Visual outcomes following vitrectomy and peeling of epiretinal membrane

Title - Long term outcomes of vitrectomy and ERM peel: Can pre-operative metamorphopsia measured using the D-Chart help improve surgical candidate selection?

PURPOSE

To assess the predictive value of pre-operative metamorphopsia, measured using the D-Chart, in patients undergoing epiretinal membrane (ERM) surgery and how this relates to improvement in quality of life after surgery.

METHODS

17 patients from vitreo-retinal surgery clinics at a tertiary ophthalmology centre were recruited when listed for pars plana vitrectomy (PPV) with ERM peel between September 2019 - February 2020. Pre-operatively patients underwent visual acuity (VA), Visual-Function Index 14 (VF-14) and metamorphopsia (D-Chart-Thomson Software Solutions) assessment and answered a questionnaire regarding cardinal ERM symptoms. Post-operatively patients were re-assessed in the same domains.

RESULTS

13 patients completed the protocol (inclusion rate 76%) with a mean follow-up of 32.1 (± 3.1) months. Mean pre-operative VA of the affected eye was 0.42 logMAR (± 0.25). Mean pre-operative VF-14 score was 81.51 (± 12.8) and mean M-Score of the affected eye was 14.6 (± 12.7). Post-operatively, mean VA of the operated eye was 0.11 logMAR (± 0.11), mean VF-14 score was 97.4 (± 3.8) and mean M-Score was 1.31 (± 2.8). Mean improvement in VA was 0.31 logMAR (p < 0.001), in VF-14 15.9 (p = 0.002), and M-Score -13.3 (p = 0.003). There was a significant association between pre-operative D-Chart score and improvement in VA (r = -0.570, p = 0.042), visual functioning (r = 0.606 p = 0.028) and metamorphopsia (r = 0.916 p < 0.001), with those demonstrating poorer D-Chart scores showing greater improvements.

CONCLUSION

Pre- and post-operative visual distortion measured using the D-Chart, correlates with vision related quality of life in patients undergoing epiretinal membrane surgery. Patients with worse pre-operative distortion scores noticed the greatest improvements in distortion and vision related quality of life following surgery. With a mean follow-up time of 32.1 months, this long-term follow-up data further reinforces the efficacy of vitrectomy and ERM peel by demonstrating significant and sustained improvement in visual acuity, metamorphopsia and visual functioning. The authors suggest there is a role for D-Chart assessment pre-operatively to improve selection of patients in ERM surgery.

Quantitative evaluation of metamorphopsia with M-CHARTS™ and evaluation of retinal morphologic changes by optical coherence tomography before and after pars plana vitrectomy in patients with idiopathic epiretinal membrane

PURPOSE

We aimed to quantitatively evaluate metamorphopsia pre- and postoperatively in patients with idiopathic epiretinal membrane(iERM) using M-CHARTS™ and to evaluate the relationship between morphological changes in retinal layers on optical coherence tomography (OCT) and metamorphopsia scores.

MATERIALS AND METHODS

This prospective study included 42 patients followed in Akdeniz University Hospital Ophthalmology Clinic diagnosed with iERM by fundus examination and OCT between 2020-2022. Detailed ophthalmologic findings, visual acuities, metamorphopsia scores, and OCT parameters of all patients were recorded. The relationship between pre- and postoperative visual acuity, metamorphopsia scores and OCT parameters was investigated. Changes in OCT parameters were compared by evaluating patients with stable or increasing metamorphopsia scores as one group (group1) and patients with decreasing metamorphopsia scores as the other group (group 2).

RESULTS

In "group 2", preoperative Ganglion Cell Layer+Inner Plexiform Layer (Central) (GCL+IPL (C)) was significantly (P: 0.028) higher than in "group 1".

CONCLUSION

A statistically significant preoperative thickness difference in the OCT parameters of the GCL+IPL (C) layer was associated with the quantitative metamorphopsia complaints of the patients. The thickness of the preoperative GCL+IPL (C) layer can be considered an important indicator of symptoms of metamorphopsia determining functional success after surgery.

Changes in Metamorphopsia in Patients Undergoing Treatment for Vitreoretinal Disorders

PURPOSE

To quantify and compare the severity of metamorphopsia in patients undergoing vitrectomy for vitreoretinal disorders.

METHODS

Data were collected evaluated from 319 patients with vitreoretinal disorders, including epiretinal membrane (ERM), macular hole (MH), cystoid macular edema with branch retinal vein occlusion (BRVO-CME), CME with central retinal vein occlusion (CRVO), diabetic macular edema (DME), macula-off rhegmatogenous retinal detachment (M-off RD), and macula-on RD (M-on RD). Metamorphopsia was recorded with the M-CHARTS preoperatively and at 3 and 6 months postoperatively.

RESULTS

Preoperative and 6-month postoperative metamorphopsia scores were 0.69 ± 0.50 and 0.50 ± 0.52, respectively. Before surgery, 94% of patients presented with metamorphopsia (score ≥0.2). Preoperative metamorphopsia scores were significantly correlated with postoperative metamorphopsia scores (r = 0.378, p < 0.0001). Preoperative metamorphopsia score was significantly higher for ERM (0.89) than for DME (0.51). Vitrectomy significantly improved metamorphopsia in ERM and MH but not in the other disorders. In contrast, treatment improved visual acuity for all disorders except CRVO-CME and M-on RD.

CONCLUSION

This quantitative study indicated that metamorphopsia is present in most patients undergoing surgery for vitreoretinal diseases and is most severe in ERM. In these patients, vitrectomy improved visual acuity but not metamorphopsia.

Idiopathic epiretinal membranes: postoperative changes in morphology

OBJECTIVE

To describe retinal morphology in idiopathic epiretinal membranes (ERMs) and to evaluate factors influencing function at different postoperative times up to 24 months.

DESIGN

Retrospective study.

PARTICIPANTS

A total of 121 eyes of 117 patients followed with spectral-domain optical coherence tomography for 24 months.

METHODS

The following details were analyzed: type of ERM, central retinal thickness, and status of all retina layers in the fovea, especially the outer nuclear layer (ONL) and photoreceptor layer. We evaluated the presence of disorganization of retinal inner layers (DRIL), ectopic inner foveal layer (EIFL), elevation (stretching) of the ONL, cotton ball sign, and type connection between the retina and ERMs (complete adherence or multiple junction spots).

RESULTS

The percentage of DRIL, EIFL, and stretched ONL decreased. Several factors negatively influenced visual acuity during the early postoperative controls: age, interdigitation zone defects; presence of cotton ball sign, DRIL, EIFL, and stretched ONL; and strong adhesion of the ERMs to the retina. Twenty-four months after surgery, only DRIL and strong adhesion between ERMs and the retina remained statistically significant.

CONCLUSIONS

Younger patients (p < 0.001) and patients without DRIL (p < 0.001) experienced a faster recovery of function. The length of follow-up was associated with a decrease of factors influencing the final outcome. After 24 months, only the presence of DRIL and strong adhesion between the ERMs and the retina were significant. Assuming that DRIL appears in more advanced stages when compared with EIFL, this allows us to suggest that earlier surgery might be of more benefit in idiopathic ERMs.

Idiopathic Epiretinal Membrane Surgery in Patients Aged Over 80 Years: Efficacy and Safety

Purpose

To evaluate the efficacy and safety of idiopathic epiretinal membrane (ERM) surgery in patients aged over 80 years.

Methods

Consecutive patients who underwent pars plana vitrectomy (PPV) combined with ERM and internal limiting membrane (ILM) peeling with retrobulbar anesthesia were recruited. Based on age, the patients were divided into the elderly group (≥ 80 years of age) and the control group (< 80 years of age). The best-corrected visual acuity (BCVA) and surgical complications were regarded as the main measurement indicators.

Results

This study included 43 eyes from 43 patients aged 80 to 91 years and 86 eyes from 86 patients aged 54 to 79 years. Surgical intervention substantially improved BCVA both in the elderly and control groups (p = 0.005 and p < 0.001, respectively). Statistical analyses showed no significant difference in the incidence of surgical complications between the two groups (p = 0.631). The operations in either group were not delayed or canceled for the reason of complications of retrobulbar anesthesia, severe anxiety, or physical discomfort in the perioperative period. Moreover, no patient required a second operation. Also, no stroke, myocardial infarction, or death occurred during the follow-up period. All the surgical complications were treated satisfactorily.

Conclusion

Our outcomes indicate that PPV combined with ERM and ILM peeling with retrobulbar anesthesia is effective and safe in elderly patients aged 80 years or older. Based on age alone, we believe that advancing age should not be the risk factor for idiopathic ERM surgery.

TOPOGRAPHIC ASSESSMENT OF INTRARETINAL CYSTOID SPACE AND ITS PROGNOSTIC VALUES IN IDIOPATHIC EPIRETINAL MEMBRANE

PURPOSE

To assess the topographical distribution of intraretinal cystoid space (IRC) and its prognostic value in idiopathic epiretinal membrane (iERM).

METHODS

One hundred twenty-two eyes of iERM that had been followed up for 6 months after membrane removal were included. Based on the baseline IRC distribution, the eyes were divided into Groups A, B, and C (absence, IRC within 3 mm, and 6 mm from the fovea, respectively). The best-corrected visual acuity (BCVA), central subfield macular thickness (CSMT), ectopic inner foveal layer, and microvascular leakage (ML) were assessed.

RESULTS

Fifty-six eyes (45.9%) had IRC, of which 35 (28.7%) were in Group B and 21 (17.2%) in Group C at baseline. Compared with group B, group C showed worse BCVA, thicker CSMT, and a greater association with ML (OR = 5.415; P = 0.005) at baseline; and also presented with worse BCVA, thicker CSMT, and wider distribution of IRC postoperatively. A wide distribution of IRC was an unfavorable baseline factor in achieving good visual acuity (OR = 2.989; P = 0.031).

CONCLUSION

Widely distributed IRCs were associated with advanced disease phenotype as poor BCVA, thick macula, and baseline ML in iERM and also showed a poor visual outcome after membrane removal.

PREDICTING VISUAL OUTCOME AFTER SURGERY IN PATIENTS WITH IDIOPATHIC EPIRETINAL MEMBRANE USING A NOVEL CONVOLUTIONAL NEURAL NETWORK

PURPOSE

To develop a deep convolutional neural network that enables the prediction of postoperative visual outcomes after epiretinal membrane surgery based on preoperative optical coherence tomography images and clinical parameters to refine surgical decision making.

METHODS

A total of 529 patients with idiopathic epiretinal membrane who underwent standard vitrectomy with epiretinal membrane peeling surgery by two surgeons between January 1, 2014, and June 1, 2020, were enrolled. The newly developed Heterogeneous Data Fusion Net was introduced to predict postoperative visual acuity outcomes (improvement ≥2 lines in Snellen chart) 12 months after surgery based on preoperative cross-sectional optical coherence tomography images and clinical factors, including age, sex, and preoperative visual acuity. The predictive accuracy, sensitivity, specificity, and area under the receiver operating characteristic curve of the convolutional neural network model were evaluated.

RESULTS

The developed model demonstrated an overall accuracy for visual outcome prediction of 88.68% (95% CI, 79.0%-95.7%) with an area under the receiver operating characteristic curve of 97.8% (95% CI, 86.8%-98.0%), sensitivity of 87.0% (95% CI, 67.9%-95.5%), specificity of 92.9% (95% CI, 77.4%-98.0%), precision of 0.909, recall of 0.870, and F1 score of 0.889. The heatmaps identified the critical area for prediction as the ellipsoid zone of photoreceptors and the superficial retina, which was subjected to tangential traction of the proliferative membrane.

CONCLUSION

The novel Heterogeneous Data Fusion Net demonstrated high accuracy in the automated prediction of visual outcomes after weighing and leveraging multiple clinical parameters, including optical coherence tomography images. This approach may be helpful in establishing personalized therapeutic strategies for epiretinal membrane management.

Long-Term Visual Acuity and Optical Coherence Tomography Changes After Vitrectomy for Idiopathic Epiretinal Membranes

Objective

To evaluate the long-term visual acuity and retinal thickness changes after pars plana vitrectomy (PPV) for idiopathic epiretinal membranes (ERM).

Methods

We performed a retrospective analysis of 72 patients who underwent PPV for idiopathic ERM in a tertiary hospital over 5 consecutive years. The main outcome measurement was change in visual acuity and macular thickness as recorded with optical coherence tomography (OCT).

Results

Medical records of 239 patients with a diagnosis of ERM who underwent PPV with or without internal limiting membrane (ILM) peeling were reviewed; of these, 72 patients with idiopathic ERM were included in the final analysis. All patients completed at least one year of follow-up, and 23 patients (30%) had 5 or more years of follow-up. The mean preoperative best corrected visual acuity (BCVA) was 20/65, and mean preoperative central macular thickness (CMT) on OCT was 434 microns (µm). Mean postoperative BCVA and CMT at one year were 20/40 and 303 µm, respectively (p<0.0001). A total of 42 patients (58%) improved by 2 or more lines; BCVA and CMT continued to improve postoperatively for up to 5 years of the follow-up period. There was no significant difference in BCVA or CMT between phakic and pseudophakic patients, and ILM peeling was performed in 67% of patients. Improved BCVA at 1 year was associated with younger age (p<0.0001) and ILM peeling (p=0.020).

Conclusion

PPV is an effective treatment for idiopathic ERM, and ILM peel may be of benefit. BCVA continues to improve up to 2 years and beyond after surgery regardless of the duration of symptoms.

Essential Role of Multi-Omics Approaches in the Study of Retinal Vascular Diseases

Retinal vascular disease is a highly prevalent vision-threatening ocular disease in the global population; however, its exact mechanism remains unclear. The expansion of omics technologies has revolutionized a new medical research methodology that combines multiple omics data derived from the same patients to generate multi-dimensional and multi-evidence-supported holistic inferences, providing unprecedented opportunities to elucidate the information flow of complex multi-factorial diseases. In this review, we summarize the applications of multi-omics technology to further elucidate the pathogenesis and complex molecular mechanisms underlying retinal vascular diseases. Moreover, we proposed multi-omics-based biomarker and therapeutic strategy discovery methodologies to optimize clinical and basic medicinal research approaches to retinal vascular diseases. Finally, the opportunities, current challenges, and future prospects of multi-omics analyses in retinal vascular disease studies are discussed in detail.

Changes in the Hyperreflective Bands of Outer Retinal Layers after Idiopathic Epiretinal Membrane Surgical Removal

Purpose: The purpose of this study was to describe the relationship between the outer retinal hyperreflective bands and visual acuity recovery after idiopathic epiretinal macular membrane (ERM) surgical removal.Methods: A prospective longitudinal non-comparative study was conducted that included a total of 68 patients with idiopathic ERM, who underwent consecutive 23 G pars plana vitrectomy (PPV) at San Juan University Hospital (Alicante, Spain) from January 2019 to January 2021. All patients underwent a complete preoperative standard ophthalmic examination, including measurement of best corrected visual acuity (BCVA) and spectral-domain optical coherence tomography (SD-OCT) examination. This protocol was repeated at 1 and 3 months after surgery.Results: Mean preoperative decimal BCVA was 0.30 ± 0.13 and disruption of the first, second, third and fourth outer retinal hyperreflective bands was observed by SD-OCT in 9 (27.9%), 27 (39.7%), 33 (48.5%) and 17 patients (25%), respectively. BCVA improved after ERM peeling at 1 and 3 months in all patients, regardless of the presence of disruption in any hyperreflective band. Significantly larger improvement of BCVA was found at 3 months after surgery in patients not showing disruption of hyperreflective bands 1 and 4 (p = 0.048 and 0.001, respectively).Conclusions: The integrity of the outer retinal hyperreflective bands by SD-OCT in patients with idiopathic ERM is a valuable tool to determine the visual prognosis of the surgical treatment of this condition. A successful recovery of hyperreflective bands 1 and 4 with ERM surgery may be a potential biomarker of the visual improvement achieved due to their important anatomical relation with cone photoreceptors at the foveal level.

Visual outcomes of epiretinal membrane removal after diffractive-type multifocal intraocular lens implantation

Background

To assess visual outcomes of epiretinal membrane (ERM) removal in multifocal intraocular lens (MIOL)-implanted eyes, according to ERM stage.

Methods

Retrospective chart reviews were undertaken in patients with diffractive-type MIOL implants, each undergoing pars plana vitrectomy and ERM removal between February 2018 and November 2020 at Gyeongju St. Mary's Eye Clinic and KEYE Eye Center. Assessments focused on monocular uncorrected and corrected values of distant visual acuity (UDVA and CDVA) and uncorrected near visual acuity (UNVA) at postoperative 12 months according to the stage of ERM.

Results

The present study included a total of 49 MIOL-implanted eyes from 49 enrollees, 25 undergoing pars plana vitrectomy for ERM removal (11 eyes with Stage 2 and 14 eyes with Stage 3), and 24 acting as age-matched controls. There was a significant difference in UDVA and UNVA between control and Stage 3 ERM (UDVA; 0.01 ± 0.04 for control, and 0.07 ± 0.08 for stage 3 ERM, p = 0.035, UNVA; 0.03 ± 0.05 for control, and 0.13 ± 0.16 for Stage 3 ERM, p = 0.029). There were no significant differences in CDVA between groups (p = 0.121, ANOVA test).

Conclusions

Eyes with Stage 3 ERM did not achieve visual acuity comparable to control eyes, suggesting the necessity of an early intervention for ERM in eyes with diffractive type MIOL. A meticulous preoperative retinal evaluation for ERM development is mandatory when planning diffractive-type MIOL implantation.

Natural History and Surgical Timing for Idiopathic Epiretinal Membrane

PURPOSE

This study assessed the prevalence of progression to surgery on idiopathic epiretinal membrane (iERM) and compared the results with those of immediate surgery.

DESIGN

Retrospective study with nested case-control comparison.

SUBJECTS

Patients with mild iERM at initial presentation METHODS: A retrospective study with a nested case-control study was conducted to compare the outcomes of those who later progressed to surgery ("deferred surgery") with those of a control group that underwent surgery within 6 months of initial presentation ("immediate surgery").

MAIN OUTCOME MEASURES

The prevalence of performing vitrectomy with membrane peeling after initial deferral, features associated with deferred surgery, and the visual acuity (VA) outcomes of surgery compared with those with immediate surgery.

RESULTS

A total of 413 patients were included in the base study cohort: 369 did not undergo iERM peeling, whereas 44 (10.7%) underwent deferred surgery at a mean duration of 18.1 months after initial presentation. The factor most associated with later progression to surgery, determined using a multivariate analysis, was symptoms at initial presentation (odds ratio [95% confidence interval], 8.75 [3.80-20.15]; P < 0.0001). The immediate surgical group (controls) had a poorer logarithm of the minimum angle of resolution (logMAR) best-corrected visual acuity (BCVA) at presentation compared with the deferred surgery group (cases), but this decreased in the latter group to about the same preoperative level immediately before the deferred surgery (typically why they underwent surgery). The final logMAR BCVA was similar in the deferred and immediate surgical groups when only pseudophakic cases were analyzed. An analysis of the change from preoperative BCVA (instead of initial) to final BCVA showed no difference in the magnitude of change between the pseudophakic subgroups of the deferred and immediate surgery groups (median [interquartile range] preoperative VA of 0.52 [0.40-0.60] in the deferred surgery group and 0.44 [0.39-0.60] in the immediate surgery group [P = 0.7256]). Within the deferred and immediate surgery groups, the median change from preoperative BCVA to final BCVA in the pseudophakic subgroups was 0.22 (P = 0.0082) in the former and 0.21 (P = 0.0001) in the latter.

CONCLUSIONS

The vast majority of eyes with iERM remain stable after initial presentation. The deferral of surgery in the minority of patients who progress does not have a disadvantageous final outcome compared with immediate surgery.

Retinal misregistration and effect of surgery on its improvement in patients with epiretinal membrane

PURPOSE

To evaluate the prevalence of retinal misregistration, that is, misalignment of retinal elements that affect central and peripheral fusion, and the effect of surgery in patients with epiretinal membrane (ERM).

METHODS

This prospective interventional case-series was performed on 32 patients with symptomatic ERM with the complaint of binocular diplopia or decreased visual acuity. After the diagnosis of ERM, optotype frame, synoptophore, and lights on-off tests were used to evaluate retinal misregistration. Patients with severe symptoms underwent surgery and were followed for 3 months.

RESULTS

Of the 32 patients, 6 (19%) had preoperative diplopia. Optotype frame, synoptophore, and lights on-off tests had positive results in 20 (63%), 19 (63%), and 11 (34%) cases, respectively. Of the 6 diplopia cases, 5 showed positive results in all 3 tests and 1 was positive on optotype frame and synoptophore testing. Of the 26 cases without diplopia, 15 (58%) showed positive results in at least one test, including 6 (23%) in all three tests, 6 (23%) in two tests, and 3 (12%) in only one test. Ten patients underwent surgery. Postoperatively, all patients had negative lights on-off test, but optotype frame and synoptophore tests were negative in eight patients (80%). Two cases (20%) had postoperative diplopia, including 1 case with postoperative new-onset diplopia.

CONCLUSIONS

The prevalence of retinal misregistration was higher than the rate of diplopia. Surgery improved diplopia and results of tests of retinal misregistration.

[Disorders of the visual system following vitreoretinal and macular surgery]

The visual system is highly complex. Monocular or binocular disorders can develop, for example during tractive alterations of the macula, such as in epimacular membranes, and result in symptoms, such as double vision, aniseikonia or metamorphopsia. These symptoms are also observed following vitreomacular or vitreoretinal surgery, especially after treatment of large retinal detachment involving the macular area using pars plana vitrectomy or scleral buckle surgery but also as a result of vitreomacular interventions, such as membrane peeling in epimacular gliosis. Some patients have preoperatively existing latent conditions, which are not explicitly addressed during routine preoperative diagnostics. For patients and surgeons it is worth noting that these troublesome symptoms are often manifested in patients with good restoration of best corrected visual acuity following vitreomacular surgery. In such cases, patients tend to be dissatisfied with the surgical result despite good visual acuity. Treatment of postoperative metamorphopsia, aniseikonia and double vision is often difficult. In clinical studies, the maximum depth of tractive retinal folds has been described as a reliable morphological biomarker for the occurrence of metamorphopsia in epimacular gliosis. As metamorphopsia tends to postoperatively resolve slowly and even persist in ca. 30% of cases, this biomarker can have an impact on preoperative consulting and postoperative monitoring. Persistent binocular discomfort is often treatable by exact refraction correction and by applying a vertical and, if necessary, a horizontal prism. This often requires patience on the part of both the patient and the physician but is mostly successful due to fusion and adaptability.

Prevalence and predictive factors for posterior vitreous attachment in eyes undergoing epiretinal membrane surgery

BACKGROUND

To report the prevalence of posterior vitreous attachment (PVA) in patients with idiopathic epiretinal membrane (iERM) and to determine associated preoperative predictive factors.

METHODS

Retrospective observational case series of 408 eyes who underwent surgery for iERM without vitreomacular traction. The status of the posterior hyaloid was assessed intraoperatively. Predictive factors were analysed using univariate and multivariate logistic regression. We also evaluated the effect of PVA on the anatomical and functional outcomes of surgery.

RESULTS

Eighty-two (20.1%) eyes were found to have an undetached posterior hyaloid during vitrectomy. In multivariate analysis, axial length (AL) and lens status were strongly associated with the posterior vitreous status (p = 0.031 and p = 0.048). The odds of having a PVA decreased by a factor 0.81 per mm of AL (95% CI, 0.66-1.00). Phakic eyes had a 2.88-fold increased risk of exhibiting PVA compared to those with previous cataract extraction (95% CI, 1.10-7.52). The presence of PVA did not have any effect on postoperative anatomical and functional outcomes. In contrast, we found that eyes with shorter axial length, low preoperative visual acuity and disruption of the ellipsoid zone exhibited worse visual recovery (p = 0.006, p < 0.001 and p = 0.037).

CONCLUSION

PVA was observed in 20.1% of eyes undergoing vitrectomy for iERM. Shorter AL and phakic status were strong predictive factors of PVA in those eyes. However, the morphological features and the surgical prognosis of iERMs with PVA did not differ from those with posterior vitreous detachment.

Idiopathic Epiretinal Membranes: Visual Outcomes and Prognostic Factors

Objectives

To evaluate the associations between anatomical changes and visual outcomes in patients with idiopathic epiretinal membrane (ERM).

Materials and Methods

We performed a prospective study of 130 consecutive idiopathic ERM patients and report their visual outcomes and the factors associated with visual outcome and anatomical changes.

Results

Of 130 eyes of 130 patients, 87 eyes underwent surgery, while the remaining 43 eyes were observed. At 6-month follow-up, the best-corrected visual acuity (BCVA) increased in the whole population. Mean Early Treatment Diabetic Retinopathy Study letter score changed from 51 to 65 in the surgical group and from 67 to 68 in the non-surgical group. The surgical group had improvement in BCVA at all ERM stages and grades of disorganization of the retinal inner layers (DRIL) (p<0.01). In multivariable analysis of the surgical group, factors associated with BCVA of ETDRS 60 letters or more were no or mild DRIL and the absence of ellipsoid zone disruption at baseline (p=0.002 and p=0.034, respectively) and this statistically significant positive correlation was still maintained at 12-month follow-up.

Conclusion

Baseline DRIL grade and presence of ellipsoid zone disruption were the most informative prognostic factors in patients with idiopathic ERMs. Patients with severe DRIL and/or advanced ERMs had improved vision after ERM removal.

Efficacy and safety of primary posterior capsulotomy during phaco-vitrectomy for epiretinal membrane

Purpose

To evaluate the necessity and safety of primary posterior capsulotomy during phaco-vitrectomy for idiopathic epiretinal membrane (ERM).

Setting

Seoul National University Bundang Hospital, Seongnam, Korea.

Design

Retrospective consecutive cohort analysis.

Methods

This study enrolled 219 patients (228 eyes) who underwent combined 25-gauge phaco-vitrectomy for idiopathic ERM and cataract, divided into capsulotomy (−) group (152 eyes, 144 patients) and capsulotomy (+) group (76 eyes, 75 patients). The main outcomes were rate of posterior capsular opacity (PCO) occurrence and postoperative complications. Ophthalmic examinations were performed at baseline, 1, 3, 6, and 12 months postoperatively.

Results

PCO only occurred in capsulotomy (−) group (20 eyes, 13.2%), with mean onset of 10.59 months. Visually-significant PCO that needed Nd:YAG posterior capsulotomy was present in 9 eyes (45.0% of PCO eyes). The rate of cystoid macular edema (CME) was higher in capsulotomy (+) group (6.6% vs. 15.8%, p = 0.026) with longer duration (1.50 vs. 3.36 months, p = 0.019). Female sex and posterior capsulotomy were significant risk factors for CME occurrence (p < 0.05).

Conclusion

Primary posterior capsulotomy during phaco-vitrectomy for idiopathic ERM obviated the need for Nd:YAG posterior capsulotomy, but visually-significant PCO that needed Nd:YAG laser was not common. Considering the low rate of visually-significant PCO and high rate of postoperative CME, routine posterior capsulotomy during phaco-vitrectomy may not be necessary for preventing PCO in ERM.

Two-year Changes in Postoperative Central Macular Thickness and Subfoveal Choroidal Thickness in Epiretinal Membrane Patients

Purpose: To evaluate changes in central macular thickness (CMT) and subfoveal choroidal thickness (SFCT) after phacovitrectomy over a 2-year period in idiopathic epiretinal membrane (ERM) patients.Methods: The records of 52 idiopathic ERM patients (52 eyes) who underwent phacovitrectomy, without recurrence of the condition over a 2-year follow-up period, were reviewed retrospectively. Changes in CMT and SFCT, as measured by optical coherence tomography, were analyzed and compared with those of a normal control group over a 2-year period.Results: The mean preoperative CMT and SFCT were 425.67 ± 84.67 and 257.56 ± 90.13 μm, respectively. Postoperative CMT was reduced significantly to 372.17 ± 45.26 μm at 1 year and 363.15 ± 47.35 μm at 2 years (p < 0.001). SFCT at 1 and 2 years postoperatively was significantly reduced to 238.85 ± 84.85 and 230.31 ± 87.95 μm, respectively (p < 0.001). In the control group, there was no significant change in CMT; however, the SFCT decreased by 11.09 ± 22.36 μm during the 2-year follow-up (p = 0.007). In contrast, in the patient group, CMT and SFCT decreased by 62.52 ± 71.45 and 27.25 ± 41.97 μm, respectively, showing a significant difference from the control group (p < 0.001 and p = 0.043, respectively). Both before surgery and at 1 year postoperatively, the thinner the CMT, the better the best-corrected visual acuity (BCVA) (p = 0.010 and p = 0.018, respectively). A better postoperative BCVA at 2 years was associated with a thinner CMT and better BCVA before surgery (p < 0.001 and p < 0.001, respectively).Conclusions: Following a phacovitrectomy procedure, ERM patients showed significant reductions in both the CMT and SFCT at the 2-year follow-up.

MICROVASCULAR LEAKAGE IS A POOR PROGNOSTIC FACTOR FOR IDIOPATHIC EPIRETINAL MEMBRANE: A Fluorescein Angiography Study

PURPOSE

To investigate the angiographic findings assessed using fluorescein angiography and their prognostic values of idiopathic epiretinal membrane.

METHODS

Seventy-three eyes of idiopathic epiretinal membrane that had been followed up for 6 months after surgical treatment were included. Midphase fluorescein angiography images were obtained at baseline. Structural changes, including central subfield macular thickness, intraretinal cystic lesion, and ectopic inner retinal layer on the fovea, were assessed using optical coherence tomography. The main outcome measures were microvascular leakage (ML) and its association with optical coherence tomography findings and best-corrected visual acuity (BCVA).

RESULTS

Of a total of 73 eyes, 37 showed ML and had worse BCVA (P = 0.040), greater central subfield macular thickness (P = 0.028), and more ectopic inner retinal layer (P < 0.001) than those without ML at baseline. Also, ML was associated with worse postoperative BCVA (P < 0.001) and ectopic inner retinal layers (P < 0.001; P = 0.034) at baseline and 6 months. The baseline factors associated with postoperative BCVA of ≥20/25 were better BCVA (P = 0.027) and the absence of ML (P < 0.001).

CONCLUSION

Half of the idiopathic epiretinal membrane eyes showed that ML was associated with inner retinal deformity and poor visual recovery. Fluorescein angiography helped to predict visual prognosis after idiopathic epiretinal membrane surgery.

The contribution of the proximity of the retinal detachment to the fovea for postoperative metamorphopsia after 27-gauge pars plana vitrectomy for the primary rhegmatogenous retinal detachment

Purpose

To investigate clinical factors contributing to metamorphopsia after 27-gauge pars plana vitrectomy (27GPPV) for primary rhegmatogenous retinal detachment (RRD) to reveal whether the proximity of the preoperative retinal detachment to the fovea is associated with postoperative metamorphopsia.

Methods

We retrospectively reviewed medical records of 77 eyes of 77 patients after 27GPPV for RRD. Patients were subdivided into three groups using optical coherence tomography findings: Group A, patients with RRD outside the vascular arcade; Group B, patients whose condition was present within the vascular arcade, but without foveal detachment; and Group C, patients with foveal detachment.

Results

The average metamorphopsia score (°) assessed with M-charts 12 months after surgery was 0.01 ± 0.04 in Group A (24 eyes), 0.08 ± 0.18 in Group B (20 eyes), and 0.49 ± 0.48 in Group C (33 eyes) (p<0.001). Logistic regression analysis revealed that metamorphopsia at 12 months after surgery significantly correlated with the proximity of the retinal detachment to the fovea (p = 0.007).

Conclusion

Metamorphopsia after 27GPPV for RRD correlated with the proximity of the preoperative retinal detachment to the fovea. Attention should be paid to the possibility of postoperative metamorphopsia development when retinal detachment is present within a vascular arcade even if the fovea is not involved.

MORE EFFECTIVE SCREENING FOR EPIRETINAL MEMBRANES WITH MULTICOLOR SCANNING LASER OPHTHALMOSCOPE THAN WITH COLOR FUNDUS PHOTOGRAPHS

PURPOSE

To assess the ability of the multicolor scanning laser ophthalmoscope (MC-SLO) to screen for epiretinal membranes (ERMs).

METHODS

A retrospective cross-sectional study of 35 eyes of 32 patients with an ERM detected by optical coherence tomography and 46 eyes of 23 healthy volunteers. The detection of the ERM was graded into three visibility scores-1, not visible, 2, barely visible, and 3, clearly visible-by retina specialists or by ophthalmology residents. The sensitivity and specificity of the detection with the merged image of the MC-SLO or color fundus photographs (CFPs) were calculated.

RESULTS

The sensitivity for ERM detection in the MC-SLO and CFP were 91.4% and 65.7% by specialists and 97.1% and 60.0% by residents. The specificity for both devices was 100% by specialists and residents. The visibility score for the MC-SLO images were significantly higher than that for the CFP by both specialists and residents. In addition, the visibility score for the MC-SLO determined by residents was significantly higher than that for the CFP by specialists.

CONCLUSION

The detection of an ERM is better with the MC-SLO images than with CFP. Furthermore, the ERM detection in the MC-SLO images by residents was comparable to that by specialists.

Vitreous from idiopathic epiretinal membrane patients induces glial-to-mesenchymal transition in Müller cells

Idiopathic epiretinal membranes (ERMs) are fibrocellular membranes containing extracellular matrix proteins and epiretinal cells of retinal and extraretinal origin. iERMs lead to decreased visual acuity and their pathogenesis has not been completely defined. Macroglial Müller cells appear to play a pivotal role in the pathogenesis of iERM where they may undergo glial-to-mesenchymal transition (GMT), a transdifferentiation process characterized by the downregulation of Müller cell markers, paralleled by the upregulation of pro-fibrotic myofibroblast markers. Previous observations from our laboratory allowed the molecular identification of two major clusters of iERM patients (named iERM-A and iERM-B), iERM-A patients being characterized by less severe clinical features and a more "quiescent" iERM gene expression profile when compared to iERM-B patients. In the present work, Müller MIO-M1 cells were exposed to vitreous samples obtained before membrane peeling from the same cohort of iERM-A and iERM-B patients. The results demonstrate that iERM vitreous induces proliferation, migration, and GMT in MIO-M1 cells, a phenotype consistent with Müller cell behavior during iERM progression. However, even though the vitreous samples obtained from iERM-A patients were able to induce a complete GMT in MIO-M1 cells, iERM-B samples caused only a partial GMT, characterized by the downregulation of Müller cell markers in the absence of upregulation of pro-fibrotic myofibroblast markers. Together, the results indicate that a relationship may exist among the ability of iERM vitreous to modulate GMT in Müller cells, the molecular profile of the corresponding iERMs, and the clinical features of iERM patients.

Vitreomacular disorders: a review of the classification, pathogenesis and treatment paradigms including new surgical techniques

This review explores how optical coherence tomography has guided our assessment of vitreomacular disorders. Vitreomacular disorders (VMD), such as macular holes and epiretinal membranes are common and potentially sight threatening. The introduction and widespread use of optical coherence tomography (OCT) imaging technology has transformed our ability to visualise the vitreoretinal interface. This review discusses the pathogenesis and updated classification scheme for VMD in the OCT era. Imaging biomarkers and the treatment algorithm, including the role of novel therapeutics, for managing patients with VMD are presented.

Comparison of the effect of air tamponade versus no tamponade after pars plana vitrectomy for idiopathic epiretinal membrane

This study aimed to compare the surgical outcomes of pars plana vitrectomy (PPV) with and without air tamponade in patients with idiopathic epiretinal membrane (iERM). We prospectively enrolled 145 patients with iERM who underwent a 25-gauge transconjunctival sutureless PPV. Patients were assigned to either the air tamponade (air) group (79 eyes) or balanced salt solution (BSS; no tamponade) group (66 eyes). The central macular thickness (CMT), peripapillary retinal nerve fiber layer (pRNFL) thickness, and best-corrected visual acuity (BCVA) were compared for two years. At baseline, there were no significant differences between the two groups. CMT and BCVA were not significantly different between the groups for 2 years. However, the air group had a significantly lower thickness in the superior temporal pRNFL sector at 1 month (p = 0.01) and in the inferior temporal and superior temporal pRNFL sectors at 3 months (p = 0.02 for both). There were no significant differences between both groups in all the pRNFL sectors from 6 months to 2 years. The outcomes of PPV with air tamponade and that with no tamponade appear to be equivalent. This shows that air tamponade may not be an imperative procedure for iERM surgery and has no additional benefit.

POSTOPERATIVE MOVEMENT OF THE FOVEA AFTER SUCCESSFUL SURGERY IN PATIENTS WITH IDIOPATHIC EPIRETINAL MEMBRANES

PURPOSE

To evaluate the change in the fovea's postoperative location after successful pars plana vitrectomy with combined epiretinal and internal limiting membrane peeling in patients with idiopathic epiretinal membranes (iERMs).

METHODS

In this prospective study 32 eyes of 32 patients with iERMs were followed from baseline before until 3 months after surgery. Study measures included 4-m Early Treatment Diabetic Retinopathy Study best-corrected visual acuity, enhanced-depth imaging-optical coherence tomography, and intraoperative fundus photographs. Foveal movement was assessed by measuring the change in the papillofoveal distance (∆PFD).

RESULTS

Mean ∆PFD in the study eye was -124 µm (±138) and -272 µm (±213) one day and 3 months after surgery, respectively. Mean ∆PFD after 3 months was greater in the study than in the fellow eye (P < 0.001). ∆PFD at Month 3 did not correlate with the internal limiting membrane area peeled (P = 0.78).

CONCLUSION

Foveal movement starts immediately after surgery and causes a statistically significant reduction in PFD after uneventful macular pucker surgery. ∆PFD correlates statistically significantly with baseline best-corrected visual acuity and baseline central retinal thickness. The internal limiting membrane peeling size had no significant effect on the amount of postoperative foveal dislocation.

PREOPERATIVE DOMED MACULAR CONTOUR CORRELATES WITH POSTOPERATIVE VISUAL GAIN AFTER VITRECTOMY FOR SYMPTOMATIC EPIRETINAL MEMBRANE

PURPOSE

Evaluate macular features on preoperative ocular coherence tomography as indicators of postoperative visual gain following vitrectomy for epiretinal membrane (ERM).

METHODS

A retrospective chart review of 66 eyes that underwent vitrectomy with membrane and internal limiting membrane peeling for symptomatic ERM. Inclusion criteria required a pre-op visual acuity of at least 20/200 and minimum follow-up of 1 year. In addition, 31 of these eyes with complete 5-line raster pre-op ocular coherence tomography had segmentation analysis which included noncentral ERM to inner nuclear layer and ERM to outer plexiform layer measurements.

RESULTS

Eyes with "domed" pre-op macular contour had a mean preoperative acuity of 20/70 and gained a mean 2.4 lines at one year, compared with those with "flat" or "depressed" macular contour, having a 20/60 mean preoperative acuity and 0.6 lines gained (P = 0.02). Changes for other ocular coherence tomography features examined were not statistically significant. Paracentral ERM to inner nuclear layer measurements had moderate correlation, whereas paracentral ERM to outer plexiform layer measurements had weak correlation with gain in visual acuity.

CONCLUSION

An inner macular-domed contour in eyes with ERM predicted better visual gain after vitrectomy with ERM and internal limiting membrane peeling compared with a flat or depressed contour.

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

BACKGROUND/OBJECTIVES

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

SUBJECTS/METHODS

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

RESULTS

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

CONCLUSION

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

Anatomical and Functional Recovery Kinetics After Epiretinal Membrane Removal

Purpose

To investigate the nature of anatomical and functional recovery kinetics after epiretinal membrane (ERM) removal.

Methods

The records of 42 patients (45 eyes) with idiopathic ERM treated with pars plana vitrectomy and surgical peeling of the ERM performed by a single surgeon at Massachusetts Eye and Ear between 2012 and 2017 were retrospectively reviewed. Outcome measures included spectral domain optical coherence tomography-measured central macular thickness (CMT) pre-operatively and at post-operative day 1, week 1, months 1, 3, 6, 12 and 24 as well as best-corrected visual acuity (BCVA). Correlations between baseline or early values and final anatomical and functional outcomes were investigated.

Results

Improvement in CMT was statistically significant after 1 week, 1, 3, 6, 12 and 24 months (p < 0.01). BCVA improvement was statistically significant after 1, 6, 12 and 24 months follow-up (p<0.01). The improvement of BCVA and CMT with time was found to be logarithmic (R² =0.96, R² =0.84) suggesting that early (<30 days) post-operative functional and anatomical changes may be predictive of long-term outcomes. Preoperative BCVA and CMT revealed a weak positive correlation with the respective BCVA and CMT at 24 months (R²=0.13 and R²=0.16). When plotted as a percentage of the fellow normal eye CMT, first week proportional improvement in CMT from pre-operative baseline was found to be correlated with final CMT proportional decrease (R²=0.72) suggesting that first week postoperative CMT could be predictive of final CMT.

Conclusion

There is a logarithmic improvement in CMT and BCVA after ERM peel with BCVA improvement following the CMT improvement. Early (less than 30 days) post-operative anatomical changes can be predictive of long-term anatomical outcomes.

Usefulness of the Components of Full-Field Electroretinography to Predict Postoperative Visual Outcomes in Patients With Epiretinal Membranes

Purpose

To confirm the predictors of postoperative visual outcomes by performing full-field electroretinography (ffERG) before surgery in patients with epiretinal membranes (ERMs).

Methods

Sixty-one eyes of patients with ERMs who underwent pars plana vitrectomy with membrane peeling were prospectively reviewed. Correlations between preoperative data (ffERG and optical coherence tomography) and postoperative best-corrected visual acuity (BCVA) were investigated. Receiver operating characteristic (ROC) curve analysis was performed to obtain cutoff values of the ffERG parameters predicting good visual outcome (final BCVA ≥ 20/30).

Results

Postoperative BCVA was significantly correlated with the implicit time and amplitude of the b-wave in light-adapted (LA) 3.0 electroretinography (ERG), with the amplitude difference between N1 and P1 in the LA 30-Hz flicker ERG, and with the sum of the amplitudes of OS1, OS2, and OS3 in dark-adapted (DA) oscillatory potential (OP) ERG (P < 0.01). The area under the ROC curve to predict good visual outcome was statistically significant for the four parameters (0.787, 0.815, 0.757, and 0.792, respectively).

Conclusions

The postoperative BCVA in patients with ERM was significantly correlated with the implicit time and amplitude of the b-wave in the LA 3.0 ERG, the amplitude difference between N1 and P1 in the LA 30-Hz flicker ERG, and the sum of the amplitudes of OS1, OS2, and OS3 in DA OP ERG of ffERG. It is thought that ffERG before surgery may help predict visual outcomes after surgery.

Translational Relevance

It was confirmed that the degree of retinal function in the ERM can predict BCVA after treatment.

Correlations among metamorphopsia test scores, optical coherence tomography findings and multifocal electroretinogram responses in epiretinal membrane patients

PURPOSE

To quantify metamorphopsia with a novel objective method in patients with epiretinal membrane (ERM) and to compare the relationships among metamorphopsia scores, spectral-domain optical coherence tomography (OCT) findings, and multifocal electroretinogram (mfERG) results.

METHODS

This study included 52 eyes of 52 patients with idiopathic ERM who underwent comprehensive ophthalmologic examinations, including measurement of best-corrected visual acuity (BCVA), OCT, and mfERG. The degree of metamorphopsia was quantified using MonPack One® (Metrovision, Perenchies, France). On the topographic map of the early treatment diabetic retinopathy (ETDRS) grid, retinal thickness in the central, superior, inferior, nasal, and temporal subfields were measured, and metamorphopsia scores for each corresponding subfield were also obtained. The amplitudes and implicit times of mERG were elicited from each subfield. Then, the correlations among metamorphopsia scores, OCT findings, and mfERG responses were analyzed.

RESULTS

The mean age of the patients was 65.3 ± 18.5 y, and the average metamorphopsia score of the individual subfields was 2.03 ± 1.18. Initial BCVA was 0.50 ± 0.12 logMAR, but there was no significant correlation between metamorphopsia scores and BCVA. The metamorphopsia scores from the central subfields showed significant correlations with central retinal thickness (CRT) (p = 0.001). The mean metamorphopsia scores in the central subfield showed a significant relationship with the mean N1 and P1 amplitudes (p = 0.001, p = 0.048, respectively), while no relationship was observed between metamorphopsia scores and mfERG amplitudes in other subfields.

CONCLUSIONS

The degree of metamorphopsia in patients with ERM could be objectively quantified in each subfield using a novel metamorphopsia test. The metamorphopsia scores were significantly correlated with retinal thickness, especially at the central subfields, and the scores in the central subfields were significantly correlated with the N1 and P1 amplitudes of mfERG. Thus, the metamorphopsia test can be a useful method to evaluate metamorphopsia symptoms for patients with ERM.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Outcomes of Epiretinal Membrane Removal Utilizing Triamcinolone Acetonide Visualization and Internal Limiting Membrane Forceps

Purpose

To evaluate epiretinal membrane (ERM) removal utilizing internal limiting membrane (ILM) forceps and visualization with triamcinolone acetonide (TA).

Methods

Retrospective interventional case series of eyes undergoing ERM removal with TA visualization with follow-up of up to five years. Best-corrected visual acuity (BCVA), central macular thickness (CMT), and incidence of complications were reviewed.

Results

A total of 132 eyes were included with 54 and 16 eyes completing 3- and 5-year follow-up, respectively. Mean BCVA and CMT improved significantly at all postoperative evaluations compared to baseline (p<0.001). Pre-operative presence of PVD did not affect outcome measures. No intraoperative complications were reported. Immediate post-operative complications included one case of sterile endophthalmitis and one case of vitreous and perimacular hemorrhage. At one year, complications included progression of cataract in phakic eyes (65.4%), steroid-induced glaucoma (2.2%), retinal tear (0.8%), recurrent ERM (4.5%), and recurrent macular edema (11.3%). No further complications were reported at three- and five-year follow-up.

Conclusion

Combination ILM forceps and TA visualization offers an affordable and safe option for ERM removal with comparable or better outcomes than traditional methods of ERM surgery.

Outer Plexiform Layer Angle: A Prognostic Factor for Idiopathic Macular Pucker Surgery

Purpose. To investigate the efficacy of idiopathic macular pucker (epimacular membrane) surgery and to identify the possible prognostic factor. Methods. This was a retrospective study which enrolled 38 patients with idiopathic macular pucker who underwent 23-gauge pars plana vitrectomy (PPV) with indocyanine green-assisted peeling of epiretinal membrane (ERM) and internal limiting membrane (ILM). Visual outcomes were assessed at the baseline and during the follow-up including best-corrected visual acuity (BCVA) and metamorphopsia score, as well as outer plexiform layer (OPL) angle and central retinal thickness (CRT) using spectral-domain optical coherence tomography (SD-OCT). A comparison was made between patients with the prepeeling CRTs ≥500 μm and those <500 μm. A comparison was also made between patients with the prepeeling OPL angles ≥130° and those <130°. Based on the prepeeling parameters, the correlations between various prepeeling and postpeeling visual functions were analyzed. Results. Mean follow-up was 36.07 ± 4.62 months (range 1.30–96.70 months). BCVA was significantly improved from 0.26 ± 0.03 to 0.67 ± 0.04 $\left(p<0.001\right)$ ; metamorphopsia score was significantly reduced from 1.42 ± 0.16 to 0.61 ± 0.08 $\left(p<0.001\right)$ ; CRT was significantly decreased from 519.62 ± 13.41 μm to 385.37 ± 8.97 μm $\left(p<0.001\right)$ . Greater prepeeling OPL angle (≥130°) was associated with significantly greater BCVA improvement (Snellen E/LogMAR: $p=0.01/0.03$ ) and greater metamorphopsia reduction $\left(p=0.03\right)$ , as compared to smaller OPL angle (<130°) with less BCVA improvement and less metamorphopsia reduction. However, the final BCVA improvement and metamorphopsia reduction relevant to the prepeeling smaller CRT (<500 μm) did not significantly differ from that relevant to the prepeeling greater CRT (≥500 μm; $p>0.05$ ). Endophthalmitis, retinal tear, or retinal detachment was not observed after peeling. Conclusion. Indocyanine green-assisted ERM/ILM peeling combined with small gauge vitrectomy is associated with significant visual acuity improvement and metamorphopsia reduction in patients with idiopathic macular pucker. Greater prepeeling OPL angle rather than CRT might act as a useful prognostic factor in predicting better final visual functional outcomes.

Relation of anatomy with function following the surgical treatment of idiopathic epiretinal membrane: a multicenter retrospective study

PURPOSE

To investigate the prognostic factors associated with functional and anatomical outcomes and to assess the longitudinal course of visual acuity and retinal morphology after vitreoretinal surgery for idiopathic epiretinal membrane (ERM).

METHODS

This multicenter, retrospective study included a total of 634 eyes who underwent surgery for idiopathic ERM in 22 academic centers nationwide in Turkey. Data on best-corrected visual acuity (BCVA) and optical coherence tomography features (central foveal thickness (CFT), ERM and foveal contour morphology, ellipsoid zone (EZ) integrity) were collected and compared at baseline, 6-month, 12-month, and 24-month follow-ups. Prognostic factors for functional (having ≥ 20/25 Snellen BCVA) and anatomical (having normal/shallow foveal contour) recoveries after surgery were investigated by means of multivariate regression analyses. A cutoff value of preoperative BCVA optimizing functional recovery was calculated using receiver operating characteristic curve analysis.

RESULTS

At a median follow-up of 24 months, 37.4% of the eyes achieved ≥ 20/25 BCVA and 54% regained normal or shallow foveal contour. Functional recovery was more likely in eyes with better baseline BCVA and intact EZ (R² = 0.356, p < 0.001). The cutoff baseline BCVA value for good visual prognosis was 0.35 logarithm of the minimum angle of resolution (Snellen 20/44) (sensitivity 60%, specificity 85%, p < 0.001). Anatomical recovery was negatively associated with advanced age, higher baseline CFT, foveal herniation-type ERM morphology, and internal limiting membrane (ILM) peeling (R² = 0.225, p < 0.001). The negative effect of ILM peeling on anatomical recovery was not significant after the first postoperative year (p = 0.05). Mean BCVA values and foveal morphology progressively improved at each visit. Cases with convex baseline foveal contour continued to change towards normal foveal depression over 24 months of follow-up, which took longer than the eyes with shallow/flat contoured cases. One-third of eyes with severe baseline EZ defects showed recovery at follow-up and achieved significantly greater visual acuity gains than the remaining eyes with persistent defects (p < 0.001).

CONCLUSIONS

Functional and anatomical restoration of the eyes appears to be a slow process after ERM surgery. This process may take much longer in eyes with worse foveal morphology at baseline. Although photoreceptor disruption may be reversible in some eyes, full functional recovery is unlikely when it persists.

Association of macular choroidal thickness with optical coherent tomography morphology in patients with idiopathic epiretinal membrane

PURPOSE

To compare macular choroidal thickness of idiopathic epiretinal membrane (ERM) and fellow eyes, and before and after vitrectomy in terms of the morphological features on spectral-domain optical coherent tomography (SD-OCT).

METHODS

Eighty-four patients with unilateral idiopathic ERM were involved. Patients were categorized into: Group 1, ERM without membrane contraction; Group 2, ERM with membrane contraction and retinal folding; and Group 3, ERM with membrane contraction and macular edema. Twenty-two patients received surgical removal of ERM. Choroidal thickness was compared between ERM and fellow eyes, and before and after treatment.

RESULTS

Mean choroidal thickness was significantly greater in ERM eyes than in fellow eyes (234.4 ± 22.5 vs 220.6 ± 20.8 μm; P<0.01). Group 1 (n = 20) showed no significant difference in choroidal thickness between ERM and fellow eyes. Eyes in Group 2 (n = 27) and Group 3 (n = 37) showed statistically significant differences in mean choroidal thickness between ERM and fellow eyes (229.6 ± 23.8 vs 220.8 ± 19.6 μm; 242.6 ± 27.8 vs 221.0 ± 21.8 μm, respectively; P<0.05). In Group 2 (n = 8) and Group 3 (n = 16), choroidal thickness in ERM eyes decreased significantly at 1 month and 6 months after surgery, compared with that before surgery (P<0.05 for all comparisons).

CONCLUSIONS

Membrane contraction contributed to the increase in choroidal thickness in idiopathic ERM patients. This finding may help to elucidate the pathophysiologic features of idiopathic ERM as well as the response to treatment in these patients.

Validation of a novel functional test for assessing metamorphopsia using epiretinal membranes as a model

Current tests for assessing metamorphopsia do not account for confounders such as perceptual filling-in and spatial redundancy, which affect its sensitivity and repeatability. This proof-of-concept study aimed to assess the performance of a novel laboratory-based psychophysical test (Line Sag Test, LST) which addresses these issues for quantification of metamorphopsia in idiopathic epiretinal membranes. The LST quantifies perpendicular metamorphopsia at three eccentricities (3°, 6°, and 9°) along eight meridians (45° steps). Metamorphopsia was assessed using the LST and Amsler grid and the hit rates of both tests for detecting metamorphopsia were compared. Normal metamorphopsia scores using the LST did not differ significantly from 0 and fell within one step-size (p = 0.500). The LST detected significantly more cases of metamorphopsia than the Amsler grid (14/21 versus 3/21) (p = 0.003). Similarly, significantly more cases of visual distortions in asymptomatic iERMs were detected using the LST than the Amsler grid (11/18 versus 0/18) (p = 0.008). The LST has a higher hit rate compared to the Amsler grid (67% versus 14%). This work demonstrates a psychophysically-robust functional test addressing perceptual confounders is more sensitive for quantifying and localising metamorphopsia in macular disease, particularly in asymptomatic disease.

Gene expression analysis identifies two distinct molecular clusters of idiopatic epiretinal membranes

Idiopathic epiretinal membranes (ERMs) are fibrocellular membranes containing extracellular matrix proteins and epiretinal cells of retinal and extraretinal origin. iERMs lead to decreased visual acuity and their pathogenesis has not been completely defined. Aim of this study was to provide a molecular characterization of iERMs by gene expression analysis. To this purpose, 56 iERMs obtained by pars plana vitrectomy were analyzed for the expression levels of genes encoding biomarkers of the cellular and molecular events occurring in iERMs. RT-qPCR analysis showed significant differences in the levels of cell population, extracellular matrix and cytokine/growth factor biomarkers among the iERMs investigated. Hierarchical clustering of RT-qPCR data identified two distinct iERM clusters, Cluster B samples representing transcriptionally "activated" iERMs when compared to transcriptionally "quiescent" Cluster A specimens. Further, Cluster B could be subdivided in two subgroups, Cluster B1 iERMs, characterized by a marked glial cell activation, and Cluster B2 samples characterized by a more pro-fibrotic phenotype. Preoperative decimal best-corrected visual acuity and post-surgery inner segment/outer grading values were higher in Cluster A patients, that showed a prevalence of fovea-attached type iERMs with near-normal inner retina, than in Cluster B patients, that presented more severe clinical and spectral domain optical coherence tomography (SD-OCT) features. In conclusion, this molecular characterization has identified two major clusters of iERM specimens with distinct transcriptional activities that reflect different clinical and SD-OCT features of iERM patients. This retrospective work paves the way to prospective whole-genome transcriptomic studies to allow a molecular classification of iERMs and for the identification of molecular signature(s) of prognostic and therapeutic significance.

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.

Comparative analysis of metamorphopsia and aniseikonia after vitrectomy for epiretinal membrane, macular hole, or rhegmatogenous retinal detachment

This study investigated postoperative changes in metamorphopsia and aniseikonia in eyes that underwent vitrectomy for epiretinal membrane (ERM), macular hole (MH), or rhegmatogenous retinal detachment (RRD). In total, 166 eyes were included from 166 patients with ERM, MH, or RRD who underwent primary vitrectomy. Metamorphopsia and aniseikonia were quantified by M-CHARTS and the New Aniseikonia Test (NAT). Best-corrected visual acuity (BCVA), M-CHARTS, NAT assessments, and OCT examination were performed at 1, 3, and 6 months postoperatively. Of the 166 eyes, 65 had ERM, 21 had MH, 42 had macula-off RRD, and 38 had macula-on RRD. BCVA improved significantly between 1 and 6 months postoperatively in eyes with ERM, MH, and macula-off RRD (P = 0.0057, P = 0.0065, and P = 0.0021, respectively). M-CHARTS scores at 1 month postoperatively significantly decreased in eyes with ERM (P = 0.0034) and tended to decrease in eyes with MH (P = 0.068). NAT scores did not change between baseline and 1 month postoperatively in eyes with ERM or MH. Between 1 and 6 months postoperatively, M-CHARTS and NAT scores significantly decreased in eyes with macula-off RRD (P = 0.0064 and P = 0.0009, respectively), but not in eyes with ERM, MH, or macula-on RRD. At 6 months postoperatively, significant metamorphopsia was evident in 33.3% of eyes with ERM, 29.2% of eyes with MH, and 35.7% of eyes with macula-off RRD; 61.5% of eyes with ERM showed macropsia and 52.3% of eyes with macula-off RRD showed micropsia. In eyes with ERM, more central retinal thickness (CRT) correlated with postoperative BCVA, and deep retinal folds on enface OCT image correlated with postoperative metamorphopsia. In eyes with macula-off RRD, less CRT correlated with postoperative BCVA, and tended to correlate with postoperative micropsia. Macular morphologies could contribute to differences in postoperative visual acuity, metamorphopsia, and aniseikonia.

Long-Term Outcomes After Idiopathic Epiretinal Membrane Surgery

Purpose

To report anatomic and logMAR best-corrected visual acuity (BCVA) outcomes with long-term follow-up after pars-plana vitrectomy and epiretinal membrane peeling (PPV-MP).

Design

A retrospective case-series.

Participants

Patients with epiretinal membrane (ERM) who underwent PPV-MP performed by one surgeon.

Methods

Best-corrected visual acuity (BCVA) was recorded as a logMAR preoperatively and, when available, at 1, 2, 3, 5, 8, 10 years after surgery. The integrity of outer retinal layers was evaluated using spectral domain optical coherence tomography (SD-OCT).

Main Outcome Measures

Postoperative BCVA at different follow-up visits and its correlation with different OCT parameters.

Results

Fifty-five eyes of 49 patients were followed postoperatively with a mean of 8.6± 2.6 years (median: 9 years, range 5–16 years). The mean BCVA improved from 0.56±0.29 (20/72) preoperatively to 0.33±0.25 (20/42) at 1 year, 0.29±0.27 (20/38) at 2 years, 0.25±0.28 (20/35) at 3 years, 0.29±0.32 (20/38) at 5 years, 0.28±0.31 (20/38) at 8 years, and 0.28±0.25 (20/38) at 10 years (p<0.001). The BCVA improved at each of the first 3 years postoperatively and remained stable at 5, 8, and 10 years. Postoperative improvement in the integrity of ELM, and EZ, on SD-OCT correlated with improved BCVA.

Conclusion

BCVA continues to improve after PPV-MP during the first 3 years postoperatively and remains stable. Improved anatomic integrity of outer retinal layers correlated with improved BCVA.

Preoperative aniseikonia is a prognostic factor for postoperative stereopsis in patients with unilateral epiretinal membrane

PURPOSE

To investigate stereopsis and other visual functions in patients with unilateral epiretinal membrane (ERM) and to identify vision-related parameters affecting stereopsis.

METHODS

This prospective study included 63 consecutive patients who were scheduled to undergo vitrectomy for unilateral idiopathic ERM. We examined stereopsis (Titmus Stereo Test, TST; TNO stereotest, TNO), best-corrected visual acuity (BCVA), letter contrast sensitivity, severity of metamorphopsia, and degree of aniseikonia preoperatively and 6 months postoperatively.

RESULTS

Preoperatively, we observed significant correlation between TST scores and other vision-related parameters except severity of metamorphopsia and between TNO score and all the vision-related parameters. Multiple regression analysis showed that preoperative TST and TNO scores were significantly associated with the degree of aniseikonia (both P < 0.01). ERM surgery significantly improved stereopsis, BCVA, contrast sensitivity, and metamorphopsia, but not aniseikonia. Postoperatively, TST was significantly associated with BCVA, and TNO showed association with BCVA and aniseikonia. Postoperative TST and TNO scores showed significant correlation with preoperative aniseikonia (P < 0.005 and P < 0.001, respectively).

CONCLUSIONS

Impairment of stereopsis in patients with unilateral ERM was considered to be due to retinally induced aniseikonia. Aniseikonia did not improve by surgery, and preoperative aniseikonia can be a prognostic factor for postoperative stereopsis.

Choroidoscleral Interface Irregularity Index: A novel optical coherence tomography-based parameter in patients with epiretinal membrane

This study aimed to assess the regularity of the choroidoscleral interface (CSI) using a novel parameter, CSI irregularity index, before and after epiretinal membrane (ERM) surgery. This study included 36 patients with idiopathic ERM who underwent pars plana vitrectomy and ERM removal. All subjects underwent ocular examinations at baseline and at 1, 2, 4, and 6 months after surgery. The regular contour of the CSI was found in 14 patients (38.9%); mean CSI irregularity index was 14.84 ± 11.01 in this group. The irregular contour of the CSI was found in 22 patients (61.1%); mean CSI irregularity index was 33.96 ± 20.64 in this group. The CSI irregularity index decreased gradually after ERM surgery, and was correlated with postoperative best-corrected visual acuity. The CSI irregularity index could serve as a surrogate marker to quantitatively represent the CSI morphology. We observed the gradual decrease of the CSI irregularity index after ERM surgery in quantitative manner. This study showed correlations between the CSI irregularity index and visual outcomes after ERM surgery. Our results suggest that the CSI irregularity index might be an intuitive anatomic indicator of the CSI and might be useful as a possible prognostic marker for patients undergoing ERM surgery.

Survival Time of Visual Gains after Diabetic Vitrectomy and Its Relationship with Ischemic Heart Disease

Vitrectomy surgery in proliferative diabetic retinopathy improves the vision-related quality of life. However, there is lack of data on the duration of maintenance of visual gains post vitrectomy. This study thus aimed to determine the survival time of visual gains and the prognostic factors of vision loss after vitrectomy surgery for complications of proliferative diabetic retinopathy. A retrospective cohort study was conducted in an ophthalmology clinic in Malaysia. We included 134 patients with type 2 diabetes mellitus on follow-up after vitrectomy for proliferative diabetic retinopathy. Visual acuity was measured using the log of minimum angle of resolution (LogMar). A gain of ≥0.3 LogMar sustained on two subsequent visits was considered evidence of visual improvement post vitrectomy. Subjects were considered to have vision loss when their post-operative visual acuity subsequently dropped by ≥0.3 LogMar. Kaplan–Meier analysis was used to determine the survival time of visual gains. Cox Proportional Hazard regression was used to determine the prognostic factors of vision loss. The median age of patients was 56.00 years (IQR ± 10.00). The median duration of diabetes mellitus was 14.00 years (IQR ± 10.00). Approximately 50% of patients with initial improvement post vitrectomy subsequently experienced vision loss. The survival time, i.e., the median time from surgery until the number of patients with vision loss formed half of the original cohort, was 14.63 months (95% CI: 9.95, 19.32). Ischemic heart disease was a significant prognostic factor of vision loss. Patients with underlying ischemic heart disease (adjusted HR: 1.97, 95% CI: 1.18, 3.33) had a higher risk of vision loss post vitrectomy, after adjusting for other factors. Approximately half the patients with initial visual gains post vitrectomy maintained their vision for at least one year. Ischemic heart disease was a poor prognostic factor for preservation of visual gains post vitrectomy.

The Clinical Course of Patients with Idiopathic Epiretinal Membranes and Good Visual Acuity Managed Without Surgery

Background/aims

To report the clinical course of patients with idiopathic epiretinal membranes (iERMs) and good baseline best-corrected visual acuity (BCVA) managed without surgical treatment.

Methods

Retrospective, observational case series of patients with iERMs and 20/50 or better BCVA who did not undergo surgery between January 2014 and December 2017 with a 1-year follow-up. Secondary epiretinal membranes were excluded. iERMs were stratified into two groups: Group I (BCVA 20/30 or better) and Group II (BCVA 20/40 to 20/50). The main outcome measures included baseline and final follow-up BCVA, central macular thickness (CMT) on OCT.

Results

The study included 174 eyes (145 patients): 139 eyes (79.8%) had typical iERMs and 35 eyes (18%) had LMH. For Group I typical iERMs, the logMAR baseline and final mean BCVA were 0.09 ± 0.1 (Snellen equivalent 20/25) and 0.10 ± 0.1 (20/25⁺) respectively (p = 0.22). In this group, the baseline and final mean CMT were 335 ± 73µm and 342 ± 78µm, respectively (p = 0.47). For Group II typical iERMs, the logMAR baseline and final mean BCVA were 0.3 ± 0.1 (20/44) and 0.4 ± 0.2 (20/45) respectively (p = 0.31). In this group, the baseline and final mean CMT were 386 ± 95µm and 391 ± 93µm, respectively (p = 0.84).

Conclusion

The clinical course of patients with iERM and good baseline BCVA is generally favorable without surgery and includes stable BCVA and OCT measurements after at least one year.

Automatic Identification and Intuitive Map Representation of the Epiretinal Membrane Presence in 3D OCT Volumes

Optical Coherence Tomography (OCT) is a medical image modality providing high-resolution cross-sectional visualizations of the retinal tissues without any invasive procedure, commonly used in the analysis of retinal diseases such as diabetic retinopathy or retinal detachment. Early identification of the epiretinal membrane (ERM) facilitates ERM surgical removal operations. Moreover, presence of the ERM is linked to other retinal pathologies, such as macular edemas, being among the main causes of vision loss. In this work, we propose an automatic method for the characterization and visualization of the ERM's presence using 3D OCT volumes. A set of 452 features is refined using the Spatial Uniform ReliefF (SURF) selection strategy to identify the most relevant ones. Afterwards, a set of representative classifiers is trained, selecting the most proficient model, generating a 2D reconstruction of the ERM's presence. Finally, a post-processing stage using a set of morphological operators is performed to improve the quality of the generated maps. To verify the proposed methodology, we used 20 3D OCT volumes, both with and without the ERM's presence, totalling 2428 OCT images manually labeled by a specialist. The most optimal classifier in the training stage achieved a mean accuracy of 91 . 9 % . Regarding the post-processing stage, mean specificity values of 91 . 9 % and 99 . 0 % were obtained from volumes with and without the ERM's presence, respectively.

Prospective study of vitrectomy for epiretinal membranes in patients with good best-corrected visual acuity

Background

To evaluate the efficacy of epiretinal membrane removal in patients with good best-corrected visual acuity (BCVA) for improving visual function and quality of life (QOL).

Methods

This prospective case study compared 37 subjects with preoperative BCVA ≦ 0.046 logMAR (Good group) to 35 patients with 0.10–0.52 logMAR (Moderate group) at 3 and 6 months. Linear mixed-effect models were used for statistical analysis. The primary outcome was the horizontal metamorphopsia score (MH) at 6 months postoperatively (post-6 M), while secondary outcomes were postoperative BCVA, vertical metamorphopsia score (MV), aniseikonia, stereopsis and central foveal thickness. In the Good group, QOL was assessed using the National Eye Institute Visual Functioning Questionnaire-25 (NEI VFQ-25) at 6 and 12 months.

Results

MH was significantly improved at post-3 M and post-6 M in the both groups but there were no significant differences between the two groups. MV showed no improvement at the final observation in either group. LogMAR BCVA was significantly improved at post-6 M in the Good group, which had significantly better vision than the Moderate group. Preoperative vertical and horizontal aniseikonia scores remained unchanged in the Good group at post-6 M but worsened in the Moderate group. The NEI VFQ-25 score improved in the Good group, reflecting improved general health, general vision, and mental health.

Conclusions

Early epiretinal surgery for patients with BCVA ≦ 0.046 logMAR was effective for improvement of HM, BCVA, and QOL and prevented worsening of aniseikonia.

Trial registration

UMIN000021220. Registered 10 September 2015.

UMIN Clinical Trials Registry.

Assessment of the deformation of the outer nuclear layer in the Epiretinal membrane using spectral-domain optical coherence tomography

Background

We aimed to investigate the deformation of the outer nuclear layer using optical coherence tomography in patients with epiretinal membrane (ERM) and its relationship with metamorphopsia.

Methods

Thirty-nine eyes from 39 patients with ERM were included in the study. Patients with the subtypes of pseudo macula hole and lamellar hole were excluded. Twenty-one fellow eyes without macular disease were included as normal controls. Forty-nine B-scan images were obtained in the range of 20 degrees around the macula using SD-OCT. The outer nuclear layer (ONL) was evaluated as a three-dimensional image (3D-ONL) reconstructed using the distance between the ONL and retinal pigment epithelium (RPE) line. The deformation of the ONL was figured at the reference plane and evaluation plane (ONL-B). The characteristic parameters of the ONL-B were defined as circularity, area ratio, and axis ratio. The correlations between these parameters and visual acuity and MCHART score ratio (MH/MV) were then evaluated.

Results

ONL height was significantly higher in ERM patients than in normal controls (54.1 ± 5.3 μm and 84.1 ± 12.9 μm, respectively; P < 0.001). In ERM patients, the MV score was 0.53 ± 0.50, the MH score was 0.71 ± 0.61, and the distance from the RPE line to the ONL-B was 153.5 ± 13.5 μm. The axis of the ONL-B in normal controls and ERM patients was − 6.25 ± 21.8 and − 1.28 ± 29.1, respectively, which indicates that the ONL is horizontally long in both normal individuals and ERM patients. The circularity and area ratio were significantly smaller in ERM patients than in normal controls. In all ERM patients, MH/MV had a significant correlation with axis (r = − 0.29, p = 0.034), circularity (r = − 0.28, p = 0.044), and area ratio (r = − 0.47, p = 0.001). Moreover, we found that the correlation was more significant if the subjects had an axis of the ONL within ±10 degrees (n = 16); the correlations of MH/MV with axis (r = − 0.29, p = 0.034), circularity (r = − 0.53, p = 0.021), and area ratio were more significant (r = − 0.78, P < 0.0001).

Conclusion

The ONL is horizontally long in normal individuals and ERM patients. The direction of metamorphopsia is correlated with the direction of ONL deformation.