Surgical results of idiopathic and secondary epiretinal membrane

Development of a generative deep learning model to improve epiretinal membrane detection in fundus photography

BACKGROUND

The epiretinal membrane (ERM) is a common retinal disorder characterized by abnormal fibrocellular tissue at the vitreomacular interface. Most patients with ERM are asymptomatic at early stages. Therefore, screening for ERM will become increasingly important. Despite the high prevalence of ERM, few deep learning studies have investigated ERM detection in the color fundus photography (CFP) domain. In this study, we built a generative model to enhance ERM detection performance in the CFP.

METHODS

This deep learning study retrospectively collected 302 ERM and 1,250 healthy CFP data points from a healthcare center. The generative model using StyleGAN2 was trained using single-center data. EfficientNetB0 with StyleGAN2-based augmentation was validated using independent internal single-center data and external datasets. We randomly assigned healthcare center data to the development (80%) and internal validation (20%) datasets. Data from two publicly accessible sources were used as external validation datasets.

RESULTS

StyleGAN2 facilitated realistic CFP synthesis with the characteristic cellophane reflex features of the ERM. The proposed method with StyleGAN2-based augmentation outperformed the typical transfer learning without a generative adversarial network. The proposed model achieved an area under the receiver operating characteristic (AUC) curve of 0.926 for internal validation. AUCs of 0.951 and 0.914 were obtained for the two external validation datasets. Compared with the deep learning model without augmentation, StyleGAN2-based augmentation improved the detection performance and contributed to the focus on the location of the ERM.

CONCLUSIONS

We proposed an ERM detection model by synthesizing realistic CFP images with the pathological features of ERM through generative deep learning. We believe that our deep learning framework will help achieve a more accurate detection of ERM in a limited data setting.

Assessment of Risk Factors Affecting Refractive Outcomes after Phacovitrectomy for Epiretinal Membrane

PURPOSE

To investigate factors associated with refractive outcomes after phacovitrectomy for epiretinal membrane (ERM).

METHODS

Retrospective review of patients undergoing phacovitrectomy for ERM was done. The main outcome measure was predictive refraction error (PE), defined as observed refraction error - target refraction error, calculated by the SRK/T, Haigis, and SRK II formulae. PE was measured at postoperative 1, 3, and 6 months. Simple and multiple linear regression analysis were used to evaluate factors associated with PE.

RESULTS

A total of 53 eyes of 53 patients were included. The mean PEs at postoperative 1, 3, and 6 months were all negative, implying myopic shift in all patients regardless of the intraocular lens formula used. Haigis formula showed the least myopic shift among the three formulae (p = 0.001, Friedman test). There was no significant difference in PE depending on preoperative central macular thickness (CMT) in subgroup analysis. On stepwise multiple linear regression analysis, ERM etiology (β = 0.759, p = 0.004, SRK/T formula; β = 0.733, p = 0.008, Haigis formula; β = 0.933, p < 0.001, SRK II formula), preoperative anterior chamber depth (β = -0.662, p = 0.013, Haigis formula; β = -0.747, p = 0.003, SRK II formula), and decrease of CMT (β = -0.003, p = 0.025, SRK/T formula) were significantly associated with PE at postoperative 6 months.

CONCLUSIONS

Myopic shift in PE was observed after combined phacovitrectomy for epiretinal membrane. ERM etiology, preoperative anterior chamber depth, and decrease of CMT were significantly associated with PE at postoperative 6 months. There was no difference in PE after surgery between the two groups defined by CMT (≥500 and <500 μm).

Comparison of surgical outcomes after removal of epiretinal membrane associated with retinal break and idiopathic epiretinal membrane

PURPOSE

To compare the surgical outcomes of epiretinal membranes (ERMs) associated with retinal break and idiopathic ERMs.

METHODS

This retrospective study included patients with an idiopathic ERM or an ERM associated with retinal break, who were followed up for ≥ 6 months after ERM removal. The postoperative functional and anatomical outcomes were compared between the groups.

RESULTS

A total of 160 and 38 eyes (198 patients) were in the idiopathic and retinal break groups, respectively. There was no significant difference in the baseline anatomical and functional parameters between the groups. At 6 months after surgery and at the final follow-up, best-corrected visual acuity, central foveal thickness, and ectopic inner foveal layer improved significantly in both groups, but there was no significant difference between the groups. In latter 49.0% of patients, tests for metamorphopsia and aniseikonia were performed. There was a significant improvement in the scores of metamorphopsia (0.40 ± 0.38 to 0.27 ± 0.28; p < 0.001) and aniseikonia (6.07 ± 4.46 to 4.11 ± 3.52; p < 0.001) in the idiopathic group at 6 months after surgery, but not in the retinal break group. The idiopathic group had significantly greater circularity of ERM extent compared to the retinal break group (p = 0.025).

CONCLUSION

Visual and anatomical improvements after removal of ERMs associated with retinal break and idiopathic ERMs were comparable. However, metamorphopsia and aniseikonia improved only after removal of idiopathic ERMs.

Visual outcomes of primary versus secondary epiretinal membrane following vitrectomy and cataract surgery

PURPOSE

To compare visual outcomes, incidence of cystoid macular edema (CME), and rate of repeat epiretinal membrane (ERM) surgery following phacovitrectomy for primary and secondary ERM.

METHODS

Retrospective review of 178,856 cataract surgeries from 2003 to 2015. Eyes that underwent cataract surgery combined with ERM peel were included (n = 708). Eyes were divided into primary (n = 538) and secondary (n = 170) ERM groups. Patient demographics, visual acuity (VA), and postoperative CME were recorded.

RESULTS

Patients with secondary ERM had worse preoperative VA, 0.9 ± 0.6 logMAR (20/160 Snellen equivalent) as compared to patients with primary ERM, 0.6 ± 0.3 (20/80), respectively (p < 0.0001). There was no difference between the secondary and primary ERM groups in postoperative vision (0.5 ± 0.4 logMAR vs. 0.5 ± 0.3; p = 0.9962) or proportion with VA ≥ 20/40 (46.4% vs. 43.1%; p = 0.6744) at 12-24 weeks. Postoperative CME was twice as likely in the secondary ERM group (16.5%) compared to the primary ERM group (7.8%) (p = 0.0018). There was no difference in the rate of repeat ERM surgery between the secondary ERM group (1.8%) and the primary ERM group (1.5%) (p = 0.7308).

CONCLUSION

Eyes with secondary ERM had significant postoperative improvement in VA. They had worse preoperative VA and had a twofold increase in postoperative CME than primary ERM.

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.

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.

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.

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.

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.

Effect of Internal Limiting Membrane Peeling on Macular Structure and Metamorphopsia Scores in Idiopathic Epiretinal Membrane Surgery

Backgrounds and Objective:

Pars Plana Vitrectomy (PPV) and epiretinal membrane (ERM) peeling is the standard surgical procedure of ERM surgery. However, the effect of adding Internal Limiting Membrane (ILM) peeling to the standard surgery on macular function and structure remains still controversial. This study was aimed at investigating the effect of ILM peeling on the macular function and structure in idiopathic ERM surgery.

Method:

Thirty-six eyes of 34 patients were evaluated in this prospective study. The patients were divided into two groups (ILM peeling and non-ILM peeling group). While the removal of ERM was undergone alone in 19 eyes, it was combined with ILM peeling in 17 eyes. Metamorphopsia scores Vertical Metamorphopsia (VM) and Horizontal Metamorphopsia (HM), were measured at preoperative and 4 months postoperatively.

Results:

There was a statistically significant decrease in metamorphopsia (VM and HM) scores in both groups after the surgery. However, no statistically significant difference was found between the two groups in terms of reduction in VM scores and HM scores after surgery.

Conclusion:

Our study indicated that ILM peeling combined with ERM did not affect metamorphopsia scores.

The effect of multiple vitrectomies and its indications on intraocular pressure

Background

To assess the relationship between different indications for trans pars plana vitrectomies (PPV’s) and the intraocular pressure (IOP), and the effect of multiple PPV’s on the IOP. We also examined whether there were differences in the number of IOP-lowering medications or surgeries before and after PPV.

Methods

A retrospective study including all patients that underwent at least one PPV in the period from 2001 till 2014 at our clinic. Medical records of all patients were reviewed and clinically relevant data were entered in a database. Generalized estimating equations models for repeated measurements were used to examine the effect of the number of PPV’s on the IOP and on the risk of undergoing glaucoma surgery, for each of the indications for PPV.

Results

Of 1072 PPV’s 447 eyes fulfilled the inclusion criteria. The IOP increased with 3.0 mmHg after a PPV with indication retinal detachment (p < 0.001), but remained stable after PPV for epiretinal membrane (p = 0.555), macular hole (p = 0.695), and vitreous hemorrhage (p = 0.787). At the end of the follow-up period the number of IOP-lowering medications was significantly higher compared to baseline, except in the macular hole group (p = 0.103). Also, the number of eyes that underwent glaucoma surgery was significantly higher compared to the fellow (not-operated) eyes (p < 0.001). There was a significant association between the number of PPV’s and the final IOP for the indication retinal detachment (p = 0.009), and between the number of PPV’s and glaucoma surgery (odds ratio [95% confidence interval]: 2.60 [1.62–4.15]).

Conclusions

The IOP rises significantly after PPV with indication retinal detachment. This association was not found for other indications for PPV. Also, the risk of IOP-lowering surgeries was higher after PPV, but not different between the PPV indications. The IOP should be monitored carefully after PPV, since there may be a higher risk of secondary glaucoma.

Five-Year Outcomes of Surgically Treated Symptomatic Epiretinal Membranes With and Without Internal Limiting Membrane Peeling

BACKGROUND AND OBJECTIVE

The authors evaluated long-term postoperative visual outcomes and recurrence rates following surgery for symptomatic epiretinal membrane (ERM) ± internal limiting membrane (ILM) peeling.

PATIENTS AND METHODS

This was a retrospective, consecutive case series of 78 patients undergoing vitrectomy for symptomatic ERM between 1/2010 and 4/2012 with follow-up through at least postoperative year 5 (POY5). Outcomes included visual acuity (VA) (Snellen VA converted to logMAR), central retinal thickness (CRT; μm), and ERM recurrence. Subgroup analysis evaluated outcomes related to ILM peeling.

RESULTS

Subgroup analysis based on ILM peeling did not find VA (20/50 [0.430 logMAR ± 0.061 logMAR; mean ± SD] vs. 20/60 [0.518 logMAR ± 0.128 logMAR] for ILM vs. non-ILM peeling respectively; P = .513) nor macular thickness (355 μm ± 13 μm vs. 360 μm ± 42 μm; P = .410) to be significantly different at POY5. Recurrence requiring surgery with and without ILM peeling was not statistically significantly different at POY5 (1.6% and 11.8%; P = .118).

CONCLUSION

Vitrectomy for symptomatic ERM led to improved visual and anatomic outcomes with sustained benefit through 5 years. ILM peeling was was associated with reduced ERM recurrence, but this benefit was not statistically significant at POY5. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:296-302.].

TO PEEL OR NOT TO PEEL THE INTERNAL LIMITING MEMBRANE IN IDIOPATHIC EPIRETINAL MEMBRANES

BACKGROUND

Epiretinal membranes (ERMs) have been described for more than 150 years. Currently, they are a common indication for vitreoretinal surgery. Recently, there has been an increasing trend to peel the internal limiting membrane (ILM). Although ILM peeling has generally been accepted as a fundamental step in macular hole repair, its current role in ERM remains controversial.

METHODS

Literature review.

RESULTS

Proponents of ILM peeling argue that peeling of the ILM reduces the recurrence rate and facilitates a greater resolution of retinal folds. Opponents of ILM peeling show that the visual outcomes between eyes that undergo ILM peeling and those that do not have their ILM peeled are the same. Stripping of the ILM removes the Müller cell footplates, so it is reasonable to expect some Müller cell dysfunction. Adverse events such as eccentric paracentral macular holes, macular microscotomata, and retinal dimpling have been associated with ILM peeling.

CONCLUSION

Internal limiting membrane peeling does not improve the functional outcomes after ERM surgery. Internal limiting membrane peeling reduces ERM recurrences, but many recurrences are not clinically significant. It remains unclear what the long-term effects of ILM peeling are. We should err on the side of caution and avoid routine ILM peeling in primary idiopathic ERM cases and should reserve it for recurrent and high risk of recurrence cases.

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

PURPOSE

To evaluate the effects on postoperative prognosis of internal limiting membrane (ILM) peeling in conjunction with removal of idiopathic epiretinal membranes (ERMs).

METHODS

MEDLINE, Cochrane Central Register of Controlled Trials (CENTRAL), and EMBASE were systematically searched for studies that compared ILM peeling with no ILM peeling in surgery to remove idiopathic ERM. Outcome measures were best-corrected visual acuity, central macular thickness, and ERM recurrence. Studies that compared ILM peeling with no ILM peeling for the treatment of idiopathic ERM were selected.

RESULTS

Sixteen studies that included 1,286 eyes were selected. All the included studies were retrospective or prospective comparative studies; no randomized controlled study was identified. Baseline preoperative best-corrected visual acuity and central macular thickness were equal between ILM peeling and no ILM peeling groups. Postoperatively, there was no statistically significant difference in best-corrected visual acuity (mean difference 0.01 logarithm of the minimum angle of resolution [equivalent to 0.5 Early Treatment Diabetic Retinopathy Study letter]; 95% CI -0.05 to 0.07 [-3.5 to 2.5 Early Treatment Diabetic Retinopathy Study letters]; P = 0.83) or central macular thickness (mean difference 13.13 μm; 95% CI -10.66 to 36.93; P = 0.28). However, the recurrence rate of ERM was significantly lower with ILM peeling than with no ILM peeling (odds ratio 0.25; 95% CI 0.12-0.49; P < 0.0001).

CONCLUSION

Currently available evidence in the literature indicates that additional ILM peeling in vitrectomy for idiopathic ERM could result in a significantly lower ERM recurrence rate, but it does not significantly influence postoperative best-corrected visual acuity and central macular thickness.

Recurrence rate and need for reoperation after surgery with or without internal limiting membrane removal for the treatment of the epiretinal membrane

Purpose

To compare the recurrence rate and need for reoperation after epiretinal membrane surgery with and without removal of the internal limiting membrane.

Methods

In this retrospective study, 125 patients operated for epiretinal membrane removal were evaluated, with a minimum 6-month follow-up. Removal of the epiretinal membrane (ERM) was performed in 78 patients, while 47 had removal of the epiretinal membrane associated with internal limiting membrane peeling (ERM + ILM).

Results

The mean age in the ERM group was 65.8 years old, ranging from 41 to 80 years old. In the ERM + ILM group, the mean age was 67.2 years old, ranging from 52 to 82 years old. The mean preoperative visual acuity in the ERM group was 20/80p, and in the ERM + ILM group, it was 20/80. The mean postoperative visual acuity in both groups was 20/30. The mean preoperative macular thickness in the ERM group was 467 µm ranging from 281 to 663 µm; in the ERM + ILM group, the preoperative macular thickness was 497 µm, ranging from 172 to 798 µm. After surgery, a reduction in macular thickness was observed in both groups. In the ERM group, the mean macular thickness reduction was 361 ± 101. µm, whereas in the ERM + ILM group, it was 367 ± 75.2 µm. Twenty-two patients presented with a recurrence of epiretinal membrane, of which 16 (20.5%) were from the ERM group and 6 (12.8%) were from the ERM + ILM group (p = 0.39); one patient (2%) was retreated in the ERM + ILM group, whereas 5 patients (6%) where retreated in the ERM group.

Conclusion

We postulate that ILM peeling for the treatment of epiretinal membrane is not a relevant factor either for visual recovery or macular thickness reduction, but it may reduce the recurrence and reoperation rate.

Motorized Micro-Forceps with Active Motion Guidance based on Common-Path SSOCT for Epiretinal Membranectomy

In this study, we built and tested a handheld motion-guided micro-forceps system using common-path swept source optical coherence tomography (CP-SSOCT) for highly accurate depth controlled epiretinal membranectomy. A touch sensor and two motors were used in the forceps design to minimize the inherent motion artifact while squeezing the tool handle to actuate the tool and grasp, and to independently control the depth of the tool-tip. A smart motion monitoring and a guiding algorithm were devised to provide precise and intuitive freehand control. We compared the involuntary tool-tip motion occurring while grasping with a standard manual micro-forceps and our touch sensor activated micro-forceps. The results showed that our touch-sensor-based and motor-actuated tool can significantly attenuate the motion artifact during grasping (119.81 μm with our device versus 330.73 μm with the standard micro-forceps). By activating the CP-SSOCT based depth locking feature, the erroneous tool-tip motion can be further reduced down to 5.11μm. We evaluated the performance of our device in comparison to the standard instrument in terms of the elapsed time, the number of grasping attempts, and the maximum depth of damage created on the substrate surface while trying to pick up small pieces of fibers (Ø 125 μm) from a soft polymer surface. The results indicate that all metrics were significantly improved when using our device; of note, the average elapsed time, the number of grasping attempts, and the maximum depth of damage were reduced by 25%, 31%, and 75%, respectively.

THE EFFECT OF INTERNAL LIMITING MEMBRANE PEELING ON IDIOPATHIC EPIRETINAL MEMBRANE SURGERY, WITH A REVIEW OF THE LITERATURE

PURPOSE

To examine the effect of internal limiting membrane (ILM) removal on epiretinal membrane (ERM) surgery by comparing best-corrected visual acuity (BCVA), optical coherence tomography central macular thickness (CMT) changes, ERM recurrence, and need for repeat surgery.

METHODS

Retrospective study of 251 consecutive patients (251 eyes) who underwent pars plana vitrectomy for idiopathic ERM by a single surgeon with over 1 year of follow-up data. Data were collected preoperatively and postoperatively at 3 months, 1 year, 2 years, and at the last visit. The ILM was not specifically removed in the earlier group of patients and was removed after staining of the ILM in the later group.

RESULTS

One hundred and forty eyes (55.8%) did not have an ILM peel (non-ILM group), and 111 eyes (44.2%) did have an ILM peel (ILM group). There were no significant differences between groups in age, gender, preoperative BCVA, preoperative intraocular pressure, preoperative CMT on optical coherence tomography, and cataract status. Total follow-up time for the ILM group was 32.1 months and 45.4 months for the non-ILM group (P = 0.002). Both groups had improvement in BCVA. The ILM group improved by 12 Early Treatment Diabetic Retinopathy Study letters and the non-ILM group improved by 10.5 Early Treatment Diabetic Retinopathy Study letters. There was no significant difference in the final BCVA (P = 0.18) or total change of BCVA (P = 0.48). Cataract status preoperatively did not affect the total change of BCVA, but being phakic at the most recent visit was associated with a slight loss of visual acuity. Both groups had improvement in optical coherence tomography appearance, for the CMT in the ILM group decreased by 83 μm and the CMT in the non-ILM group decreased by 110 μm. There was no significant difference in the final CMT (P = 0.07); however, the non-ILM group tended to have a lower final CMT. Some degree of ERM recurrence was detected by slit-lamp biomicroscopy in 2 eyes (1.8%) of the ILM group and in 32 eyes (22.9%) of the non-ILM group (P ≤ 0.0001). None of the eyes with ILM removal required repeat vitrectomy, whereas 17 eyes (12.1%) of the non-ILM group did require vitrectomy, showing that ILM removal had a significant effect on the need for repeat vitrectomy (P < 0.0001) between non-ILM versus ILM peel groups.

CONCLUSION

The rate of recurrent ERM and need for repeat ERM surgery is lower in eyes where the ILM is removed with the ERM, whereas BCVA and CMT were similar with or without ILM removal. Complete ILM removal around the macula should be considered for the treatment of eyes with idiopathic ERMs to reduce the incidence of ERM recurrences.

Morphologic and Postoperative Fixation Characteristics of the Macular Epiretinal Membrane in Young Patients Undergoing Surgery

BACKGROUND AND OBJECTIVE

To describe morphologic characteristics, surgical outcomes, postoperative preferred retinal loci (PRL), and fixation stability of epiretinal membranes (ERMs) in young patients.

PATIENTS AND METHODS

This retrospective study analyzed 43 eyes of 41 young patients (age range: 0.8 years to 28 years) with ERMs, which were divided into two groups: secondary ERMs (SERMs; n = 28) and idiopathic ERMs (IERMs; n = 13). All 43 eyes underwent 25-gauge vitrectomy and membrane peeling. Spectral-domain optical coherence tomography scans and microperimetry were used to analyze morphologic and fixation characteristics, respectively.

RESULTS

Premacular fibrosis was more common in SERMs group (P = .006). SERMs were also associated with less external limiting membrane (ELM) (P = .008) and ellipsoid zone visibility (P = .008) compared with IERMs. Best-corrected visual acuity (BCVA) improved in 20 eyes (69%) with SERMs (P = .005) and in 12 eyes (86%) with IERMs (P = .13). From the analysis of the postoperative fixation characteristics, there was a linear correlation between visual acuity and fixation stability (R² = 0.495).

CONCLUSION

BCVA improved significantly in young patients with ERM, even in cases with a severely disrupted ELM and ellipsoid zone. More attention should be paid to the postoperative fixation location and stability. [Ophthalmic Surg Lasers Imaging Retina. 2017;48:655-662.].

Postoperative changes in the retinal thickness and volume after vitrectomy for epiretinal membrane and internal limiting membrane peeling

The aim of the study was to investigate the thickness and volume profiles of each retinal layer in postoperative patients with epiretinal membranes.Twenty-four patients who underwent pars plana vitrectomy with internal limiting membrane (ILM) peeling for epiretinal membrane were included. The best corrected visual acuity, thickness, and volume were recorded from the medical records through a retrospective review. Spectral domain optical coherence tomography was used to measure the average thickness and volume of each retinal layer before surgery and 6 months postoperatively.All 24 patients were monitored for 60 months after surgery. In all Early Treatment Diabetic Retinopathy Study (ETDRS) subfields, the thickness and volume of the retinal nerve fiber layer and the inner retinal layer decreased significantly. In contrast, the thickness and volume of the ganglion cell layer, inner nuclear layer, inner plexiform layer, and outer plexiform layer only decreased in some ETDRS subfields. Finally, there was no significant change in the thickness or volume of the outer nuclear layer (ONL), retinal pigment epithelium (RPE), and photoreceptor layers in all ETDRS subfields.The thickness and volume of the inner retina layer decreased significantly after pars plana vitrectomy using ILM peeling. However, there was no significant change in the thickness and volume of the outer retinal layers (ONL, RPE, and photoreceptor) after surgery.

Epiretinal membrane: optical coherence tomography-based diagnosis and classification

Epiretinal membrane (ERM) is a disorder of the vitreomacular interface characterized by symptoms of decreased visual acuity and metamorphopsia. The diagnosis and classification of ERM has traditionally been based on clinical examination findings. However, modern optical coherence tomography (OCT) has proven to be more sensitive than clinical examination for the diagnosis of ERM. Furthermore, OCT-derived findings, such as central foveal thickness and inner segment ellipsoid band integrity, have shown clinical relevance in the setting of ERM. To date, no OCT-based ERM classification scheme has been widely accepted for use in clinical practice and investigation. Herein, we review the pathogenesis, diagnosis, and classification of ERMs and propose an OCT-based ERM classification system.

Long-Term Anatomical and Functional Results in Patients Undergoing Observation for Idiopathic Nontractional Epiretinal Membrane

Purpose

To evaluate the anatomical and functional course without surgical intervention in patients with nontractional epiretinal membrane (ERM) using spectral-domain optical coherence tomography (SD-OCT) in a long-term follow-up of 38.2 ± 30.6 months.

Methods

Participants were 58 patients with nontractional ERM, which was defined as a tear or rip of the ERM in at least one line of OCT scan. All patients were observed without any surgical intervention. All patients underwent ophthalmologic examination, including best-corrected visual acuity (BCVA) measurement, funduscopy, and SD-OCT. Routine follow-up visits were performed every 6 months or earlier at the discretion of the investigator.

Results

There was no statistically significant difference in BCVA or central foveal thickness (CFT) at all time points of the follow-up. About 84.4% of patients presented improvement or stabilization in BCVA at the end of the follow-up, while 53.4% of patients had a decrease in CFT. All patients had intact ellipsoid zone and none of them needed surgical intervention at the end of the follow-up of 38.2 ± 30.6 months.

Conclusions

In patients with nontractional ERM, BCVA and CFT may remain stable in a long-term follow-up. Therefore, if ellipsoid zone is intact and there is a tear or rip of ERM in at least one OCT scan, patients can be monitored and surgery may be deferred because of high percentage of structural and functional stability.

Comparison of photoreceptor outer segment length in diabetic and idiopathic epiretinal membranes

PURPOSE

Idiopathic and diabetic epiretinal membranes (ERMs) differ significantly in terms of macular morphology. Our aim was to compare the photoreceptor outer segment (PROS) length in diabetic and idiopathic ERMs before and after surgery.

METHODS

Fifty-two eyes of 50 patients who underwent pars plana vitrectomy (PPV) due to idiopathic and diabetic ERMs were included in this retrospective case series. All of the patients underwent ERM and internal limiting membrane (ILM) removal. The patients had been followed up 6 months postoperatively. Spectral-domain optical coherence tomography (OCT) was used to measure the PROS length, overall PR length and central foveal thickness (CFT).

RESULTS

The PROS length, overall PR length, and CFT were statistically significantly lower at all the postoperative visits when compared to preoperative values in both the idiopathic and diabetic ERM groups (P<0.001). The amount of decrease in PROS and overall PR length were similar in both groups after surgery (P>0.05). There was no relation between amount of PROS length change and visual acuity gain in both groups (P>0.05).

CONCLUSIONS

Postoperative change of PROS length was similar in idiopathic and diabetic ERMs. PROS length change may not be an indicator of postoperative visual acuity.