized clinical trial Setting: Multi-centre 80 patients scheduled to undergo vitrectomy surgery for idiopathic ERM were randomized to receive either IVTA (4 mg/0.1 cc) at the end of surgery, topical nepafenac sodium 0.1% TID for 1 month post-operation or no adjuvant treatment (NAT). Optical coherence tomography (OCT) imaging, best-corrected visual acuity and intraocular pressure (IOP) were measured before surgery, and 1 and 2 months post-operation.

RESULTS

Although all three groups showed reduction in macular thickness post-operation, the NAT group showed the most improvement, with a reduction of 136.18 ± 29.84 μm at two months. There was no statistically significant difference in macular thickness between the groups at each time point, p = 0.158. The NAT group also had the best recovery in BCVA with an improvement of 0.207 logMAR (10.35 letters) at two months post-operation. There was no statistically significant difference in BCVA between the groups, p = 0.606. There was statistically significant difference in the IOP between the three groups, p = 0.04 only at 1-month visit. The IVTA group had the highest rise in average IOP at both 1 and 2 months post-operation (2.72 and 1.58 mmHg, respectively).

CONCLUSION

Our study data suggest there was no advantage in the use of topical nepafenac or IVTA for post-vitrectomy ERM surgery.

Ectopic inner foveal layer as a factor associated with metamorphopsia after vitrectomy for epiretinal membrane

PURPOSE

To analyse the relationship between the extent of metamorphopsia and optical coherence tomography (OCT) parameters including the ectopic inner foveal layer (EIFL) in patients with epiretinal membrane (ERM) who underwent pars plana vitrectomy (PPV).

METHODS

This study included 63 eyes of 62 patients who underwent PPV for ERM. Metamorphopsia was assessed by measuring the metamorphopsia score for vertical lines (MV) and metamorphopsia score for horizontal lines (MH) using M-CHARTS. Central retinal thickness (CRT), EIFL thickness and disruption of outer retinal layers were measured before and after surgery, and the relationship of these parameters with metamorphopsia scores at 3 months after vitrectomy was analysed.

RESULTS

Preoperative MV correlated with preoperative CRT and EIFL (p = 0.005 and 0.045 respectively). Postoperative MH correlated with preoperative CRT (p = 0.048), while postoperative MV correlated with preoperative CRT and EIFL (p = 0.002 and 0.0006 respectively). Postoperative MH correlated with postoperative CRT and EIFL (p = 0.001 and 0.002 respectively), and postoperative MV also correlated with postoperative CRT and EIFL (p = 0.0008 and < 0.0001 respectively). MH and MV did not correlate with outer retinal layer disruptions, both before and after vitrectomy. When multiple regression analysis was performed on preoperative and postoperative OCT parameters that correlated with postoperative metamorphopsia scores, only postoperative EIFL was identified as an independent factor associated with postoperative MV (p = 0.042).

CONCLUSION

When PPV was conducted for ERM, postoperative EIFL was found to be a significant factor associated with postoperative metamorphopsia score.

Predictive value of ectopic inner foveal layer without internal limiting membrane peeling for idiopathic epiretinal membrane surgery

PURPOSE

To investigate the clinical importance of ectopic inner foveal layer (EIFL) grading (mild to severe) in patients diagnosed with idiopathic epiretinal membrane (iERM) and had pars plana vitrectomy (PPV) with solely ERM peeling.

MATERIALS AND METHODS

Patients diagnosed with iERMs who had undergone PPV including only ERM peeling were enrolled in the study, and follow-up findings were recorded at baseline, and at 3, 6, 12 months and final examinations. EIFL was categorized into four grades, from mild to severe. Pre- and postoperative anatomical changes were measured using spectral domain optical coherence tomography (SD-OCT) imaging. The association between EIFL and other SD-OCT parameters with best-corrected visual acuity (BCVA) was assessed before and after PPV surgery.

RESULTS

One-hundred thirty-eight eyes of 106 patients with mild to severe EIFL were included in the study. Higher EIFL thickness was significantly correlated with lower baseline (r = 0.575, p = 0.020) and final BCVA (r = 0.748, p = 0.001). Although EIFLs continued in advanced-stage cases (stage 3 and 4) (64 eyes [82%]) at the final visit, it was observed in 8 eyes (23%) in the early stage (stage 2) of iERMs. A strong positive correlation was found between EIFL thickness and recurrence rate of ERM (r = 0.876, p < 0.001). Recurrence of ERM was detected in 27 eyes; 2 (7%) at stage 1, 3 (9%) at stage 2, 10 (23%) in stage 3, and 12 (33%) in stage 4 (p < 0.001).

CONCLUSION

A negative association was found between the severity of EIFL and postoperative anatomical and visual recovery. In terms of surgical timing, early stages (stages 1 and 2) may be preferred for providing good anatomical and visual recovery and a low recurrence rate following surgery.

Changes of Fixation Stability and Location after Epiretinal Membrane Surgery

PURPOSE

The study aimed to evaluate fixation stability and position changes after epiretinal membrane (ERM) surgery.

METHODS

This is a retrospective study that included 60 consecutive eyes with idiopathic ERM. All patients received comprehensive ophthalmic examinations preoperatively and 1, 4, 10 months postoperatively. Main outcome measures included fixation stability and position, bivariate contour ellipse area (BCEA), and preferred retinal locus (PRL).

RESULTS

The number of patients with stable fixation as well as predominantly central fixation was increased significantly after ERM surgery (61.7% vs. 73.3%, P=0.001; 41.7% vs. 71.7%, P=0.037). The correlation analysis showed that the preoperative factors associated with improved postoperative fixation stability were a larger BCEA value (P<0.001), poorer visual acuity (P=0.002), advanced stage (P=0.002), thicker CFT (P=0.015), and a longer PRL-foveal distant (P=0.0025). As for improved fixation location, the associated preoperative factors were age (P=0.003), CFT (P=0.044) and PRL-foveal distant (P<0.001).

CONCLUSION

Our observations point to the changes of fixation parameters in patients after ERM surgery. We found that patients with preoperative unstable, eccentric fixation and poor BCVA can significantly benefit from the surgery. This result indicates that even in patients with severe macular damage, the ERM surgery still has great benefits in recovering visual function.

Macular pigment optical density assessed by heterochromatic flicker photometry in eyes affected by primary epiretinal membrane

PURPOSE

To compare macular pigment optical density (MPOD) in healthy eyes vs eyes affected by primary epiretinal membrane (ERM) in different stages and to assess the relation between MPOD and optical coherence tomography findings.

METHODS

Prospective cross-sectional study of 62 eyes from 62 patients affected by unilateral primary ERM. Contralateral healthy eyes from the same patients were used as a control group. Main outcome measures were MPOD, ERM stage, central foveal thickness (CFT), outer nuclear layer thickness (ONLT), integrity of outer retinal bands (ORB) and presence of Central Bouquet (CB) abnormalities.

RESULTS

In the study group mean CFT was 444±75 µm and mean ONLT was 245±40 µm, while in the control group mean CFT was 230±21 µm and mean ONLT was 102±14 µm (p<0.001). Mean MPOD was 0.86±0.07 in eyes with ERM and 0.48±0.09 in contralateral healthy eyes (p<0.001). MPOD was associated with CFT (p=0.006) and ONLT (p<0.001) while no significant associations were observed between MPOD and ORB integrity (p=0.14) and CB abnormalities (p=0.08).

CONCLUSIONS

MPOD increased in eyes affected by primary ERM proportionally to CFT and, especially, ONLT. Probably, centripetal forces exerted by ERM contraction on the retinal surface lead to a progressive foveal packing of foveal Muller cells.

Influence of postoperative ectopic inner foveal layer on visual function after removal of idiopathic epiretinal membrane

Purpose

To investigate the functional and anatomical parameters and their postoperative changes according to the ectopic inner foveal layer (EIFL) staging scheme for idiopathic epiretinal membrane (ERM).

Methods

In this prospective study, patients with idiopathic ERM underwent pars plana vitrectomy and ERM removal, and were followed-up for 6 months. The associations of EIFL with pre- and postoperative functional and anatomical parameters were analyzed.

Results

A total of 84 eyes (84 patients) were included: 39 (46.4%), 33 (39.3%), and 12 (14.3%) as EIFL stages 2, 3, and 4, respectively. At 6 months after surgery, the mean best-corrected visual acuity (BCVA) significantly improved in all EIFL stages (P ≤ 0.003); however, metamorphopsia improved only in eyes with EIFL stage 2 (P = 0.039) and 3 (P = 0.011). The aniseikonia and foveal avascular zone (FAZ) area showed no significant postoperative changes in any of the EIFL stages. Both preoperatively and during 6 months after surgery, the EIFL stage showed a significant correlation with BCVA (P ≤ 0.033), metamorphopsia (P ≤ 0.008), central macular thickness (P < 0.001), and FAZ parameters (P ≤ 0.016) at each time point, but not with aniseikonia. Significant correlations of EIFL thickness with BCVA (P = 0.028) and metamorphopsia (P = 0.006) before surgery were not persistent after surgery.

Conclusion

Both pre- and postoperatively, the staging of EIFL, rather than its thickness, is a simple and adequate surrogate marker for visual acuity and metamorphopsia in eyes with idiopathic ERM.

FOVEAL DISPLACEMENT IN EYES WITH EPIRETINAL MEMBRANE AFTER VITRECTOMY AND MEMBRANE PEELING

PURPOSE

To investigate the foveal movement in eyes with epiretinal membrane after vitrectomy and membrane peeling.

METHODS

A retrospective review of 85 eyes with epiretinal membrane treated with vitrectomy, membrane peeling, and internal limiting membrane removal. Using a self-designed computer program to compare the preoperative and postoperative images of optical coherence tomography to measure the amount of foveal movement. Analyze the relationships between foveal displacement, preoperative and postoperative best-corrected visual acuity, central foveal thickness, and the stage of epiretinal membrane.

RESULTS

Most of the fovea were nasally shifted. More movement happened in the first month and almost finished in the first year. The greater degree of foveal displacement was correlated with poorer initial visual acuity and thicker central foveal thickness. In considering with the ectopic inner foveal layer staging of epiretinal membrane by structural optical coherence tomography, the foveal realignment is greatest in Stage 4 (394.47 ± 171.44 µm), followed by Stage 1 (251.21 ± 135.40 µm), Stage 2 (235.70 ± 147.51 µm), and Stage 3 (219.86 ± 117.91 µm) at the postoperative 1 month.

CONCLUSION

Most eyes of epiretinal membrane had the foveal moved nasally after membrane peeling and internal limiting membrane peeling. The larger amount of foveal movement was correlated with poorer initial best-corrected visual acuity. Dystopia fovea may be another factor affecting visual acuity in addition to other biomarkers in optical coherence tomography.

Optical coherence tomography biomarkers for visual acuity in patients with idiopathic epiretinal membrane

PURPOSE

To investigate the correlation between outer and inner retina optical coherence tomography (OCT) biomarkers and visual acuity in patients with idiopathic epiretinal membrane (iERM) and identify which of them may be predictive of visual function.

METHODS

A retrospective cross-sectional single-center study was conducted that included patients diagnosed with iERM. Spectral domain OCT images were obtained and assessed qualitatively and quantitatively. The association of OCT parameters with best corrected visual acuity was analyzed.

RESULTS

Charts of 97 eyes of 97 patients were reviewed. Central foveal thickness, maximal retinal thickness (MRT), photoreceptor outer segment length, outer foveal thickness, ganglion cell-inner plexiform layer complex thickening, inner retinal thickness and inner retinal layer irregularity index were among the major outcome measures. OCT scans were also assessed for the presence of cotton ball sign, ellipsoid zone disruption, ectopic inner foveal layer, disorganization of retinal inner layers (DRIL), intraretinal fluid, subretinal fluid (SRF) and epimacular membrane rip. Univariate analysis showed statistically significant association between all the aforementioned parameters with worse vision, except for cotton ball sign and SRF. Multivariate analysis found that MRT and severe DRIL were strongly correlated with worse vision (p < 0.001).

CONCLUSION

MRT and severe DRIL should be considered as negative prognostic factors for visual acuity.

Pars Plana Vitrectomy for Idiopathic Epiretinal Membrane: Optical Coherence Tomography Biomarkers of Visual Outcomes in 322 Eyes

OBJECTIVE

To investigate optical coherence tomography (OCT)-based biomarkers of visual acuity (VA) in eyes with idiopathic epiretinal membranes (ERM) undergoing surgical intervention.

PURPOSE

To assess surgical outcomes of pars plana vitrectomy (PPV) and membrane peel (MP) surgery in eyes with idiopathic ERM and identify potential imaging-based biomarkers of vision outcomes.

METHODS

Retrospective, consecutive case series of eyes with idiopathic ERM that underwent PPV and MP surgery between 1/1/2017 and 1/1/2019. A previously described ERM grading scale was utilized for OCT analysis. The primary outcome was VA at post-operative month 6 and final follow-up. A secondary outcome was the association of OCT structural features, including ectopic inner foveal layers (EIFL), inner microcystoid changes, and ellipsoid zone (EZ) disruption, with VA outcomes.

RESULTS

A total of 322 eyes with idiopathic ERM were included. Mean (± SD) follow-up was 506.6 ± 324.6 days after MP surgery. VA improved from logMAR 0.49 ± 0.27 (Snellen 20/61) pre-MP to 0.41 ± 0.30 (Snellen 20/51, p< 0.001) at 6 months after MP and 0.31 ± 0.29 (Snellen 20/41, p<0.001) at final follow-up. A total of 21 (6.5%) eyes were graded as Stage 1, 38 (11.8%) as Stage 2, 188 (58.4%) as Stage 3, and 75 (23.3%) as Stage 4, with higher ERM stages associated with worse pre-MP VA (p<0.001). Presence of inner microcystoid changes was associated with worse pre-MP VA (p=0.04). Stage 4 ERM characteristics (p=0.03), presence of EZ disruption (p=0.01) at month 3, and presence of inner microcystoid changes at month 3 (p=0.02) were associated with worse VA at 6 months. Presence of EIFL was not associated with 6 month or final VA on multivariate analysis. When analyzed within defined age groups, patients older than 80 years old had worse final VA (p=0.02) and were more likely to have inner microcystoid changes on OCT (p=0.01).

CONCLUSIONS

VA improvement was noted after surgery in eyes with idiopathic ERM across all stages. Pre-operative stage 4 characteristics were associated with worse VA at 6 months. Post-operative inner microcystoid changes and EZ disruption at month 3 were additional OCT biomarkers associated with worse 6 month and final VA outcomes.

Swept-source OCT reduces the risk of axial length measurement errors in eyes with cataract and epiretinal membranes

AIMS

To compare the biometric data from partial coherence interferometry (PCI) and swept-source OCT (SS-OCT) in patients with age-related cataract and epiretinal membrane (ERM): ERM, ERM with foveoschisis and macular pseudohole.

METHODS

49 eyes of 49 subjects including 36 ERM, 9 ERM foveoschisis and 4 macular pseudohole were analysed to evaluate the axial length (AL) measurements and the presence of AL measurement errors, defined basing on the shape of the biometric output graphs and on the concordance of AL values between instruments. Eyes with ERM were divided in four stages according to OCT features (i.e. presence/absence of the foveal pit, presence of ectopic inner foveal layers, disrupted retinal layers).

RESULTS

The devices provided similar mean AL measurements in all subgroups, with differences <0.1 mm in 41/49 cases (83.6%). AL measurement errors were observed in ERM stages 3 and 4, characterized by ectopic inner foveal layers, and were significantly more frequent with the PCI (8/17, 47%) as compared with the SS-OCT device (2/17, 12%), p = 0.02. The refractive prediction error in cases with AL measurement errors was significantly greater using the PCI compared to the SS-OCT device (p<0.05).

CONCLUSION

Both devices provide reliable biometric data in the majority of patients and can be used in the preoperative assessment of patients with age-related cataract and ERM. In eyes with ectopic inner foveal layers, attention should be paid as AL measurement and refractive prediction errors may occur, more frequently with the PCI device.

TEMPORAL CHANGES OF PARAFOVEAL MICROVASCULATURE AFTER EPIRETINAL MEMBRANE SURGERY: An Optical Coherence Tomography Angiography Study

PURPOSE

To investigate whether the parafoveal capillary architecture predicts clinical course and visual outcomes after epiretinal membrane (ERM) surgery.

METHODS

A total of 71 eyes of 71 patients treated with vitrectomy for idiopathic ERM were enrolled. The parafoveal capillary displacement and fractal geometries were compared according to the stage of ERM. Correlations between the parafoveal capillary displacement in the superficial capillary plexus, the fractal dimension and lacunarity in the deep capillary plexus (DCP), foveal thickness, and visual outcomes were evaluated.

RESULTS

Compared with eyes with mild ERM, eyes with severe ERM exhibited higher parafoveal capillary displacement in the superficial capillary plexus, lower fractal dimension and higher lacunarity in the DCP, and greater foveal thickness (P < 0.05). The parafoveal capillary displacement in the superficial capillary plexus and fractal dimension and lacunarity in the DCP improved significantly, particularly at 1 month postoperatively (P < 0.05) and reached a plateau thereafter. The preoperative fractal dimension in the DCP showed a significant correlation with the best-corrected visual acuity at all follow-up time points (P < 0.05).

CONCLUSION

The parafoveal fractal dimension in the DCP was significantly correlated with the visual acuity before and after ERM surgery. The parafoveal fractal dimension may serve as a predictive marker for visual outcomes after ERM surgery.

Increased risk of postsurgical macular edema in high stage idiopathic epiretinal membranes

PURPOSE

To assess the rate of occurrence and the risk factors of postsurgical macular edema (PSME) in eyes with idiopathic epiretinal membrane (iERM) or full-thickness macular hole (FTMH).

METHODS

Retrospective longitudinal analysis of all subjects scheduled for vitrectomy with or without combined cataract surgery over a 6-month period. Electronic medical charts and imaging data were analyzed preoperatively and at 1, 3 and 6 months after surgery.

RESULTS

From 101 patients diagnosed with iERM or FTMH, 71 patients were eligible for the study. Forty-nine eyes with iERM (69.0%) and 22 eyes with FTMH (31.0%) underwent vitrectomy either isolated (31.0%) or combined with cataract extraction (69.0%). The overall rate of PSME was 26.7%, without differences between the two groups (P = 0.9479). Combined cataract extraction did not affect the overall occurrence of PSME rate in both groups (P = 0.9255 in FTMH and P = 0.8658 in iERM). If grouped by stage, eyes with stage 4 iERM though disclosed an increased rate of PSME (57.1%) compared to lower (1 to 3) stages (14.3%, P = 0.0021), particularly when combined with cataract surgery (71.4% vs. 15.4% in stages ≤ 3, P = 0.0021). The PSME odds ratio for a stage 4 iERM is 8 (95% CI: 1.933-33.1; P = 0.0041) compared to stages 3 and below.

CONCLUSIONS

PSME remains a clinically relevant and frequent event after surgery for iERM and FTMH. Patients with stage 4 iERM have an 8-fold higher likelihood of developing PSME in a 6-month postsurgical period compared to iERM in 1-3 stages, especially when combined with cataract extraction.

MISALIGNMENT BETWEEN CENTER OF FOVEAL AVASCULAR ZONE AND CENTER OF FOVEAL PHOTORECEPTORS IN EYES WITH IDIOPATHIC EPIRETINAL MEMBRANE

PURPOSE

To determine the degree of misalignment between the center of foveal avascular zone and the center of foveal photoreceptors in eyes with an idiopathic epiretinal membrane (ERM).

METHODS

We reviewed the medical records of 61 eyes with an idiopathic ERM. A 3 × 3 mm area centered on the fovea was scanned with optical coherence tomography angiography before and at 6 months after surgery. The center of foveal avascular zone and the center of foveal photoreceptors were detected by en-face optical coherence tomography angiography images and sequential optical coherence tomography B-sections in the macular region. The presence or absence of ectopic inner foveal layers was also evaluated.

RESULTS

The mean distance from the center of foveal photoreceptors to the center of foveal avascular zone was 111.7 ± 106.8 µm in eyes with preoperative ERM. This distance was significantly correlated with the preoperative central foveal thickness (r = 0.33, P = 0.0104). Preoperatively, the ectopic inner foveal layers were present in 27 (44.3%) of 61 eyes. The foveal misalignment was greater in eyes with ectopic inner foveal layers than in those without ectopic inner foveal layers (158.6 ± 140.0 vs. 74.4 ± 45.4 µm, P < 0.0003). At 6 months after ERM surgery, the foveal misalignment was significantly reduced to 73.7 ± 48.0 µm (P = 0.0018).

CONCLUSION

Determining the degree of misalignment between the center of foveal avascular zone and the center of foveal photoreceptors might be a useful way to evaluate the degree of ERM traction.

Evaluation of postoperative visual function based on the preoperative inner layer structure in the epiretinal membrane

PURPOSE

To evaluate the postoperative visual function using a preoperative epiretinal membrane (ERM) classification based on the status of the inner layer structure.

METHODS

We assessed 62 eyes, one from each patient undergoing vitrectomy with internal limiting membrane (ILM) peeling for unilateral ERM. The inclusion criteria were as follows: (1) the presence of idiopathic ERM based on optical coherence tomography and a healthy contralateral eye, (2) successful surgery after 25- or 27-gauge transconjunctival 3-port pars plana vitrectomy with ILM peeling, and (3) a minimum follow-up period of 12 months. We included patients with preoperative ERM morphology with no disruption of the inner retinal layer in group A (37 eyes) and those with disruption in group B (25 eyes) and compared the visual acuity, central visual-field sensitivity (CVFS) measured using the Humphrey field analyzer 10-2 program, and detection rate of micro-scotoma (< 10 dB) at baseline and 12 months postoperatively between the groups.

RESULTS

Visual acuity at 12 months showed greater improvement in group A than in group B (P = .03). There was no significant difference in CVFS at baseline; however, that of the nasal area was substantially lower after surgery in group B than in group A (P = .02). The 12-month postoperative detection rate of micro-scotoma was significantly higher in group B than in group A (P = .002).

CONCLUSION

ERM that has preoperatively disrupted the inner layer poses the risks of CVFS reduction and micro-scotoma formation after vitrectomy. Evaluating the inner layer could be an important prognostic factor in determining retinal function in ERM.

Müller cells and astrocytes in tractional macular disorders

Tractional deformations of the fovea mainly arise from an anomalous posterior vitreous detachment and contraction of epiretinal membranes, and also occur in eyes with cystoid macular edema or high myopia. Traction to the fovea may cause partial- and full-thickness macular defects. Partial-thickness defects are foveal pseudocysts, macular pseudoholes, and tractional, degenerative, and outer lamellar holes. The morphology of the foveal defects can be partly explained by the shape of Müller cells and the location of tissue layer interfaces of low mechanical stability. Because Müller cells and astrocytes provide the structural scaffold of the fovea, they are active players in mediating tractional alterations of the fovea, in protecting the fovea from such alterations, and in the regeneration of the foveal structure. Tractional and degenerative lamellar holes are characterized by a disruption of the Müller cell cone in the foveola. After detachment or disruption of the cone, Müller cells of the foveal walls support the structural stability of the foveal center. After tractional elevation of the inner layers of the foveal walls, possibly resulting in foveoschisis, Müller cells transmit tractional forces from the inner to the outer retina leading to central photoreceptor layer defects and a detachment of the neuroretina from the retinal pigment epithelium. This mechanism plays a role in the widening of outer lameller and full-thickness macular holes, and contributes to visual impairment in eyes with macular disorders caused by conractile epiretinal membranes. Müller cells of the foveal walls may seal holes in the outer fovea and mediate the regeneration of the fovea after closure of full-thickness holes. The latter is mediated by the formation of temporary glial scars whereas persistent glial scars impede regular foveal regeneration. Further research is required to improve our understanding of the roles of glial cells in the pathogenesis and healing of tractional macular disorders.

Foveal configurations with disappearance of the foveal pit in eyes with macular pucker: Presumed role of Müller cells in the formation of foveal herniation

Many eyes with macular pucker are characterized by a centripetal displacement of the inner foveal layers which may result in a disappearance of the foveal pit. In this retrospective case series of 90 eyes with macular pucker of 90 patients, we describe using spectral-domain optical coherence tomography different foveal configurations with ectopic inner foveal layers, document the relationship between posterior vitreous detachment (PVD) and idiopathic epiretinal membrane (ERM) formation and spontaneous and postoperative morphological alterations of the fovea, and propose an active role of Müller cells in the development of foveal herniation. We found that ERM were formed during or after partial perifoveal PVD, or after foveal deformations caused by tissue edema. The ERM-mediated centripetal displacement of the inner foveal layers and in various eyes anterior hyaloidal traction caused a disappearance of the foveal pit and an anterior stretching of the foveola with a thickening of the central outer nuclear layer (ONL). After the edges of the thickened inner layers of the foveal walls moved together, continuous centripetal displacement of the inner foveal layers generated a bulge of the fovea towards the vitreous (foveal herniation). Macular pseudoholes with a herniation of the inner foveal layers show that the outer layer of the protruding foveal walls is the outer plexiform layer (OPL). If the ERM covered the foveal walls and parafova, but not the foveola, the inner layers of the foveal walls were not fully centripetally displaced and the foveal pit was present. The visual acuity of eyes with ectopic inner foveal layers was inversely correlated with the thickness of the foveal center. Spontaneous morphological alterations after disappearance of the foveal pit may include the development of cystoid macular edema or additional thickening of the foveal tissue and foveal herniation. The foveal configuration with ectopic inner layers of the foveal walls and a thick central ONL persisted over longer postoperative time periods. The data show that the centripetal displacement of the inner foveal layers in eyes with macular pucker, which results in a disappearance of the foveal pit, may also generate foveal herniation which is suggested to be caused by contraction of Müller cell processes in the OPL. The centripetal displacement of the inner foveal layers and the formation of foveal herniation are suggested to reverse the foveal pit formation during development.

Epiretinal Membrane Surgery after Retinal Detachment Repair: Visual Acuity Outcomes and OCT Analysis

PURPOSE

To assess visual acuity (VA) outcomes of epiretinal membrane (ERM) surgery following primary rhegmatogenous retinal detachment (RD) repair and to identify OCT features predictive of visual outcomes.

DESIGN

Retrospective, consecutive case series.

SUBJECTS

Eyes undergoing pars plana vitrectomy (PPV) with membrane peel (MP) surgery for ERM following primary RD repair (PPV with or without scleral buckle (SB) and gas tamponade).

METHODS

Retrospective chart review from 2015 to 2018. A previously described ERM grading scale was utilized for OCT structural analysis.

MAIN OUTCOME MEASURES

Visual acuity (VA) and change in VA from pre- MP to 6 months and final follow-up. Secondary outcomes included RD and OCT features predictive of VA, as well as RD factors associated with need for subsequent MP surgery.

RESULTS

53 eyes of 53 patients underwent MP following RD repair. VA improved significantly from logMAR 1.00 ± 0.51 (Snellen 20/200) pre-MP to 0.45 ± 0.41 (20/56) at 6 months and 0.42 ± 0.41 (20/53) at final follow-up, (p<0.001) for each respectively. Macula on eyes had better 6 month [0.29 ± 0.18 (20/39) vs. 0.51 ± 0.46 (20/65), p=0.02] and final VA [0.29 ± 0.14 (20/39) vs. 0.46 ± 0.47 (20/58), p=0.04] after MP surgery. VA improved significantly from pre-MP to 6 months and final follow-up regardless of macula status. MP occurring ≤180 days from RD repair and IS/OS loss were associated with worse pre-MP VA [1.13 ± 0.09 (20/270) vs. 0.82 ± 0.07(20/132), p=0.01 and 1.21 ± 0.07 (20/324) vs. 0.74 ± 0.09 (20/110) p=0.0003, respectively]. IS/OS loss [adjusted means 0.54 ± 0.07 (20/69) vs. 0.25 ± 0.08 (20/36) at final visit, p=0.006] and RD repair with PPV/SB [0.53 ± 0.08 (20/68) vs. 0.31 ±0.07 (20/41) at final visit, p=0.03] were significantly associated with worse VA at both 6 months and final follow-up.

CONCLUSIONS

Eyes undergoing MP after RD repair have significant visual acuity gains independent of macula-status at time of RD repair. Pre-operative IS/OS disruption was the OCT feature best predictive of visual acuity.

Epiretinal membrane: A review

The prevalence of epiretinal membrane (ERM) is 7% to 11.8%, with increasing age being the most important risk factor. Although most ERM is idiopathic, common secondary causes include cataract surgery, retinal vascular disease, uveitis and retinal tears. The myofibroblastic pre-retinal cells are thought to transdifferentiate from glial and retinal pigment epithelial cells that reach the retinal surface via defects in the internal limiting membrane (ILM) or from the vitreous cavity. Grading schemes have evolved from clinical signs to ocular coherence tomography (OCT) based classification with associated features such as the cotton ball sign. Features predictive of better prognosis include absence of ectopic inner foveal layers, cystoid macular oedema, acquired vitelliform lesions and ellipsoid and cone outer segment termination defects. OCT-angiography shows reduced size of the foveal avascular zone. Vitrectomy with membrane peeling remains the mainstay of treatment for symptomatic ERMs. Additional ILM peeling reduces recurrence but is associated with anatomical changes including inner retinal dimpling.

The Role of OCT Angiography in the Assessment of Epiretinal Macular Membrane

Background

The aim of this observational study is to assess pre- and postoperative retinochoroidal vascular changes in patients undergoing epiretinal macular membrane (ERM) surgery by using optical coherence tomography angiography (OCTA).

Materials and Methods

23 eyes affected by ERM and those which underwent phacovitrectomy associated with ERM peeling were enrolled. They were evaluated using structural OCT and OCTA before surgery and at 1, 3, and 6 months postoperatively.

Results

We found a statistically significant (p < 0.05) increase in the superficial capillary plexus vessel density (VD) from baseline to the 6-month follow-up. We observed a large increase in both the perfusion density (PD) and the VD of the deep capillary plexus between baseline and the 6-month follow-up (p < 0.001). A significant decrease in the VD and PD of the choriocapillaris (CC) from baseline to the 1^st month and a significant increase in CC perfusion density at the 6-month follow-up compared to the preoperative value were revealed. The FAZ area and perimeter after surgery significantly increased during the follow-up (p < 0.001) at baseline retinal and choroidal plexi with a lower PD or VD correlated with worse visual acuity (p < 0.05 for all plexi). At baseline and at the 1-month follow-up, a significant correlation was found with the FAZ area and the FAZ perimeter: a smaller FAZ area or a smaller FAZ perimeter was correlated to a lower visual acuity. Before surgery, negative correlations (p < 0.05) were found between the Govetto ERM stages and perfusion density of the SCP and the DCP and between the Govetto stages and vessel density of the DCP.

Conclusions

In our study, OCTA detected vascular alterations induced by the presence of the ERM, allowing several correlations with functional data. In these patients, OCTA may be useful to add new potential surgical prognostic factors.

[Optical coherence tomography biomarkers in epimacular membranes and vitreomacular traction syndrome]

Using high-resolution imaging, such as optical coherence tomography (OCT), the different layers of the retina as well as the vitreoretinal interface and its alterations can be very clearly differentiated. This includes the morphological characteristics of tractive maculopathies, such as epiretinal gliosis and vitreomacular traction syndrome. Additionally, structural alterations of the various layers of the neurosensory retina as a result of traction due to these pathologies can be demarcated. The latter have been investigated in clinical trials and evaluated as OCT biomarkers with respect to their prognostic and predictive value. In this review we would like to present and discuss various OCT biomarkers in the context of epimacular membranes and vitreomacular traction syndrome.

Prognostic factors of idiopathic epiretinal membrane surgery and evolution of alterations of the central cone bouquet

PURPOSE

To describe the structural changes observed postoperatively in epiretinal membranes (ERM), in particular the alterations in the central cone bouquet (CB), and to identify prognostic factors that might predict postoperative outcome.

METHODS

We included 125 eyes of 117 patients who underwent idiopathic ERM removal with at least a 6-month follow-up. For each patient, spectral-domain optical coherence tomography (SD-OCT) was performed and best-corrected visual acuity (BCVA) was measured, before and after surgery.

RESULTS

Before surgery, 44 eyes (35.2%) presented CB alterations: 65.9% a cotton ball sign, 15.9% a foveolar detachment and 18.2% a pseudovitelliform lesion. Median BCVA increased from 20/63 to 20/32 post-operatively (p = .001) with a mean follow-up of 17 months. The disappearance of CB alterations after surgery was observed in 97.7% of eyes. In stage 3 and 4 ERM, ectopic inner foveal layers persisted in 76.7% of eyes after surgery. Postoperative BCVA was correlated with change in central macular thickness and initial BCVA and was not correlated with the presence of preoperative CB alteration, the initial stage of ERM, the presence of postoperative dissociated optical nerve fiber layer, and the disappearance of ectopic inner fiber layers. The combination of cataract surgery and capsulotomy did not seem to change visual outcome and seemed to accelerate visual recovery. Incidentally, general anesthesia was correlated with final BCVA.

CONCLUSION

ERM surgery allowed a significant gain in BCVA and the disappearance of CB alterations in the great majority of cases. CB alteration did not show to be associated with poor visual prognosis.

Functional and Morphological Results of Epiretinal Membrane Surgery in Idiopathic versus Diabetic Epiretinal Membranes

PURPOSE

Idiopathic and diabetic epiretinal membranes (ERM) are different in terms of pathophysiology, etiology, and macular morphology, and thus might respond to surgical treatment differently. We aimed to compare the surgical results of two groups.

METHODS

Retrospective case series study of 71 eyes of 66 patients who underwent pars plana vitrectomy (PPV) due to idiopathic or diabetic ERM with at least 1-year follow-up. Examinations were performed before, and 1, 3, 6, and 12 months after surgery. The average macular thicknesses in nine sectors described by the Early Treatment Diabetic Retinopathy Study (ETDRS) were measured with spectral-domain optical coherence tomography (OCT), and BCVA was evaluated. ERM recurrence rates were investigated.

RESULTS

In both idiopathic and diabetic groups, retinal thickness (RT) changes occurred as long as 12 months after vitrectomy surgery for ERM. However, in the idiopathic group, significant changes were mainly seen in the first 6 months, while in the diabetic group changes slowed considerably between the third and sixth months, but again accelerated (becoming significant) during the last 6 months.

CONCLUSIONS

According to the findings of this study, as compared to those with idiopathic ERM, diabetic patients would likely see continuing benefits from ERM surgery 6 to 12 months post surgery. The BCVA changes of the two groups were similar. ILM peeling decreased ERM recurrence in the idiopathic group but not in the diabetic group.

The predictive value of ectopic inner retinal layer staging scheme for idiopathic epiretinal membrane: surgical results at 12 months

BACKGROUND/OBJECTIVES

To assess the effect of ectopic inner foveal layers (EIFL) based staging scheme, foveal avascular zone (FAZ) alterations and other microstructural optical coherence tomography (OCT) findings on visual function for patients undergoing idiopathic epiretinal membrane (iERM) surgery.

SUBJECTS/METHODS

In this retrospective study, patients who underwent 27 G pars plana vitrectomy (PPV) for idiopathic ERM with a minimum follow-up of 12 months were included. Preoperative and postoperative OCT scans, FAZ area measurements on en face OCT angiography images and mean retinal sensitivity (MRS) using microperimetry were recorded in all cases. The correlation of FAZ area, EIFL and other OCT parameters with preoperative and postoperative best-corrected visual acuity (BCVA) was analysed.

RESULTS

In all, 112 eyes of 112 patients were included. Visual acuity improvement was statistically significant in all four stages; however, differences between Stages 2, 3 and 4 ERMs remained significant (p < 0.05). The presence and thickness of the EIFL was associated with worse baseline (p = 0.013; p = 0.005, respectively) and final (p < 0.001 for both) BCVA. The presence of cystoid macular oedema was associated with worse BCVA at baseline (p = 0.027) and postoperative month-6 (p = 0.04). The mean FAZ area was significantly reduced in all stages of ERM compared with the fellow eyes (p < 0.05 for all). Postoperative retinal sensitivity improvement was statistically significant in Stage 1 and Stage 2.

CONCLUSION

The presence of EIFL is an independent predictor of worse postoperative BCVA. Accordingly, despite significant BCVA improvements in all stages of ERM, visual acuity gain remains limited in eyes with Stage 3 and Stage 4 ERM.

The visual outcomes of idiopathic epiretinal membrane removal in eyes with ectopic inner foveal layers and preserved macular segmentation

PURPOSE

To analyze the functional impact of ectopic inner foveal layers (EIFL), along with other clinical and optical coherence tomography biomarkers, on patients with epiretinal membrane (ERM) and preserved foveal layers' segmentation undergoing ERM removal.

METHODS

Retrospective review of consecutive patients with ERM who underwent pars plana vitrectomy with ERM peeling from December 2018 to December 2019. Baseline factors including age, gender, lens status, phacoemulsification at the time of surgery, tamponade agent, dye used for ERM and internal limiting membrane (ILM) enhancement, ILM peeling, best-corrected visual acuity (BCVA) and central macular thickness (CMT), presence and thickness of EIFL, thickness of outer nuclear layer (ONL), presence of a cotton ball, subfoveal state of photoreceptors, and presence of cystoid macular edema were included in a multivariable model having the BCVA at 12 months as the main outcome. The changes in EIFL and ONL thickness over time were also analyzed.

RESULTS

Fifty-one patients (58 eyes, 23 eyes in the no EIFL group, and 35 eyes in the EIFL group) were enrolled. The BCVA significantly improved over 12 months after surgery, regardless of the presence of EIFL (p < 0.001). Eyes with no EIFL had better BCVA at month 3 (p = 0.04), but this difference was no longer detectable at 6 and 12 months. The presence of EIFL was not associated with the final BCVA (p = 0.9), while the CMT at 12 months correlated with EIFL thickness (r = 0.8, p = 0.008).

CONCLUSION

Patients with EIFL could reach optimal visual acuity in the absence of disorganization of the inner retinal layers but should be warned of potentially longer healing times. None of the morphologic signs included in this study precluded good visual recovery on long-term follow-up.

Influences of Central Bouquet Alterations on the Visual Outcome in Eyes Receiving Epiretinal Membrane Surgery

Background: Previous studies have shown that epiretinal membranes (ERMs) may be associated with abnormal outer retinal anatomy. However, long-term morphological and functional results of pars plana vitrectomy (PPV) with ERM and internal limiting membrane (ILM) peeling in eyes with central bouquet (CB) alterations have not yet been investigated. Methods: In a retrospective, consecutive study all patients underwent best corrected visual acuity (BCVA) testing and spectral domain optical coherence tomography (SD-OCT) before and after a mean of 20 months (range 3–70 months) postoperatively. CB abnormalities and ERMs were classified according to Govetto’s staging systems. Results: Of the 67 eyes, 22 (34%) showed CB abnormalities at baseline. The mean BCVA increased from 0.42 at baseline to 0.20 LogMAR at final follow-up (p < 0.001). Neither ERM stage (p = 0.06) nor CB stage (p = 0.939) at baseline were significant predictors of vision improvement following surgery. Conclusions: Our results show that baseline BCVA, but not classification of CB changes and ERM at baseline, seems to be a useful predictor for functional outcomes following PPV with ERM and ILM peeling in the long-term.

Epiretinal membrane surgery outcome in eyes with abnormalities of the central bouquet

Background

Clinical studies have shown that epiretinal membranes (ERM) as well as abnormalities of the central foveal bouquet (CB) can be classified in different stages according to their morphological appearance. Furthermore, visual acuity correlates with the different stages of these features. The present study evaluated how these findings change after the surgical removal of the ERM and their impact on functional outcomes.

Methods

In this retrospective study eyes with ERM were evaluated by SD-OCT scans before and after pars plana vitrectomy (PPV) with macular ERM and internal limiting membrane (ILM) peeling. CB abnormalities were classified according to their morphological appearance from stage 0 (no abnormalities) to stage 3 (acquired vitelliform lesion). ERMs were classified ranging from stage 0 (absence of ERM) to stage 4 (ERM with significant anatomic disruption of macula). Changes in morphology were correlated with visual acuity before and after surgery.

Results

151 eyes were included into the study. Before surgery 27.2% (n = 41) of eyes showed CB abnormalities with stage 1 being the most common (11.9%, n = 18). Before surgery ERM was seen in all patients. The most common form was stage 1 (28.5%, n = 43), followed by stage 3 (27.8%, n = 42) and 2 (25.2%, n = 38). Only 18.5% (n = 28) presented with stage 4 ERM. The mean BCVA was 0.42 (logMAR) before and increased to 0.19 (logMAR) 8 weeks after vitrectomy (95% CI 0.20–0.28; p < 0.001). Patients who suffered from CB abnormalities had less increase in BCVA than patients who had no evidence of CB (0.28 vs. 0.14 logMAR; p < 0.001). Of all the patients with CB abnormalities at baseline, 68% had lower CB grading after the surgery (n = 28; 95% CI; p < 0.001). All patients showed an improvement of their ERM grading, with 98.7% reaching stage 0 (n = 151 vs. n = 149; 95% CI; p < 0.001).

Conclusions

The study indicates that the presence of CB abnormalities correlates with worse visual function. They are furthermore associated with worse visual outcomes after PPV with ERM and ILM peeling. These findings are valuable for deciding on PPV in patients with ERM.

Visual Acuity Inadequately Reflects Vision-Related Quality of Life in Patients After Macula-Off Retinal Detachment Surgery

Purpose

To determine the impact of postoperative visual function on the vision-related quality of life (VRQoL) in patients after anatomically successful surgery for macula-off rhegmatogenous retinal detachment (RRD) and to propose a classification to grade the extent of macular detachment using preoperative optical coherence tomography (OCT) scans.

Methods

This prospective study evaluated 48 patients. At 12 months after surgery, visual function assessments were as follows: metamorphopsia (M-CHARTS), aniseikonia (New Aniseikonia Test), best corrected visual acuity (BCVA) (Early Treatment Diabetic Retinopathy Study [ETDRS]), low contrast BCVA (10% ETDRS), color vision (Hardy Rand Rittler), and stereopsis (Titmus Fly). VRQoL was assessed by the National Eye Institute Visual Functioning Questionnaire-25 (NEIVFQ-25). Associations between visual function parameters and NEIVFQ-25 scores were evaluated. Preoperative OCT-scans were classified into six stages according to the extent of macular detachment based on an ETDRS-grid: incomplete perifoveal detachment (1), incomplete parafoveal detachment (2), incomplete foveal detachment (3), complete foveal detachment (4), complete parafoveal detachment (5), and complete perifoveal detachment (6).

Results

General vision and driving were the lowest scoring categories. General vision had the strongest correlation with low contrast BCVA (r = −0.41, P = 0.002), while driving had the strongest correlation with stereopsis (r = −0.39, P = 0.008). All macular detachments were graded stage 3 or beyond. Patients with stage 3 macular detachments had the highest visual function values compared to the other stages. The highest percentage of patients with metamorphopsia, aniseikonia and BCVA>0.1 logMAR was found in stages 5 and 6.

Conclusions

Macula-off RRD particularly affects general vision and driving. The extent of macular detachment is a potential predictor for visual function and can be graded using the proposed classification.

Epiretinal Membrane Surgery: Structural Retinal Changes Correlate with the Improvement of Visual Function

Several parameters have been studied for identifying the visual outcomes after pars plana vitrectomy (PPV) for epiretinal membrane (ERM) peeling. This retrospective study aimed to analyze structural retinal changes with spectral domain-optical coherence tomography (SD-OCT) and their correlations with visual acuity improvement in patients with ERM undergoing PPV. Twenty-one pseudophakic eyes were enrolled in the study. Ophthalmic evaluations included best corrected visual acuity (BCVA) and retinal layer thickness measurements with SD-OCT. The segmentation of the retina was divided into four parts: the inner retinal layer (IRL), composed of an internal limiting membrane, retinal nerve fiber layer, ganglion cell layer, and inner plexiform layer; inner nuclear layer (INL); outer plexiform layer (OPL); and outer nuclear layer (ONL). Correlations between changes in retinal layer thicknesses and BCVA were explored over a 6 month follow-up period. The postoperative thickness decrease of the INL was significantly correlated with thickness changes in all other measured retinal layers (p < 0.001). Non-parametric linear regression showed that postoperative improvement in BCVA was associated with a postoperatively decreased thickness in the IRL (p = 0.021), INL (p = 0.039), and OPL (p = 0.021). In eyes undergoing PPV, postoperative thickness decreases of the IRL, INL, and OPL were correlated with visual acuity improvements. Re-compaction of these retinal layers after relieving ERM-induced traction may be an important factor in postoperative visual function improvement.

Novel Optical Coherence Tomography Parameters as Prognostic Factors for Stage 3 Epiretinal Membranes

Purpose

We aimed to describe the visual prognosis of eyes with ectopic inner foveal layers (EIFLs) after epiretinal membrane (ERM) surgery.

Methods

This retrospective study enrolled patients diagnosed with stage 3 ERM based on the EIFL staging scheme who underwent ERM surgery with a minimum follow-up period of 12 months. Central foveal thickness (CFT), EIFL thickness, and the length of the ellipsoid zone defect were evaluated at baseline and at 1 month, 6 months, and 12 months after surgery based on pre- and postoperative swept-source optical coherence tomography (OCT) images. The association of EIFL thickness and other OCT parameters with pre- and postoperative best-corrected visual acuity (BCVA) was analyzed.

Results

Sixty-nine eyes with stage 3 ERMs were analyzed. Preoperative BCVA was correlated with preoperative CFT (r = 0.517, p < 0.001) and preoperative EIFL thickness (r = 0.652, p < 0.001). At 12 months, postoperative BCVA was correlated negatively with preoperative CFT (r = 0.470, p=0.016) and preoperative EIFL thickness (r = 0.582, p=0.004). The improvement in BCVA was not associated with postoperative reduction in CFT (p=0.06), although it was significantly associated with postoperative reduction in EIFL thickness (r = 0.635, p=0.007).

Conclusions

EIFL thickness should be considered a negative prognostic factor for postoperative anatomical and functional recovery in patients with stage 3 ERMs.

Relationship between morphological changes in the foveal avascular zone of the epiretinal membrane and postoperative visual function

Objective

To investigate the relationship between the preoperative morphology of the foveal avascular zone (FAZ) and postoperative visual function in patients with idiopathic epiretinal membrane (ERM).

Methods and analysis

This retrospective study enrolled 36 patients who underwent a unilateral internal limiting membrane peeling with vitrectomy for idiopathic ERM. We measured the area of superficial FAZ in the eyes with ERM and in the contralateral control eyes preoperatively and at 6 months postoperatively using optical coherence tomography (OCT) angiography. The ERM stage was measured using swept-source OCT. We evaluated the FAZ area ratio (preoperative FAZ of the ERM eye/FAZ of the control eye) to indicate the degree of FAZ contraction in the ERM eyes compared with the control eyes. The correlations between the FAZ area ratio and postoperative visual function and changes in macular morphology were assessed.

Results

Preoperative mean best-corrected visual acuity (BCVA) significantly improved from the logarithm of the minimum angle of resolution 0.20±0.24 to 0.01±0.13 at 6 months postoperatively (p<0.01). The mean area of the FAZ increased significantly from 0.06±0.07 mm² preoperatively to 0.09±0.07 mm² after vitrectomy (p<0.01). FAZ area ratio showed significant negative correlations with changes in BCVA (r=-0.44, p<0.01) and the ERM stages (r=-0.56, p<0.01).

Conclusion

The FAZ is reduced as ERM progresses and enlarges after vitrectomy. The FAZ area ratio based on preoperative FAZ may predict postoperative visual acuity.

Correlation between new OCT parameters and metamorphopsia in advanced stages of epiretinal membranes

PURPOSE

To correlate metamorphopsia provided by M-CHARTS and ectopic inner foveal layers (EIFL) or 'central bouquet' abnormality (CBA) in patients with advanced stages of epiretinal membrane (ERM) following the novel Optical Coherence Tomography (OCT)-based grading scheme.

METHODS

In 60 eyes of 57 patients affected by ERM (stages 3 and 4), the degree of metamorphopsia using the M-CHARTS was evaluated (M-SCORE) and correlated with EIFL, CBA and central foveal thickness (CFT) as measured on OCT scans.

RESULTS

A total of 37 and 23 eyes were diagnosed having ERM stages 3 and 4, respectively. Mean vertical and horizontal M-SCORE (M-V and M-H) were 0.64 ± 0.43 and 0.58 ± 0.37 standard deviations, respectively. Mean M-SCORE exhibited a statistically significant correlation with EIFL and CFT (both p < 0.0001), but not with CBA (p = 0.84). Analysing the direction of metamorphopsia separately, M-H and M-V were significantly correlated with EIFL (both p < 0.0001), but not with CBA thickness (p = 0.70 and 0.33 respectively). Ectopic inner foveal layers (EIFL) was significantly influenced by the presence of CBA (CBA present, 158.29 ± 63.53 micron; CBA absent, 107.05 ± 94.13 micron, p = 0.04). No significant differences were found for both M-V and M-H with respect to the presence of CBA.

CONCLUSIONS

Based on the novel OCT-based grading scheme for ERMs, our results demonstrate that EIFL, but not CBA, might be considered a good indicator for metamorphopsia in patients with advanced ERMs.

Analysis of Three-Dimensional Choroidal Volume with Enhanced Depth Imaging Findings in Patients with Recurrent Vogt-Koyanagi-Harada Disease

Purpose: To demonstrate changes in three-dimensional choroidal volume with enhanced depth imaging optical coherence tomography (EDI-OCT) in patients with recurrent stage of Vogt-Koyanagi-Harada disease (VKH).Materials and Methods: This prospective comparative case series included 9 patients with recurrent VKH, 10 patients with quiet VKH, and 15 healthy controls after sample size was calculated. All VKH cases with recurrences underwent raster scanning with EDI-OCT at active and inactive stages of the disease.Results: All choroidal parameters in the active stage significantly reduced when the inflammation subsided: total choroidal volume (P = .02), central choroidal volume (P = .01), central choroidal thickness (P = .03). The changes in central choroidal volume over the resolution phase were more pronounced than the changes in central choroidal thickness in 56% of cases. Two cases presenting with only subclinical posterior segment recurrence had their choroidal parameters recovered after prompt treatment.Conclusions: In the recurrent stage of VKH, alteration in choroidal volume was evident by EDI-OCT even in an absence of anterior segment inflammation. Central choroidal volume may serve as a biomarker for detecting choroidal morphological change.

Effect of Phacoemulsification on Outcomes after Vitrectomy with Membrane Peeling regarding New Intraretinal Cystoid Changes and Transient Macular Edema

PURPOSE

The aim of the present study was to analyze the effect of phacoemulsification on outcomes among patients undergoing vitrectomy with membrane peeling for idiopathic epiretinal membranes, with respect to new postoperative intraretinal cystoid changes and early transient macular edema.

PROCEDURES

This retrospective analysis included patients from 6 prospective studies, examining outcomes of 23G pars plana vitrectomy with membrane peeling due to idiopathic epiretinal membranes. Phacovitrectomy with membrane peeling was performed only in the case of coexisting vision affecting cataract. Optical coherence tomography was performed prior to surgery, in the first week, and 3 months after surgery.

RESULTS

In total, 183 patients were included. The occurrence of new postoperative intraretinal cystoid changes and early transient macular edema showed a trend toward being higher among patients undergoing phacovitrectomy with membrane peeling, compared to vitrectomy with membrane peeling alone, but it did not reach statistical significance (p = 0.5 and p = 0.186). The final best corrected distance visual acuity (BCVA) 3 months after surgery was significantly lower among patients with new postoperative intraretinal cystoid changes compared to patients without (with a median difference of 1 line between groups; p = 0.016).

CONCLUSIONS

New postoperative intraretinal cystoid changes and early transient macular edema are more frequent among patients undergoing phacovitrectomy with membrane peeling compared to patients with vitrectomy with membrane peeling alone.

Smaller Foveal Avascular Zone in Deep Capillary Plexus Is Associated with Better Visual Acuity in Patients after Macula-off Retinal Detachment Surgery

Purpose

To associate the change in the foveal avascular zone (FAZ) and vessel density (VD) with final best corrected visual acuity (BCVA) in eyes after macula-off rhegmatogenous retinal detachment surgery, and to investigate the evolution of FAZ and VD during 12 months of follow-up.

Methods

We prospectively evaluated 47 patients with macula-off rhegmatogenous retinal detachment and healthy fellow eyes. At 1.5, 3.0, 6.0, and 12.0 months postoperatively, optical coherence tomography angiography scans were obtained from both eyes on a 3.0 × 3.0 mm macula-centered grid. En face images of the superficial vascular plexus, intermediate capillary plexus and deep capillary plexus were used to quantify FAZ and VD. BCVA was assessed with ETDRS-charts (logarithm of the minimal angle of resolution).

At 12 months postoperatively, the association between the change in optical coherence tomography angiography parameters and visual function in study eyes was evaluated using the Spearman correlation coefficient. We calculated the BCVA difference and the percentage difference of FAZ and VD between the study and control eye. The evolution of FAZ and VD was investigated with linear mixed-effects models with nested random effects (eyes nested within patients).

Results

At 12 months postoperatively, FAZ difference of the deep capillary plexus and BCVA difference were correlated (P = 0.0004, r_s = 0.5). Furthermore, there was no evidence that FAZ and VD changed during follow-up.

Conclusions

Although FAZ and VD remained stable during 12 months after surgery for macula-off rhegmatogenous retinal detachment, a smaller FAZ in the deep capillary plexus is associated with better BCVA.

Translational relevance

Reduction in FAZ area may be caused by angiogenesis to counteract ischemia, therefore therapeutic stimulation of angiogenesis could be beneficial to visual recovery.

Long-Term Outcome of Epiretinal Membrane Surgery in Patients with Internal Limiting Membrane Dehiscence

PURPOSE

To identify the effect of internal limiting membrane (ILM) dehiscence on surgical outcomes in eyes that have undergone epiretinal membrane (ERM) removal.

METHODS

Consecutive eyes with performed vitrectomy for ERM removal were included. Subjects were divided into two groups: patients with ILM dehiscence (group 1) and without ILM dehiscence (group 2). The best-corrected visual acuity (BCVA) and retinal layer thickness before and after surgery were compared between the two groups.

RESULTS

A total of 86 eyes were enrolled. Forty-six eyes (53.5%) showed ILM dehiscence before surgery. The baseline BCVAs were 0.46 ± 0.29 and 0.45 ± 0.25 in groups 1 and 2, respectively (p = 0.801). The BCVAs at 3, 6, and 12 months after surgery differed significantly between the two groups. The subfoveal thickness and inner retinal layer thickness (IRLT) of group 1 vs. 2 were 507.4 ± 80.0 vs. 417.6 ± 63.6 μm, and 270.2 ± 74.3 vs. 182.6 ± 60.4 μm, respectively (both p < 0.001). These differences between the groups remained significant until 12 months after surgery. In multivariate analyses, the location of ILM dehiscence (B = -0.105, p = 0.034) and final IRLT (B = 0.001, p = 0.046) were significant factors affecting the final BCVA.

CONCLUSIONS

ILM dehiscence is a relatively common finding and associated with preoperative and postoperative increased IRLT, which results in worse surgical outcomes compared to the absence of ILM dehiscence in patients with ERM. Additionally, the final BCVA was significantly affected by its location and final IRLT in patients with ILM dehiscence.

Long-term natural history of the idiopathic epiretinal membrane in children and young adults

PURPOSE

To evaluate the natural history of the idiopathic epiretinal membrane (ERM) in children and young adults.

METHODS

This retrospective study included 52 patients younger than 40 years who had been diagnosed with idiopathic ERM. Best-corrected visual acuity (BCVA) and central retinal thickness (CRT) measured at diagnosis were compared with those at the final visit. Incidence and factors predictive of the spontaneous release of ERM were additionally investigated. Moreover, the proportion of eyes that eventually underwent surgery was identified.

RESULTS

The mean age of the patients was 32.5 ± 6.7 years, and the mean follow-up duration was 34.5 ± 23.4 months. The mean logarithm of the minimal angle of resolution BCVA (0.05 ± 0.10, Snellen equivalents = 20/22) and CRT (340.6 ± 61.6 μm) at diagnosis were not different from BCVA (0.06 ± 0.10, 20/23) (P = 0.928) and CRT (326.6 ± 70.8 μm) (P = 0.079) at the final follow-up. Two lines or greater deterioration in the BCVA was noted in 2 eyes (3.8%). Spontaneous release of ERM was noted in 14 eyes (26.9%). The release of ERM was more frequently noted in eyes without cystoid intraretinal edema or retinoschisis (P = 0.020) or eyes with loss of foveal concavity at diagnosis (P = 0.008). During the follow-up period, 5 eyes (9.6%) underwent surgery.

CONCLUSIONS

The natural history of the idiopathic ERM in children and young adults was generally favorable with definite deterioration in visual acuity noted only in a limited proportion of patients. Baseline retinal morphology may be predictive of the spontaneous release of ERM.

Glaucoma-related central visual field deterioration after vitrectomy for epiretinal membrane: topographic characteristics and risk factors

BACKGROUND/OBJECTIVES

To identify risk factors for glaucoma-related central visual field (VF) deterioration after vitrectomy with internal limiting membrane (ILM) peeling for epiretinal membrane (ERM).

SUBJECTS/METHODS

A prospective cohort study consisting of cases with or without glaucoma (33 eyes of 33 patients in each group) who underwent vitrectomy with ILM peeling for ERM. Humphrey 10-2 VFs and ganglion cell complex (GCC) thickness were measured at baseline and about 3, 6, and 12 months postoperatively. Longitudinal changes in VF indices and factors associated with their postoperative changes were investigated using mixed-effects models, as was sectorwise total deviation (TD) analysis using six sectors consisting of outer/inner arcuate and cecocentral sectors in each hemifield.

RESULTS

VF mean deviation significantly deteriorated postoperatively only in the glaucoma group (P < 0.001). Older age, longer axial length, preoperative worse mean deviation, and thinner GCC were significant risk factors for postoperative deterioration (coefficient ± standard errors: -0.139 ± 0.067, -0.740 ± 0.241, 0.16 ± 0.07, 0.050 ± 0.020; P = 0.038, P = 0.002, P = 0.024, P = 0.012, respectively). Sectorwise analysis revealed that TD in the superior/inferior outer arcuate sectors significantly deteriorated only in the glaucoma group. Preoperative worse TD and thinner GCC were significant risk factors for deterioration in the superior outer arcuate sector (0.65 ± 0.11, 0.08 ± 0.03; P < 0.001, P = 0.042, respectively).

CONCLUSIONS

Central VF deterioration, especially in the outer arcuate sectors, found to be glaucoma-related changes after vitrectomy with ILM peeling for ERM. Preoperative worse VF and thinner GCC were identified as risk factors for postoperative VF deterioration.

Choroidal Vascularity Index: An In-Depth Analysis of This Novel Optical Coherence Tomography Parameter

Remarkable improvements in optical coherence tomography (OCT) technology have resulted in highly sophisticated, noninvasive machines allowing detailed and advanced morphological evaluation of all retinal and choroidal layers. Postproduction semiautomated imaging analysis with dedicated public-domain software allows precise quantitative analysis of binarized OCT images. In this regard, the choroidal vascularity index (CVI) is emerging as a new imaging tool for the measurement and analysis of the choroidal vascular system by quantifying both luminal and stromal choroidal components. Numerous reports have been published so far regarding CVI and its potential applications in healthy eyes as well as in the evaluation and management of several chorioretinal diseases. Current literature suggests that CVI has a lesser variability and is influenced by fewer physiologic factors as compared to choroidal thickness. It can be considered a relatively stable parameter for evaluating the changes in the choroidal vasculature. In this review, the principles and the applications of this advanced imaging modality for studying and understanding the contributing role of choroid in retinal and optic nerve diseases are discussed. Potential advances that may allow the widespread adoption of this tool in the routine clinical practice are also presented.

Elevated M2 Macrophage Markers in Epiretinal Membranes With Ectopic Inner Foveal Layers

Purpose

To analyze the differences in the vitreous cytokine profiles in epiretinal membrane eyes with and without an ectopic inner foveal layer (EIFL).

Methods

Sixty eyes with epiretinal membrane (32 eyes without EIFL and 28 eyes with EIFL) were included. The vitreous samples were collected during surgery for epiretinal membrane. The cytokine levels of the vitreous were measured using a multiplex bead analysis.

Results

The mean logMAR visual acuity was worse (0.42 vs. 0.37; P = 0.331) and the central foveal thickness was higher in the EIFL group (496.9 µm vs. 434.2 µm; P = 0.007) than they were in the group without EIFL. The mean EIFL thickness was 164.1 ± 67.7 µm in the EIFL group. On multiplex analysis of the vitreous cytokines, the levels of CD163 (21529 pg/dL vs. 10877 pg/dL; P = 0.002) and macrophage colony-stimulating factor (206 pg/dL vs. 159 pg/dL, P = 0.004) were significantly higher in the EIFL group than they were in the group without EIFL.

Conclusions

Eyes with EIFL had increased vitreous levels of M2 macrophage markers. The activation of glial cell proliferation by M2 macrophages may contribute to EIFL formation.

Effect of Air Tamponade on Postoperative Visual Acuity and Intraretinal Cystoid Changes after Peeling of Idiopathic Epiretinal Membranes in Pseudophakic Patients

PURPOSE

Epiretinal membrane is a macular disorder leading to metamorphopsia and decreased visual acuity. The aim of the present study was to assess the possible effects of air tamponade, balanced salt solution (BSS), and combined phacoemulsification on functional and anatomical outcomes.

PROCEDURES

This prospective exploratory analysis included 72 eyes with idiopathic epiretinal membranes, scheduled to undergo 23-G pars plana vitrectomy with membrane peeling. Air tamponade or BSS was used in all cases. Optical coherence tomography (OCT) imaging was performed intraoperatively, and follow-up including visual acuity testing and OCT measurements was conducted until 3 months postoperatively.

RESULTS

Mean best-corrected visual acuity improved between +2.1 and +3.1 letters, and mean central subfield thickness of the macula decreased between -29.6 and -76 µm in the examined groups, without significant differences between the air tamponade and BSS groups. There was no significant difference in the presence of intraretinal cystoid changes between the groups.

CONCLUSIONS

The use of air tamponade did not show any significant differences in the anatomical and functional postoperative results compared to BSS. Furthermore, phacovitrectomy did not result in significantly more intraretinal cystoid changes 3 months after surgery.

Idiopathic epiretinal membrane surgery: safety, efficacy and patient related outcomes

This review aims to give to the reader an overview selectively oriented on safety and efficacy of surgery, providing concise and direct answers about crucial questions of trainees and experts. Surgery for idiopathic epiretinal membrane (ERM) is a safe and effective procedure that can achieve long-term stable postoperative visual and anatomical improvement, with an overall low recurrence and complication rate. Young patients, with a short onset of symptoms and with better initial visual acuity achieve higher levels of visual outcome. The preoperative degree of metamorphopsia is the prognostic factor for their postoperative degree. Successful results may be obtained in eyes with specific optical coherence tomography criteria, such as thin ganglion cell layers, thin internal plexiform layer, longer photoreceptors outer segment, regular ellipsoid zone and cone outer segment tips line, and without ectopic inner foveal layer. Internal limiting membrane peeling demonstrates positive anatomical and functional outcomes, but final positions about its safety remain controversial.

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

PURPOSE

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.

DESIGN

Retrospective study.

PARTICIPANTS

Patients with ERMs before and after surgery and healthy controls.

METHODS

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.

MAIN OUTCOME MEASURES

Retinal layer thickness and reflectance.

RESULTS

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).

CONCLUSIONS

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.

Inner Retinal Layer and Outer Retinal Layer Findings after Macular Hole Surgery Assessed by means of Optical Coherence Tomography

AIM

To summarize the spectrum of optical coherence tomography (OCT) and OCT angiography (OCTA) features after full-thickness macular hole (MH) repair surgery.

METHODS

A PubMed engine search was carried out using the terms "Macular Hole," "Optical Coherence Tomography," and "Optical Coherence Tomography Angiography." All reports published in English up to October 2018, irrespective of their publication status, were included. Tomographic signs analyzed were divided according to the involved portion of the retina in "inner retinal layers" and "external retinal layers." Despite predominantly involving the inner retinal layers, cystoid macular edema (CME) has been treated as a separate entity. Finally, report on vessel density (VD) changes and the foveal avascular zone (FAZ) area modifications have been included.

RESULTS

Different clinical findings can be observed on OCT of patients who underwent MH repair surgery. There is general consent that retinal thinning involving primarily the retinal nerve fiber layer and the ganglion cell layer takes place after surgery. In the postoperative period, the outermost retinal layers get progressively restored. Persistent defects in the ellipsoid zone or in the external limiting membrane correlate with worse postoperative visual outcome. OCTA has globally demonstrated that eyes after MH closure show a reduction in macular and paramacular VD and smaller FAZ areas, compared with control or fellow eyes.

CONCLUSION

Clinicians should be aware of the most common tomographic findings to properly manage each condition. In addition, significant advantages for the postoperative application of OCT and OCTA include noninvasiveness, rapid and simple execution, repeatability, and precise measurements.

Intraretinal changes in idiopathic versus diabetic epiretinal membranes after macular peeling

Introduction

Epiretinal traction is not responsible only for epiretinal but also intraretinal changes. This study aims to describe structural and vascular intraretinal changes after macular peeling in idiopathic (iERM) vs diabetic ERM (dERM).

Methods

We conducted a prospective interventional study on forty-two eyes, 23 with iERMs and 19 with dERMs, undergoing ERM-ILM peeling. We performed SD-OCT preoperatively, 1 and 6 months postoperatively to assess central macular thickness (CMT), intraretinal cysts (IC) and/or continuous ectopic inner foveal layers (CEIFL), superficial and deep capillary free zone (CFZ) area on OCT-A. Glial fibrillary acidic protein (GFAP), as a Müller cells marker, was detected immunohistochemically on ILM specimens, to assess Müller cells iatrogenic damage.

Results

The CEIFLs were significantly more common in iERMs (12 (52.2%) in iERMs vs 2 (10.5%) in dERMs, p = 0.004), whereas ICs in dERMs (6 (26.1%) in iERMs vs 17 (89.5%) in dERMs, p<0.001). Median preoperative and postoperative BCVA was 20/50 [20/40-20/66] and 20/33 [20/25-20/40] in iERMs and 20/100 [20/66-20/200] and 20/50 [20/50-20/66] in dERMs, respectively. Median preoperative and postoperative CMT was 423 [370–488] and 364 [329–382] μm in iERM group and 465 [447–503] and 378 [359–433] μm in dERM group, respectively. The BCVA improvement and reduction of CMT thickness were significant in both groups (p<0.001). The presence of CEIFL was associated with lower BCVA in iERMs. Deep CFZ network significantly increased only in dERMs, passing from 0.34 [0.29–0.42] mm² preoperatively to 0.56 [0.46–0.6] mm² at 6-month follow-up (p<0.001). The GFAP expression was significantly higher in dERMs (p = 0.001).

Conclusion

The intraretinal changes are different in iERMs and dERMs, as increased expression of CEIFLs in iERMs vs ICs in dERMs. The CEIFLs are associated with worse anatomical and functional outcomes in iERMs, whereas GFAP espression in peeled ILMs is higher in dERMs.

Clinical significance of ectopic inner foveal layers in patients with idiopathic epiretinal membranes

BACKGROUND/OBJECTIVES

To evaluate the relationship between the presence of ectopic inner foveal layers (EIFL), choroidal thickness, and visual acuity (VA) in patients with epiretinal membranes (ERM) staged by spectral-domain optical coherence tomography (SD-OCT).

SUBJECTS/METHODS

A total of 242 eyes of 121 patients with unilateral idiopathic ERM were prospectively evaluated. ERM stages were defined based on the SD-OCT staging system as stage 1: negligible morphological or anatomical disruption, retinal layers, and foveal pit are identified; stage 2: characteristic stretching of the outer nuclear layer, absence of foveal depression, retinal layers are identified; stage 3: continuous EIFL crossing the central foveal area, absence of foveal depression, retinal layers are identified; and stage 4: anatomical disruption of the fovea, continuous EIFL crossing the entire foveal area, retinal layers are distorted.

RESULTS

Of 121 eyes with ERM, 23.1% had stage 1, 26.5% had stage 2, 39.7% had stage 3, and 10.7% had stage 4 disease. VA was better in eyes with stage 1 or 2 ERM than stage 3 or 4 ERM (p < 0.001). VA in logMAR was positively correlated with central foveal thickness (r = 0.557, p < 0.001) and EIFL thickness (r = 0.526, p < 0.001), but not with an outer nuclear layer thickness (r = 0.233, p = 0.123). In multivariate analysis, the presence of EIFL was an independent predictor of VA in eyes with ERM (p < 0.001). The presence and stage of ERM did not have a significant effect on choroidal thickness (p > 0.05).

CONCLUSIONS

The SD-OCT staging system according to the presence of EIFL is effective for grading retinal damage and visual loss in eyes with ERM.