Retromode Imaging Modality of Epiretinal Membranes

(1) Purpose: To determine the characteristics of macular epiretinal membranes (ERM) using non-invasive retromode imaging (RMI) and to compare retromode images with those acquired via fundus autofluorescence (FAF) and fundus photography. (2) Methods: Prospective observational case-series study including patients with macular ERM with no other ocular disease affecting their morphology and/or imaging quality. We compared RMI, FAF and fundus photography features by cropping and overlapping images to obtain topographic correspondence. (3) Results: In total, 21 eyes (21 patients) affected by ERM were included in this study. The mean area of retinal folds detected by RMI was significantly higher than that detected by FAF (11.85 ± 3.92 mm2 and 5.67 ± 2.15 mm2, respectively, p < 0.05) and similar to that revealed by fundus photography (11.85 ± 3.92 mm2 and 10.58 ± 3.45 mm2, respectively, p = 0.277). (4) Conclusions: RMI appears to be a useful tool in the evaluation of ERMs. It allows for an accurate visualization of the real extension of the retinal folds and provides a precise structural assessment of the macula before surgery. Clinicians should be aware of RMI’s advantages and should be able to use them to warrant a wide range of information and, thus, a more personalized therapeutic approach.

Success of iOCT in surgical management of ERM peeling

PURPOSE

Epiretinal membranes (ERM) are a disorder leading to progressive vision loss and metamorphopsia. The ERM is treated through a pars-plana vitrectomy (PPV) with membrane peeling. The aim of this study was to define the success of intraoperative optical coherence tomography (iOCT) in ERM surgery to standard surgical visualization techniques and enhance our current approach to clinical practice.

METHODS

This study included 56 eyes of 54 patients who underwent surgical intervention for management of idiopathic ERM. Patients were recruited between February 2018 and March 2020 at "Francesco Miulli" Hospital ophthalmology department in Acquaviva delle Fonti, Bari, Italy.

RESULTS

in 28 eyes, ERM peeling was performed without staining and without iOCT; 25% of these eyes peeling ERM (n   =   7) was performed easily, while 75% of eyes peeling ERM (n   =   21) was not possible without staining and was necessary staining with Brillant Blu G.In 28 eyes ERM peeling were performed with iOCT; in 92.5% of these eyes (n   =   26) ERM peeling was easily done without staining, while in 7.5% of this group of eyes (n   =   2) ERM peeling was not possible without staining.

CONCLUSIONS

Our study shows how iOCT has successfully assisted the surgeon to complete peeling in most of the cases treated without the use of a chromovitrectomy dye; in flat ERM was more difficult and iOCT failed to visualize the inner limiting membrane (ILM).

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

Purpose

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

Methods

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

Results

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

Conclusions

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

Translational Relevance

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

Macular vascular circulation and retinal oxygen saturation changes for idiopathic macular epiretinal membrane after vitrectomy

PURPOSE

To investigate the postoperative changes in retinal-choroidal blood flow area and retinal vascular oxygen saturation among patients with idiopathic macular epiretinal membranes (iERMs).

METHODS

This study prospectively included 24 eyes of 24 consecutive patients who underwent vitrectomy for iERMs. The flow area of choriocapillary layer, retinal superficial capillary plexuses (SCPs) and retinal deep capillary plexuses (DCPs) were performed using optical coherence tomography angiography with angiovue prototype software, and retinal vascular oxygen saturation was measured using retinal oximeter with the built-in software. The flow area of choriocapillary layers and mean retinal vessel oxygen saturation before and after surgery were compared.

RESULTS

Three months after vitrectomy, the foveal flow area of choriocapillary layer increased clinically significantly from 1.5 ± 0.2 to 1.6 ± 0.2 mm² (p = 0.02). The retinal vascular changes of SCPs and DCPs were not statistically significant. The mean retinal arterial oxygen saturation was 89.9 ± 11.3% preoperatively and increased to 94.5 ± 9.7% postoperatively (p = 0.04). Foveal retinal thickness revealed a clinically significant decrease from 547.8 ± 88.2 μm to 403.0 ± 47.5 μm after surgery (p < 0.05). Postoperative best corrected visual acuity had no statistically significant correlation with foveal flow area of the choriocapillary layer and retinal vascular oxygen saturation.

CONCLUSIONS

There was a decrease of retinal thickness, an improved flow area of choriocapillary layer in macular region, and an increase of retinal arterial vascular oxygen among iERMs patients after vitrectomy.

An Examination of the Frequency of Paravascular Defects and Epiretinal Membranes in Eyes With Early Glaucoma Using En-face Slab OCT Images

PURPOSE

To examine the frequency of paravascular defects (PDs) and macular epiretinal membranes (ERMs) in eyes categorized as having mild glaucoma or glaucoma suspect using en-face slab analysis of optical coherence tomography (OCT) scans.

MATERIALS AND METHODS

Fifty-seven glaucomatous eyes, 44 low-risk suspect eyes, and 101 healthy control eyes were included in the study. The 101 glaucomatous and suspect eyes had a mean deviation better than -6 dB on the 24-2 visual field, and a spherical refractive error between±6 D or axial length <26.5 mm. Two OCT-graders masked to eye classification identified ERMs and PDs on en-face slab images of the macula and peripapillary retina using horizontal B-scans and derived vertical B-scans.

RESULTS

Glaucomatous eyes had a significantly higher number of PDs and ERMs than healthy controls (PD, P<0.001; ERM, P=0.046) and low-risk glaucoma suspects (PD, P=0.004; ERM, P=0.043). PDs and/or ERMs were present in 16 of 57 (28.1%) glaucomatous eyes, 2 of 44 (4.5%) suspect eyes, and 3 of 101 (3.0%) control eyes. Further, PDs were present in 11 of the 57 (19.3%) glaucomatous eyes, 1 of the 44 (2.3%) suspect eyes and 0 of the 101 (0%) control eyes, ERMs were seen in 7 of the 57 (12.3%) glaucomatous eyes, 1 of the 44 (2.3%) suspects, and 3 of the 101 (3.0%) control eyes.

CONCLUSIONS

Eyes with early glaucoma have a higher frequency of PDs and ERMs than suspects or controls and exhibit PDs even in the absence of ERMs or high myopia.

Risk factors for postoperative intraretinal cystoid changes after peeling of idiopathic epiretinal membranes among patients randomized for balanced salt solution and air-tamponade

PURPOSE

Epiretinal membranes (ERM) are macular disorders leading to loss of vision and metamorphopsia. Vitrectomy with membrane peeling displays the gold standard of care. Aim of this study was to assess risk factors for postoperative intraretinal cystoid changes in a study population randomized for balanced salt solution and air-tamponade at the end of surgery.

METHODS

A prospective randomized study, including 69 eyes with idiopathic ERM. Standard 23-gauge three-port pars plana vitrectomy with membrane peeling, using intraoperative optical coherence tomography (OCT), was performed. Randomization for BSS and air-tamponade was performed prior to surgery.

RESULTS

Best-corrected visual acuity improved from 32.9 letters to 45.1 letters 3 months after surgery. Presence of preoperative intraretinal cystoid changes was found to be the only risk factor for presence of postoperative intraretinal cystoid changes 3 months after surgery (p = 0.01; odds ratio: 8.0). Other possible risk factors such as combined phacoemulsification with 23G-ppv and membrane peeling (p = 0.16; odds ratio: 2.4), intraoperative subfoveal hyporeflective zones (p = 0.23; odds ratio: 2.6), age over 70 years (p = 0.29; odds ratio: 0.5) and air-tamponade (p = 0.59; odds ratio: 1.5) were not found to be significant.

CONCLUSION

There is strong evidence that preoperative intraretinal cystoid changes lead to smaller benefit from surgery.

Expression of wild-type p53-induced phosphatase 1 in diabetic epiretinal membranes

Objective

The aims of the present study were to investigate the expression and distribution of Wild-type p53-induced phosphatase 1 (Wip1) in diabetic patients with proliferative diabetic retinopathy (PDR) with epiretinal membranes (ERMs) meanwhile analyze the colocalization of Wip1 and nuclear factor kappa-B (NF-κB) p65 in ERMs.

Methods

ERMs samples were collected from patients with PDR (PDR group) or non-diabetic patients with idiopathic epiretinal membranes (iERMs) (control group) during pars plana vitrectomy. Real-Time PCR analysis was carried out to examine the mRNA expression of Wip1 in ERMs. Immunohistochemical analysis and Immunofluorescent analysis were performed to detect the protein expression of Wip1 in ERMs. Double immunofluorescent staining was performed to detect the colocalization of Wip1 and glial fibrillary acidic protein (GFAP) (retinal glial cells marker), also Wip1 and NF-κB.

Results

ERMs were obtained from 17 eyes of 17 patients with PDR (the PDR group) and 9 eyes of 9 nondiabetic patients (the control group) with iERMs. Our results showed high expression levels of Wip1 mRNAs in ERMs after PDR, but low in iERMs. In addition, both immunohistochemistry and immunofluorescence assay showed strong immunoreactivity for Wip1 in PDR ERMs. Furthermore, Wip1 and GFAP were coexpressed in PDR membranes. Finally, the expression of Wip1 was paralleled with NF-κB.

Conclusion

These data support the notion that Wip1 contributes to the formation of the ERMs in PDR membranes via NF-κB signaling.

Prevalence and risk factors of epiretinal membranes: a systematic review and meta-analysis of population-based studies

OBJECTIVE

This study was to aggregate the prevalence and risks of epiretinal membranes (ERMs) and determine the possible causes of the varied estimates.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

The search strategy was designed prospectively. We searched PubMed, Embase and Web of Science databases from inception to July 2016. Reference lists of the included literatures were reviewed as well.

STUDY SELECTION

Surveys published in English language from any population were included if they had a population-based design and reported the prevalence of ERM from retinal photography with or without optical coherence tomography. Eligibility and quality evaluation was conducted independently by two investigators.

DATA EXTRACTION

The literature search generated 2144 records, and 13 population-based studies comprising 49 697 subjects were finally included. The prevalence of ERM and the ORs of potential risk factors (age, sex, myopia, hypertension and so on) were extracted.

RESULTS

The pooled age-standardised prevalence estimates of earlier ERM (cellophane macular reflex (CMR)), advanced ERM (preretinal macular fibrosis (PMF)) and any ERM were 6.5% (95% CI 4.2% to 8.9%), 2.6% (95% CI 1.8% to 3.4%) and 9.1% (95% CI 6.0% to 12.2%), respectively. In the subgroup analysis, race and photography modality contributed to the variation in the prevalence estimates of PMF, while the WHO regions and image reading methods were associated with the varied prevalence of CMR and any ERM. Meta-analysis showed that only greater age and female significantly conferred a higher risk of ERMs.

CONCLUSIONS

Our findings suggest that ERMs are relatively common among aged population. Race, image taking and reading methodology may play important roles in influencing the large variability of ERM prevalence estimates.

Two Orthoptic Treatments in Dragged-Fovea Diplopia Syndrome

BACKGROUND

"Dragged-fovea diplopia syndrome" is a type of central binocular diplopia that is secondary to a foveal displacement, caused by epiretinal membranes (ERMs) or other macular diseases. Its management is difficult, because prisms are not effective.

CASE REPORTS

Two cases of dragged-fovea diplopia syndrome were presented. Both patients were affected with a unilateral epiretinal membrane. Therefore, the pathophysiology underlying their diplopia was the conflict between central and peripheral fusion mechanisms.

CONCLUSIONS

Diplopia caused by ERM "shift" deserves a complex management. We suggest to be careful about subjective symptoms and to optimize the residual visual function to customize the orthoptic management. A strict cooperation between ophthalmologists and orthoptists could lead to a successful outcome.

Reflectivity and thickness analysis of epiretinal membranes using spectral-domain optical coherence tomography

AIM

To compare thickness and reflectivity spectral domain optical coherence tomography (SD-OCT) findings in patients with idiopathic epiretinal membranes (ERMs), before and after ERM peeling surgery, with normal controls.

METHODS

A retrospective study analyzed SD-OCTs of eyes with ERMs undergoing ERM peeling surgery by one surgeon from 2008 to 2010 and normal control eyes. SD-OCTs were analyzed using a customized algorithm to measure reflectivity and thickness. The relationship between the SD-OCT findings and best corrected visual acuity (BCVA) outcomes was also studied.

RESULTS

Thirty-four ERM eyes and 12 normal eyes were identified. Preoperative eyes had high reflectivity and thickness of the group of layers from the internal limiting membrane (ILM) to the retinal pigment epithelium (RPE) and the group of layers from the ILM to the external limiting membrane (ELM). The values of reflectivity of these two groups of layers decreased postoperatively, but were still higher than normal eyes. In contrast, preoperative eyes had lower reflectivity of two 10×15 pixel regions of interest (ROIs) incorporating: 1) ELM + outer nuclear layer (ONL) and 2) photoreceptor layer (PRL) + RPE, compared to controls. The values of reflectivity of these ROIs increased postoperatively, but were still lower than normal controls. A larger improvement in BCVA postoperatively was correlated with a greater degree of abnormal preoperative reflectivity and thickness findings.

CONCLUSION

Quantitative differences in reflectivity and thickness between preoperative, postoperative, and normal SD-OCTs allow assessment of changes in the retina secondary to ERM. Our study identified hyperreflective inner retina changes and hyporeflective outer retina changes in patients with ERMs. SD-OCT quantitative measures of reflectivity and/or thickness of specific groups of retinal layers and/or ROIs correlate with improvement in BCVA.

Intraocular lens power estimation in combined phacoemulsification and pars plana vitrectomy in eyes with epiretinal membranes: a case-control study

PURPOSE

To evaluate the accuracy of postoperative refractive outcomes of combined phacovitrectomy for epiretinal membrane (ERM) in comparison to cataract surgery alone.

MATERIALS AND METHODS

Thirty-nine eyes that underwent combined phacovitrectomy with intraocular lens (IOL) implantation for cataract and ERM (combined surgery group) and 39 eyes that received phacoemulsification for cataract (control group) were analyzed, retrospectively. The predicted preoperative refractive aim was compared with the results of postoperative refraction.

RESULTS

In the combined surgery group, refractive prediction error by A-scan and IOLMaster were -0.305±0.717 diopters (D) and -0.356±0.639 D, respectively, compared to 0.215±0.541 and 0.077±0.529 in the control group, showing significantly more myopic change compared to the control group (p=0.001 and p=0.002, respectively). Within each group, there was no statistically significant difference in refractive prediction error between A-scan and IOLMaster (all p>0.05). IOL power calculation using adjusted A-scan measurement of axial length based on the macular thickness of the normal contralateral eye still resulted in significant postoperative refractive error (all p<0.05). Postoperative refraction calculated with adjusted axial length based on actual postoperative central foveal thickness change showed the closest value to the actual postoperative achieved refraction (p=0.599).

CONCLUSION

Combined phacovitrectomy for ERM resulted in significantly more myopic shift of postoperative refraction, compared to the cataract surgery alone, for both A-scan and IOLMaster. To improve the accuracy of IOL power estimation in eyes with cataract and ERM, sequential surgery for ERM and cataract may need to be considered.

Nestin positive cells in adult human retina and in epiretinal membranes

BACKGROUND/AIM

Nestin is an intermediate filament marker for neural progenitor cells. The authors aimed to identify nestin positive cells in adult human retina and within surgically removed epiretinal membranes.

METHODS

Adult human retina and epiretinal membranes were studied. Tissue was fixed and processed for semithin sections or whole mount preparations for immunohistochemical detection of nestin and glial fibrillary acidic protein (GFAP) expression.

RESULTS

Nestin positive cells are most prominent at the ora serrata, possess fibrillary processes, small amounts of perinuclear cytoplasm, and are arranged radially within or superficially on the retina. In the posterior retina, speckled cytoplasmic nestin staining is seen around the nuclei of neurons. In the peripapillary retina most of the cells in the retinal ganglion cell layer are nestin positive. These cells appear to represent nestin positive neurons. Speckled cells are also seen in the myelinated portion of the optic nerve. In epiretinal membranes patches of elongated nestin positive cells were found. These cells were also positive for GFAP.

CONCLUSIONS

Some neurons and glia in the adult human retina are nestin positive. Their pattern in anterior retina suggests an analogy with the ciliary marginal zone found in many other species. The role of these cells in pathological responses to retinal disease is suggested by the presence of large numbers of ectopic nestin positive cells in epiretinal membranes. The authors hypothesise that nestin positive cells represent a population of progenitor cells from normal adult human retina that differentiate to make up retinal scar tissue.

Double vital staining using trypan blue and infracyanine green in macular pucker surgery

AIMS

To study the clinical properties of double vital staining in premacular fibrosis, facilitating complete removal of all epiretinal tissue.

METHODS

In a two step surgery, the epiretinal pucker was removed after staining with trypan blue, whereafter the inner limiting membrane was peeled after staining with infracyanine green.

RESULTS

In all 30 patients, a separate epiretinal layer and inner limiting membrane were removed from the macular area. Pathological examination showed different histological properties of the removed layers. An increased visual acuity was measured in 26 patients, and a slightly decreased visual acuity in one patient.

CONCLUSION

The described double staining technique could be a novel valuable tool that may help to achieve optimal anatomical and functional recovery after surgery for premacular fibrosis