Associations between preoperative OCT parameters and visual outcome 3 months postoperatively in patients undergoing vitrectomy for idiopathic epiretinal membrane

Effect of Air Tamponade among Patients with Epiretinal Membranes and Intraretinal Cystoid Changes Undergoing Vitrectomy with Membrane Peeling - A Prospective Randomized Trial

BACKGROUND

The effect of air tamponade among patients undergoing vitrectomy with membrane peeling for removal of epiretinal membranes (ERM) is controversially discussed. The aim of the present study was to analyze differences in outcomes between air tamponade and balanced salt solution (BSS) in a study population with preoperative intraretinal cystoid changes.

PATIENTS AND METHODS

This randomized study included patients scheduled for pars plana vitrectomy with membrane peeling owing to ERM and intraretinal cystoid changes. Air tamponade or BSS at the end of surgery was applied according to preoperative randomization. Optical coherence tomography and best-corrected distance visual acuity (DCVA) measurements were performed before surgery, 5 days after surgery, and 3 months after surgery.

RESULTS

From 96 patients included, 85 eyes had full follow-up and could be included for analysis. Median improvement of DCVA was + 16 EDTRS letters (IQR: 8 to 22) among patients with BSS, while it was + 13 EDTRS letters (IQR: 8 to 17) among patients with air tamponade. There was a trend for better improvement of DCVA when BSS was left at the end of surgery, compared to air tamponade, but not reaching statistical significance.

CONCLUSIONS

There were no statistically significant differences concerning resorption of preoperative intraretinal cystoid changes, improvement of visual acuity, and final DVCA between air tamponade and BSS.

Diagnostic Reliability of Optical Coherence Tomography Biomarkers for Postsurgical Success in Visual Acuity in Patients with Idiopathic Epiretinal Membranes

INTRODUCTION

Several optical coherence tomography (OCT) biomarkers for postsurgical success in patients with idiopathic epiretinal membranes (iERMs) have been described in single predictor analyses. The aim of this study was to assess the reliability of diagnosis of OCT biomarkers and to calculate their impact on postsurgical visual acuity by applying multiple regression analysis.

METHODS

This retrospective study included patients scheduled for pars plana vitrectomy with membrane peeling for iERMs. Presurgical OCT scans were analyzed for the presence of OCT biomarkers by two reviewers. Intra- and interobserver reliability was calculated with the Kuder-Richardson 20 test.

RESULTS

Among the 136 patients included, intra-/interobserver reliability of the OCT biomarkers was 0.89/0.70 for ectopic inner foveal layer (EIFL), 0.82/0.53 for disorganization of retinal inner layer (DRIL), 0.93/0.89 for intraretinal cystoid changes, 0.84/0.78 for alterations of the ellipsoid zone, 0.84/0.72 for cotton ball sign, 0.68/0.58 for hyperreflective foci, 0.55/0.47 for epimacular membrane rips (EMM-rips), and 0.87/0.60 for retinal contraction. Only DRIL and central subfield macular thickness (CMT) were significant predictors for BCVA 3 months after surgery in a multiple regression analysis.

CONCLUSION

Intraobserver reliability of OCT biomarkers was higher than interobserver reliability, reflecting both clinical and grading experience with respect to OCT biomarker evaluation. DRIL and CMT were shown to be significant predictors in a multiple regression analysis, with potential for negative influence on final BCVA after vitrectomy with membrane peeling for iERMs.

Sphingosine-1-phosphate expression in human epiretinal membranes

The abnormal posterior vitreous detachment (PVD) is speculated as an important mechanism of the development of the epiretinal membrane (ERM). However, there is only limited information about the molecular mechanism. Sphingosine-1-phosphate (S1P) is a mediator of the mechanosensitive response in several cell types that may have a role in the pathogenesis of ERM during abnormal PVD. Therefore, we evaluated the expression of S1P in the human ERM and the role of S1P in cultured human Muller glial cells. Among 24 ERM specimens, seven specimens (29.2%) exhibited S1P expression. Patients with secondary ERM or ellipsoid zone defects, which suggest abnormal PVD presented a significantly higher S1P+ cell density (secondary ERM: 128.20 ± 135.61 and 9.68 ± 36.01 cells, p = 0.002; EZ defects: 87.56 ± 117.79 vs 2.80 ± 8.85, p = 0.036). The addition of S1P increased the migrative ability and expression of N-cadherin and α-SMA in human Muller glial cells, suggesting S1P is a potential causative molecule for the development of ERM during abnormal PVD.

Influence of Preoperative Foveal Layers’ Thickness on Visual Function and Macular Morphology by Phacovitrectomy for Epiretinal Membrane

Background. The aim of this retrospective study with short, differently dispersed follow-up is to record the relationships between the pathologies of the individual foveal layers, measured by spectral domain optical coherence tomography (SD-OCT), and to investigate their influence on pre- and postoperative best-corrected decimal far visual acuity (BCVA) by phacovitrectomy for epiretinal membrane (ERM) in comorbidity with cataract. Patients and Methods. 208 eyes of 173 patients with symptomatic idiopathic ERM and moderate cataract were included. Results. In all OCT morphological stages of ERM, as well as in their combination with macular lamellar hole (MLH) and vitreomacular traction (VMT), a significant difference in the thickness of the individual fovea layers was found. In addition, the entire fovea thickening led to the proportional thickening of the individual fovea layers ( $p<0.001$ ). The larger the central foveolar (CFT, R2 = −0.238, $p=0.002$ ), maximum foveal (MFT, R2 = −0.267, $p=0.001$ ), and ONL thickness (R2 = −0.16, $p=0.044$ ) were preoperatively, the worse the initial visual acuity was at all OCT stages of ERM. This was even more significant in the presence of a tractive component in the case of MLH or VMT ( $p<0.001$ ). In ERM without a traction component, only ONL thickening led to significant postoperative visual acuity reduction (R2 = −0.163, $p=0.047$ ). The foveolar retinal thickening (CFT and MFT) of the pure ERM is directly associated with distortion of the retinal layers (R2 = 0.292, $p<0.001$ and R2 = 0.287, $p<0.001$ ) as well as with separation of the ERM (R2 = 0.168, $p=0.034$ and R2 = 0.187, $p=0.018$ ). When ERM was combined with tractive component, CFT, ONL, and INL thickness correlated (positively) with the integrity of ellipsoid zone (R2 = 0.342, $p<0.05$ ) and external limiting membrane (R2 = 0.548, $p<0.001$ ). Conclusions. ONL thickening in ERM without a tractive component serves as a limited prognostic factor of postoperative visual acuity decrease. The preoperative BCVA in the groups of ERM with traction component showed significant correlation with CFT as well as with the thickness of individual foveal layers. VMT in ERM correlates with the disintegration of the ellipsoid zone.

Non-vasogenic cystoid maculopathies

Besides cystoid macular edema due to a blood-retinal barrier breakdown, another type of macular cystoid spaces referred to as non-vasogenic cystoid maculopathies (NVCM) may be detected on optical coherence tomography but not on fluorescein angiography. Various causes may disrupt retinal cell cohesion or impair retinal pigment epithelium (RPE) and Müller cell functions in the maintenance of retinal dehydration, resulting in cystoid spaces formation. Tractional causes include vitreomacular traction, epiretinal membranes and myopic foveoschisis. Surgical treatment does not always allow cystoid space resorption. In inherited retinal dystrophies, cystoid spaces may be part of the disease as in X-linked retinoschisis or enhanced S-cone syndrome, or occur occasionally as in bestrophinopathies, retinitis pigmentosa and allied diseases, congenital microphthalmia, choroideremia, gyrate atrophy and Bietti crystalline dystrophy. In macular telangiectasia type 2, cystoid spaces and cavitations do not depend on the fluid leakage from telangiectasia. Various causes affecting RPE function may result in NVCM such as chronic central serous chorioretinopathy and paraneoplastic syndromes. Non-exudative age macular degeneration may also be complicated by intraretinal cystoid spaces in the absence of fluorescein leakage. In these diseases, cystoid spaces occur in a context of retinal cell loss. Various causes of optic atrophy, including open-angle glaucoma, result in microcystoid spaces in the inner nuclear layer due to a retrograde transsynaptic degeneration. Lastly, drug toxicity may also induce cystoid maculopathy. Identifying NVCM on multimodal imaging, including fluorescein angiography if needed, allows guiding the diagnosis of the causative disease and choosing adequate treatment when available.

DEEP LEARNING-BASED PREDICTION OF OUTCOMES FOLLOWING NONCOMPLICATED EPIRETINAL MEMBRANE SURGERY

PURPOSE

We used deep learning to predict the final central foveal thickness (CFT), changes in CFT, final best corrected visual acuity, and best corrected visual acuity changes following noncomplicated idiopathic epiretinal membrane surgery.

METHODS

Data of patients who underwent noncomplicated epiretinal membrane surgery at Severance Hospital from January 1, 2010, to December 31, 2018, were reviewed. Patient age, sex, hypertension and diabetes statuses, and preoperative optical coherence tomography scans were noted. For image analysis and model development, a pre-trained VGG16 was adopted. The mean absolute error and coefficient of determination (R 2 ) were used to evaluate the model performances. The study involved 688 eyes of 657 patients.

RESULTS

For final CFT, the mean absolute error was the lowest in the model that considered only clinical and demographic characteristics; the highest accuracy was achieved by the model that considered all clinical and surgical information. For CFT changes, models utilizing clinical and surgical information showed the best performance. However, our best model failed to predict the final best corrected visual acuity and best corrected visual acuity changes.

CONCLUSION

A deep learning model predicted the final CFT and CFT changes in patients 1 year after epiretinal membrane surgery. Central foveal thickness prediction showed the best results when demographic factors, comorbid diseases, and surgical techniques were considered.

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.

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.

Changes of Fixation Stability and Location after Epiretinal Membrane Surgery

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Association of Microvasculature and Macular Sensitivity in Idiopathic Macular Epiretinal Membrane: Using OCT Angiography and Microperimetry

Purpose: To investigate the correlation between retinal capillary structure and macular function in patients with idiopathic epiretinal membrane (iERM) by using optical coherence tomography angiography (OCTA) and microperimetry.

Methods: This retrospective and observational study included 30 idiopathic ERM eyes of 30 consecutive patients. OCTA was performed to evaluate macular microvasculature including the superficial capillary plexus, deep capillary plexus, and foveal avascular zone. Best corrected visual acuity (BCVA) and microperimetry were measured at baseline and 3 months after surgery. Associations between macular microvasculature and visual function were assessed.

Results: Visual function including BCVA and macular sensitivity improved significantly at 3 months post-operatively (p < 0.001). At baseline, BCVA was positively correlated with foveal or parafoveal sensitivities and negatively correlated with central foveal thickness (p < 0.05). Pre-operative foveal sensitivity was significantly correlated with the vessel density of foveal or parafoveal superficial capillary plexus (p < 0.05). A multiple regression model revealed that pre-operative vessel density of foveal deep capillary plexus was an independent positive prognostic factor for post-operative BCVA (B = −0.020 ± 0.006, p = 0.006) and macular sensitivity (B = 0.200 ± 0.081, p = 0.027).

Conclusion: Integrated evaluation of iERM by using OCTA and microperimetry shows an association between microvasculature and macular sensitivity. Pre-operative vessel density of foveal deep capillary plexus assessed by OCTA may be a potentially valuable prognostic factor for iERM surgery.

Characterizing right-angled vessel in macular telangiectasia type 2 with structural optical coherence tomography

We investigated the structural findings on spectral-domain optical coherence tomography (SD-OCT) related to the presence of right-angled vessels (RAV) in patients with macular telangiectasia (MacTel) type 2 with severity 3 in Korea. A retrospective multicenter cross-sectional study was conducted in six tertiary hospitals in Korea; the study included 116 MacTel type 2 eyes with severity 3. The SD-OCT findings were compared between eyes with RAV on fundus photography or fluorescein angiography and those without RAV. Logistic regression was performed to determine factors associated with the presence of RAV. Fifty eyes presented with RAV and 61 eyes without RAV. More eyes presented with only inner retinal (IR) cavities on SD-OCT among eyes without RAV than among those with RAV (P < 0.001). However, eyes with RAV presented with IR disorganization, outer retinal (OR) cavity, and ellipsoid zone (EZ) disruption more frequently than eyes without RAV did (all P < 0.001). These SD-OCT findings were significantly associated with the presence of RAV. The presence of RAV was closely related to IR disorganization, OR cavities, and EZ disruption on SD-OCT. These findings suggest an advanced phase of MacTel type 2.

Effect of Periocular Triamcinolone Acetonide on Prevention of Postsurgical Intraretinal Cystoid Changes after Vitrectomy with Membrane Peeling

BACKGROUND

Newly developed intraretinal cystoid changes after vitrectomy with membrane peeling for removal of epiretinal membranes have the potential to lead to worse postsurgical results compared to patients without. The aim of the present study was to evaluate the feasibility of additional periocular application of triamcinolone acetonide as a routine adjunct at the end of vitrectomy with membrane peeling, and to compare the presence of postsurgical intraretinal cystoid changes in the first 3 months after surgery among patients with idiopathic epiretinal membranes to a historical group of patients that did not receive triamcinolone acetonide.

PATIENTS AND METHODS

The medical records of 41 eyes of 41 patients that underwent 23 G or 25 G pars plana vitrectomy with membrane peeling for removal of epiretinal membranes and additional periocular triamcinolone acetonide application at the end of surgery were retrospectively reviewed. Optical coherence tomography findings during routine follow-ups at 3 - 5 days, 1 month, and 3 months and visual acuity at 3 months after surgery were evaluated and compared to preoperative findings. Furthermore, postsurgical intraocular pressure was assessed.

RESULTS

Periocular triamcinolone acetonide at the end of surgery was well tolerated among all patients. In total, 10% of patients had an increased intraocular pressure at least at one follow-up. Best-corrected visual acuity improved in 91% of patients with idiopathic epiretinal membranes with a mean improvement of + 3 ± 2 lines (Snellen) and was comparable to a historic group of patients (p = 0.307). Early transient macular edema could not be detected in any of the patients, while there were cases with this pathology in the historic group of patients, but neither occurrence of newly developed intraretinal cystoid changes nor macular thickness at 3 months after surgery were significantly different between patients with and without triamcinolone acetonide (p = 0.385 and p = 0.879).

CONCLUSIONS

Periocularly applied triamcinolone acetonide at the end of vitrectomy with membrane peeling was well tolerated and showed prevention of early transient macular edema but did not prevent the development of new postoperative intraretinal cystoid changes.

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.

Clinical and Optical Coherence Tomography Analysis of Intraretinal Microcysts in Patients with Epiretinal Membrane

Purpose: To perform clinical and optical coherence tomography analysis of intraretinal microcysts (IRM) in patients undergoing pars plana vitrectomy (PPV) for primary epiretinal membrane (ERM) treatment.Materials and Methods: The files of 137 patients who were operated on by a single surgeon for primary epiretinal membrane treatment in our clinic between September 2017 and January 2020 were retrospectively reviewed. Patients with ERM due to secondary pathology were excluded from the study. Twenty patients with post-operative IRM (group 1) were determined and were included as the study group. To determine the effect of IRMs on visual acuity 20 patients who did not have IRM, had primary ERM and underwent PPV for treatment were included as the control group (group 2). The demographic, clinical, and operative data of the patients were obtained from the hospital database. Retinal analysis of the patients before the operation and at the earliest 6 months after the operation was performed using 6 × 6 mm images taken with the macular cube 512 × 128 protocol on the Cirrus HD-OCT (Carl Zeiss Meditec, Dublin, CA, USA) device in our clinic.Results: Intraretinal microcysts were present in 8 (5.8%) of preoperative 137 patients and 20 (14.6%) of 137 postoperative patients. All 8 patients with preoperative cysts in group 1 also had postoperative IRMs. Excluding patients with preoperative cysts, the postoperative IRM incidence was found to be 12/137 (8.75%). Preoperative (p = .392) and postoperative (p = .978) visions were similar in group 1 and group 2. Preoperative (p = .745) and postoperative retinal thicknesses were similar in both groups (p = .989). The incidence of postoperative (p = .642) IRM was similar in patients who underwent ERM and ERM + internal limiting membrane (ILM) peeling in group 1.Conclusions: Intraretinal microcysts may sometimes be seen before and after ERM surgery. The preoperative cyst presence in ERM patients is an important risk factor for postoperative cyst presence. The peeling of ILM with ERM does not increase the probability of IRM occurrence. The presence of these cysts before and/or after the operation does not affect the visual prognosis and macular thickness in ERM patients.

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.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Postoperative outcomes of idiopathic epiretinal membrane associated with foveoschisis

AIMS

To analyse the prevalence and postoperative outcomes of a particular form of epiretinal membrane (ERM) with foveoschisis-like stretched hyporeflective spaces in emmetropic eyes.

METHODS

A retrospective study of all consecutive eyes operated for primary ERM over a 46-month period was conducted. The presence of foveoschisis-like stretched hyporeflective spaces was assessed on the preoperative optical coherence tomography B-scan in all eyes. Highly myopic eyes were excluded. Preoperative and postoperative characteristics of eyes with foveoschisis were compared with those of a control group of 100 consecutive eyes with primary ERM without cystoid spaces.

RESULTS

Of 544 eyes with primary ERM, 17 had foveoschisis, corresponding to a prevalence of 3.1%. After a mean postoperative follow-up of 17.9±10.9 months, the foveoschisis had completely resolved in 76.5% of eyes (n=13/17). In the four eyes (23.5%) with persistent foveoschisis, the remaining hyporeflective cystoid spaces were located exclusively in the inner nuclear layer. The postoperative visual acuity and central macular thickness did not differ between both groups at the final visit. However, an acute postoperative macular oedema occurred in 24% (n=4/17) of cases (vs 3% in the control group; p=0.0084).

CONCLUSION

Foveoschisis was found in about 3% of eyes with idiopathic ERM. After peeling, the foveoschisis usually resolves completely with functional outcomes similar to those achieved with other primary ERM. However, this feature was associated with a higher risk of postoperative macular oedema (in 1/4 of cases).

Optical coherence tomography biomarkers as predictive factors for postoperative visual acuity in patients with epiretinal membrane treated with vitrectomy

BACKGROUND:

The purpose of this retrospective study was to evaluate potential predictive factors of postoperative visual outcome in patients with idiopathic epiretinal membrane (iERM), treated with pars plana vitrectomy (PPV).

METHODS:

Participants in the study were 46 patients diagnosed with iERM, who underwent PPV. Best-corrected visual acuity measurement and spectral domain-optical coherence tomography (OCT) were performed at baseline (preoperatively), and at months 6 and 12 postoperatively. Demographic characteristics and OCT parameters were assessed as potential predictive factors for postoperative visual outcome.

RESULTS:

Increasing age, retinal thickness, presence of disorganization of inner retinal layers, ellipsoid zone disruption, and presence of vitreomacular traction were found to be negatively associated with postoperative visual acuity. Gender, presence of subretinal fluid, cysts in the inner or outer nuclear layer, and hyperreflective foci were not found to affect visual acuity. There was statistically significant improvement in visual acuity and central retinal thickness between baseline and months 6 and 12 in the study sample.

CONCLUSIONS:

It is important to determine predictive factors for visual outcome, so as to inform patients about prognosis and help in the decision-making of patients' management.

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.

Baseline visual acuity and interdigitation zone as predictors in idiopathic epiretinal membranes: A retrospective cohort study

OBJECTIVE

Determine which functional and anatomical characteristics may be predictors of final visual acuity in patients with idiopathic ERM (iERM) submitted to pars plana vitrectomy (PPV) with ERM and internal and internal limiting membrane (ILM) peeling.

DESIGN

Retrospective cohort study.

SUBJECTS

Patients with iERM submitted to PPV between 2016 and 2017.

METHODS

Data regarding the best-corrected visual acuity (BCVA) and the characteristics of the retinal layers observed in SD-OCT were collected preoperatively and until 12 months postoperatively. Central macular thickness (CMT), disorganization of the retinal inner layers (DRIL), outer nuclear layer (ONL) thickness, integrity of subfoveal external limiting membrane (ELM), ellipsoid zone (EZ), and interdigitation zone (IZ) were evaluated.

RESULTS

A total of 128 eyes with iERM from 121 patients were included. BCVA improved significantly (p < 0.001). Significant improvement of BCVA, CMT, DRIL, ONL, ELM, and EZ were obtained. The final IZ was not different from baseline until the end of the study. A significant correlation was observed between the baseline BCVA, EZ, IZ, and the postoperative BCVA (p < 0.001). However, only the baseline BCVA and the integrity of the subfoveal baseline IZ were predictive factors for final BCVA (p < 0.005 and p < 0.001, respectively).

CONCLUSION

PPV provides a significant improvement of BCVA and retinal anatomy recovery in iERM eyes. Baseline IZ didn't change during the 12 months following surgery. Baseline BCVA and subfoveal IZ at baseline were prognostic factors for the final BCVA.

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.

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.

Effect of axial length and age on the visual outcome of patients with idiopathic epiretinal membrane after pars plana vitrectomy

We evaluated predictive factors for visual outcomes in patients with idiopathic epiretinal membrane (iERM) after pars plana vitrectomy (PPV). Clinical records for 114 eyes (114 patients, mean age: 70.6 years) with iERM treated by PPV between March 2012 and March 2018 were retrospectively reviewed. Overall, the mean postoperative best-corrected visual acuity (BCVA) and central retinal thickness measured by optical coherence tomography improved as early as 1 month after surgery, and further improved until 3 months (P < 0.01). Multiple linear regression analyses adjusted for the preoperative BCVA showed that older age (B, 0.010; 95% confidence interval, 0.003 to 0.016; P = 0.003) and a shorter axial length (AL; B, −0.059; 95% confidence interval, −0.099 to −0.019; P = 0.005) predicted worse postoperative BCVA. The Mann-Whitney U test showed that the postoperative BCVA was worse in eyes with AL < 23.6 mm than in eyes with AL ≥ 23.6 mm (P = 0.037), and in patients aged ≥69 years than in patients aged <69 years (P = 0.024). The findings may help in evaluating surgical indications for each patient to obtain satisfactory outcomes, irrespective of the preoperative BCVA.

EVALUATION OF ACCURACY AND UNIFORMITY OF THE NOMENCLATURE OF VITREORETINAL INTERFACE DISORDERS

PURPOSE

To evaluate the accuracy and uniformity of the definitions used to diagnose vitreoretinal (VR) interface disorders and to assess it after review of its definitions.

METHODS

A case-series study, consisting of a questionnaire of 46 optical coherence tomography images of six VR interface disorders: vitreomacular adhesion, vitreomacular traction, epiretinal membrane, full-thickness macular hole, lamellar macular hole, and pseudohole. Images were presented to 41 practicing ophthalmologists (13 residents, 11 VR specialists, and 17 non-VR specialists), and a diagnosis was recorded for each image. The questionnaire was repeated after review of the International Vitreomacular Traction Study (IVTS) group classification. Rates of accuracy and uniformity for each condition were analyzed.

RESULTS

Overall correct identification rates according to the IVTS classification were achieved in 67.4% of cases and were highest for epiretinal membrane and full-thickness macular hole, followed by vitreomacular adhesion, vitreomacular traction, and lamellar macular hole, and were significantly lower for pseudohole (P < 0.001). Accuracy was higher among VR specialists and was associated with previous familiarity with the IVTS classification (P = 0.043) but not with length of experience in ophthalmology (P = 0.74). After review of the IVTS classification, overall correct identification rates improved to 71.7% (P = 0.004), with the significant improvement in pseudohole identification (P = 0.002).

CONCLUSION

The IVTS classification is effective in standardizing the diagnosis of VR interface disorders. It is expected to become increasingly assimilated among ophthalmologists over time, leading to higher rates of accuracy and uniformity in diagnosing VR interface disorders.

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.

The Role of Disorganization of Retinal Inner Layers as Predictive Factor of Postoperative Outcome in Patients with Epiretinal Membrane

PURPOSE

The purpose of this retrospective study was to evaluate the disorganization of the retinal inner layers (DRIL) as a potential predictive factor of postoperative visual outcome in patients with idiopathic epiretinal membrane (iERM), treated with pars plana vitrectomy (PPV).

METHODS

Participants in the study were 46 consecutive patients diagnosed with iERM, who underwent PPV. Best corrected visual acuity (BCVA) measurement and spectral-domain optical coherence tomography (SD-OCT) were performed at baseline (preoperatively), and at months 3 and 6 postoperatively. DRIL and additional OCT parameters were assessed at 1-mm-wide foveal centered area.

RESULTS

DRIL was observed in 47.8% of patients at baseline. There was statistically significant improvement in BCVA and central retinal thickness (CRT) between baseline and months 6 and 12 in all patients. There was a statistically significant difference in BCVA and CRT change between patients with and without DRIL at months 6 and 12 compared to baseline, showing that there was a correlation between change in BCVA or CRT and baseline DRIL. Ellipsoid zone and external limiting membrane were intact in 91.3 and 95.7%, respectively, not affecting our results.

CONCLUSIONS

Baseline DRIL has been shown to be predictive of postoperative visual outcome in patients with iERM, treated with PPV.

Treatment of Macular Edema after Pars Plana Vitrectomy for Idiopathic Epiretinal Membrane Using Intravitreal Dexamethasone Implant: Long-Term Outcomes

PURPOSE

The aim of this study was to investigate the efficacy and safety of intravitreal dexamethasone implant for the treatment of macular edema after pars plana vitrectomy (PPV) for epiretinal membrane (ERM) removal.

METHODS

This prospective study included 27 patients who were diagnosed with macular edema after PPV for ERM removal and who were treated with either intravitreal dexamethasone implant (n = 15) or were observed without intervention (n = 12). Changes in best-corrected visual acuity (BCVA) and central retinal thickness (CRT) were assessed 1, 6, and 12 months -after treatment.

RESULTS

Patients treated with intravitreal dexamethasone implant showed significant improvement in BCVA and reduction in CRT at months 1, 6, and 12 after treatment, while patients in the control group showed improvement that did not reach statistical significance. The two groups differed significantly in terms of BCVA and CRT at all time points of the follow-up period, in favor of the dexamethasone implant group. Eighty percent of the patients treated with intravitreal dexamethasone needed only one implant until month 12, while no serious adverse events were noticed in any group.

CONCLUSIONS

Intravitreal dexamethasone implant was found to be effective and safe for the treatment of macular edema after PPV for ERM removal.

Disorganization of Retinal Inner Layers as a Biomarker for Idiopathic Epiretinal Membrane After Macular Surgery-The DREAM Study

PURPOSE

Epiretinal membrane (ERM) can cause distortion and disorganization of all inner retinal layers. The purpose of our study was to evaluate the extent of disorganization of the retinal inner layers (DRIL) and to investigate its predictive value for visual outcome in cases of idiopathic ERM that were treated by pars plana vitrectomy (PPV) and ERM peeling.

DESIGN

Multicenter international retrospective case series.

METHODS

In 90 eyes from 90 patients with idiopathic ERM treated by PPV and membrane peeling with 12-month follow-up, optical coherence tomography (OCT) scans previous to surgery were evaluated for presence and severity of DRIL, central foveal subfield thickness (CST), maximal retinal thickness (MRT), presence of intraretinal cystoid changes and subretinal fluid, and integrity of the inner/outer segment layer and of the interdigitation zone. Best-corrected visual acuity (BCVA), CST, and MRT were recorded at baseline and at 3, 6, and 12 months after surgery. Correlations between baseline OCT measures (DRIL) and functional and visual outcome were analyzed. Main outcome measures are presence and severity of DRIL at baseline; anatomic and functional outcomes after 3, 6, and 12 months; and the correlation between DRIL and baseline characteristics and outcome measures.

RESULTS

Patients without and with mild DRIL had a significantly better baseline BCVA compared with patients with severe DRIL (0.61 ± 0.13, 0.56 ± 0.23, 0.73 ± 0.20 [logMAR], respectively). BCVA, CST, and MRT at baseline were statistically significantly correlated with DRIL severity (P = .003, P < .001, and P < .001, respectively). DRIL status before surgery showed a statistically significant interaction with change in BCVA, CST, and MRT over 12 months (P < .001 for all). Patients without and with mild DRIL gained a mean of 3 lines of vision after 12 months, in contrast to 1 line in patients with severe DRIL.

CONCLUSIONS

DRIL grading correlates with functional and anatomic measures in patients with idiopathic ERM and could serve as a biomarker to predict outcome after surgery. Patients with severe DRIL have limited benefits from surgery. This should be considered in the decision process whether to perform ERM peeling in this patient group.

Predicting Surgical Success in Patients with Idiopathic Epiretinal Membrane Using the Spectral-Domain Optical Coherence Tomography Segmentation Module for Single Retinal Layer Analysis

INTRODUCTION

Idiopathic epiretinal membrane (ERM) is a proliferation of cells formed on the internal surface of the retina and may cause a slow decrease in visual acuity (VA). The aim of this study was to evaluate the individual layers of the retina by optical coherence tomography (OCT) before and after vitrectomy with ERM peeling in order to refine surgical decision-making.

METHODS

Forty-seven eyes of 45 patients (aged 55-87 years) with ERM were enrolled retrospectively from a tertiary referral center. OCT examination was performed preoperatively and at a mean of 3.2 months postoperatively in all cases. Nine retinal surfaces were subjected to automated all-layer segmentation using the manufacturer's software and assessed for their correlation with VA.

RESULTS

There was a significant correlation between the initial retinal morphology and change in VA postoperatively. Patients who gained at least two lines of VA had a significantly higher total retinal perimacular volume and retinal nerve fiber layer (each p < 0.0001) preoperatively.

CONCLUSION

Patients with high preoperative retinal volumes and therefore increased tractive components seemed to benefit more from surgery than those with low tractive components.