Epiretinal membrane: optical coherence tomography-based diagnosis and classification

A classification of idiopathic epiretinal membrane based on foveal avascular zone area using optical coherence tomography angiography

OBJECTIVE

To evaluate the characteristics and prognoses of idiopathic macular epiretinal membrane (iERM) using a classification based on the foveal avascular zone (FAZ) area.

METHOD

IERMs were classified into four stages based on the FAZ area. Baseline FAZ-related parameters, pre-and postoperative central macular thickness (CMT), and best corrected visual acuity (BCVA) were observed and compared between different stages. The correlations of structural parameters with pre-and postoperative logMAR BCVA were analyzed.

RESULTS

162 iERM eyes were enrolled, including 105 eyes followed up for 12 months after surgery. The preoperative BCVA was better at the early stage. Postoperative BCVA at Stages 2 and 3 were better compared to Stage 4. The early stage was associated with thinner CMT pre-and postoperatively. However, there was no significant difference in CMT between postoperative Stages 1 and 2 or Stages 3 and 4. Preoperative logMAR BCVA was negatively correlated with FAZ area, perimeter, and FD-300 and was positively correlated with CMT and acircularity index (AI). CMT correlated positively with BCVA for each stage, except Stage 4; FAZ area, perimeter, and FD-300 had a negative correlation at Stage 1. Baseline BCVA and CMT positively correlated with BCVA at the last follow-up, while FAZ area and FD-300 were negatively correlated. Baseline BCVA had a positive correlation for each stage, except Stage 1; FD-300 had a negative correlation at Stages 2 and 3; CMT had a positive correlation at Stage 3.

CONCLUSION

A classification based on the FAZ area was established innovatively. This classification can reflect the progression of iERM and is helpful to the postoperative prognosis.

Proportion and risk factors of epiretinal membrane in residents of Brussels with versus without diabetes mellitus

PURPOSE

To compare the proportion of epiretinal membrane (ERM) between individuals with diabetes mellitus (DM) and without DM, who live in Brussels, to investigate possible risk factors for ERM formation and to compare the results with the ones of large population studies.

METHODS

Participants were divided into two groups; 99 patients with DM (group A) and 103 individuals without DM (group B). All participants underwent an undilated 7-field color fundus photography and a spectral domain optical coherence tomography (SD-OCT). Age, gender, race, type of diabetes, duration of medical treatment of diabetes, HbA1C rate, smoking, previous cataract surgery and educational level were investigated as possible risk factors.

RESULTS

Epiretinal membrane was detected in 17.2% of group A and in 11.7% of group B participants. The difference is not statistically significant (χ2 (1) = 1.252, p = 0.263). The proportion of ERM was significantly associated with age in both groups (p = .009 and p < .001 respectively), as well as with smoking (p = .023) and previous cataract surgery (p = .028) in patients with DM.

CONCLUSION

There is no statistically significant difference of ERM proportion between the two groups of the study. Age was recognized as a risk factor for both groups, while smoking and previous cataract surgery were identified as predictors only for diabetics.

Epiretinal membranes in patients with uveitis: an update on the current state of management

PURPOSE

This review aims to summarize the current knowledge concerning the clinical features, diagnostic work-up, and therapeutic approach of uveitic epiretinal membranes (ERM).

METHODS

A thorough investigation of the literature was conducted using the PubMed database. Additionally, a complementary search was carried out on Google Scholar to ensure the inclusion of all relevant items in the collection.

RESULTS

ERM is an abnormal layer at the vitreoretinal interface, resulting from myofibroblastic cell proliferation along the inner surface of the central retina, causing visual impairment. Known by various names, ERM has diverse causes, including idiopathic or secondary factors, with ophthalmic imaging techniques like OCT improving detection. In uveitis, ERM occurrence is common, and surgical intervention involves pars plana vitrectomy with ERM peeling, although debates persist on optimal approaches.

CONCLUSIONS

Histopathological studies and OCT advancements improved ERM understanding, revealing a diverse group of diseases without a unified model. Consensus supports surgery for uveitic ERM in progressive cases, but variability requires careful consideration and effective inflammation management. OCT biomarkers, deep learning, and surgical advances may enhance outcomes, and medical interventions and robotics show promise for early ERM intervention.

Ocular Brugia pahangi Filariasis Complicated by Severe Macular Damage in Thailand: Case Report and Literature Review

Extralymphatic filariasis caused by filaria of zoonotic origins has been frequently reported in Thailand over recent years. Here, we report the first case of ocular filariasis in a 7.5-year-old Thai boy who initially presented with progressive conjunctival redness and blurred vision in his right eye. A small, slender, coiled worm was found and surgically removed from the right anterior chamber. Histopathological examination illustrated predominant eosinophilic inflammation surrounding the parasite, which showed smooth and thin cuticle, prominent lateral chords, flat and broad muscle cells, one intestine, and two reproductive tubes with unsegmented ova, typically characteristic of a female adult Brugia filarial nematode. The parasite was also molecularly identified as B. pahangi, based on mitochondrial cytochrome c oxidase subunit I sequence analysis. The patient was then empirically prescribed albendazole, systemic prednisolone, and topical methylprednisolone. Unfortunately, his vision did not recover after 2 months due to severe maculopathy, most likely resulting from parasitic infestation and subsequent vitreous inflammation. To the best of our knowledge, this is the first case of ocular infestation by B. pahangi with visual complications that occurred outside a filariasis-endemic area of Thailand. Furthermore, this report provides clinical data on preceding cases of B. pahangi filariasis formally reported in southeast Asian countries, including Thailand and Malaysia, which facilitate a better understanding of the epidemiology of this sporadic zoonotic infection for effective disease elimination.

[Epiretinal membrane: diagnostics, indications and surgical treatment]

An epiretinal membrane (ERM) is a frequently occurring disease affecting the macula, which can be associated with visual impairment and metamorphopsia, depending on the severity and location. A distinction is made between an idiopathic form caused by age-related changes of the vitreous body and a secondary form associated with diseases of the posterior segment. The development of fibrocellular epiretinal membranes formed by dedifferentiation of intraretinal and extraretinal cells at the level of the vitreomacular interface plays a major role in the pathogenesis. The diagnostics and indications for surgical treatment of ERM are based on the visual acuity, evidence of metamorphopsia, ophthalmoscopic findings and optical coherence tomography (OCT) of the macula. In addition to the possibility of observation of the course where benign spontaneous courses are not uncommon, pars plana vitrectomy (PPV) with peeling of the ERM and internal limiting membrane (ILM) to prevent recurrences is the treatment of choice in symptomatic patients. The prognosis after surgical treatment is very good. In approximately two thirds of the cases, an improvement in visual acuity and/or a reduction of metamorphopsia can be achieved, with a number of predictive, primarily OCT-based factors enabling a prediction of the functional prognosis. Comprehensive patient education regarding the generally long duration of postoperative rehabilitation and the possibility of persistent symptoms or visual deterioration despite successful membrane removal is essential.

Prevalence of visual impairment and eye diseases in Malaysia: A cross-sectional prospective study at the University of Malaya Medical Centre

Introduction

The prevalence of visual impairment and ocular diseases changes over time. This measure can help general practitioners in anticipating common eye disorders that may require ophthalmological referrals to government hospitals. This study aimed to evaluate the prevalence of visual impairment and ocular diseases in an outpatient ophthalmology clinic in a public hospital and the types of investigations frequently conducted to diagnose these diseases.

Methods

A cross-sectional prospective study was conducted over three weeks in the eye clinic of the University of Malaya Medical Centre. The electronic medical records of all patients who attended the outpatient clinic were assessed to collect data on sex, age, type of visit, visual acuity, ocular presentation, investigations conducted and diagnosis of eye diseases. Visual impairment and blindness were categorised as per the World Health Organization criteria.

Results

Among 1002 patients, 327 had visual impairments (32.63%), and nine had blindness (0.9%). Cataracts were the most common ocular disease diagnosed (n=294, 29.74%), followed by glaucoma (n=123, 12.28%) and diabetic retinopathy (n=84, 8.38%). Optical coherence tomography was the most common investigation performed (n=272, 64.9%), followed by Humphrey visual field testing (n=53,12.6%).

Conclusion

Untreated refractive error is the leading cause of visual impairment in children, while cataract, glaucoma and diabetic retinopathy are the main contributors to visual impairment and blindness in elderly individuals. Our study highlights the urgent need for general practitioners to recognise avoidable visual impairment in all age groups to help prevent blindness.

Increased serum cystatin C levels in patients with idiopathic epiretinal membrane

CLINICAL RELEVANCE

Increased serum cystatin C may play a role in the pathogenesis of idiopathic epiretinal membrane (IERM). Physicians should be aware of this relationship and should refer patients to the ophthalmology clinic for screening.

BACKGROUND

To evaluate the serum cystatin C level in patients with IERM, and its associations with visual acuity.

METHODS

Sixty-eight patients with IERM and sixty-nine controls were enrolled in this cross-sectional study. Based on the results of optical coherence tomography, patients with IERM were divided into four stages (I, II, III and IV). Serum cystatin C was measured in all participants. Serum cystatin C levels were compared between the control group and IERM group and between the IERM group with different optical coherence tomography stages. Multiple linear regression was used to evaluate the relationship between serum cystatin C and IERM stages and best corrected visual acuity.

RESULTS

Serum cystatin C level was higher in the IERM group than in the control group (P < 0.001). There were statistically significant differences in serum cystatin C among different stages of IERM (PI vs II = 0.011, PI vs IV < 0.001 and PIII vs IV = 0.040, respectively). There were significant differences in best corrected visual acuity among different stages of IERM (PI vs III = 0.018, PI vs IV < 0.001, PII vs IV < 0.001 and PIII vs IV < 0.001, respectively). Regression analysis showed a positive correlation between serum cystatin C and best corrected visual acuity (t = 2.238 P = 0.029). The cut-off value of receiver operation characteristic curve of serum cystatin C for IERM was 0.775.

CONCLUSION

This study revealed that serum cystatin C may be involved in the pathogenesis of IERM and can predict its occurrence. Elevated serum cystatin C appears to be associated with the severity of the disease and relatively poor vision acuity in IERM patients.

Clinical evaluation of deep learning systems for assisting in the diagnosis of the epiretinal membrane grade in general ophthalmologists

BACKGROUND

Epiretinal membrane (ERM) is a common age-related retinal disease detected by optical coherence tomography (OCT), with a prevalence of 34.1% among people over 60 years old. This study aims to develop artificial intelligence (AI) systems to assist in the diagnosis of ERM grade using OCT images and to clinically evaluate the potential benefits and risks of our AI systems with a comparative experiment.

METHODS

A segmentation deep learning (DL) model that segments retinal features associated with ERM severity and a classification DL model that grades the severity of ERM were developed based on an OCT dataset obtained from three hospitals. A comparative experiment was conducted to compare the performance of four general ophthalmologists with and without assistance from the AI in diagnosing ERM severity.

RESULTS

The segmentation network had a pixel accuracy (PA) of 0.980 and a mean intersection over union (MIoU) of 0.873, while the six-classification network had a total accuracy of 81.3%. The diagnostic accuracy scores of the four ophthalmologists increased with AI assistance from 81.7%, 80.7%, 78.0%, and 80.7% to 87.7%, 86.7%, 89.0%, and 91.3%, respectively, while the corresponding time expenditures were reduced. The specific results of the study as well as the misinterpretations of the AI systems were analysed.

CONCLUSION

Through our comparative experiment, the AI systems proved to be valuable references for medical diagnosis and demonstrated the potential to accelerate clinical workflows. Systematic efforts are needed to ensure the safe and rapid integration of AI systems into ophthalmic practice.

Long-Term Visual Outcomes in Patients With Idiopathic Epiretinal Membrane Surgery

BACKGROUND AND OBJECTIVE

Our aim was to assess long-term outcomes following surgical repair of idiopathic epiretinal membrane (ERM) with pars plana vitrectomy (PPV) and membrane peel (MP).

PATIENTS AND METHODS

A retrospective study evaluated patients with idiopathic ERM who underwent surgical repair at a single academic tertiary center with five to nine years of postoperative follow-up, assessing preoperative characteristics, surgical techniques, best visual acuity (BVA), and optical coherence tomography biomarkers at various time points.

RESULTS

The study involved 67 patients (72 eyes) with an average postoperative follow-up of 82.8 ± 18.8 months. Patients with cone outer segment tips integrity at initial presentation and 1-year follow-up and patients with external limiting membrane and ellipsoid zone integrity at 1-year follow-up were noted to have significantly better long-term visual acuity than those without. More than 85% of patients achieved a BVA > 70 seven years after surgical repair.

CONCLUSIONS

Vitreoretinal surgery for idiopathic ERM resulted in improved anatomical recovery and sustained visual acuity gain over long-term follow-up. [Ophthalmic Surg Lasers Imaging Retina 2024;55:70-77.].

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.

Impact of intravitreal triamcinolone injection following epiretinal membrane peeling on ectopic inner foveal layer classification

PURPOSE

This study aimed to evaluate the impact of intravitreal triamcinolone acetonide (TA) administration after peeling of idiopathic epiretinal membranes (iERM) on both anatomical and visual outcomes, utilizing the ectopic inner foveal layer (EIFL) staging scheme.

METHODS

In this retrospective case-control study, we analyzed 43 eyes from 43 patients diagnosed with iERM between June 2019 and December 2021. All participants were categorized into the TA or control groups based on administering intravitreal TA injection following ERM peeling. We thoroughly reviewed the clinical data, including the preoperative and postoperative best-corrected visual acuity (BCVA), central foveal thickness (CFT), and macular cube volume (VOL), with ERM stages classified according to the EIFL staging scheme.

RESULTS

The study enrolled 22 eyes in the TA and 21 in the control groups. Following a mean follow-up period of 11.07 ± 2.02 months, noteworthy improvements in EIFL stages were observed in both cohorts (p < 0.01), but without significant distinctions between groups. In the TA group, 63.64% of eyes demonstrated improvements in EIFL stages, while the control group exhibited 76.19% (p = 0.37). At the final visit, both groups experienced a noteworthy reduction in the postoperative CFT and VOL (p < 0.05), coupled with significant improvement in BCVA (p < 0.01). No substantial differences appeared between the two groups concerning BCVA, CFT, and VOL (all p > 0.05).

CONCLUSIONS

Our study suggested that concurrent intravitreal TA injection following ERM removal did not provide additional benefits regarding anatomical and visual improvement in iERM cases classified as Stages 2 and 3.

Choroidal Vascularity Index Fluctuations in Epiretinal Membranes in Vitreoretinal Surgery: Comparison Between Idiopathic and Diabetic Ones

Purpose

The aim of the study was to analyze choroidal vascularity index (CVI) fluctuations in patients with epiretinal membrane after vitreoretinal surgery, comparing idiopathic and secondary diabetic ones.

Methods

Thirty eyes suffering from idiopathic ERMs (I-ERMS; n = 15) and diabetic ERMs (D-ERMS; n = 15) were analyzed in this observational prospective study. Anatomical (central macular thickness) and functional (best-corrected visual acuity) parameters were analyzed preoperatively and at 1 and 3 months after vitrectomy. Perfusion findings regarding CVI and luminal area were also calculated.

Results

At 1 month after surgery, the luminal area and CVI significantly decreased in the I-ERMS group, whereas they were increased in the D-ERMS group. At the 3-month follow-up, the CVI tended to return to baseline values in I-ERMS and to reduce in D-ERMS, but without any statistical differences.

Conclusions

The significant change in the CVI after surgery seems to imply that the choroidal layer is affected by vitreomacular disease and can become a novel potential biomarker of predictiveness in vitreoretinal surgery.

Translational Relevance

The aim of the study was to focus on the early choroidal changes to better understand initial predictive elements of long-term functional postoperative outcomes.

Central posterior hyaloid fibrosis: evolution and outcomes

PURPOSE

To report contributory factors and clinical outcomes of central posterior hyaloid fibrosis (CPHF) associated with neovascular age-related macular degeneration (nAMD).

METHODS

In this retrospective, single-center study, patients with CPHF and nAMD were included. Demographic and imaging characteristics, as well as the anatomical and functional outcomes, of these patients were analysed.

RESULTS

We identified 530 eyes in 273 patients with chronic predominantly scarred macular neovascularisation (MNV), and 32 eyes in 29 patients revealed CPHF, representing a prevalence of 6%. Patients had a mean age of 72.76 years. Before and during the development of CPHF, Type 2 MNV was observed in all eyes. At the time of MNV diagnosis, mean logMAR visual acuity was 1.308 ± 0.559 (20/407). The average time to develop CPHF was 27.3 months since the diagnosis of MNV. At the time of CPHF identification, the mean logMAR visual acuity was 1.498 ± 0.374 (20/630). RPE tear was observed in 6% (n = 2) of CPHF eyes. The average number of intravitreal anti-VEGF injections administered prior to the diagnosis of CPHF was 2.4 and after the onset of CPHF was 0.9. The final visual acuity was not significantly different at the final follow-up visit [1.304 ± 0.42 (20/402); p = 0.646].

CONCLUSION

Rarely observed in eyes with predominantly scarred subfoveal type 2 MNVs and extensive subretinal fibrosis, CPHF is associated with poor visual outcomes. Its presence could possibly suggest a profibrotic effect of MNV on the posterior hyaloid.

TRIAL REGISTRATION NUMBER

Not applicable.

Pathophysiology and clinical aspects of epiretinal membrane - review

The epiretinal membrane (ERM) is a pathological tissue formed at the vitreoretinal interface. The formation of this tissue is associated with numerous symptoms related to disturbances of vision. These types of lesions may arise idiopathically or be secondary to eye diseases, injuries and retinal surgeries. ERM tissue contains numerous cell types and numerous cytokines, which participate in its formation. The aim of this paper is to summarize information about the etiology, epidemiology, pathophysiology and treatment of ERM, with a brief description of the main cells that build the ERM - as well as the cytokines and molecules related to ERM pathogenesis - being provided in addition.

Co-Expression of Podoplanin and CD44 in Proliferative Vitreoretinopathy Epiretinal Membranes

Epiretinal membranes (ERMs) are sheets of tissue that pathologically develop in the vitreoretinal interface leading to progressive vision loss. They are formed by different cell types and by an exuberant deposition of extracellular matrix proteins. Recently, we reviewed ERMs' extracellular matrix components to better understand molecular dysfunctions that trigger and fuel the onset and development of this disease. The bioinformatics approach we applied delineated a comprehensive overview on this fibrocellular tissue and on critical proteins that could really impact ERM physiopathology. Our interactomic analysis proposed the hyaluronic-acid-receptor cluster of differentiation 44 (CD44) as a central regulator of ERM aberrant dynamics and progression. Interestingly, the interaction between CD44 and podoplanin (PDPN) was shown to promote directional migration in epithelial cells. PDPN is a glycoprotein overexpressed in various cancers and a growing body of evidence indicates its relevant function in several fibrotic and inflammatory pathologies. The binding of PDPN to partner proteins and/or its ligand results in the modulation of signaling pathways regulating proliferation, contractility, migration, epithelial-mesenchymal transition, and extracellular matrix remodeling, all processes that are vital in ERM formation. In this context, the understanding of the PDPN role can help to modulate signaling during fibrosis, hence opening a new line of therapy.

Associations between macular retinal vasculature and severity of idiopathic epiretinal membrane

BACKGROUND

To demonstrate the associations between the morphology of macular retinal vasculature and disease severity of idiopathic epiretinal membrane (ERM).

METHODS

Macular structures were assessed using optical coherence tomography (OCT), and were classified as "with pseudohole" or "without pseudohole". The 3 × 3 mm macular OCT angiography images were analyzed using the Fiji software to obtain the vessel density, skeleton density, average vessel diameter, vessel tortuosity, fractal dimension, and foveal avascular zone (FAZ)-related parameters. The correlations between these parameters and ERM grading as well as visual acuity were analyzed.

RESULTS

For ERM with or without a pseudohole, increased average vessel diameter, decreased skeleton density, and decreased vessel tortuosity were all associated with inner retinal folding and thickened inner nuclear layer, indicating more severe ERM. In 191 eyes without a pseudohole, the average vessel diameter increased, fractal dimension decreased and vessel tortuosity decreased with increasing ERM severity. The FAZ was not associated with ERM severity. Decreased skeleton density (r = -0.37), vessel tortuosity (r = -0.35), and increased average vessel diameter (r = 0.42) were correlated with worse visual acuity (All P < 0.001). In 58 eyes with pseudoholes, a larger FAZ was associated with a smaller average vessel diameter (r = -0.43, P = 0.015), higher skeleton density (r = 0.49, P < 0.001), and vessel tortuosity (r = 0.32, P = 0.015). However, none of the retinal vasculature parameters correlated with visual acuity and central foveal thickness.

CONCLUSION

Increased average vessel diameter, decreased skeleton density, decreased fractal dimension and decreased vessel tortuosity were good indicators of ERM severity and associated visual impairment.

The Classification of Stages of Epiretinal Membrane using Convolutional Neural Network on Optical Coherence Tomography Image

BACKGROUND AND OBJECTIVE

The gold standard for diagnosing epiretinal membranes is to observe the surface of the internal limiting membrane on optical coherence tomography images. The stages of the epiretinal membrane are used to decide the condition of the health of the membrane. The stages are not detected because some of them are similar. To accurately classify the stages, a deep-learning technology can be used to improve the classification accuracy.

METHODS

A combinatorial fusion with multiple convolutional neural networks (CNN) algorithms are proposed to enhance the accuracy of a single image classification model. The proposed method was trained using a dataset of 1947 optical coherence tomography images diagnosed with the epiretinal membrane at the Taichung Veterans General Hospital in Taiwan. The images consisted of 4 stages; stages 1, 2, 3, and 4.

RESULTS

The overall accuracy of the classification was 84%. The combination of five and six CNN models achieves the highest testing accuracy (85%) among other combinations, respectively. Any combination with a different number of CNN models outperforms any single CNN algorithm working alone. Meanwhile, the accuracy of the proposed method is better than ophthalmologists with years of clinical experience.

CONCLUSIONS

We have developed an efficient epiretinal membrane classification method by using combinatorial fusion with CNN models on optical coherence tomography images. The proposed method can be used for screening purposes to facilitate ophthalmologists making the correct diagnoses in general medical practice.

EPIRETINAL MEMBRANE WITH FOVEAL HERNIATION: Visual and Surgical Outcomes

PURPOSE

Foveal herniation occurs when neuroretinal tissue protrudes through and above the level of an epiretinal membrane. This study describes the visual symptoms and spectral domain optical coherence tomography findings associated with foveal herniation and evaluates the postoperative visual, anatomical, and surgical outcomes.

METHODS

A multicenter retrospective review of patients diagnosed with epiretinal membrane identified 59 patients with preoperative foveal herniation on spectral domain optical coherence tomography. Data regarding visual symptoms, preoperative and postoperative best-corrected visual acuity (BCVA), central retinal thickness, macular volume, and size of foveal herniation were collected, and statistical analysis was performed.

RESULTS

A total of 58 of the 59 patients with foveal herniation underwent surgical epiretinal membrane peeling, with foveal contour restored in 53.5% of patients after surgery. Average BCVA improved from 20/80 to 20/40 Snellen equivalent at most-recent postoperative visit (P < 0.0001). The average central retinal thickness decreased from 632 µm to 432 µm (P < 0.0001) and the average macular volume decreased from 11.3 mm3 to 9.5 mm3 (P < 0.0001) at 3 months postoperatively. Preoperatively, greater herniation height was associated with worse BCVA (P = 0.008), greater central retinal thickness (P = 0.01), retinoschisis, cystoid macular edema, foveolar detachment, ellipsoid zone abnormality, and external limiting membrane abnormalities (P < 0.05). Postoperatively, there was a decrease in retinoschisis, cystoid macular edema, foveolar detachment, ellipsoid zone, and external limiting membrane abnormality (P < 0.05) on spectral domain optical coherence tomography.

CONCLUSION

Patients with larger foveal herniation height had greater preoperative central retinal thickness, worse preoperative and postoperative BCVA, and more intraretinal abnormalities on spectral domain optical coherence tomography. Surgical epiretinal membrane peeling in patients with foveal herniation resulted in a significant improvement in patients' BCVA and microstructural abnormalities.

Prediction of Visual Impairment in Epiretinal Membrane and Feature Analysis: A Deep Learning Approach Using Optical Coherence Tomography

PURPOSE

The aim was to develop a deep learning model for predicting the extent of visual impairment in epiretinal membrane (ERM) using optical coherence tomography (OCT) images, and to analyze the associated features.

METHODS

Six hundred macular OCT images from eyes with ERM and no visually significant media opacity or other retinal diseases were obtained. Those with best-corrected visual acuity ≤20/50 were classified as "profound visual impairment," while those with best-corrected visual acuity >20/50 were classified as "less visual impairment." Ninety percent of images were used as the training data set and 10% were used for testing. Two convolutional neural network models (ResNet-50 and ResNet-18) were adopted for training. The t-distributed stochastic neighbor-embedding approach was used to compare their performances. The Grad-CAM technique was used in the heat map generative phase for feature analysis.

RESULTS

During the model development, the training accuracy was 100% in both convolutional neural network models, while the testing accuracy was 70% and 80% for ResNet-18 and ResNet-50, respectively. The t-distributed stochastic neighbor-embedding approach found that the deeper structure (ResNet-50) had better discrimination on OCT characteristics for visual impairment than the shallower structure (ResNet-18). The heat maps indicated that the key features for visual impairment were located mostly in the inner retinal layers of the fovea and parafoveal regions.

CONCLUSIONS

Deep learning algorithms could assess the extent of visual impairment from OCT images in patients with ERM. Changes in inner retinal layers were found to have a greater impact on visual acuity than the outer retinal changes.

Fundus Photography Methodologies to Assess RP Patients

The development of fundus photography and imaging has improved our ability to diagnose and monitor inherited retinal degenerations. Nowadays, color fundus photography has become a staple in evaluating patients with retinitis pigmentosa (RP). Other important multimodal forms of fundus photography used today include red-free fundus photography, short-wavelength autofluorescence, and near-infrared autofluorescence. These photography methodologies provide valuable information on the natural history of disease progression, which in turn can lead to the identification of viable outcome measurements for current and future therapeutic trials. Further advances and developments in the field of fundus imaging will help in our understanding of RP and allied disorders.

Correlations between Clinical and Histopathologic Characteristics in Idiopathic Epiretinal Membrane

PURPOSE

To investigate correlations between clinical and histopathologic characteristics of idiopathic epiretinal membrane (ERM).

DESIGN

Retrospective interventional case series.

PARTICIPANTS

In total, 87 eyes from 87 patients with idiopathic ERM who underwent pars plana vitrectomy with peeling of the ERM from 2019 to 2020 were included.

METHODS

The outcomes of clinical ophthalmic examination, including measurement of best-corrected visual acuity (BCVA) and spectral-domain OCT (SD-OCT), before and after surgery were reviewed. Surgical specimens were fixed in formalin and embedded in paraffin for histologic and immunohistochemical analysis.

MAIN OUTCOMES MEASURES

The association between morphological characteristics revealed on SD-OCT images and the cellular composition of the surgically excised ERM demonstrated with immunohistochemical staining were the main outcome measures. Changes in the BCVA and central macular thickness (CMT) were assessed through a comparison of preoperative and postoperative measurements.

RESULTS

Based on SD-OCT morphological characteristics in the foveal area, 15 cases were classified into group 1A (mainly outer retinal thickening), 39 into group 1B (more tenting of the outer retina and distorted inner retina), and 33 into group 1C (prominent inner retina thickening). Overall, postoperative final BCVA and CMT at 1 year improved in all groups. Patients who presented with a better initial BCVA exhibited a more favorable final BCVA. Epiretinal membranes in group 1C demonstrated the greatest decrease in CMT compared with those in groups 1B and 1A, but the final CMT did not differ among the groups. A negative correlation between the density of hyalocytes (P = 0.003) and myofibroblasts (P = 0.047) was noted between the 3 groups. Total cell density and glial cell density of the ERMs were strongly associated with poor final BCVA and BCVA improvement.

CONCLUSIONS

The present study provides new histopathologic information regarding the formation and progression of idiopathic ERM. Glial cell proliferation plays a predominant role in these processes. Epiretinal membranes with high cellularity and glial cell density may cause damage to the retina structure, resulting in poor postoperative visual outcomes. These findings provide additional evidence supporting early surgical intervention in patients with idiopathic ERM reported with visual disturbance.

Visual, Anatomic Outcomes, and Natural History of Retinal Nerve Fiber Layer Schisis in Patients Undergoing Epiretinal Membrane Surgery

PURPOSE

To evaluate the anatomic and visual outcomes of patients with idiopathic epiretinal membranes (ERMs) complicated by schisis of the retinal nerve fiber layer (sRNFL) in routine clinical practice.

DESIGN

Retrospective case-control study.

PARTICIPANTS

Patients undergoing idiopathic ERM surgery at Cole Eye Institute from 2013 to 2021.

METHODS

Patients were grouped by the presence or absence of sRNFL before surgery. Preoperative and postoperative data were collected regarding visual acuity (VA), changes in central subfield thickness (CST) over time, and presence of cystoid macular edema.

MAIN OUTCOME MEASURES

Frequency of sRNFL in patients undergoing idiopathic ERM surgery.

RESULTS

Overall, 48 (53.9%) of 89 patients presented with sRNFL. Schisis of the retinal nerve fiber layer patients presented with significantly decreased VA compared with those without (58.63 ± 12.48 vs. 67.68 ± 7.84 ETDRS letters, P < 0.001, respectively). At the final follow-up after ERM removal, there was no significant difference in final VA in patients with sRNFL compared with those without (71.16 ± 2.93 vs. 74.11 ± 2.76, P = 0.467). At presentation, patients with sRNFL had greater CST than those without (454 ± 10.01 vs. 436 ± 0.23, P = 0.23). This difference persisted at the 90-day follow-up after ERM removal (402 ± 8.08 vs. 375 ± 10.19 μm, P = 0.043). The resolution of sRNFL was reported at postoperative week 1 in 30 (96.7%) of 31 cases.

CONCLUSIONS

Schisis of the retinal nerve fiber layer is a microstructural feature in > 50% of idiopathic ERMs in routine clinical practice and carries visual significance on presentation and anatomic significance postoperatively.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

Automated Detection of Epiretinal Membranes in OCT Images Using Deep Learning

INTRODUCTION

Development and validation of a deep learning algorithm to automatically identify and locate epiretinal memberane (ERM) regions in OCT images.

METHODS

OCT images of 468 eyes were retrospectively collected from a total of 404 ERM patients. One expert manually annotated the ERM regions for all images. A total of 422 images (90%) and the remainig 46 images (10%) were used as the training dataset and validation dataset for deep learning algorithm training and validation, respectively. One senior and one junior clinician read the images. The diagnostic results were compared.

RESULTS

The algorithm accurately segmented and located the ERM regions in OCT images. The image-level accuracy was 95.65%, and the ERM region-level accuracy was 90.14%, respectively. In comparison experiments, the accuracies of the junior clinician improved from 85.00% to 61.29% without the assistance of the algorithm to 100.00% and 90.32% with the assistance of the algorithm. The corresponding results of the senior clinician were 96.15%, 95.00% without the assistance of the algorithm, and 96.15%, 97.50% with the assistance of the algorithm.

CONCLUSIONS

The developed deep learning algorithm can accurately segment ERM regions in OCT images. This deep learning approach may help clinicians in clinical diagnosis with better accuracy and efficiency.

Combined epiretinal and internal limiting membrane retracting door flaps for large macular holes associated with epiretinal membranes

PURPOSE

To assess the closure rate of large full-thickness macular holes (FTMH) associated with epiretinal membrane (ERM) with a combined epiretinal and internal limiting membrane retracting door flap.

METHODS

Retrospective chart review of patients treated at a single tertiary retina practice between January 2017 and November 2019. Individuals with FTMH larger than 400 μm and co-diagnosis of ERM who underwent surgical repair with an ERM flap were included. Patients underwent pars plana vitrectomy with peeling of ERM that was positioned as a retracting door flap to cover the FTMH. Primary outcome was closure rate at 6 months following surgery. Final surgical success rate and visual acuity were secondary outcomes.

RESULTS

Among 7 eyes of 7 patients, 6 eyes achieved primary surgical success and final surgical success rate was achieved in all 7 eyes with a large FTMH repaired with ERM flap. The mean minimum linear diameter of the FTMH was 681 μm ± 295. All patients had follow-up greater than 6 months, with a mean duration of 17 months (range 14-23 months). Visual acuity improved from a mean of 0.9 ± 0.3 logMar (20/160) before surgery to 0.3 ± 0.5 logMar (Snellen 20/40), postoperatively.

CONCLUSION

Large FTMH with concurrent ERM that are managed with an ERM flap have high single-surgery success rate.

The frequency of early age-related macular degeneration and its relationship with dietary pattern in Hunan, China: a cross-sectional study

PURPOSE

To estimate the frequency of age-related macular degeneration (AMD) among people who underwent health examination in Hunan, China and to determine the relationship between dietary pattern and the risk of AMD.

METHODS

The Questionnaire was used to collect dietary data from 56,775 study participants of ≥ 50 years old who underwent health examination at the Department of Health Management, the Third Xiangya Hospital of Central South University between January 2017 and December 2019. The diagnosis of AMD was based on the results of color fundus photography (CFP), spectral-domain optical coherence tomography (OCT) and multispectral imaging (MSI). After excluding participants with incomplete records or other ocular disease that may affect the results of fundus examination, a total of 43,672 study participants were included. The univariate and multivariate logistic regression analyses were used to determine the relationship between dietary pattern and the frequency of AMD.

RESULTS

Among the 43,672 study participants, 1080 (2.5%) had early AMD: the frequencies were 2.6% (n = 674) in men and 2.3% (n = 406) in women; the frequencies were 1.0% (n = 289), 3.6% (n = 401), 9.1% (n = 390) in 50-59, 60-69, ≥ 70 years old, respectively. And the age-standard frequency was 6.6% over the 60 years old in Hunan China. The high-salt intake increased the risk of early AMD [odds ratio (OR) = 1.61, 95% confidence interval (CI) = 1.54-1.68], whereas the intake of meat decreased the risk (OR = 0.90, 95% CI = 0.81-0.99).

CONCLUSION

In Hunan China, there was a high frequency of early AMD detected through health examination over the 60 years old. And high-salt intake increases the risk of early AMD, whereas intake of meat decreases the risk. Modulating the dietary pattern and reducing the salt intake as an AMD prevention strategy warrant further study.

Effects of Ectopic Inner Foveal Layers on Foveal Configuration and Visual Function after idiopathic Epiretinal Membrane Surgery

PURPOSE

To investigate the effects of ectopic inner foveal layers (EIFLs) on foveal configuration recovery and visual acuity (VA) after idiopathic epiretinal membrane (iERM) removal and analyze the relationship of foveal configuration recovery between 1-month and long-term postoperatively.

METHODS

This retrospective study included 216 consecutive eyes with iERM that underwent vitrectomy surgery. A comprehensive ophthalmic examination was performed for all patients before and 1, 4,10, and 24 months after surgery. We observed the postoperative anatomical and functional recovery of eyes with and without EIFLs and analyzed the association between short-term and long-term anatomical recovery.

RESULTS

The presence of EIFL was associated with severe preoperative visual damage (P＜0.001) and was considered as a negative factor for postoperative foveal depression recovery (P＜0.001). No significant difference was found in postoperative BCVA between the eyes with and without EIFLs (P=0.442). For eyes with stage II ERMs, 17.6% developed EIFLs postoperatively, which did not affect the final BCVA. Overall, 24.5% of ERMs restored the foveal configurations at 1 month postoperatively, and 14.7% continued recovering during the follow-up. Foveal structure recovery in eyes with EIFLs was associated with earlier stage, fewer microcystic macular edema, complete IZ layer, and a thinner CFT (All P＜0.05) at 1-month postoperatively.

CONCLUSIONS

The EIFL is associated with severe preoperative visual damage and is a negative factor for postoperative anatomical recovery, but it is a minor factor for postoperative VA. We also found an association of foveal configuration recovery between 1-month and long-term after surgery.

Finite Element Analysis of the Epiretinal Membrane Contraction

The epiretinal membrane is a thin sheet of fibrous tissue that can form over the macular area of the retina, and may result in the loss of visual acuity or metamorphopsia, due to superficial retinal folds. A vitrectomy surgery, the current treatment procedure for this pathology, is only performed after symptoms are present. However, sometimes the patients do not present any vision improvements after the surgery. The use of computational methods for a patient-specific biomechanical analysis can contribute to better understanding the mechanisms behind the success or failure of a vitrectomy. Using medical data from two patients who underwent a vitrectomy, one with substantial improvements and another with no improvements, an analysis of the retinal displacement due to the contraction of the epiretinal membrane was performed. Our results suggest a causal effect between the magnitude of the retinal displacements caused by the epiretinal membrane contraction and the outcome of the vitrectomy procedure.

LONGITUDINAL ELLIPSOID ZONE AND OUTER RETINAL INTEGRITY DYNAMICS AFTER EPIRETINAL MEMBRANE SURGERY

PURPOSE

To quantify ellipsoid zone (EZ) changes in integrity after epiretinal membrane (ERM) surgery, correlate findings to visual acuity, and determine predictors for prognosis.

METHODS

A post hoc analysis of eyes undergoing ERM surgery pooled from the prospective DISCOVER intraoperative optical coherence tomography study and eyes undergoing conventional ERM surgery without intraoperative optical coherence tomography. Quantitative EZ features were extracted using a multilayer machine learning enabled automated segmentation platform after image analyst review/correction for segmentation accuracy. Visual acuity and EZ integrity were quantitatively assessed and correlated before and after ERM surgery. Multiple linear regression was performed to assess preoperative visual acuity and EZ features as predictors for improvement in visual acuity or EZ integrity.

RESULTS

There were 177 eyes from 177 subjects that underwent ERM surgery from the DISCOVER and conventional arms. Improvement in visual acuity and multiple EZ integrity features was noted after ERM surgery, including EZ partial attenuation and EZ-retinal pigment epithelium (RPE) volume (P < 0.05). A reduction in EZ partial attenuation and increase in EZ-RPE central subfield thickness (EZ-RPE CST) was significantly correlated with improved visual acuity after ERM surgery (P < 0.05). More robust EZ-RPE CST at baseline predicted visual acuity improvement after ERM peel in regression modeling (β = 0.005, P < 0.05).

CONCLUSIONS

Longitudinal assessment of EZ features demonstrates significant postoperative improvement in multiple EZ integrity metrics after ERM surgery. Improving EZ integrity was correlated to improving the visual acuity. Ellipsoid zone integrity and visual acuity were significant predictors in regression modeling and may have value in clinical prognostication.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Structure-function analysis for macular surgery in patients with coexisting glaucoma

PURPOSE

To develop methods to assess the effects of epiretinal membranes (ERM) and macular holes (MH) coexisting with glaucoma on pre-operative retinal structure and function and evaluate post-operative outcomes.

METHODS

Seven eyes of 7 patients with glaucoma, 6 with ERMs and 1 with MH, were enrolled; 4 underwent vitrectomy for ERM and one for MH. Visual fields (VFs) and optical coherence tomography (OCT) scans were obtained pre- and post-operatively. The 10-2VF deviation map was overlayed on ganglion cell and inner plexiform layer (GCL + IPL) and retinal nerve fiber layer (RNFL) deviation maps derived from OCT macula and disc cube scans. Optic nerve circle scans were obtained to assess RNFL thickness, and OCT b-scans associated with VF defects were compared pre- and post-operatively.

RESULTS

Examination of pre-operative VFs and OCT scans showed the importance of determining the extent to which glaucomatous damage contributed to VF loss; verifying automated segmentation of the GCL + IPL and RNFL; and assessing foveal anatomy. Evaluation of post-operative structure-function outcomes required correction of magnification changes in OCT scans and repeated follow-up visits to clarify the origin of VF changes.

CONCLUSIONS

Pre-operative comparisons of VFs and OCT scans may be beneficial in guiding surgical planning, and evaluating outcomes, in eyes with glaucoma undergoing macular surgery.

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.

Relationship of Epiretinal Membrane Formation and Macular Edema Development in a Large Cohort of Uveitic Eyes

Purpose: To identify the temporal relationship and clinical characteristics of epiretinal membrane (ERM) and macular edema (ME) formation in uveitic eyes.Methods: A total of 269 subjects (444 uveitic eyes) met study inclusion criteria. Comprehensive ophthalmic examination, spectral domain-optical coherence tomography (SD-OCT), and clinical testing were carried out.Results: Of the 444 uveitic eyes, 229 eyes (51.6%) developed an ERM, whereas 87 eyes (19.1%) developed ME. The odds ratios (ORs) of systemic disease causing uveitis and resulting in ERM and ME were significantly higher in posterior uveitis (OR 6.56, 95% CI 2.98-14.46; p < .0001) and panuveitis (OR 10.09, 95% CI 4.05-25.15; p < .0001). Temporal analysis revealed that an ERM was noted concurrently or prior to ME development in 93.8% of eyes.Conclusions: ERM and ME are primarily observed in posterior uveitis and panuveitis associated with systemic diseases. The temporal relationship highlights the importance of characterization of ERM as it relates to the development of uveitic ME.

INTERNAL LIMITING MEMBRANE PEELING VERSUS NONPEELING TO PREVENT EPIRETINAL MEMBRANE DEVELOPMENT IN PRIMARY RHEGMATOGENOUS RETINAL DETACHMENT: A Swept-Source Optical Coherence Tomography Study With a New Postoperative Classification System

PURPOSE

To determine whether internal limiting membrane peeling in primary rhegmatogenous retinal detachment prevents epiretinal membrane (ERM) development. Secondarily, we propose a classification system for postoperative ERMs.

METHODS

Retrospective, interventional, comparative case series. Consecutive eyes with primary rhegmatogenous retinal detachment (n = 140) treated by a single surgeon. The presence of postoperative ERMs was assessed with swept-source optical coherence tomography.

RESULTS

An ERM was detected in 26 eyes (46.4%) in the nonpeeling group and in one eye (1.8%) in the internal limiting membrane peeling group (P ≤ 0.001). The median visual acuity significantly improved in both groups (P ≤ 0.001). Inner retinal dimples were observed in 41.1% of eyes in the internal limiting membrane peeling group versus 0% in the nonpeeling group (P ≤ 0.001), and they were not correlated with visual acuity (r = 0.011; P = 0.941). Based on swept-source optical coherence tomography findings, we identified three different types of ERMs: 7 (26.9%) were classified as Type 1, 12 (46.1%) as Type 2, and 7 (26.9%) as Type 3. Superficial retinal plexus deformations observed on optical coherence tomography angiography and en face images were detected in 100% of Type 3 ERMs, 41.6% of Type 2, and 0% of Type 1 (χ = 14.3; P = 0.001). Interestingly, all of the patients who presented these alterations also had metamorphopsia.

CONCLUSION

Internal limiting membrane peeling in primary rhegmatogenous retinal detachment seems to prevent postoperative ERM development. Swept-source optical coherence tomography analysis is helpful to define and classify different types of ERMs and to establish the surgical indication for their removal.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Epiretinal membrane: A review

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

Ocular Hypotension and Epiretinal Membrane as Risk Factors for Visual Deterioration Following Glaucoma Filtering Surgery

PRECIS

Postsurgical hypotension at 1 week and the presence of an epiretinal membrane (ERM) were significant risk factors for the deterioration of postsurgical visual acuity (VA) at 3 and 12 months, respectively.

PURPOSE

The purpose of this study was to assess the effects of an ERM and postsurgical hypotension <6 mm Hg at 1 week on postsurgical VA loss.

PATIENTS AND METHODS

A total of 69 patients (69 eyes) who underwent trabeculectomy with adjunctive mitomycin C between 2017 and 2019 (mean follow-up period: 22.8 mo) were enrolled, and 14 parameters that could be associated with the deterioration of VA at 3 and 12 months were studied.

RESULTS

There was a significant association between VA loss at 3 months and postsurgical intraocular pressure at 1 week (P=0.006 by multiple regression) and hypotony maculopathy (P=0.024 by Fisher exact test). However, this association was lost at 12 months. Instead of postsurgical hypotension, the presence of an ERM was significantly associated with VA loss at 12 months (P=0.035 by Fisher exact test, and P=0.023 by logistic regression).

CONCLUSIONS

Postsurgical hypotension at 1 week was significantly associated with mid-term, but not long-term, postsurgical VA loss. The presence of an ERM, which was not a risk factor for mid-term acuity loss, was a significant risk factor for VA loss at 12 months.

A novel quantitative analysis method for idiopathic epiretinal membrane

PURPOSE

To introduce a novel method to quantitively analyse in three dimensions traction forces in a vast area of the ocular posterior pole.

METHODS

Retrospective analysis of 14 eyes who underwent peeling surgery for idiopathic, symptomatic and progressive epiretinal membrane. The technique measures the shift in position of vascular crossings after surgery from a fixed point, which is the retinal pigmented epithelium. This shift is defined as the relaxation index (RI) and represents a measure of the postoperative movement of the retina due to released traction after surgery.

RESULTS

Best-corrected visual acuity was significantly better than baseline at all follow ups while the RI had its maximum value at baseline. Moreover, we found a significant correlation between best-corrected visual acuity at 6 months and RI at baseline.

CONCLUSION

While all previous published methods focused on bi-dimensional changes observed in a small region, this study introduces a three-dimensional assessment of tractional forces. Future integration of RI into built-in processing software will allow systematic three-dimensional measurement of intraretinal traction.

Assessment of epiretinal membrane formation using en face optical coherence tomography after rhegmatogenous retinal detachment repair

PURPOSE

To investigate epiretinal membrane (ERM) formation using en face optical coherence tomography (OCT) after vitrectomy for rhegmatogenous retinal detachment (RRD).

METHODS

We retrospectively reviewed the medical records of 64 consecutive eyes (64 patients) with RRD treated by vitrectomy without ERM and internal limiting membrane peeling. ERMs and retinal folds were detected by B-scan and en face imaging. The maximum depth of retinal folds (MDRF) was quantified using en face imaging. ERM severity was staged using B-scan imaging. Main outcome measures were ERM detection rate with B-scan and en face imaging, MDRF, ERM staging, postoperative best-corrected visual acuity (BCVA; logarithm of the minimum angle of resolution), and risk factors for ERM formation.

RESULTS

The detection rate for ERM formation was significantly higher with en face imaging (70.3%) than with B-scan imaging (46.9%; P = 0.007). There was no significant difference in postoperative BCVA between eyes with ERM formation (0.06 ± 0.26) and those without ERM formation (0.01 ± 0.14; P = 0.298). Forty of 45 (88.9%) eyes with ERM formation were classified as stage 1. Twenty-seven of 45 (60.0%) eyes with ERM formation developed parafoveal retinal folds. The mean MDRF was 27.4 ± 32.2 μm. Multiple retinal breaks and a maximum retinal break size of ≥ 2 disc diameters were significantly associated with ERM formation (P = 0.033 and P = 0.031, respectively).

CONCLUSION

Although ERM formation was observed in 70.3% patients after RRD repair, the formed ERM was not severe and had minimal impact on the postoperative visual acuity.

Epiretinal Membrane Surgery Using Intraoperative OCT-Guided Membrane Removal in the DISCOVER Study versus Conventional Membrane Removal

PURPOSE

To provide a comparative assessment of clinical outcomes between patients undergoing intraoperative OCT (iOCT) and conventional surgery for pars plana vitrectomy (PPV) with epiretinal membrane (ERM) peel.

DESIGN

Case-control retrospective, comparative assessment.

PARTICIPANTS

Patients undergoing PPV with membrane peel for ERM with eyes pooled from the prospective Determination of Feasibility of Intraoperative Spectral Domain Microscope Combined/Integrated OCT Visualization During En Face Retinal and Ophthalmic Surgery (DISCOVER) iOCT study and eyes undergoing conventional ERM surgery without iOCT.

METHODS

Visual acuity and OCT assessment before ERM surgery and at 1-, 3-, 6-, and 12-month follow-up after standard small-gauge PPV with iOCT feedback (iOCT DISCOVER group) or PPV with compulsory internal limiting membrane (ILM) peeling (conventional group). Visual acuity, central subfield thickness (CST), reoperation rate, and ERM recurrence were determined by record review and post hoc assessment of clinical OCTs after ERM peel.

MAIN OUTCOME MEASURES

Visual acuity and ERM recurrence.

RESULTS

A total of 262 eyes were included. Visual acuity (VA) improved 11.9 letters in the iOCT group (P < 0.0001) and 12.1 letters in the conventional group (P < 0.0001) at 12 months after ERM surgery. Visual acuity improvement did not differ between the iOCT and conventional groups at 1, 3, 6, or 12 months after surgery (P > 0.05 for each time point). Preoperative mean CST decreased in the iOCT group (P < 0.0001) and conventional group (P < 0.0001) with no difference between groups in CST reduction at 12 months (P = 0.36). No reoperations or visually significant recurrent ERMs occurred in either cohort.

CONCLUSIONS

Intraoperative OCT-guided ERM removal without mandated ILM peeling provided similar VA and anatomic results to conventional ILM peeling for ERM. Future randomized prospective studies are needed to assess fully the possible role of iOCT in ERM surgery and to evaluate the potential impact of nonfoveal ERM persistence or recurrence in comparison with conventional surgery.

[Tomographic appearance and etiologies of epimacular membranes in Cotonou]

PURPOSE

To study the tomographic appearance and etiologies of epimacular membranes in Cotonou.

PATIENTS, MATERIALS AND METHODS

This was a descriptive, analytical study with retrospective data collection. It took place at the Cotonou Retinal Testing Center and included all patients who underwent macular OCT testing between January 1, 2016 and June 30, 2018.

RESULTS

Of the 604 subjects examined, 32 patients (5.3%) exhibited an epimacular membrane. Epimacular membrane in combination with posterior vitreous detachment and contraction accounted for 44.74% of cases. 42.31% of the fellow eyes had developed a posterior vitreous detachment. The majority of the membranes were idiopathic. Proliferative diabetic retinopathy and posterior uveitis were the main risk factors for secondary membranes.

CONCLUSION

Epimacular membrane is a potentially blinding condition. The risk of bilateral involvement is significant, and patient access to OCT remains a concern in developing countries.

Epiretinal membrane vitrectomy: outcomes with or without cataract surgery and a novel prognostic factor for cystoid macular edema

PURPOSE

To assess the outcomes of vitrectomy with or without cataract surgery for the treatment of idiopathic ERM in phakic eyes and evaluate predictors of functional and anatomical outcomes.

METHODS

Retrospective cohort of consecutive phakic ERM eyes distributed in three groups: a) combined (phacovitrectomy) group, b) PPV-only group, and c) consecutive group (PPV followed by cataract surgery). Main outcomes were final visual acuity (VA) and cystoid macular edema (CME) occurrence. Potential predictors of VA or CME included clinical variables and SD-OCT parameters.

RESULTS

A total of 108 eyes were included in this study. There were no differences in the final VA between consecutive and combined groups (0.22 vs 0.10 logMAR, p = 0.851). Twelve eyes from the combined group (23%) and one eye from the PPV-only group presented CME (p = 0.001). There were no differences between postoperative CME occurrence in combined versus consecutive group (12 vs 7, p = 0.38). The presence of cotton-ball sign predicted the development of CME [OR 2.86 (95%CI 1.01-8.18), p = 0.049] while separated ERM-ILM complex was found to be protective [OR 0.25 (95%CI 0.08-0.77), p = 0.015].

CONCLUSIONS

Functional and anatomical results of PPV with ERM and ILM peeling combined with cataract surgery was equivalent to the consecutive procedure, with both strategies being effective. Separated ERM-ILM complex has prognostic value in these patients, as its presence at baseline was found to be protective for postoperative CME.

Biomarkers of Neurodegeneration and Precision Therapy in Retinal Disease

Vision-threatening retinal diseases affect millions of people worldwide, representing an important public health issue (high social cost) for both technologically advanced and new-industrialized countries. Overall RD group comprises the retinitis pigmentosa, the age-related macular degeneration (AMD), the diabetic retinopathy (DR), and idiopathic epiretinal membrane formation. Endocrine, metabolic, and even lifestyles risk factors have been reported for these age-linked conditions that represent a "public priority" also in this COVID-19 emergency. Chronic inflammation and neurodegeneration characterize the disease evolution, with a consistent vitreoretinal interface impairment. As the vitreous chamber is significantly involved, the latest diagnostic technologies of imaging (retina) and biomarker detection (vitreous) have provided a huge input at both medical and surgical levels. Complement activation and immune cell recruitment/infiltration as well as detrimental intra/extracellular deposits occur in association with a reactive gliosis. The cell/tissue aging route shows a specific signal path and biomolecular profile characterized by the increased expression of several glial-derived mediators, including angiogenic/angiostatic, neurogenic, and stress-related factors (oxidative stress metabolites, inflammation, and even amyloid formation). The possibility to access vitreous chamber by collecting vitreous reflux during intravitreal injection or obtaining vitreous biopsy during a vitrectomy represents a step forward for an individualized therapy. As drug response and protein signature appear unique in each single patient, therapies should be individualized. This review addresses the current knowledge about biomarkers and pharmacological targets in these vitreoretinal diseases. As vitreous fluids might reflect the early stages of retinal sufferance and/or late stages of neurodegeneration, the possibility to modulate intravitreal levels of growth factors, in combination to anti-VEGF therapy, would open to a personalized therapy of retinal diseases.

OCT-A in the Management of Vitreoretinal Diseases and Surgery

ABSTRACT

Optical coherence tomography angiography is a relatively new noninvasive technique that is changing our approach in the management of several retinal diseases such as neovascular age-related macular degeneration, occlusive retinal diseases, or diabetic retinopathy, but it could also be useful in nonprimary vascular retinal pathologies such as vitreoretinal interface surgical disorders.In idiopathic vitreoretinal interface disorders and surgical retinal diseases, the study of vascular involvement, not commonly assessed by invasive methods, could be useful to reveal specific vascular abnormalities. Such information may be useful for a more detailed phenotyping of each clinical picture before and after surgical treatment, providing potential new prognostic biomarkers.The review discusses the current and potential utility of optical coherence tomography angiography to study vitreoretinal pathologies of surgical interest.

Multicolor Scanning Laser Ophthalmoscopy Strengthens Surgeons' Preoperative Decision-Making and Intraoperative Performance on Epiretinal Membrane

Purpose

To determine whether multicolor scanning laser ophthalmoscopy (MC-SLO) was better than color fundus photography (CFP) to enhance residents and specialists’ preoperative decision-making and intraoperative performance on the epiretinal membrane (ERM).

Methods

Consecutive patients with idiopathic ERM were recruited prospectively. All the patients underwent MC-SLO and CFP imagings and were randomized into MC-SLO (n = 20) and CFP (n = 20) groups. Preoperatively, residents and specialists were required to have ERM delineation and select an optimal location for initial ERM peeling independently, based on the MC-SLO (MC-SLO group) or CFP (CFP group) images. Intraoperative optical coherence tomography (iOCT) was introduced to evaluate the accuracy.

Results

Preoperatively, residents and specialists acted more effectively in ERM delineation and selection of initial grasping location in the MC-SLO group (both P < 0.001). In the MC-SLO group, higher resident–specialist agreements were achieved in ERM delineation (P = 0.002) and selection of initial grasping location (P = 0.035). The iOCT revealed greater interobserver (iOCT–resident and iOCT–specialist) agreements of ERM delineation in MC-SLO group (P < 0.001 and = 0.027, respectively). Surgeons acted more effectively on completely peeling the ERM in the MC-SLO group (P < 0.001).

Conclusions

MC-SLO provided a better visual reference for residents and specialists in ERM delineation and the selection of an initial grasping location for the surgery, compared with CFP.

Translational Relevance

MC-SLO is able to help surgeons achieve better intraoperative performance and shorten the learning process for residents.

Visualization of different anatomical parts of the enucleated human eye using X-ray micro-CT imaging

Micro-CT visualization allows reconstruction of eye structures with the resolution of light microscopy and estimation of tissue densities. Moreover, this method excludes damaging procedures and allows further histological staining due to the similar steps in the beginning. We have shown the feasibility of the lab-based micro-CT machine usage for visualization of clinically important compartments of human eye such as trabecular outflow pathway, retina, iris and ciliary body after pre-treatment with iodine in ethanol. We also identified the challenges of applying this contrasting technique to lens, cornea, and retina and proposed alternative staining methods for these tissues. Thereby this work provides a starting point for other studies for imaging of human eyes in normal and pathological conditions using lab-based micro-CT systems.