Effect of topical bromfenac on intraretinal cystoid lesion in simultaneous cataract and idiopathic epiretinal membrane surgery.

PURPOSE: To investigate the effect of topical nonsteroidal anti-inflammatory drugs (NSAIDs,) bromfenac on the intraretinal cystic lesions (IRC) when performing simultaneous cataract and idiopathic epiretinal membrane (iERM) surgery. METHODS: This study included patients with iERM who had been followed up for 6 months after vitrectomy, membrane removal, and concurrent cataract surgery. Eyes were treated with topical bromfenac or not. The baseline fluorescein angiography (FA) was obtained to assess the microvascular leakage (ML). Structural changes of macula, including IRC and central macular thickness (CMT) were assessed using optical coherence tomography (OCT). The main outcome measures were changes in IRCs and best-corrected visual acuity (BCVA) regarding FA findings. RESULTS: One hundred eighteen eyes were included. IRC and ML were observed in 51 eyes (43.2%) and 63 eyes (53.4%), respectively. The IRC did not show any association with the ML. Of total, 29 eyes (24.6%) were treated with topical bromfenac (Group A). Compared to Group B, topical bromfenac did not show beneficial effects in aspect of preventions for the newly developed IRC and treatment for pre-existed IRC. Whether the ML existed or not, topical bromfenac did not show any different effect on the changes in BCVA and IRC. CONCLUSION: When performing simultaneous cataract and ERM surgery, topical NSAIDs, bromfenac did not show beneficial effects on the preventions and treatment of IRC in both eyes with and without the ML.

EVALUATION OF PARAVASCULAR INNER RETINAL DEFECTS USING EN FACE OPTICAL COHERENCE TOMOGRAPHY.

PURPOSE: To evaluate the prevalence and risk factors for development of paravascular inner retinal defects (PIRDs) using en face optical coherence tomography. METHODS: This is a retrospective cross-sectional study. En face and cross-sectional optical coherence tomography images were reviewed (9 × 9 mm or 12 × 12 mm). Paravascular inner retinal defects were classified as either Grade 1 (i.e., paravascular inner retinal cysts) when the lesion was confined within the nerve fiber layer without any communication to the vitreous cavity or Grade 2 (i.e., paravascular lamellar hole) when the defects communicated to the vitreous. Paravascular inner retinal defect grading was correlated with presence of high myopia, stage of posterior vitreous detachment, and presence of epiretinal membrane and retinoschisis. RESULTS: Of 1,074 patients (2,148 eyes), PIRDs were detected in 261 eyes with a prevalence of 261 per 2,148 eyes (12.2%) and 176 per 1,074 patients (16.4%). A total of 116 eyes (44.4%) displayed Grade 2 PIRDs while 145 eyes (55.6%) were Grade 1. In the multivariate logistic regression model, the presence of partial/complete posterior vitreous detachment, retinoschisis, and epiretinal membrane was significantly correlated with PIRDs (OR = 2.78 [1.7-4.4], P < 0.001; OR = 2.93 [1.7-5], P < 0.001; and OR = 25.9 [2.8-242.5], P < 0.001, respectively). The presence of partial/complete posterior vitreous detachment and epiretinal membrane was also significantly associated with Grade 2 PIRDs versus Grade 1 PIRDs ( P = 0.03 and P < 0.001). CONCLUSION: Our results indicate that wide-field en face optical coherence tomography facilitates the identification of PIRDs over a large area of retina with a single capture. The presence of PIRDs was significantly associated with posterior vitreous detachment, epiretinal membrane, and retinoschisis, confirming the role of vitreoretinal traction in the pathogenesis of PIRDs.

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.

Characterization of Different Types of Epiretinal Proliferations by Synchrotron Radiation-Based Fourier Transform Infrared Micro-Spectroscopy.

Pathological tissue on the surface of the retina that can be of different etiology and pathogenesis can cause changes in the retina that have a direct consequence on vision. Tissues of different etiology and pathogenesis have different morphological structures and also different macromolecule compositions usually characteristic of specific diseases. In this study, we evaluated and compared biochemical differences among samples of three different types of epiretinal proliferations: idiopathic epiretinal membrane (ERMi), membranes in proliferative vitreoretinopathy (PVRm), and proliferative diabetic retinopathy (PDRm). The membranes were analyzed by using synchrotron radiation-based Fourier transform infrared micro-spectroscopy (SR-FTIR). We used the SR-FTIR micro-spectroscopy setup, where measurements were set to achieve a high resolution that was capable of showing clear biochemical spectra in biological tissue. We were able to identify differences between PVRm, PDRm, and ERMi in protein and lipid structure; collagen content and collagen maturity; differences in proteoglycan presence; protein phosphorylation; and DNA expression. Collagen showed the strongest expression in PDRm, lower expression in ERMi, and very low expression in PVRm. We also demonstrated the presence of silicone oil (SO) or polydimethylsiloxane in the structure of PVRm after SO endotamponade. This finding suggests that SO, in addition to its many benefits as an important tool in vitreoretinal surgery, could be involved in PVRm formation.

Update on the utility of en face optical coherence tomography in the assessment of vitreoretinal diseases.

En face optical coherence tomography (EF-OCT) is a rapid, non-invasive, high-resolution imaging technique that has evolved in recent years to be a routine examination for the assessment and follow-up of various vitreoretinal diseases. With the introduction of swept-source OCT (SS-OCT), which can achieve up to 100,000 A-scans per second and better-quality imaging of deeper structures using a longer wavelength (1050nm), EF-OCT reconstruction can produce high-resolution frontal images of the retina and choroid (C-Scans) that give an overview of disease extent. These images allow a more accurate study of vitreoretinal interface pathologies such as epiretinal membranes, macular holes, and vitreomacular traction. They also provide key information in the study of various retinal vascular diseases and the differential diagnosis of cystic macular edema. EF-OCT provides valuable information about the severity of vitreoretinal interface alterations and precisely assesses the choriocapillaris and choroidal vasculature in pachychoroid disorders. Finally, this technique provides valuable information about atrophic and neovascular age-related macular degeneration and various uveitic entities. This review aims to describe the current clinical applications of EF-OCT in various vitreoretinal diseases as well as the latest findings and future perspectives.

INTERNAL LIMITING MEMBRANE PEELING DISTORTS THE RETINAL LAYERS AND INDUCES SCOTOMA FORMATION IN THE PERIFOVEAL TEMPORAL MACULA.

PURPOSE: To determine whether internal limiting membrane peeling damages retinal function in patients with an idiopathic macular hole. METHODS: Retrospective case series. Forty-five eyes of 45 idiopathic macular hole patients who underwent vitrectomy with internal limiting membrane peeling with a minimum follow-up of 6 months. Each patient received a complete ophthalmological examination. The eyes were examined by microperimetry MP-3 in the central 20° visual field and optical coherence tomography angiography in the central 6 × 6 mm area. RESULTS: Six months after the surgery, macular hole closed in each patient. Retinal sensitivity decreased significantly in the perifoveal temporal ETDRS sector (from 24.97 ± 2.67-19.98 ± 5.68 dB, P = 0.001) but not in the other sectors. Six patients (13%) developed 24 scotomas, 62.5% presented in the perifoveal temporal sector. Anatomically, bumps in the outer nuclear layer were discovered concurrent with inner retinal dimples on B-scan images, predominantly (76.8%) in the perifoveal temporal sector, which have not been previously reported. The incidence of outer nuclear layer bumps was significantly higher in patients with scotomas than in those without (83% vs. 18%, P = 0.014). CONCLUSION: Internal limiting membrane peeling induced functional changes specifically in the perifoveal temporal macula. Distortion in the retinal layers is proposed to underly scotomas pathogenesis.

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.

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.

Aqueous Lumican Correlates with Central Retinal Thickness in Patients with Idiopathic Epiretinal Membrane: A Proteome Study.

Idiopathic epiretinal membrane (iERM) is a pathological fibrocellular change in the vitreoretinal junction over the macular area; however, possible pathogenic mechanisms remain unclear. Changes in the differential protein composition of the aqueous humor (AH) may represent potential molecular changes associated with iERM. To gain new insights into the molecular mechanisms of iERM pathology, a sensitive label-free proteomics analysis was performed to compare AH protein expressions in patients with cataracts with or without iERM. This study employed nanoflow ultra-high-performance liquid chromatography-tandem mass spectrometry to investigate protein compositions of the AH obtained from individual human cataract eyes from 10 patients with iERM and 10 age-matched controls without iERM. Eight proteins were differentially expressed between the iERM and control samples, among which six proteins were upregulated and two were downregulated. A gene ontology (GO) analysis revealed that iERM was closely associated with several biological processes, such as immunity interactions, cell proliferation, and extracellular matrix remodeling. Additionally, multiple proteins, including lumican, cyclin-dependent kinase 13, and collagen alpha-3(VI) chain, were correlated with the central retinal thickness, indicating a multifactorial response in the pathogenic process of iERM. Changes in the AH level of lumican between iERM and control samples were also confirmed by an enzyme-linked immunosorbent assay. In conclusion, several pathological pathways involved in iERM were identified in the AH by a proteomic analysis, including immune reactions, cell proliferation, and remodeling of the extracellular matrix. Lumican is a potential aqueous biomarker for predicting iERM development and monitoring its progression. More clinical parameters also need to be identified to complete the analysis, and those could provide additional targets for treating and preventing iERM.

Long-term follow-up of a case of Coats disease in a 10-year-old boy with spontaneous peeling of preretinal macular fibrosis: a case report.

BACKGROUND: Coats disease is a retinal vascular disorder characterized by aneurysms and telangiectasias. Macular fibrosis is a complication of Coats disease that results in vision loss. Macular fibrosis rarely develops in the natural course and often occurs after treatment with intravitreal bevacizumab, photocoagulation, or cryotherapy. Here, we have described an unusual case of spontaneous peeling of preretinal macular fibrosis in a patient with untreated Coats disease. CASE PRESENTATION: A 10-year-old Japanese boy presented with vision loss in his left eye. The patient's left visual acuity was 20/28. Fundus examination of his left eye revealed thick preretinal macular fibrosis around the optic disc and macula. In addition, retinal telangiectasis, microaneurysms, hard exudates, and retinal hemorrhages were observed in the left peripheral temporal retina. We diagnosed his condition as Coats disease with preretinal macular fibrosis. Two months later, optical coherence tomography revealed preretinal macular fibrosis detachment at the foveal lesion without any treatment. During follow-up, preretinal macular fibrosis at the macular lesion was completely detached. Further, posterior vitreous detachment was observed and the shape of the macula and the patient's left visual acuity had improved. CONCLUSIONS: In our case, both formation and spontaneous peeling of preretinal macular fibrosis occurred without any treatment for Coats disease, which is an unusual finding. Vitreous changes might have occurred during the natural clinical course, causing subsequent posterior vitreous detachment and resulting in spontaneous peeling of fibrosis.

Limited hyperoxia-induced proliferative retinopathy: A model of persistent retinal vascular dysfunction, preretinal fibrosis and hyaloidal vascular reprogramming for retinal rescue.

BACKGROUND: Retinopathy of prematurity (ROP) remains the leading cause for blindness in children. Limited hyperoxia induced proliferative retinopathy (L-HIPR) was recently introduced as a potential animal model for ROP and persistent fetal vasculature; however, the detailed pathological changes remain unclear. METHODS: To model L-HIPR, we placed C57BL/6J mice in 65% oxygen from birth to post-natal day 7 (P7). We examined eyes at intervals between P12 and P30. Retinal morphometry, thickness, and preretinal fibrosis were quantified at different time points on histological sections stained with hematoxylin and eosin (H&E) and Masson Trichrome, respectively. Vascular development, angiogenesis, inflammation, and pericyte coverage were analyzed using immunohistochemistry staining in retinal flat mounts and cross sections. RESULTS: In L-HIPR, the hyaloidal vessels persisted until the latest time point in this study, P30 and began to invaginate the peripheral then central retina starting at P12. Central retinal distortion was noted beginning at P17, while the peripheral retina demonstrated a trend of thinning from P12 to P30. We found that L-HIPR was associated with delayed and abnormal retinal vascular development with subsequent retinal inflammation, pericyte loss and preretinal fibrosis. CONCLUSION: Our study presents a detailed analysis of the L-HIPR animal model demonstrating vitreoretinal pathologic changes, preretinal fibrosis and persistent hyaloidal vessels into adulthood. Based on our findings, we suggest that the persistence and peculiar stepwise migration of the hyaloidal vessels into the retina may provide a potential rescue mechanism for inner retinal development that deserves further study.

Epiretinal Membrane Surgery in Eyes with Glaucoma: Visual Outcomes and Clinical Significance of Inner Microcystoid Changes.

OBJECTIVE: To investigate visual acuity (VA) outcomes and OCT-based biomarkers of vision outcomes in eyes with glaucoma undergoing pars plana vitrectomy (PPV) for idiopathic epiretinal membrane (ERM). DESIGN: Retrospective, consecutive case-control series. A previously described ERM grading scale was utilized for OCT analysis. SUBJECTS: Eyes with glaucoma undergoing PPV for idiopathic ERM. INTERVENTION: PPV with membrane peel (MP) surgery. MAIN OUTCOME MEASURES: The primary outcome was VA at postoperative month 6. Outcomes were compared to a contemporary, matched control group of eyes without concurrent glaucoma undergoing PPV for idiopathic ERM. RESULTS: A total of 103 eyes from 103 patients with ERM and glaucoma were followed for a mean (± standard deviation) of 656 (± 421) days after PPV with MP surgery. Glaucoma was classified as open angle in 98 (95.1%) eyes and closed angle in 5 (4.9%) eyes. Visual acuity improved from 0.72 ± 0.48 (20/105) to 0.55 ± 0.51 (20/71) at 6 months and to 0.50 ± 0.56 (20/63) at final follow-up (P < 0.001 for both the time points). Eyes with preoperative inner microcystoid changes (n = 59; 57.3%) had significantly worse preoperative VA, postoperative VA at month 6, and final VA compared to eyes without inner microcystoid changes (P = 0.028, 0.004, and 0.007, respectively). Eyes were then compared to a matched control group of 139 eyes without glaucoma. Eyes with ERM and glaucoma had a higher rate of microcystic changes both before surgery (P < 0.001) and at postoperative month 6 (P < 0.001), and had a worse VA at 6 months (P = 0.03) and final follow-up (P = 0.04) compared to control eyes without glaucoma. Advanced disc cupping was the only factor independently correlated with worse 6-month (P = 0.01) and final (P = 0.007) VA in multivariate analysis. CONCLUSIONS: Preoperative inner microcystoid changes on OCT were present in over half of eyes with ERM and concurrent glaucoma, and may be a poor prognostic OCT biomarker. Eyes with ERM and concurrent glaucoma experienced worse vision outcomes compared to eyes with ERM alone, particularly those with advanced disc cupping.

In-Depth Molecular Characterization of Neovascular Membranes Suggests a Role for Hyalocyte-to-Myofibroblast Transdifferentiation in Proliferative Diabetic Retinopathy.

Background: Retinal neovascularization (RNV) membranes can lead to a tractional retinal detachment, the primary reason for severe vision loss in end-stage disease proliferative diabetic retinopathy (PDR). The aim of this study was to characterize the molecular, cellular and immunological features of RNV in order to unravel potential novel drug treatments for PDR. Methods: A total of 43 patients undergoing vitrectomy for PDR, macular pucker or macular hole (control patients) were included in this study. The surgically removed RNV and epiretinal membranes were analyzed by RNA sequencing, single-cell based Imaging Mass Cytometry and conventional immunohistochemistry. Immune cells of the vitreous body, also known as hyalocytes, were isolated from patients with PDR by flow cytometry, cultivated and characterized by immunohistochemistry. A bioinformatical drug repurposing approach was applied in order to identify novel potential drug options for end-stage diabetic retinopathy disease. Results: The in-depth transcriptional and single-cell protein analysis of diabetic RNV tissue samples revealed an accumulation of endothelial cells, macrophages and myofibroblasts as well as an abundance of secreted ECM proteins such as SPARC, FN1 and several types of collagen in RNV tissue. The immunohistochemical staining of cultivated vitreal hyalocytes from patients with PDR showed that hyalocytes express α-SMA (alpha-smooth muscle actin), a classic myofibroblast marker. According to our drug repurposing analysis, imatinib emerged as a potential immunomodulatory drug option for future treatment of PDR. Conclusion: This study delivers the first in-depth transcriptional and single-cell proteomic characterization of RNV tissue samples. Our data suggest an important role of hyalocyte-to-myofibroblast transdifferentiation in the pathogenesis of diabetic vitreoretinal disease and their modulation as a novel possible clinical approach.

Influence of postoperative ectopic inner foveal layer on visual function after removal of idiopathic epiretinal membrane.

PURPOSE: To investigate the functional and anatomical parameters and their postoperative changes according to the ectopic inner foveal layer (EIFL) staging scheme for idiopathic epiretinal membrane (ERM). METHODS: In this prospective study, patients with idiopathic ERM underwent pars plana vitrectomy and ERM removal, and were followed-up for 6 months. The associations of EIFL with pre- and postoperative functional and anatomical parameters were analyzed. RESULTS: A total of 84 eyes (84 patients) were included: 39 (46.4%), 33 (39.3%), and 12 (14.3%) as EIFL stages 2, 3, and 4, respectively. At 6 months after surgery, the mean best-corrected visual acuity (BCVA) significantly improved in all EIFL stages (P ≤ 0.003); however, metamorphopsia improved only in eyes with EIFL stage 2 (P = 0.039) and 3 (P = 0.011). The aniseikonia and foveal avascular zone (FAZ) area showed no significant postoperative changes in any of the EIFL stages. Both preoperatively and during 6 months after surgery, the EIFL stage showed a significant correlation with BCVA (P ≤ 0.033), metamorphopsia (P ≤ 0.008), central macular thickness (P < 0.001), and FAZ parameters (P ≤ 0.016) at each time point, but not with aniseikonia. Significant correlations of EIFL thickness with BCVA (P = 0.028) and metamorphopsia (P = 0.006) before surgery were not persistent after surgery. CONCLUSION: Both pre- and postoperatively, the staging of EIFL, rather than its thickness, is a simple and adequate surrogate marker for visual acuity and metamorphopsia in eyes with idiopathic ERM.

The effect of phacoemulsification performed with vitrectomy on choroidal vascularity index in eyes with vitreomacular diseases.

This study evaluated the effects of cataract surgery combined with pars plana vitrectomy (ppV) on choroidal vascularity index (CVI) in eyes with epiretinal membrane (ERM) and full thickness macular hole (FTMH). Medical records of 132 eyes with ERM or FTMH were retrospectively reviewed and classified into a ppV group and a ppV combined with cataract surgery group (phaco + ppV group). The CVI were measured at baseline, 1, 3 and 6 months after the surgery, using the selected swept-source (SS) optical coherence tomography (OCT) scan passing through the central fovea, which was then segmented into luminal and stromal area by image binarization. The mean CVI of phaco + ppV group were 61.25 ± 1.97%, 61.66 ± 1.81%, and 62.30 ± 1.92% at baseline, 1 and 3 months, respectively (p < 0.001). The mean CVI of ppV group were 62.69 ± 1.92%, 62.03 ± 1.51%, and 61.45 ± 1.71% at baseline, 1 and 3 months, respectively (p < 0.001). The final CVI were measured at 6 months and compared with the baseline CVI. The mean CVI of phaco + ppV group were 61.21 ± 1.99% at baseline and 60.68 ± 2.02% at 6 months (p < 0.001). The mean CVI of ppV group were 62.93 ± 1.70% at baseline and 61.77 ± 1.74% at 6 months (p < 0.001). Vitrectomy significantly decreases CVI in vitreomacular diseases possibly due to the removal of vitreomacular traction or postoperative oxygenation change in the eye. On the contrary, combined surgery of vitrectomy and cataract surgery significantly increases CVI in the early stage of postoperative period, which suggests choroidal vascular dilatation or congestion due to postoperative inflammation. Although the CVI were measured lower than the baseline in the end, more thorough inflammation control may be essential after combined surgery.

Contractility of temporal inverted internal limiting membrane flap after vitrectomy for macular hole.

We investigated the postoperative visual outcomes and morphological changes of the internal limiting membrane (ILM) flap, in patients who underwent the temporal inverted ILM flap technique for macular hole (MH). Between August 2018 and February 2020, 22 eyes of 22 patients with idiopathic or myopic MH who underwent vitrectomy with ILM flap were included in this study and followed-up for more than 6 months. Postoperative MH status, comparison of best-corrected visual acuity (BCVA) before and 6 months after surgery, changes in the ILM flap area at 1 and 6 months postoperatively, and the factors related to changes in ILM flap size, were analyzed. MH closure was achieved in all of the patients. The BCVA at 6 months postoperatively (0.18 ± 0.15) was significantly better than the preoperative BCVA of 0.63 ± 0.37 (P < 0.001, paired t test). The area of the ILM flap decreased significantly from 3.25 ± 1.27 mm2 at 1 month to 3.13 ± 1.23 mm2 at 6 months (P = 0.024, Wilcoxon signed-rank test). Two eyes showed an ILM flap contraction of more than 20%, and one eye required reoperation due to an increase in metamorphopsia and decreased visual acuity. Among age, sex, ILM flap area at 1 month, preoperative BCVA, and axial length, ILM flap contraction was correlated with patient age and ILM flap area. Although vitrectomy with the inverted ILM flap technique confers a good visual outcome, the ILM flap may contract in younger patients.

Total venous nature of retinal deep capillary plexus inferred by continuity of prominent middle limiting membrane sign in optical coherence tomography.

This study aimed to theoretically identify the vascular nature of the deep capillary plexus (DCP) by examining patients presenting with both paracentral acute middle maculopathy (PAMM) and prominent middle limiting membrane (p-MLM) sign and p-MLM sign alone in spectral-domain optical coherence tomography (SD-OCT). A retrospective review of the medical records of patients with retinal vein or artery occlusion from two tertiary medical centers was performed. Consecutive patients with a clinical diagnosis of all categories of retinal artery occlusion (RAO) and retinal vein occlusion (RVO) (branch or central and ischemic or non-ischemic) who had undergone SD-OCT imaging from January 2015 to May 2020 were recruited and their p-MLM signs and PAMM lesions were assessed. We included 118 patients who presented with p-MLM sign with or without PAMM lesions. Amon them, 40 were female and 78 were male, with a mean age of 61.1 years. Of the 109 patients with both p-MLM sign and PAMM lesions, 23 had branch RAO, two had branch RVO, 67 had central RAO, 13 had central RVO, and four had a combination of central RAO and central RVO. All nine patients with the p-MLM sign alone had central RVO accompanied by cystoid macular edema. In all the enrolled patients, the hyperreflective lines of the p-MLM sign were continuous, regardless of the type of PAMM lesions. In conclusion, when PAMM and p-MLM sign are examined together, further proof regarding the possible complete venous nature of the vasculature of the retinal DCP might be speculated.

Inner Macular Changes in Fellow Eye of Patients With Unilateral Idiopathic Epiretinal Membrane.

Purpose: We evaluated a series of fellow eyes (FEs) in patients affected by unilateral idiopathic epiretinal membrane (IERM) with spectral-domain optical coherence tomography (SD-OCT) and OCT angiography (OCT-A) to determine if a previous defect in the inner retina is present before the mechanical damage to the inner limiting membrane (ILM) caused by posterior vitreous detachment. Methods: In patients with IERM (N = 39), ganglion cell layer (GCL) thickness in FEs was assessed with SD-OCT; in a subgroup (N = 25) the vessel density (VD) at the superficial (SCP) and deep capillary plexus (DCP) was assessed with swept-source OCT-A (SS-OCT-A). These values were then compared with 30 age-matched healthy control eyes (CEs). The statistical analyses used SPSS software version 15.0 (SPSS, Inc., Chicago, IL, USA). Data collected underwent 1-way ANOVA. A level of P < 0.05 was accepted as statistically significant. Results: The GCL thickness in the FEs was significantly lower than in CEs, with a significant thinning in all sectors except temporal ones (mean P < 0.001, superior P = 0.0002, superonasal P < 0.001, inferonasal P < 0.001, and inferior P = 0.002). The VD was significantly lower in the FEs in all sectors of SCP (mean P = 0.009, inner ring P = 0.028, and outer ring P = 0.007). Conclusions: GCL and SCP are significantly reduced in the FEs. These data suggest that a vascular defect in the SCP could cause a cellular loss in the inner retina that may determine the cascade events leading to the IERM proliferation; the diagnosis in a preclinical phase could provide a treatment strategy to prevent the progression of the disease.

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.

Histologic, immunohistochemical, and scanning electron microscopic comparison of pre-iridal monocellular and fibrovascular membranes in normal and glaucomatous canine globes.

OBJECTIVES: (i) To evaluate immunohistochemical labeling of pre-iridal monocellular and fibrovascular membranes and (ii) describe the light and scanning electron microscopic (SEM) characteristics of these membranes in glaucomatous and normal/control canine globes. MATERIALS AND METHODS: All globes were evaluated with light microscopy. Immunohistochemical labeling for CD18, Smooth muscle actin (SMA), and CD117 was completed on 40 canine globes with congenital/anterior segment dysgenesis-associated glaucoma (n = 10), primary/goniodysgenesis-associated glaucoma (n = 10), secondary glaucoma (n = 10), and normal/control globes (n = 10). SEM was completed on 10 globes: 5 with monocellular membranes, 3 with fibrovascular membranes, and 2 without a histologically detectable membrane. RESULTS: Monocellular membranes were detected in all normal/control globes with light microscopy and appeared to be morphologically very similar to those in diseased globes. CD18 labeling was detected in 9/10 monocellular membranes in normal/control globes, 15/23 monocellular, and 7/8 fibrovascular membranes in globes with glaucoma. SMA and CD117 labeling was not detected in monocellular membranes of normal/control globes. SMA was expressed in 10/23 monocellular and 7/8 fibrovascular membranes of glaucomatous globes. CD117 was expressed in 7/23 monocellular and 5/8 fibrovascular membranes of glaucomatous globes. SEM of monocellular membranes revealed a continuous sheet of mostly spindle cells and few individual round cells that extended over the anterior iris face in normal/control and all glaucomatous globes. CONCLUSION: Pre-iridal monocellular membranes are a normal component of the anterior iris surface, and CD18 immunoreactivity suggests some cells within these are of leukocytic origin. SMA and CD117 labeling of monocellular membranes in glaucomatous, but not normal/control globes, suggest metaplastic cellular change secondary to intraocular pathology related to glaucoma.