EFFECTS OF INTERNAL LIMITING MEMBRANE PEELING COMBINED WITH REMOVAL OF IDIOPATHIC EPIRETINAL MEMBRANE: A Systematic Review of Literature and Meta-Analysis

Exploratory analysis of choriocapillaris vasculature as a biomarker of idiopathic epiretinal membrane

PURPOSE

To investigate the preoperative choriocapillaris perfusion (CCP) as a biomarker in patients with idiopathic epiretinal membrane (iERM).

MATERIALS AND METHODS

28 patients (28 eyes) with unilateral iERM who received pars plana vitrectomy (PPV) with internal limiting membrane (ILM) peeling were included for retrospective observational study. Optical coherence tomography (OCT) and angiography (OCTA) was performed before and after PPV. Area, perimeter, and circularity of superficial foveal avascular zone (FAZ) were analyzed preoperatively in both eyes using OCTA. Preoperative CCP was also analyzed with binarized en-face OCTA images. Measurements of best-corrected visual acuity (BCVA) and central foveal thickness (CFT) by OCT were conducted at the baseline and 6 months following the surgery. The correlations of preoperative OCT parameters with postoperative BCVA and CFT reduction were analyzed.

RESULTS

CCP was significantly lower (p < 0.001) and FAZ had shrunk (p < 0.001) in eyes with iERM compared to unaffected fellow eyes before surgery. BCVA and CFT became significantly improved after surgery (p = 0.001, p < 0.001). Multiple regression analysis revealed that preoperative CCP was significantly related with BCVA improvement (β = 0.185, p = 0.005), postoperative BCVA (β = 0.108, p = 0.023) and ratio of post- to preoperative CFT (β = 0.106, p = 0.044).

CONCLUSIONS

Preoperative CCP is a biomarker for poor functional and anatomical prognosis after surgery in iERM.

Pros and cons of internal limiting membrane peeling during epiretinal membrane surgery: a randomised clinical trial with microperimetry (PEELING)

BACKGROUND

After idiopathic epiretinal membrane (iERM) removal, it is unclear whether the internal limiting membrane (ILM) should be removed. The objective was to assess if active ILM peeling after iERM removal could induce microscotomas.

METHODS

The PEELING study is a national randomised clinical trial. When no spontaneous ILM peeling occurred, patients were randomised either to the ILM peeling or no ILM peeling group. Groups were compared at the month 1 (M1), M6 and M12 visits in terms of microperimetry, best-corrected visual acuity (BCVA) and optical coherence tomography findings. The primary outcome was the difference in microscotoma number between baseline and M6.

RESULTS

213 patients were included, 101 experienced spontaneous ILM peeling and 100 were randomised to the ILM peeling (n=51) or no ILM peeling group (n=49). The difference in microscotoma number between both groups was significant at M1 (3.9 more microscotomas in ILM peeling group, (0.8;7.0) p=0.0155) but not at M6 (2.1 more microscotomas in ILM peeling group (-0.5;4.7) p=0.1155). Only in the no ILM peeling group, the number of microscotomas significantly decreased and the mean retinal sensitivity significantly improved. The ERM recurred in nine patients in the no ILM peeling group (19.6%) versus zero in the ILM peeling group (p=0.0008): two of them underwent revision surgery. There was no difference in mean BCVA and microperimetry between patients experiencing or not a recurrence at M12.

CONCLUSION

Spontaneous ILM peeling is very common. Active ILM peeling prevents anatomical ERM recurrence but may induce retinal impairments and delay visual recovery.

TRIAL REGISTRATION

NCT02146144.

Selective ILM Staining and Safety of Two Vital Dyes During a Human-Like Pars Plana Vitrectomy Ex Vivo in Porcine Eyes

PURPOSE

An ideal dye for intraocular use should effectively stain the target tissue while being easy to apply and remove. Additionally, it should not have any adverse effects resulting from prolonged contact with the retinal tissue. Recently, concerns have been raised about the safety of some vital dyes during surgical procedures as they may cross the internal limiting membrane and deposit on the retina. In this study, we aimed to investigate whether commercially available vital dyes, VIEW-ILM® and TWIN® (AL.CHI.MI.A. S.r.l., Ponte San Nicolò, Padova, Italy), have the potential to cross the internal limiting membrane during vitreoretinal surgery and deposit on the retina. Furthermore, we evaluated their safety in vitro and in vivo.

METHODS

A human-like pars plana vitrectomy was performed on porcine eyes ex vivo, with VIEW-ILM® or TWIN® used to stain the internal limiting membrane either with or without subsequent internal limiting membrane peeling. The two dyes were then extracted from retinal punches with or without internal limiting membrane, and quantified using high performance liquid chromatography. Safety was evaluated through in vitro cytotoxicity tests and in vivo skin sensitization and irritation tests according to ISO standards.

RESULTS

High performance liquid chromatography analyses demonstrated that VIEW-ILM® and TWIN® effectively stained the internal limiting membrane without crossing the membrane. No residual dyes were found in the retinal layers after internal limiting membrane removal. Furthermore, both in vitro and in vivo safety tests confirmed the absence of cytotoxicity, skin sensitization, and irritation.

CONCLUSION

The results of this study support the safety and efficacy of VIEW-ILM® and TWIN® for internal limiting membrane staining. The experimental protocol described in this study could be utilized to gain a comprehensive understanding of the characteristics of vital dyes.

Optical coherence tomography biomarkers as outcome predictors to guide dexamethasone implant use in patients with iERM: a randomized controlled trial

BACKGROUND

We aimed to investigate the anatomical features of optical coherence tomography (OCT) and vitreous cytokine levels as predictors of outcomes of combined phacovitrectomy with intravitreal dexamethasone (DEX) implants for idiopathic epiretinal membrane (iERM) treatment.

METHODS

A prospective, single-masked, randomized, controlled clinical trial included 48 eyes. They were randomly assigned in a 1:1 ratio to undergo the DEX group (combined phacovitrectomy with ERM peeling and Ozurdex implantation) and control group (phacovitrectomy only). Best-corrected visual acuity (BCVA) and central macular thickness (CMT) were assessed at 1 d, 1 week, 1 month, and 3 months. The structural features of OCT before surgery were analysed for stratified analysis. Baseline soluble CD14 (sCD14) and sCD163 levels in the vitreous fluid were measured using ELISA.

RESULTS

BCVA and CMT were not significantly different in the DEX and control groups. Eyes with hyperreflective foci (HRF) at baseline achieved better BCVA (Ptime*group=0.746; Pgroup=0.043, Wald χ²=7.869) and lower CMT (Ptime*group = 0.079; Pgroup = 0.001, Wald χ²=6.774) responses to DEX during follow-up. In all patients, the mean vitreous level of sCD163 in eyes with HRF was significantly higher than that in eyes without HRF (P = 0.036, Z=-2.093) at baseline. In the DEX group, higher sCD163 predicted greater reduction in CMT from baseline to 1 month (r = 0.470, P = 0.049).

CONCLUSIONS

We found that intraoperative DEX implantation did not have beneficial effects on BCVA and CMT over a 3-month period in all patients with iERM, implying that the use of DEX for all iERM is not recommended. In contrast, for those with HRF on OCT responded better to DEX implants at the 3-month follow-up and thier vitreous fluid expressed higher levels of sCD163 at baseline. These data support the hypothesis that DEX implants may be particularly effective in treating cases where ERM is secondary to inflammation.

TRIAL REGISTRATION

The trail has been registered at Chinese Clinical Trail Registry( https://www.chictr.org.cn ) on 2021/03/12 (ChiCTR2100044228). And all patients in the article were enrolled after registration.

Injectable in situ cross-linking hyaluronan hydrogel for easier removal of posterior vitreous cortex in vitrectomy

PURPOSE

Removing transparent vitreous tissues, such as a residual vitreous cortex (VC) or proliferative membrane, without damaging the retina is often problematic in vitrectomy. We examined the feasibility of an injectable in situ cross-linking hyaluronan hydrogel (XL-HA) for vitrectomy.

STUDY DESIGN

Experiments using ex vivo and in vivo animal models.

METHODS

HA-dibenzocyclooctyne and HA-azidoethylamine solutions were mixed to form XL-HA, which then gradually formed a hydrogel. We tested the function of XL-HA in ex vivo porcine eyes. We then examined the performance of XL-HA in in vivo rabbit models of posterior vitreous detachment, posterior VC removal, and proliferative vitreoretinopathy.

RESULTS

The ex vivo study showed that XL-HA rapidly embedded triamcinolone acetonide, mimicking VC attached to the retina, and became hard enough to be pinched with tweezers within 3 minutes, allowing us to remove only the triamcinolone acetonide without impairing the internal limiting membrane. In the in vivo rabbit models, XL-HA injection improved posterior vitreous detachment, and the thin and fragile posterior VC or fibrous proliferative membrane was readily peeled off without any damage to the underlying retina as compared with untreated controls. A short-term intraocular biocompatibility test demonstrated that the intraocular pressure remained normal with XL-HA injected into the eye. In addition, transmission electron microscopy showed no obvious abnormalities in the cornea or in the inner and outer retina.

CONCLUSION

The results indicate that XL-HA is a potential adjunctive device to help make vitrectomy safe, effective, and successful.

Surgical management, use and efficacy of adjuvant dyes in idiopathic epiretinal membranes: a systemic review with network meta-analysis

BACKGROUND

The epiretinal membrane (ERM) is a nonvascular fibrocellular tissue formed by cellular metaplasia and proliferation at the vitreoretinal surface and is generally treated by pars plana vitrectomy (PPV) with or without internal limiting membrane (ILM) peeling. This network meta-analysis aimed to compare the efficacy of all available ERM removal interventions and assessed the use and efficacy of surgical dyes in managing idiopathic ERMs.

METHODS

MEDLINE, EMBASE, Cochrane CENTRAL, and the US National Library of Medicine were searched (June 28, 2023). Clinical studies that included patients with ERMs were included. Randomized controlled trials (RCTs) were also appraised using Cochrane risk of bias (ROB).

RESULTS

Ten RCTs and ten non-RCTs were included in this study. A pairwise meta-analysis between ERM removal and combined ERM and ILM removal showed no significant difference in visual outcome (change in BCVA) 1 year postintervention (MD = - 0.0034, SE = 0.16, p = 0.832). Similarly, there was no significant difference in the central macular thickness postoperatively between the two groups (MD = - 4.95, SE = 11.11, p = 0.656) (Q = 4.85, df = 3, p = 0.182, I2 = 41.21%). The difference in ERM recurrence between the groups was also not statistically significant (OR = 4.64, p = 0.062, I2 = 0). In a network meta-analysis, there was no significant difference in visual outcomes between ERM removal only and other treatment modalities: combined ILM and ERM removal (MD = 0.039, p = 0.837) or watchful waiting (MD = 0.020, p = 0.550). In a network meta-analysis, there was no significant difference in the visual outcomes between ERM removal alone and dye-stained combined ERM and ILM peeling (MD = 0.122, p = 0.742 for brilliant blue G; BBG and MD = 0.00, p = 1.00 for membrane blue-dual; MBD). The probability of being a better surgical dye for better visual outcomes was 0.539 for the MBD group and 0.396 for the BBG group. The recurrence of ERM was not significantly different when the ILM was stained with any of the dyes. No study was judged on ROB assessment as having low ROB in all seven domains.

CONCLUSION

The two types of surgical modalities provided comparable efficacy, with no significant differences between the outcomes. Among the dye-assisted ILM peeling methods, the membrane blue-dual dye was the most effective in providing better structural and functional outcomes.

Epiretinal membrane fragments: the origin of recurrent membranes after epiretinal membrane peeling

OBJECTIVE

To investigate the participation of residual fragments of epiretinal membranes (ERMs) in recurrent ERMs after pars plana vitrectomy (PPV) for ERMs.

DESIGN

Retrospective comparison study.

PARTICIPANTS

Consecutive 195 eyes of 195 patients with ERMs who underwent PPV.

METHODS

Internal limiting membrane (ILM) was removed without use of Brilliant Blue G (BBG) dye in any eyes until May 2017 (group 1) and thereafter using BBG dye in all eyes (group 2). Optical coherence tomography (OCT) images were obtained 3 days and 3 years after PPV.

RESULTS

Group 1 was made up of 87 eyes, and group 2 was made up of 108 eyes. OCT images obtained 3 days after PPV showed ERM fragments with retinal surface wrinkling in 53 eyes (27.2%) and retinal surface wrinkling alone in 9 eyes (4.6%). OCT images obtained 3 years postoperatively showed ERMs in 63 eyes (32.3%), all of which except 1 eye had ERM fragments and (or) retinal surface wrinkling on OCT image 3 days after PPV. Residual ERM 3 days postoperatively grew in 20 (64.5%) of the 31 eyes with residual ERM 3 days postoperatively in group 1 and 5 (22.7%) of the 22 eyes with residual ERM 3 days postoperatively in group 2, which rates were significantly different (p = 0.003).

CONCLUSIONS

ERM fragments may be the source of recurrent ERMs after PPV, and ILM peeling assisted with BBG dye may prevent growth of residual ERM. Eliminating ERM and ILM fragments intraoperatively may effectively reduce another surgery for ERM peeling.

[Effects of internal limiting membrane peeling in epiretinal membrane surgery on OCT-angiography]

PURPOSE

To assess macular microvascular parameters using OCT-angiography (OCT-A) in idiopathic epiretinal membrane surgery with or without internal limiting membrane peeling.

MATERIALS AND METHODS

We retrospectively studied 17 eyes of 17 patients who underwent vitrectomy surgery for idiopathic epiretinal membrane with (n=10) or without (n=7) internal limiting membrane peeling. Patients operated on between July 2020 and June 2022 at the Colmar Hospital (France) by a single surgeon were evaluated before and 1 month after surgery, using OCT-A (Spectralis OCT-A module, Heidelberg Engineering®, Germany). The parameters studied were the area, perimeter and acircularity index of the foveal avascular zone (FAZ), the foveolar (FVD) and parafoveolar (PRVD) perfusion density and the macular vessel density ratio (MVR) in the superficial vascular complex (SVC) and the deep vascular complex (DVC). These parameters were measured using ImageJ software (National Institutes of Health, Bethesda, Maryland, USA).

RESULTS

We found no statistically significant difference between the two groups postoperatively in either area, perimeter, or acircularity index of the FAZ, FVD, PRVD, or MVR in either the SVC or DVC.

CONCLUSION

Our results with regard to macular microvasculature demonstrate no difference related to peeling of the internal limiting membrane and thus do not argue against this practice during epiretinal membrane surgery.

[Clinical and pathophysiological contribution of OCT-angiography to epiretinal membranes]

Epiretinal membranes may lead to centripetal contraction forces on the retina and its vessels. OCT-Angiography (OCT-A) is a recent tool which permits a non-invasive understanding of these vascular changes. This review focuses on the OCT-A findings in idiopathic epiretinal membranes, before and after surgery, and the role of internal limiting membrane peeling. It appears that contraction of the epiretinal membrane is associated with both a reduction in the area and perimeter of the foveal avascular zone and alterations in the superficial and deep capillary plexuses. These changes mainly reflect a vascular shift from the perifoveal to the foveal region, increasing with retinal deformation, but also probable dynamic changes in vascular flow. Membrane peeling allows at least partial improvement of these microvascular parameters. Nevertheless, some limitations of OCT-A, such as segmentation errors on a retina with highly modified architecture, can lead to a selection bias in the studies and should call for caution in the interpretation of the results. Finally, internal limiting membrane peeling contributes to changes in the retinal architecture after surgery, in particular by causing a centripetal movement of the macular capillaries and a displacement of the fovea toward the optic nerve head. This role should be clarified in future studies.

Long-Term Changes in Retinal Nerve Fiber Layer Thickness after Vitrectomy for Epiretinal Membrane Using Optical Coherence Tomography Images

This study investigated the long-term effects of epiretinal membrane (ERM) surgery on peripapillary retinal nerve fiber layer (RNFL) thickness using optical coherence tomography (OCT) images. We included 30 patients with idiopathic ERM who underwent a vitrectomy for ERM removal with internal limiting membrane peeling. The patients were followed up for 5 years after surgery, and their medical records were reviewed for best-corrected visual acuity (BCVA) and OCT parameters. The study population comprised 24 females (80.0%), and the mean age was 65.4 ± 7.2 years. The baseline BCVA significantly improved from 0.28 ± 0.24 to 0.12 ± 0.09 logMAR (p < 0.001) 1 year after surgery and continued to improve for 5 years after surgery. The peripapillary RNFL thickness initially increased after surgery and then gradually decreased. The peripapillary RNFL thicknesses of the global and temporal sectors showed significant reductions 2 years after surgery, whereas those of the nasal sectors did not significantly change. The peripapillary RNFL thickness was thinner in the global and temporal areas of the operated eyes than in those of the fellow eyes 4 and 5 years after surgery. In conclusion, peripapillary RNFL thicknesses decreased in the global and temporal areas after ERM surgery, whereas peripapillary RNFL thicknesses in the nasal sectors did not change significantly during the long-term follow-up.

Microperimetric evaluation for different methods of epiretinal membrane surgery

PURPOSE

To investigate the anatomic and functional outcomes using microperimetry for the surgical methods for idiopathic epiretinal membranes (ERM).

METHODS

This retrospective study included 41 eyes from 41 patients. All patients underwent combined epiretinal membrane and cataract surgery. Best-corrected visual acuity (BCVA), optical coherence tomography, and microperimetry were performed before and 6 months and 1 year after surgery. The patients were divided into 3 groups; "ERM removal only without indocyanine green (ICG) staining", "ERM and internal limiting membrane (ILM) removal without ICG staining", and "ERM and ILM removal with ICG staining".

RESULTS

Preoperatively, the ages, BCVAs, central macular thickness (CMT), and mean retinal sensitivities of central 6° (MRSs) of the groups were not significantly different (p > 0.05). Postoperatively, the MRSs of the "ERM removal only without ICG staining" and "ERM and ILM removal without ICG staining" groups were not significantly different (p > 0.05). The MRSs of the "ERM and ILM removal without ICG staining" and "ERM and ILM removal with ICG staining" groups were not significantly different (p > 0.05). However, the MRSs of the "ERM and ILM removal with ICG staining" group significantly reduced than "ERM removal only without ICG staining" group (p < 0.05).

CONCLUSION

This retrospective study found reduced retinal sensitivity in ERM and ILM removal with ICG staining group compared to ERM removal only without ICG staining. Further studies with larger sample sizes are required.

Morphologic analysis of the foveal avascular zone for prediction of postoperative visual acuity in advanced idiopathic epiretinal membrane

To investigate the preoperative morphology of the foveal avascular zone (FAZ) for prediction of the postoperative visual acuity in advanced idiopathic epiretinal membrane (ERM). 28 patients (28 eyes) with unilateral idiopathic ERM who underwent pars plana vitrectomy with internal limiting membrane peeling were included. Superficial FAZ was measured preoperatively in both eyes using optical coherence tomography angiography. Area, perimeter, and circularity of FAZ were achieved, and the differences between the ERM eyes and the contralateral eyes were evaluated to analyze the degree of FAZ distortion in diseased eyes. The best-corrected visual acuity (BCVA) and central foveal thickness (CFT) were measured at baseline and more than 6 months after surgery. The correlations of the preoperative FAZ with BCVA and CFT were assessed. The FAZ in the eyes with ERM was significantly reduced, and the BCVA was significantly correlated with the FAZ area (FAZa) (P = 0.001) and the FAZ perimeter (FAZp) (P < 0.001) before surgery. LogMAR BCVA and CFT were significantly improved from 0.550 ± 0.221 to 0.354 ± 0.229 (P = 0.008), and from 524.393 ± 93.575 µm to 400.071 ± 75.979 µm (P < 0.001) after surgery. The preoperative FAZa and FAZp were significantly associated with letter score gain (P < 0.001, P < 0.001) and the postoperative final BCVA (P = 0.026, P = 0.006). The preoperative FAZp had correlation with ratio of postoperative to preoperative CFT (P = 0.016). The preoperative FAZp is a predictor of visual acuity and morphological prognosis after surgery in advanced idiopathic ERM.

THREE-DIMENSIONAL HEADS-UP VITRECTOMY VERSUS CONVENTIONAL MICROSCOPIC VITRECTOMY FOR PATIENTS WITH EPIRETINAL MEMBRANE

PURPOSE

To investigate the efficacy and safety of 3D heads-up display (3D-HUD) vitrectomy compared with conventional microscopy (CM) vitrectomy in epiretinal membrane (ERM) surgery.

METHODS

Epiretinal membrane removal with or without internal limiting membrane (ILM) peeling was performed using a 3D-HUD or CM system. The mean changes in best-corrected visual acuity (BCVA) and in central macular thickness (CMT) and postoperative complications were assessed.

RESULTS

Baseline demographics were comparable except for the follow-up period. Both BCVA and CMT improved at the final visit (all P < 0.05). The ERM recurrence and dissociated optic nerve fiber layer (DONFL) rates were lower in the 3D group (both P < 0.05). conventional microscopic vitrectomy (odds ratio [OR] = 12.86, P = 0.02) and absence of ILM peeling (OR = 45.25, P < 0.05) were associated with ERM recurrence. In the DONFL, CM vitrectomy (OR = 1.98, <0.05) and combined phacovitrectomy (OR = 2.33, P = 0.03) were analyzed as risk factors for DONFL.

CONCLUSION

The improvement in BCVA and CMT in ERM surgery using a 3D-HUD is comparable with that of CM vitrectomy, with a significantly low rate of ERM recurrence and DONFL occurrence. Therefore, 3D vitrectomy might have an advantage for ERM surgery.

A factor for predicting simultaneous internal limiting membrane peeling during epiretinal membrane removal: swept-source optical coherence tomography-based evaluation of epiretinal membrane adhesion to the retina

PURPOSE

To investigate preoperative factors associated with simultaneous internal limiting membrane (ILM) peeling during epiretinal membrane (ERM) removal.

STUDY DESIGN

Observational cross-sectional study.

METHODS

We retrospectively reviewed 60 eyes with idiopathic ERM that underwent vitrectomy. The gap between the ERM and ILM was visualized using en face optical coherence tomography. The depth and width of the ERM-ILM gap at the initiation site of ERM removal were measured, and the relationship between preoperative factors including these parameters and simultaneous ILM peeling during ERM removal was investigated.

RESULTS

The ILM was simultaneously peeled during ERM removal in 30 eyes, but not in the other 30 eyes. Age was significantly higher (P = 0.017) and the width of the ERM-ILM gap was significantly smaller (P < 0.001) in the simultaneous ILM peeling (+) group than in the simultaneous ILM peeling (-) group. Multivariate logistic regression analysis confirmed the width of the ERM-ILM gap as a significant negative predictor for simultaneous ILM peeling (odds ratio, 0.992; 95% confidence interval, 0.986-0.997; P = 0.003). Receiver operating characteristic curve analysis of the width of the ERM-ILM gap revealed that the optimal cutoff for predicting simultaneous ILM peeling was 187.1 µm.

CONCLUSION

The small width of the ERM-ILM gap at the initiation site of ERM removal was significantly associated with simultaneous ILM peeling, indicating that the adhesion strength between the ERM and ILM at the initial ERM grasping site determines whether simultaneous ILM peeling will occur during ERM removal.

Mid-term safety and effectiveness of macular peeling one month after intravitreal dexamethasone implant for tractional diabetic macular edema

Macular peeling combined or followed by intravitreal dexamethasone implant (DEX-i) was recommended as an efficacy approach for tractional diabetic macular edema (tDME). Knowing the synergistic effect of cataract surgery and DEX-i one month earlier in eyes with DME, we compared Epiretinal Membrane/Inner Limiting Membrane (ERM/ILM) peeling preceded by DEX-i one month before versus ERM/ILM peeling alone for the treatment of tDME. A retrospective study on patients affected by tDME who underwent ERM/ILM peeling one month after DEX-i (n = 11; Group A) or ERM/ILM peeling alone (n = 10; Group B) was performed. Longitudinal comparison of best-correct visual acuity (BCVA), central retinal thickness (CRT), and intraocular pressure (IOP) between the time of surgery (T₀) and each time point (months 1,3,5,6) within and among the groups were assessed. To evaluate the repeated measurements of BCVA, CRT, and IOP, a linear mixed-effects model was used. In Group A, DEX-i significantly improved mean BCVA and CRT (P < 0.001) just after 1 month (T₀). After ERM/ILM peeling, mean BCVA and CRT significantly improved from month 1 in Group A and month 3 in Group B. Mixed model revealed a significant difference in BCVA (P ≤ 0.0001) and CRT (P ≤ 0.02) at different time-points among the groups with better results in Group A. Neither complications nor uncontrolled IOP increase was detected. ERM/ILM peeling confirmed its effectiveness in treating tDME. DEX-i performed one month before surgery seemed to be a safe approach and ensured a greater and faster recovery considering functional and tomographic parameters.

Variability of Visual Recovery with Time in Epiretinal Membrane Surgery: A Predictive Analysis Based on Retinal Layer OCT Thickness Changes

Purpose: To correlate postoperative optical coherence tomography (OCT) thickness changes of each retinal layer with different patterns of visual recovery after idiopathic epiretinal membrane (ERM) surgery in a cohort of patients showing no known risk factors for poor visual recovery at preoperative imaging. Methods: Best corrected visual acuity (BCVA) and OCT images were acquired preoperatively and 1 month, 3 months and 6 months postoperatively. Patients were divided into four groups according to postoperative BCVA improvement: improvement < 15 ETDRS letters (GROUP 1), immediate improvement of BCVA without further improvements at later follow-ups (GROUP 2), immediate improvement of BCVA with further improvements at later follow-ups (GROUP 3) and delayed improvement of BCVA (GROUP 4). Results: Eighty-five patients were included. GROUP1 was the only one characterized by retinal nerve fiber layer (RNFL) thickness increase and ganglion cell layer/central macular thickness (GCL/CMT) ratio decrease at 1 month and outer nuclear layer (ONL) thickness decrease at 3 and 6 months. GROUP 2 was the only one showing a decrease in GCL/inner plexiform layer (GCL/IPL) ratio at 1 month. GROUP 3 and 4 showed higher preoperative RNFL thickness compared to the other, and GROUP 4 manifested a late increase in RNFL thickness at 6 months. Conclusions: Different patterns of VA recovery are associated with specific layer thickness changes. If further confirmed, this would help detect those cases characterized by poor or delayed visual recovery despite the absence of other known imaging risk factors.

Effect of internal limiting membrane peeling for idiopathic epiretinal membrane

Purpose

To further evaluate the necessity of internal limiting membrane (ILM) peeling for patients with idiopathic epiretinal membrane (iERM).

Method

We searched PubMed, Web of Science, Embase, Cochrane Library, and CNKI from their inception up to August 24, 2021. Eligible meta-analyses comparing iERM removal with and without ILM peeling were included. AMSTAR and GRADE classification was used to assess the methodological quality of each study and the quality for each outcome, respectively. The primary outcomes were best-corrected visual acuity (BCVA), central macular thickness (CMT), and recurrence.

Results

10 meta-analyses were included. 75.9% of studies revealed no statistically significant difference in BCVA between the groups, while only 10.3% showed better BCVA favorable to additional ILM peeling. 54.2% reported no significant difference in CMT between the groups, followed by 41.7% showing thicker CMT due to additional ILM peeling. Compared to iERM removal alone, additional ILM peeling provided a lower recurrence rate in 66.7% of studies.

Conclusion

ILM peeling could significantly reduce recurrence rate, but not significantly improve the recovery of visual outcome or decrease the thickness of central macula.

Effect of Internal Limiting Membrane Peeling or Not on Blood Flow Signal in Macular Area of Diabetic Patients with Preretinal Membrane

PURPOSE

To study the effect of intraoperative internal limiting membrane (ILM) peeling on the macular vascular structure in patients with diabetic epiretinal membrane (ERM).

METHODS

Patients with diabetic ERM were divided into an ERM + ILM peeling group (18 eyes) and an ERM peeling group (19 eyes), all of whom underwent standard vitrectomy and were followed up until 6 months postoperatively. Best-corrected visual acuity (BCVA), Central macular thickness (CMT), Vessel density (VD) and vessel length density (VLD) of the superficial as well as deep retinal capillary plexus were compared between the two groups.

RESULTS

There was no significant difference in BCVA (p = .188, .410, .901, .916) and CMT (p = .164, .128, .110, .105) between the two groups at the week 1, month 1, month 3 and month 6 after operation. In the superficial capillary plexus (SCP), the change in VD (p = .106) and VLD (p = .438) was not affected by ILM peeling, and there was no significant difference in VD (p = .154, .063, .100, .162) and VLD (p = .386, .263, .431, .391) between the two groups during the four follow-up after operation. For the deep capillary plexus (DCP), there was an effect of ILM peeling on the changes in VD (p = .024) and VLD (p = .012), ILM peeling delayed the recovery time of the VD and VLD; The VD (p = .026, .000, .003) and VLD (p = .005, .000, .000) of ERM + ILM peeling group were lower than those of ERM peeling group from the month 1 to the month 6 after operation.

CONCLUSION

Intraoperative peeling of the ILM in patients with diabetic ERM delayed the improvement of blood flow signal in the DCP but did not affect the recovery of postoperative BCVA and CMT.

Functional and Anatomical Outcomes of Pars Plana Vitrectomy for Epiretinal Membrane in Patients with Uveitis

Purpose-To evaluate the anatomical and functional outcomes of vitrectomy and epiretinal membrane (ERM) peeling in patients with uveitis. Secondarily, we evaluated the effect of internal limiting membrane (ILM) peeling on surgical outcomes, and of surgery on uveitis activity and, thus, therapeutic regime. Methods-Bicentre, retrospective, interventional case series of 29 eyes of 29 consecutive patients affected by uveitis and ERM, that had undergone pars plana vitrectomy with ERM peel between 2012 and 2020, with a minimum postoperative follow-up (FU) of six-months. Demographic data, best-corrected visual-acuity (BCVA), clinical findings, intraoperative and postoperative complications, and macular optical-coherence-tomography scans were reviewed. Results-The mean (standard deviation) duration of follow-up was 32 (22) months. At six-month FU, mean central-retinal-thickness (CRT) significantly improved (from 456 (99) to 353 (86) microns; p < 0.001), and mean BCVA improved from 0.73 (0.3) to 0.49 (0.36) logMAR (p < 0.001), with only one (3%) patient experiencing worsening of vision. The rate of concomitant cystoid macular edema decreased from 19 (66%) eyes at presentation to eight (28%) eyes at final-FU (p = 0.003). Comparing eyes in which ILM peeling was performed in addition to ERM peeling only, BCVA or CRT reduction were comparable. Only a minority of six (21%) eyes had a worsening in uveitis activity requiring additional medications, whereas most patients resumed the same treatment (52%) or received less treatment (28%) (p = 0.673). Conclusions-Vitrectomy with ERM peeling led to favourable anatomical and functional outcomes in patients with uveitis regardless of whether the ILM is peeled or not. As in most patients, no activation of the uveitis requiring additional medications was noted, we do not recommend changes in anti-inflammatory/immunosuppressive therapy postoperatively.

Risk factors for epiretinal membrane formation and peeling following pars plana vitrectomy for primary rhegmatogenous retinal detachment, an OCT guided analysis

Background

To evaluate the rate and risk factors of epiretinal membrane (ERM) formation and need for ERM peeling after pars plana vitrectomy (PPV) for uncomplicated primary rhegmatogenous retinal detachment (RRD).

Methods

Retrospective, single-center, cohort study of 119 consecutive patients (119 eyes) that underwent RRD repair using PPV. The primary outcomes were ERM formation, classified using an optical coherence tomography grading system, and the rate of ERM peeling. Visual acuity, postoperative complications, and risk factors for ERM formation and peeling were also identified.

Results

Postoperative ERM formation occurred in 69 eyes (58.0%); 56 (47.1%) were stage 1, 9 (7.6%) stage 2, 3 (2.5%) stage 3, and 1 (0.8%) stage 4. Only 6 (5.0%) eyes required secondary PPV for a visually significant ERM, with a mean time to reoperation of 488 ± 351 days. Risk factors for ERM formation included intraoperative cryotherapy, more than 1000 laser shots, 360° laser photocoagulation, and choroidal detachment (p < 0.01). Eyes with more than 3 tears had a trend towards increased ERM surgery (p = 0.10).

Conclusions

Visually significant ERM formation following PPV for primary RRD was uncommon in this cohort (5%). Half of the ERMs were detected after the first post-operative year, indicating that this complication may be underreported in studies with only 1-year follow-up.

Impacts of Surgeons' Experience on Patients with Epiretinal Membrane: A Retrospective Study from 2015 to 2020 in Wenzhou Eye Hospital

Background

To explore the impacts of surgeons’ experience in patients with epiretinal membrane (ERM).

Methods

Patients with idiopathic ERM (334 eyes) who underwent PPV and membrane peeling were included in this study. The surgeries were performed by 9 surgeons. Patients were categorized into the experienced group (surgeons who had performed more than 5000 cases of PPV) and the regular group (surgeons who had performed less than 1000 cases of PPV). The patients were also categorized into five groups according to different preoperative best corrected visual acuity (BCVA): 20/100 or worse, 20/70-20/50, 20/40-20/30, 20/25 and 20/20. Impacts of preoperative BCVA, surgeons’ experience, lens status, and internal limiting membrane (ILM) peeling on postoperative BCVA were analyzed.

Results

The postoperative BCVA was significantly better at 1 week and 1 month in the experienced group compared to the regular group (p = 0.022 and 0.045, respectively). There were no significant differences in postoperative BCVA at 3 months and 6 months between the two groups (p = 0.268 and 0.233, respectively). Postoperative BCVA at 6 months was similar in the 20/25 group and 20/20 group (p = 0.063); both groups had better BCVA compared to the other three groups. The 20/100 or worse group had the greatest visual improvement among the 5 groups at 6 months.

Conclusion

This study suggested that although the experience of surgeons had no significant impact on the final BCVA following PPV and ERM removal, the BCVA during the early postoperative phase appeared to be better in the experienced group.

Intraoperative Optical Coherence Tomography in Idiopathic Macular Epiretinal Membrane Surgery

Objective

To evaluate the feasibility and practicability of intraoperative optical coherence tomography (IOCT) in the surgery of idiopathic macular epiretinal membrane (IMM) without internal limiting membrane staining in all patients.

Methods

Patients were selected from July 2018 to June 2020, and 32 patients (32 eyes) with IMM were operated with the use of IOCT. All patients underwent standard 23g vitrectomy. The internal limiting membrane was peeled off if there were obvious retinal folds. Intraoperative and postoperative complications, macular microstructural changes, and integrity of the detached membranes were recorded. The preoperative and postoperative best corrected visual acuity were compared.

Results

The macular epiretinal membrane was completely removed in 75% (24 eyes) patients without internal limiting membrane staining, and in 15.6% (5 eyes) patients with combined internal limiting membrane stripping. The "starting point" of macular epiretinal membrane stripping was found in 75% (24 eyes), and the time required to find the best starting point ranged from 28s to 140s (mean 66 ± 15s). At 3 months after operation, 96.8% of the patients had stable or improved BCVA (p < 0.05). The central macular thickness of the affected eyes decreased significantly at 1 and 3 months after operation (p < 0.05).

Conclusion

IOCT can significantly reduce the use of internal limiting membrane staining in idiopathic macular epiretinal membrane surgery, and it is safe, feasible and practical in idiopathic macular epiretinal membrane surgery without internal limiting membrane staining in all patients.

Longitudinal Change in Retinal Nerve Fiber Layer Thickness and Its Association With Central Retinal Sensitivity After Epiretinal Membrane Surgery

PURPOSE

To investigate the longitudinal changes in the peripapillary retinal nerve fiber layer (pRNFL) thickness after epiretinal membrane (ERM) vitrectomy with internal limiting membrane (ILM) peeling, examine associations between pRNFL thickness and central retinal sensitivity, and identify predictors of postoperative pRNFL thickness.

DESIGN

Prospective, observational, cohort study.

METHODS

This study enrolled 82 eyes of 82 Japanese patients that underwent surgery for unilateral idiopathic ERM, with their fellow eyes as controls. pRNFL thickness was measured in 4 (superior, temporal, inferior, and nasal) quadrants preoperatively and at 1, 3, 6, and 12 months postoperatively. Microperimetry was performed at 12 months postoperatively to evaluate central retinal sensitivity. Regression tree analysis was performed to predict pRNFL thickness at 12 months postoperatively.

RESULTS

The temporal quadrant showed continuous pRNFL thinning after surgery, reaching statistical significance at 3, 6, and 12 months postoperatively (all P < 0.001). The pRNFL thicknesses in the fellow eyes significantly increased at all postoperative time points (all P < 0.001). At 12 months postoperatively, the average central retinal sensitivity was significantly correlated with the temporal pRNFL thickness in the eyes with ERM (r = 0.372, P < 0.001); no significant correlation was found in the fellow eyes. Regression tree analysis showed that the preoperative pRNFL thickness in the temporal quadrant and patient age were the main determinants of the temporal pRNFL thickness at 12 months postoperatively.

CONCLUSIONS

The risk of deterioration of central retinal sensitivity after ERM vitrectomy with internal limiting membrane peeling should be considered for patients with thin temporal pRNFLs and older adults.

FACTORS RELATED TO UNFAVORABLE VISUAL OUTCOME AFTER IDIOPATHIC EPIRETINAL MEMBRANE SURGERY IN PATIENTS WITH GLAUCOMA

PURPOSE

To evaluate the visual outcomes after idiopathic epiretinal membrane surgery in glaucomatous and nonglaucomatous eyes and factors related to unfavorable outcomes in glaucomatous eyes.

METHODS

This was a retrospective cohort study including patients undergoing idiopathic epiretinal membrane surgery with ≥12-month follow-up. Final visual acuity at pseudophakic status was compared among groups of glaucoma, glaucoma suspect, and nonglaucoma and correlated with optical coherence tomography and visual field characteristics in patients with glaucoma.

RESULTS

Of the 314 patients enrolled, 31 had glaucoma and 22 were glaucoma suspect. Baseline visual acuity and central foveal thickness were similar across the groups. Most patients had improved/stable visual acuity postoperatively, with a lower proportion of 83.9% with glaucoma than 96.9% and 100% without glaucoma and glaucoma suspect, respectively (P = 0.002). The mean visual acuity did not change in the glaucoma group (from 6/29 to 6/23), but it improved from 6/25 to 6/12 (a gain of 16.7 approxETDRS letters) in nonglaucoma and 6/26 to 6/14 in glaucoma suspect (a gain of 14.0 approxETDRS letters) (both P < 0.001). The change of visual acuity was correlated with preoperative visual field defects (P < 0.001, r2 = 0.554). Patients with glaucoma with more advanced, fixation-threatening defects or temporally located inner nuclear layer microcysts were more likely to have worsened visual acuity.

CONCLUSION

Visual field testing is imperative for patients with glaucoma before idiopathic epiretinal membrane surgery for outcome assessment.

Risk factors for epiretinal membrane in eyes with primary rhegmatogenous retinal detachment that received silicone oil tamponade

Background/aims

This study investigated the risk factors for epiretinal membrane (ERM) in eyes with primary rhegmatogenous retinal detachment (RRD) that received silicone oil (SO) tamponade.

Methods

This retrospective analysis included 1140 patients (1140 eyes) with RRD who underwent primary vitrectomy and SO tamponade. The prevalence of ERM was estimated and possible risk factors (eg, type 2 diabetes, proliferative vitreoretinopathy (PVR), SO tamponade time (SOTT), photocoagulation, vitreous haemorrhage, choroidal detachment, cryotherapy and retinal tear size) were analysed via multiple logistic regression.

Results

The prevalence of ERM was 12.3% (140/1140), and the accuracy of preoperative ERM diagnosis was 40.5%. Multivariate logistic regression analysis showed that risk factors for ERM in eyes with SO tamponade included preoperative PVR (OR=4.336, 95% CI 2.533 to 7.424, p<0.001), type 2 diabetes (OR=3.996, 95% CI 2.013 to 7.932, p<0.001), photocoagulation energy (OR=1.785, 95% CI 1.306 to 2.439, p<0.001) and SOTT (OR=1.523, 95% CI 1.261 to 1.840, p<0.001). No statistically significant associations were observed between the incidence of ERM and other risk factors. Preoperative PVR showed the strongest association with risk of ERM. The risk of ERM was positively associated with SOTT, photocoagulation energy and preoperative PVR grade.

Conclusion

In eyes with RRD that received SO tamponade, the prevalence of ERM was 12.3%, while the accuracy of preoperative ERM diagnosis was low. Preoperative PVR, type 2 diabetes, photocoagulation energy and SOTT were the main risk factors for ERM.

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.

Protective effect of vitrectomy on the course of diabetic retinopathy: A case report

PURPOSE

To hypothesize the protective role of vitrectomy on the natural course of diabetic retinopathy.

METHODS

Case report.

RESULTS

A 66-year-old lady with a history of type 1 diabetes mellitus since the age of 10 was referred for evaluation. She received laser treatment in her left eye for proliferative diabetic retinopathy 6 years earlier, while her right eye underwent vitrectomy for retinal detachment 17 years before. Diabetic retinopathy was found to be substantially asymmetrical, as the vitrectomized right eye had only mild macular edema without significant vascular abnormalities, whereas the left eye had a complete confluent panretinal photocoagulation with advanced atrophic macular changes. Other reasons for this asymmetry, such as axial length disparity, carotid circulation impairment, or history of branch retinal vein occlusion, were not identified.

CONCLUSIONS

Vitreous removal, performed for a reason other than diabetic retinopathy, may inhibit the retinal complications often associated with longstanding diabetes. Further clinical studies should be considered to ascertain such evidence.

Ex vivo evaluation of retinal cytotoxicity after the use of multiple medical devices in pars plana vitrectomy in porcine eyes

This study aimed to evaluate viability of retinal cells after the use of multiple intraoperative devices, namely a vitreal dye (triamcinolone acetonide,TA), a ERM/ILM dye (solution of trypan blue 0.15% and brilliant blue 0.025%), and two intraocular tamponades, namely perfluoro-n-octane, (PFO) and silicone oil (SO 1000 cSt), with minimal and maximal removal of their residues, during a simulated pars plana vitrectomy (PPV) in porcine eyes ex-vivo. The in vitro cytotoxicity of each of these compounds was verified on ARPE-19 cells by direct tests according to the ISO 10993-5 (2009). Pars plana vitrectomy was performed on 25 enucleated porcine eyes divided in five groups according to the following conditions: Group A) No surgery control: eye bulbs were kept at room temperature for 40 min; Group B) Sham surgery: PPV with the sole use of BSS for 40 min; Group C) Cytotoxic control: PPV with BSS infusion (20 min) followed by intravitreal injection of 1H-PFO (contact time: 20 min); Group D) Surgery with residues: PPV with BSS infusion and sequential intravitreal injection of TA, ERM/ILM dye, PFO and SO, with minimal removal of each compound after a specified contact-time (overall duration: 40 min); Group E) Surgery with minimal residues: PPV performed as in group D, but with maximal removal of each compound (overall duration: 40 min). All the experimental procedures were performed at room temperature. Immediately after surgery, the retina was extracted from each eye bulb and samples of 3-mm diameter were prepared. Retinal viability was determined for each sample by 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide assay. A cell viability <70% was considered the cytotoxicity threshold. Kruskal-Wallis test was used to evaluate the differences in retinal viability between groups. No cytotoxicity was detected in retinal samples in groups A, B and E. Samples from eye bulbs that had undergone surgery with minimal removal of residues (group D) and cytotoxic controls (group C) showed high retinal cytotoxicity. The tested conditions indicated that the combined use of TA, ERM/ILM dye, PFO and SO during PPV does not affect retinal cells viability if all the devices are properly removed, whereas the cytotoxicity detected in group D may suggest that the presence and accumulation of the residues of the compounds used intraoperatively could negatively impact retinal viability due to a cumulative and/or synergistic cytotoxic effect between them, supporting the crucial role of an optimal removal of the intraoperative medical devices to ensure a safe vitrectomy to the patient.

Effects of Internal Limiting Membrane Peel for Idiopathic Epiretinal Membrane Surgery: A Systematic Review of Randomized Controlled Trials

PURPOSE

The purpose of this study was to compare functional and anatomical outcomes after epiretinal membrane (ERM) peeling with internal limiting membrane (ERM/ILM) peeling and without for the treatment of idiopathic ERM.

DESIGN

Systematic review and meta-analysis.

METHODS

A comprehensive search of Cochrane CENTRAL, MEDLINE Ovid, and Embase Ovid for randomized controlled trials comparing ERM/ILM with ERM was performed. Two independent reviewers selected papers and extracted data. Methodological quality was assessed using the Cochrane Risk of Bias (RobVis) tool. Data was analyzed using RevMan 5.3. Quality of body of evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach.

RESULTS

Seven studies reporting 387 eyes overall were included. A total of 207 eyes (53%) received ERM/ILM. A total of 180 (47%) received ERM. Post-operative visual acuities (logMAR) were not significantly different between ERM/ILM and ERM, with a mean difference (MD) of 0.02 (95% confidence interval [CI]: -0.04 to 0.09; P = .45; I²= 42%; n = 101) at 1 month; 0.03 (95% CI: -0.01 to 0.06; P = .11, I² = 15%; n = 299; High Certainty of Evidence) at 3 months; 0.01 (95% CI: -0.03 to 0.04; P = .72; I² = 21%; n = 317; High Certainty of Evidence) at 6 months; and 0.01 (95% CI: -0.02 to 0.04; P = .49; I² = 39%; n = 234) at 12 months post-operatively. ERM/ILM was significantly associated with lower ERM recurrence at 6-12 months with a relative risk of 0.16 (95% CI: 0.04-0.64; P = .01; I² = 0%; n = 155; Moderate certainty of evidence) and an increased central macular thickness (micrometers) at 12 months with an MD of 20.53 (95% CI: 4.96-36.09; P = .01; I² = 12%; n = 234).

CONCLUSIONS

ERM/ILM and ERM result in similar visual acuity despite subtle differences in anatomical outcomes (central macular thickness). ERM/ILM is associated with a significantly lower rate of ERM recurrence at 6-12 months post-operatively and should be considered where recurrence prevention is the treatment priority.

WITH OR WITHOUT INTERNAL LIMITING MEMBRANE PEELING FOR IDIOPATHIC EPIRETINAL MEMBRANE: A Meta-Analysis of Randomized Controlled Trials

PURPOSE

To clarify whether internal limiting membrane (ILM) peeling provides better outcomes for patients with idiopathic epiretinal membrane.

METHODS

Randomized controlled trials comparing epiretinal membrane removal with and without ILM peeling were searched in Embase, PubMed, Web of Science, Cochrane Library, and CNKI before April 15, 2020. The pooled mean difference (MD) for best-corrected visual acuity, central macular thickness, and odds ratio for recurrence were calculated.

RESULTS

Eight randomized controlled trials involving 422 eyes were included. No significant difference in best-corrected visual acuity (final follow-up: MD, 0.03 logarithm of the minimum angle of resolution [1.5 Early Treatment Diabetic Retinopathy Study letters]; 95% confidence interval [CI], -0.04 to 0.09 [-4.5 to 2 Early Treatment Diabetic Retinopathy Study letters]; P = 0.40) or recurrence rate (odds ratio, 0.21; 95% CI, 0.04-1.05; P = 0.06) between the groups was observed. However, patients with ILM peeling presented thicker central macular thickness at 3 months (MD, 16.36; 95% CI, 1.26-31.46; P = 0.03), 6 months (MD, 22.64; 95% CI, 10.29-34.98; P = 0.0003) and the final follow-up (MD, 25.87; 95% CI, 13.96-37.79; P < 0.0001).

CONCLUSION

The study showed that ILM peeling did not significantly improve the postoperative visual outcome or decrease recurrence, but result in thicker central macular thickness, indicating that it is inessential for idiopathic epiretinal membrane.

MACULAR SENSITIVITY IN THE AREA OF INTERNAL LIMITING MEMBRANE PEELING IN EYES AFTER PARS PLANA VITRECTOMY WITH THE TEMPORAL INVERTED INTERNAL LIMITING MEMBRANE FLAP TECHNIQUE FOR A FULL-THICKNESS MACULAR HOLE

PURPOSE

To examine the relationship between retinal sensitivity and the area of internal limiting membrane (ILM) peeling during pars plana vitrectomy for a full-thickness macular hole.

METHODS

Twenty-four eyes a minimum of 6 months after temporal inverted flap pars plana vitrectomy for a full-thickness macular hole were included in the study. En face spectral-domain optical coherence tomography images were used to assess margins of the peeled ILM area. Microperimetry was performed to examine retinal sensitivity within the central 10°. Areas of peeled ILM in en face optical coherence tomography images were correlated with the average sensitivity threshold. Retinal sensitivities at the location of each measurement point were compared with structural abnormalities observed in en face spectral-domain optical coherence tomography images.

RESULTS

The mean retinal sensitivity in the area of ILM removal was significantly lower compared with the area of preserved ILM (24.29 ± 3.96 dB vs. 26.19 ± 2.10 dB, P < 0.0001, respectively). The peeled ILM area showed a negative correlation with the average sensitivity threshold (r = -0.56, P < 0.01).

CONCLUSION

A larger area of ILM peeling during temporal inverted flap pars plana vitrectomy for a full-thickness macular hole is related to lower retinal sensitivity in the central macula.

Changes in the Ganglion Cell Complex after Inner Limiting Membrane Peeling for Epiretinal Membrane in Glaucoma Patients

BACKGROUND

Epiretinal membrane (ERM) is a disease that affects the vitreoretinal interface and causes metamorphopsia, anorthopia, and decreased visual acuity. In this study, ERM patients who underwent internal limiting membrane (ILM) peeling were classified as those with glaucoma (Group G) and a control group (Group C). Changes in ganglion cell complex (GCC) thickness were compared between these groups to investigate whether such changes had an effect on progression of glaucoma from structural change.

METHODS

This was a retrospective, observational study that included 27 eyes of 27 patients. Group C included 22 eyes, and Group G included 5 eyes. Patients underwent ILM peeling, and cataract surgery was combined with vitrectomy for 16 phakic eyes; 2 phakic eyes and 9 aphakic eyes were treated only with vitrectomy. GCC thickness was measured preoperatively and at 2 weeks and 1, 3, and 6 months postoperatively, and these values and the rates of thinning were compared between the two groups.

RESULTS

The mean age of patients was 66.7±12.8 years (range 30-84 years). There was no significant difference between groups in the thickness of the GCC or its rate of thinning after ILM peeling.

CONCLUSIONS

The present results suggest that this procedure does not cause structural exacerbation of glaucoma in glaucoma patients. Although further studies of the functional effects of ILM peeling are required, the present results suggest that there is no significant difference between the two groups.

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.

Comparison of Anatomical and Functional Results of Surgeries Performed with Nitinol Flex Loop or Forceps in Primary Epiretinal Membrane

Purpose: To compare surgery's effect with nitinol flex loop (NFL) or forceps on retinal layers and functional outcomes in the primary epiretinal membrane (ERM).Methods: The operations were classified according to the use of the NFL or forceps. Automatic segmentation of the individual inner retinal layers was performed by spectral-domain optical coherence tomography software, and best-corrected visual acuity (BCVA) before surgery and at the last follow-up visit postoperatively were compared.Results: Forty-two eyes of 42 patients were included with a mean age of 66.9 ± 5.7 years. 45.2% of the surgeries were NFL assisted, 54.8% were forceps assisted. The mean follow-up duration was 9.8 ± 1.3 months. The mean BCVA was 0.79 ± 0.42 vs 0.77 ± 0.39 logMAR in the preoperative period and 0.42 ± 0.27 vs. 0.40 ± 0.21 logMAR at last follow-up in the NFL vs forceps group respectively (p= .403). The retinal nerve fiber layer (RNFL)(32.5% vs. 50.1%, p= .009), ganglion cell layer (18.1% vs. 41.4%, p= .021), inner plexiform layer (13.5% vs. 32.7%, p= .031) and inner nuclear layer (15.5% vs. 30.3%, p= .011) thickness decreased significantly more in the forceps group. The mean surgical time was not significantly different (45.2 ± 5.1 vs. 51.1 ± 6.1 minutes) in the NFL vs. forceps groups, respectively (p= .331).Conclusion: Following primary ERM surgery, the inner retinal layers become thinner; RNFL impacted the most, which was found higher in forceps assisted surgeries. This result shows that the NFL can be used safely in macular surgery.

RECURRENCE OF IDIOPATHIC EPIRETINAL MEMBRANE AND ITS PREDISPOSING FACTORS: An Optical Coherence Tomography Study

PURPOSE

To evaluate the incidence and clinical course of recurrent epiretinal membrane (ERM) after ERM surgery and to identify predisposing optical coherence tomography (OCT) findings for the recurrence.

METHODS

Postoperative ERM recurrence, defined as reappearance of the membrane after its removal or regrowth of the remnant membrane, was investigated in 301 eyes with idiopathic ERM followed up for more than 6 months after macular surgery by fundus photographs and spectral-domain OCT. The incidences of recurrent ERM and its associated clinical characteristics were assessed. Preceding OCT findings in the area subsequently showing recurrent ERM were evaluated at early postoperative periods.

RESULTS

Among the 301 eyes that underwent ERM peeling, 119 (39.5%) and 86 (28.6%) showed ERM recurrence on OCT images and biomicroscopic examination/fundus photographs, respectively, during the follow-up period (average: 18.1 months). Neighboring remnant membrane and hyperreflective dots on the retinal surface at 1 week after the surgery and postoperative inner retinal wrinkling persisting for ≥1 month were predisposing OCT findings for ERM recurrence, with an odds ratio of 6.48 (95% confidence interval, 3.51-12.0), 3.48 (95% confidence interval, 1.81-6.70), and 6.11 (95% confidence interval, 3.30-11.3), respectively (all P < 0.001).

CONCLUSION

Incidence of ERM recurrence varies depending on the definition used for the recurrence. Optical coherence tomography examination may be useful for the prediction and sensitive detection of recurrent ERM.

With or without internal limiting membrane peeling during idiopathic epiretinal membrane surgery: A meta-analysis

BACKGROUND

Although previously published meta-analyses have compared the surgical effects between the methods of Idiopathic epiretinal membrane (iERM) removal with or without ILM peeling, they did not reach an agreement.

PURPOSE

We aimed to provide more evidence for the treatment of iERM and whether additional ILM peeling was better or not by analyzing more updated studies and randomized control trials (RCTs).

METHOD

The search was conducted in Pubmed, Embase, Cochrane Library, Web of Science and Open Grey without language limitation and the studies included were from inception to December 2019. All studies of iERM with or without ILM peeling showed at least one of outcomes, such as best-corrected visual acuity (BCVA), central macular thickness (CMT) and recurrence of ERM. The pooled results between above groups were showed by the mean differences (MDs) and risk ratios (RR) with corresponding 95% confidence intervals (CIs).

RESULT

In total, 1645 eyes of five randomized controlled trials (RCTs) and fifteen retrospective studies were included. The short-term (<12 months) BCVA improvement in both groups showed no significant difference (MD = -0.01; 95% CI = -0.02 to 0.01; P = 0.36). However, the BCVA improvement was significantly better in ILM peeling eyes than in those without ILM peeling when considering the risk bias (MD = -0.04; 95% CI = -0.07 to -0.01; P = 0.008). The short-term (<12 months) CMT had a higher reduction in non ILM peeling group (MD = -9.02; 95% CI = -12.51 to -5.54; P < 0.00001) and the recurrence of ERM in ILM peeling group was lower (P < 0.00001). The long-term (≥12months) BCVA improvement ((MD = -0.00; 95% CI = -0.03 to 0.03; P = 0.97) and reduction of long-term (≥12months) CMT (MD = -1.14; 95% CI = -7.14 to -4.86; P = 0.71) were similar in both groups.

CONCLUSION

By considering the risk of bias, we should determine whether ILM peeling is beneficial for short-term changes in BCVA in patients with iERM. Nevertheless, further studies are needed to confirm this. iERM removal without ILM peeling can improve the short-term decrease in CMT and ILM peeling decreases the recurrence of ERM, but the long-term changes in BCVA and CMT are similar with or without ILM peeling. There is a need for a true large scale randomized trial that will also include microperimetry and other functional measures.

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.

En Face Image-Based Analysis of Epiretinal Membrane Formation after Surgery for Idiopathic Epiretinal Membrane

PURPOSE

To analyze en face epiretinal membrane (ERM) images constructed using swept-source (SS) OCT and to determine the incidence of ERM formation after ERM surgery and its effects on visual function.

DESIGN

Retrospective, consecutive observational study.

PARTICIPANTS

Consecutive series of 73 eyes (71 patients) with idiopathic ERM that underwent vitrectomy with both ERM and internal limiting membrane (ILM) peeling.

METHODS

We retrospectively reviewed the data of the 73 eyes included in the study. During surgery, the ERM was removed as extensively as possible, and the ILM was removed such that the area of ILM peeling was at least larger than the parafoveal area. All patients underwent comprehensive ophthalmologic examinations, including assessments of best-corrected visual acuity and metamorphopsia, before and at 2 weeks and 6 months after the surgery. En face images constructed using SS OCT were used to investigate ERM formation.

MAIN OUTCOME MEASURES

The incidence of ERM formation at 6 months after the surgery, effects of ERM formation on visual function, and the relationship between ERM formation and the extent of ERM and ILM peeling.

RESULTS

At 6 months after ERM and ILM peeling, 8 eyes (11.0%) showed ERM formation (formation group). Twenty eyes (27.4%) exhibited remnant ERM without ERM formation (remnant group), whereas 45 eyes (61.6%) showed no ERM (no ERM group). In both the remnant and no ERM groups, best-corrected visual acuity and metamorphopsia showed significant improvements after ERM surgery (both P < 0.01); these improvements were not seen in the formation group (P = 0.067 and P = 0.053, respectively). However, no significant differences were found in preoperative and postoperative best-corrected visual acuities and metamorphopsia among the 3 groups. In the formation group, ERM formation occurred only in the area with residual ILM. Most patients who underwent ILM peeling in which the area of the peeling covered the ERM belonged to the no ERM group (97.7%; P < 0.01).

CONCLUSIONS

Epiretinal membrane formation does not affect visual function significantly when the area of ILM peeling is larger than the parafoveal area. When the ILM peeling area covers the ERM area, postoperative ERM formation can be prevented.

Rates of Reoperation in 10 114 Patients with Epiretinal Membranes Treated by Vitrectomy with or without Inner Limiting Membrane Peeling

PURPOSE

To compare rates of reoperation in patients with idiopathic epiretinal membrane (ERM) who received pars plana vitrectomy (PPV) with or without inner limiting membrane (ILM) peeling and to assess trends in the overall use of ILM peeling over time.

DESIGN

Retrospective cohort study.

PARTICIPANTS

Patients included in the IBM Marketscan database between January 1, 2008, and December 31, 2016, who underwent surgery for idiopathic ERM.

METHODS

Procedure claims with laterality codes were used to determine patients with idiopathic ERM who received PPV with or without ILM peel between 2008 and 2016, and to identify cases of reoperation and subsequent retinal detachment within 1 year of index surgery.

MAIN OUTCOME MEASURES

The primary outcome was rate of reoperation for recurrent ERM according to whether or not patients receive an ILM peel during their index ERM surgery. We also assessed trends for index ERM surgery (ILM peel or no ILM peel) between 2008 and 2016, and the risk of developing retinal detachment within 1 year of the index ERM surgery.

RESULTS

A total of 10 114 patients received ERM surgery and met inclusion criteria (5310 without ILM peel and 4804 with ILM peel). The reoperation rate was significantly lower among patients who received PPV with ILM peel (0.88%) compared with patients without ILM peel (1.48%; P = 0.007). In 2008, PPV without ILM peel represented 70% of ERM procedures, but PPV with ILM peeling accounted for 52% and 70% of ERM procedures in 2013 (P < 0.001) and 2016 (P < 0.001), respectively. The rates of retinal detachment were similar between patients who received an ILM peel (0.79%) and patients who did not receive an ILM peel (0.92%) during their primary ERM surgery (P = 0.474).

CONCLUSIONS

The increasing use of PPV with ILM peeling to address ERM removal is associated with significantly reduced reoperation rates within 1 year. Future studies are needed to determine the cost-effectiveness of performing an ILM peel for initial idiopathic ERM repairs and evaluate long-term visual and structural changes related to ILM peeling.

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.

CLINICAL CHARACTERISTICS, LONG-TERM SURGICAL OUTCOMES, AND PROGNOSTIC FACTORS OF EPIRETINAL MEMBRANE IN YOUNG PATIENTS

PURPOSE

To explore the clinical characteristics, long-term surgical outcomes, and prognostic factors for vision improvement in young patients with epiretinal membrane (ERM).

METHODS

A cohort of in-patients aged <40 years and underwent surgical removal of ERM were selected from medical records between January 2009 and December 2015. Data from pre- and postoperative examinations were analyzed for evaluation of surgical outcome.

RESULTS

A total of 142 eyes of 140 patients were included. Epiretinal membrane was secondary in 64.79% of eyes and inflammation was the most common secondary cause. Epiretinal membrane in young patients was characterized by severe proliferation and a tendency to center off-macula and for optic disk involvement. Ninety-three eyes of 91 patients were included in the surgical outcome analysis. Mean follow-up time was 28.95 months. The average vision improvement was 4.2 lines, with an ERM recurrence rate of 4.3%. Patients with idiopathic ERM attained better visual outcomes, whereas those with secondary ERM showed greater improvement. Preoperative visual acuity, the duration of symptoms, and patient sex were predictive factors for visual outcome.

CONCLUSION

Surgical removal of ERM improves visual acuity, and patients with greater preoperative visual acuity and a shorter duration of symptoms attain the best visual outcomes.

Vitrectomy for the removal of idiopathic epiretinal membrane with or without internal limiting membrane peeling: a meta-analysis

Purpose:

The aim of this study is to analyze the effect of internal limiting membrane peeling in removal of idiopathic epiretinal membranes through meta-analysis.

Methods:

We searched PubMed for studies published until 30 April 2018. Inclusion criteria included cases of idiopathic epiretinal membranes, treated with vitrectomy with or without internal limiting membrane peeling. Exclusion criteria consisted of coexisting retinal pathologies and use of indocyanine green to stain the internal limiting membrane. Sixteen studies were included in our meta-analysis. We compared the results of surgical removal of epiretinal membrane, with or without internal limiting membrane peeling, in terms of best-corrected visual acuity and anatomical restoration of the macula (central foveal thickness). Studies or subgroups of patients who had indocyanine green used as an internal limiting membrane stain were excluded from the study, due to evidence of its toxicity to the retina.

Results:

Regarding best-corrected visual acuity levels, the overall mean difference was –0.29 (95% confidence interval: –0.319 to –0.261), while for patients with internal limiting membrane peeling was –0.289 (95% confidence interval: –0.334 to –0.244) and for patients without internal limiting membrane peeling was –0.282 (95% confidence interval: –0.34 to –0.225). Regarding central foveal thickness levels, the overall mean difference was –117.22 (95% confidence interval: –136.70 to –97.74), while for patients with internal limiting membrane peeling was –121.08 (95% confidence interval: –151.12 to –91.03) and for patients without internal limiting membrane peeling was –105.34 (95% confidence interval: –119.47 to –96.21).

Conclusion:

Vitrectomy for the removal of epiretinal membrane combined with internal limiting membrane peeling is an effective method for the treatment of patients with idiopathic epiretinal membrane.

One-year follow-up evaluation of combined phacovitrectomy for idiopathic epiretinal membrane

AIM

To evaluate the therapeutic effect of combined phacovitrectomy with membrane peeling and intraocular lens (IOL) implantation in patients with severe idiopathic epiretinal membrane (iERM) and concurrent cataract.

METHODS

A total of 34 eyes from 34 patients who underwent phacovitrectomy and epiretinal membrane (ERM) peeling at the First Affiliated Hospital of Zhejiang University between 2015 and 2017. The best-corrected visual acuity (BCVA) and central foveal thickness (CFT) were measured preoperatively and at 1, 3, 6mo and 1y postoperatively. Temporal changes and bivariate correlations of these parameters were analyzed.

RESULTS

Mean logMAR BCVA improved and CFT decreased significantly (P<0.001) until 6mo after surgery. Correlation analysis revealed a positive correlation between preoperative and postoperative logMAR BCVA (r=0.716, P<0.001 at 1mo, r=0.417, P=0.014 at 3mo, r=0.359, P=0.037 at 6mo, and r=0.369, P=0.032 at 12mo post-op respectively), but preoperative CFT was neither associated with postoperative CFT nor with postoperative logMAR BCVA. There was a positive correlation between CFT and logMAR BCVA at 1mo (r=0.346, P=0.045), 6mo (r=0.347, P=0.045), and 12mo (r=0.342, P=0.048) post-operatively. The intra- and postoperative complications were relatively mild, and the incidences were generally low.

CONCLUSION

For severe iERM patients with significant visual symptoms, combined phacovitrectomy with membrane peeling and IOL implantation is safe and effective in improving BCVA and decreasing CFT. Early surgery in selected patients may help preserving better visual function.

Does internal limiting membrane peeling during epiretinal membrane surgery induce microscotomas on microperimetry? Study protocol for PEELING, a randomized controlled clinical trial

Background

The epiretinal membrane (ERM) is a degenerative condition associated with age, which can cause loss of vision and/or metamorphopsia. The treatment of symptomatic ERM involves surgical removal including a vitrectomy followed by peeling of the ERM using a microforceps. As the internal limiting membrane (ILM) is adherent to the ERM, it is sometimes removed with it (spontaneous peeling). If ILM remains in place, it can be removed to reduce ERM recurrence. However, it is important to clarify the safety of ILM peeling, while it increases surgical risks and cause histological disorganization of the retina that can lead to microscotomas, may be responsible for definitive visual discomfort.

Methods

PEELING is a prospective, randomized, controlled, single-blind, and multicentered trial with two parallel arms. This study investigates the benefit/risk ratio of active ILM peeling among individuals undergoing ERM surgery without spontaneous ILM peeling. Randomization is done in the operating room after ERM removal if ILM remains in place. After randomization, the two groups—“active peeling of the ILM” and “no peeling of the ILM”—are compared during a total of three follow-up visits scheduled at month 1, month 6, and month 12. Primary endpoint is the difference in microscotomas before surgery and 6 months after surgery. Patients with spontaneous peeling are not randomized and are included in the ancillary study with the same follow-up visits and the same examinations as the principal study.

Relevant inclusion criteria involve individuals aged > 18 years living with idiopathic symptomatic ERM, including pseudophakic patients with transparent posterior capsule or open capsule or lensed patients with age-related cataracts. The calculated sample size corresponds to 53 randomized eyes (one eye/patient) per arm that means 106 randomized eyes (106 randomized patients) in total and a maximum of 222 included patients (116 spontaneous peeling).

Discussion

ILM peeling is often practiced in ERM surgery to reduce ERM recurrence. It does not impair postoperative visual acuity, but it increases the surgical risks and causes anatomical damages. If active ILM peeling is significantly associated with more microscotomas, it may contraindicate the ILM peeling during primitive idiopathic ERM surgery.

Trial registration

ClinicalTrials.gov, NCT02146144. Registered on 22 May 2014. Recruitment is still ongoing.

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.

Anatomic and functional results of idiopathic macular epiretinal membrane surgery

AIM

To assess the impact of macular surgery on the functional and anatomic outcomes in patients with grade 2 epiretinal membrane (ERM), and the effect of internal limiting membrane (ILM) peeling on visual acuity and to analyze the long-term effect of pars plana vitrectomy (PPV) on intraocular pressure (IOP).

METHODS

Pseudophakic eyes (62 eyes) diagnosed as idiopathic grade 2 ERM with at least 6mo postoperative follow-up were included in this retrospective study. The fellow eye was nonvitrectomized. Patients were divided into two groups: group 1 (29 eyes) treated with ERM and ILM peeling and group 2 (33 eyes) with only ERM peeling. Preoperative and postoperative best corrected visual acuity (BCVA), slit-lamp, and a dilated fundus examination was performed. IOP was measured with Goldman applanation tonometer before, day 1 and first week and each visit after surgery. The incidence of significant IOP elevation was compared between vitrectomized eyes and nonvitrectomized fellow eyes.

RESULTS

Visual improvement was statistically significant and similar in both groups (P=0.008 in group 1, P=0.002 in group 2, P=0.09 inter-group). The amount of decrease in central macular thickness was statistically significant and similar in both groups (P=0.005 group 1, P=0.008 group 2, P=0.37 intergroup). At the final follow-up (14.1±9.6mo) the incidence of significant IOP elevation was 4% in vitrectomized eyes (three eyes) and 3% (two eyes) in the nonvitrectomized fellow eyes (P=0.12). Four eyes (12.1%) had recurrent ERM after a mean follow-up of 8.6±1.1mo in group 2, there was no recurrence in group 1 (P=0.01).

CONCLUSION

Recurrence of ERM may be decreased by ILM peeling during ERM surgery. However, it seems that ILM peeling do not affect the functional outcome and 23-gauge PPV alone do not have a significant effect on IOP.