Risk factors for proliferative vitreoretinopathy

Outcomes after giant peripheral retinotomy and anterior flap retinectomy for rhegmatogenous retinal detachments with advanced proliferative vitreoretinopathy using small gauge vitrectomy

PURPOSE

To analyze the visual and anatomical outcomes for eyes with rhegmatogenous retinal detachment (RRD) and advanced proliferative vitreoretinopathy (PVR) undergoing giant peripheral retinotomy (GPR) using 25-gauge pars plana vitrectomy (PPV).

METHODS

In this retrospective multi-center study, patients with RRD with either anteroposterior or circumferential retinal shortening and advanced PVR requiring more than 90-degree GPR with/without relaxing retinotomy were included. Subjects of either gender, any age group, and with complete surgical notes were included. Outcome measures of the study included anatomical success (i.e. complete retinal re-attachment) at 6 months using survival analysis, visual outcomes, and post-operative complications.

RESULTS

Forty-one eyes of 41 patients (33 males) with a mean age of 44.9 ± 21.4 years were included. At 6 months follow-up, anatomical success was seen in 29 eyes (70.7%) with a cumulative re-attachment rate of 66% (95% confidence interval = 48 = 79%). All re-detachments occurred at ≤6 months with a peak at 4-6 months (n = 9). Twenty-three eyes (56%) achieved ambulatory vision (5/200) or better. Direct perfluorocarbon liquid-silicone oil exchange was performed in 20 eyes. Intra-operative complications included persistent retinal folds (2 eyes), subretinal air (1 eye), and subretinal bleed (1 eye). Eleven eyes (26.8%) developed secondary glaucoma (2 eyes required a drainage device), and hypotony of ≤6 mmHg was noted in 3 eyes (7.3%). Corneal decompensation was noted in 8 eyes (19.5%), and 3 eyes (7.3%) underwent re-surgery for re-RRD.

CONCLUSION

After GPR using small gauge PPV, two-thirds achieve anatomical success, and over half have ambulatory vision, but overall post-operative complications can occur in more than half of the eyes.

Prognostic factors associated with acute retinal necrosis treated non-surgically

OBJECTIVES

To analyse the prognostic factors for visual acuity in acute retinal necrosis (ARN) patients treated non-surgically.

METHODS

The clinical data of ARN patients who visited our hospital from January 2010 to January 2023 were retrospectively analysed.

RESULTS

Twenty-four patients (29 eyes) were included. Aqueous humour samples were collected from 20 out of 29 eyes, and PCR confirmed that 85% (17/20) of the eyes had VZV infection, 10% (2/20) had CMV infection, and 5% (1/20) had HSV infection. All patients were treated with intravenous antiviral agents. Intravitreal ganciclovir and oral corticosteroids were given according to the patients' wishes. A comparison of visual acuity at the time of first identification of inactive ARN with that at the first visit revealed that 16 (55.2%) eyes improved and 13 (44.8%) did not improve. Logistic regression analysis revealed that risk factors for failure to improve vision after treatment included retinal detachment (odds ratio [OR],33.75; 95% CI, 3.245-351.067; P = 0.003), necrotising retinitis involving the posterior pole (odds ratio [OR],8.167; 95% CI, 1.297-51.403, P = 0.025), and arteritis involving the large retinal arteries (odds ratio [OR],9.167; 95% CI, 1.493-56.297; P = 0.017). The VZV viral load in the aqueous humour at initial presentation was significantly associated with visual prognosis (r = 0.688, P = 0.013), retinal detachment (τ = 0.597, P = 0.021) and the extent of retinal necrosis (τ = 0.57, P = 0.027). The neutrophil to lymphocyte ratio (NLR) of VZV-infected patients at first presentation was significantly correlated with the prognosis of visual acuity (r = 0.616, P = 0.033) and retinal detachment (τ = 0.728, P = 0.004).

CONCLUSIONS

High NLR and viral DNA copy number in the aqueous humour at the initial presentation, as well as subsequent retinal detachment, necrotising retinitis involving the posterior pole, and arteritis involving the large retinal arteries were risk factors for poor visual prognosis in VZV-infected ARN patients.

An mRNA-encoded dominant-negative inhibitor of transcription factor RUNX1 suppresses vitreoretinal disease in experimental models

Messenger RNA (mRNA)-based therapies are a promising approach to medical treatment. Except for infectious diseases, no other disease has mRNA-based therapies available. The eye is an ideal model for mRNA therapeutic development because it requires limited dosing. Proliferative vitreoretinopathy (PVR) is a blinding condition caused by retinal detachment that now lacks available medical treatment, with surgery as the only treatment option. We previously implicated runt-related transcription factor-1 (RUNX1) as a driver of epithelial-to-mesenchymal transition (EMT) in PVR and as a critical mediator of aberrant ocular angiogenesis when up-regulated. On the basis of these findings, an mRNA was designed to express a dominant-negative inhibitor of RUNX1 (RUNX1-Trap). We show that RUNX1-Trap delivered in polymer-lipidoid complexes or lipid nanoparticles sequestered RUNX1 in the cytosol and strongly reduced proliferation in primary cell cultures established from fibrotic membranes derived from patients with PVR. We assessed the preclinical efficacy of intraocular delivery of mRNA-encoded RUNX1-Trap in a rabbit model of PVR and in a laser-induced mouse model of aberrant angiogenesis often used to study wet age-related macular degeneration. mRNA-encoded RUNX1-Trap suppressed ocular pathology, measured as pathological scores in the rabbit PVR model and leakage and lesion size in the laser-induced choroidal neovascularization mouse model. mRNA-encoded RUNX1-Trap also strongly reduced proliferation in a human ex vivo explant model of PVR. These data demonstrate the therapeutic potential of mRNA-encoded therapeutic molecules with dominant-negative properties, highlighting the potential of mRNA-based therapies beyond standard gene supplementation approaches.

Silencing the long noncoding RNA MALAT1 inhibits vitreous-induced epithelial-mesenchymal transition in RPE cells by regulating the PDGFRs/AKT axis

PURPOSE

Epithelial-mesenchymal transition (EMT) is a crucial pathological process that contributes to proliferative vitreoretinopathy (PVR), and research indicates that factors present in the vitreous that target cells play pivotal roles in regulating EMT. Experimental studies have confirmed that rabbit vitreous (RV) promotes EMT in human retinal pigment epithelial (RPE) cells. The long noncoding RNA (lncRNA) MALAT1 has been implicated in EMT in various diseases. Thus, this study aimed to investigate the involvement of lncRNA MALAT1 in vitreous-induced EMT in RPE cells.

METHODS

MALAT1 was knocked down in ARPE-19 cells by short hairpin RNA (shRNA) transfection. Reverse transcription PCR (RT‒PCR) was used to evaluate MALAT1 expression, and Western blotting analysis was used to measure the expression of EMT-related proteins. Wound-healing, Transwell, and cell contraction assays were conducted to assess cell migration, invasion, and contraction, respectively. Additionally, cell proliferation was assessed using the CCK-8 assay, and cytoskeletal changes were examined by immunofluorescence.

RESULTS

MALAT1 expression was significantly increased in ARPE-19 cells cultured with RV. Silencing MALAT1 effectively suppressed EMT and downregulated the associated factors snail1 and E-cadherin. Furthermore, silencing MALAT1 inhibited the RV-induced migration, invasion, proliferation, and contraction of ARPE-19 cells. Silencing MALAT1 also decreased RV-induced AKT and P53 phosphorylation.

CONCLUSIONS

In conclusion, lncRNA MALAT1 participates in regulating vitreous-induced EMT in human RPE cells; these results provide new insight into the pathogenesis of PVR and offer a potential direction for the development of antiproliferative drugs.

Effect of race and ethnicity on surgical outcomes for rhegmatogenous retinal detachments

OBJECTIVE

To evaluate the effect of socioeconomic and demographic factors on outcomes in rhegmatogenous retinal detachments (RRDs).

DESIGN

Retrospective cohort study.

METHODS

A total of 71 white and 124 black and/or Hispanic patients who had surgical repair of RRDs between October 2013 and September 2021 at a single-centre safety net hospital. Main outcomes were single surgery success rates (SSSR) and postoperative visual acuity at 6-month and final follow-up.

RESULTS

Black and (or) Hispanic patients were significantly younger (black and [or] Hispanic, 50.7 years vs white, 57.6 years; p = 0.003), had lower mean household incomes (black and [or] Hispanic, $80,932 vs white, $92,911; p = 0.007), were more likely to have more than 1 retinal break (black and [or] Hispanic, 65% vs white, 49%; p = 0.04), and had higher rates of proliferative vitreoretinopathy (PVR) at presentation (black and [or] Hispanic, 35% vs white, 18%; p = 0.02). SSSR was similar (black and [or] Hispanic, 73.4% vs white, 73.2%; p = 0.98), but black and (or) Hispanic patients had worse visual acuity postoperatively (black and [or] Hispanic, 20/63 vs white, 20/40 at final follow-up; p = 0.03). While race was linked to visual outcome in univariate testing; multivariate analysis revealed only macula status (p = 0.007 at 6 months; p = 0.01 at final follow-up), presence of PVR (p < 0.001 at both time points), and SSSR (p = 0.003 at final follow-up) as predictors of worse visual outcomes.

CONCLUSIONS

Preoperative factors such as higher rates of PVR may contribute to worse vision outcomes in black and (or) Hispanic patients undergoing surgical repair for RRD.

Outcomes following repair of early-onset versus delayed-onset rhegmatogenous retinal detachments after acute posterior vitreous detachment

AIM

To report anatomical and functional outcomes after surgical repair of acute-onset vs delayed-onset rhegmatogenous retinal detachments (RDs) following acute posterior vitreous detachment (PVD).

METHODS

A retrospective, comparative interventional cohort study where patients presenting to a single-centre retina practice between October 2015 and March 2020 with delayed RDs (diagnosed ≥42 days after initial presentation of acute PVD) were compared with a 2:1 age-matched and gender-matched acute RD cohort (PVD and RD at initial presentation). The primary outcome was the final attachment rate and single surgery anatomic success (SSAS) at 3 months after RD repair.

RESULTS

A total of 210 eyes were analysed-70 in the delayed RD group and 140 in the acute RD group. SSAS was 58/70 (82.9%) for the delayed RD group and 112/140 (80%) for the acute RD group (p=0.71). At the time of RD diagnosis, mean (SD) logarithm of minimum angle of resolution visual acuity (VA) was 0.51 (0.70) (Snellen, 20/65) in the delayed RD group vs 1.04 (0.92) (Snellen, 20/219) in the acute RD group (p<0.001). Mean VA was better at 1 and 3 months post-repair in the delayed RD group (p=0.005 and 0.041, respectively) but similar by 6 months, 12 months and at the final visit post-repair (p=0.48, 0.27, and 0.23, respectively).

CONCLUSIONS

Delayed-onset RDs occurring ≥6 weeks after initial presentation to a retina specialist with an acute PVD generally had better VA at the time of RD diagnosis and faster post-surgical visual recovery compared with acute-onset RDs diagnosed at the initial presentation. No significant difference in anatomic outcomes was seen between the two groups.

Comparative Analysis of Single-cell and Single-nucleus RNA-sequencing in a Rabbit Model of Retinal Detachment-related Proliferative Vitreoretinopathy

Purpose

Proliferative vitreoretinopathy (PVR) is the most common cause of failure of retinal reattachment surgery, and the molecular changes leading to this aberrant wound healing process are currently unknown. Our ultimate goal is to study PVR pathogenesis by employing single-cell transcriptomics to dissect cellular heterogeneity.

Design

Here we aimed to compare single-cell RNA sequencing (scRNA-seq)  and single-nucleus RNA-sequencing (snRNA-seq) of retinal PVR samples in the rabbit model.

Participants

Unilateral induction of PVR lesions in rabbit eyes with contralateral eyes serving as controls.

Methods

Proliferative vitreoretinopathy was induced unilaterally in Dutch Belted rabbits. At different timepoints after PVR induction, retinas were dissociated into either cells or nuclei suspension and processed for scRNA-seq or snRNA-seq.

Main Outcome Measures

Single cell and nuclei transcriptomic profiles of retinas after PVR induction.

Results

Single-cell RNA sequencing and snRNA-seq were conducted on retinas at 4 hours and 14 days after disease induction. Although the capture rate of unique molecular identifiers and genes were greater in scRNA-seq samples, overall gene expression profiles of individual cell types were highly correlated between scRNA-seq and snRNA-seq. A major disparity between the 2 sequencing modalities was the cell type capture rate, however, with glial cell types overrepresented in scRNA-seq, and inner retinal neurons were enriched by snRNA-seq. Furthermore, fibrotic Müller glia were overrepresented in snRNA-seq samples, whereas reactive Müller glia were overrepresented in scRNA-seq samples. Trajectory analyses were similar between the 2 methods, allowing for the combined analysis of the scRNA-seq and snRNA-seq data sets.

Conclusions

These findings highlight limitations of both scRNA-seq and snRNA-seq analysis and imply that use of both techniques together can more accurately identify transcriptional networks critical for aberrant fibrogenesis in PVR than using either in isolation.

Financial Disclosures

Proprietary or commercial disclosure may be found after the references.

Macular Edema Following Silicone Oil Tamponade for Retinal Detachment: A Literature Review

Macular edema (ME) is a major cause of reduced vision following intraocular surgery. Although the pathophysiology of ME is not completely understood, inflammatory mediators play a key role. The incidence of ME following pars plana vitrectomy with silicone oil tamponade varies between 13% and 27%. ME usually resolves spontaneously following silicone oil removal, but treatment may be required for resistant cases. In this review, the mechanisms of ME formation after pars plana vitrectomy, its incidence, and its possible therapeutic approaches are discussed.

Transition to Chronic Fibrosis in an Animal Model of Retinal Detachment With Features of Proliferative Vitreoretinopathy

Purpose

Proliferative vitreoretinopathy (PVR) is the most common cause of failure of surgically repaired rhegmatogenous retinal detachment (RRD). Chemically induced and cell injection PVR models do not fully simulate the clinical characteristics of PVR in the post-RRD context. There is an unmet need for translational models in which to study mechanisms and treatments specific to RRD-PVR.

Methods

RRD was induced in adult Dutch Belted rabbits. Posterior segments were fixed or processed for RNA sequencing at 6 hours and 2, 7, 14, and 35 days after induction. Histochemical staining and immunolabeling for glial fibrillary acidic protein, alpha smooth muscle actin, vascular endothelial growth factor receptor 2, CD68, and RPE 65 kDa protein were performed, and labeling intensity was scored. Single cell RNA sequencing was performed.

Results

Acute histopathological changes included intravitreal and intraretinal hemorrhage, leukocytic vitritis, chorioretinitis, and retinal rarefaction. Chronic lesions showed retinal atrophy, gliosis, fibrotic subretinal membranes, and epiretinal fibrovascular proliferation. Fibrillar collagen was present in the fibrocellular and fibrovascular membranes in chronic lesions. Moderate to strong labeling of glia and vasculature was detected in chronic lesions. At day 14, most cells profiled by single cell sequencing were identified as Mϋller glia and microglia, consistent with immunolabeling. Expression of several fibrillar collagen genes was upregulated in chronic lesions.

Conclusions

Histological and transcriptional features of this rabbit model simulate important features of human RRD-PVR, including the transition to chronic intraretinal and periretinal fibrosis. This animal model of RRD with features of PVR will enable further research on targeted treatment interventions.

The Effect of Anti-Autotaxin Aptamers on the Development of Proliferative Vitreoretinopathy

This study investigated the effect of anti-autotaxin (ATX) aptamers on the development of proliferative vitreoretinopathy (PVR) in both in vivo and in vitro PVR swine models. For the in vitro study, primary retinal pigment epithelial (RPE) cells were obtained from porcine eyes and cultured for cell proliferation and migration assays. For the in vivo study, a swine PVR model was established by inducing retinal detachment and injecting cultured RPE cells (2.0 × 106). Concurrently, 1 week after RPE cell injection, the anti-ATX aptamer, RBM-006 (10 mg/mL, 0.1 mL), was injected twice into the vitreous cavity. Post-injection effects of the anti-ATX aptamer on PVR development in the in vivo swine PVR model were investigated. For the in vitro evaluation, the cultured RPE cell proliferation and migration were significantly reduced at anti-ATX aptamer concentrations of 0.5-0.05 mg and at only 0.5 mg, respectively. Intravitreal administration of the anti-ATX aptamer also prevented tractional retinal detachment caused by PVR in the in vivo PVR model. We observed that the anti-ATX aptamer, RBM-006, inhibited PVR-related RPE cell proliferation and migration in vitro and inhibited the progression of PVR in the in vivo model, suggesting that the anti-ATX aptamer may be effective in preventing PVR.

Retinotomies and retinectomies: A review of indications, techniques, results, and complications

Retinotomy refers to "cutting" or "incising" the retina, whereas retinectomy denotes "excising" the retina. Retinotomies and retinectomies aid in tackling traction and retinal shortening that persist following membrane dissection and scleral buckling. We performed a literature search using Google Scholar and PubMed, followed by a review of the references procured. All relevant literature was studied in detail and summarized. We discuss the indications of retinotomies and retinectomies for relaxing retinal stiffness, accessing the subretinal space for choroidal neovascular membrane, hemorrhage and abscess clearance, drainage retinotomies to allow retinal flattening, radial retinotomies to release circumferential traction, harvesting free retinal grafts, and prophylactic chorioretinectomies in trauma.

Primary Retinal Detachment Repair in Eyes Deemed High Risk for Proliferative Vitreoretinopathy: Surgical Outcomes in 389 Eyes

PURPOSE

To evaluate surgical outcomes in eyes with primary rhegmatogenous retinal detachment (RRD) deemed at high risk for postoperative proliferative vitreoretinopathy (PVR).

DESIGN

Retrospective, consecutive case cohort study.

PARTICIPANTS

Eyes undergoing primary RRD repair with pars plana vitrectomy (PPV) or combined PPV with scleral buckling (PPV/SB) between January 1, 2016, and December 30, 2017, at Wills Eye Hospital.

METHODS

Eyes were defined as "high risk" if ≥ 1 of the following risk factors for PVR was present on preoperative examination: preoperative PVR grade A or B, vitreous hemorrhage, RRD involving ≥ 50% of retinal area, presence of ≥ 3 retinal breaks, history of prior cryotherapy, presence of choroidal detachment, or duration of RRD > 2 weeks. Surgical failure was defined as an additional intervention required for the retinal reattachment.

MAIN OUTCOMES MEASURES

Single surgery attachment success (SSAS) rate 3 months after first surgical intervention for primary RRD.

RESULTS

Of 2053 reviewed charts, a total of 389 eyes (18.9%) met the definition of high risk and were included in the analysis. Mean patient age was 63.5 years. PPV/SB was performed in 125 (32.1%) eyes and PPV alone in 264 (67.9%) eyes. SSAS rate of the overall cohort was 71.5% at 3 months. SSAS rate was significantly higher in eyes treated with PPV/SB compared with PPV (80.8% vs. 67%, respectively, P = 0.006). On multivariate analysis, use of PPV/SB was the only feature associated with SSAS (odds ratio, 2.04; 95% confidence interval, 1.12-3.69, P = 0.019).

CONCLUSION

In eyes with primary RRD and risk factors for PVR, overall SSAS was 71.5% after primary repair. In this cohort, use of PPV/SB was associated with a significantly higher SSAS compared with PPV alone.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Safety and efficacy of cryopexy during pars Plana vitrectomy in rhegmatogenous retinal detachment

PURPOSE

To evaluate efficacy and safety of intraoperative cryoretinopexy in cases of rhegmatogenous retinal detachment (RRD).

METHODS

In this retrospective, interventional case series, we review the medical records of 85 consecutive cases of RRD treated with pars plana vitrectomy and gas tamponade, without the use of perfluorocarbon liquids. Baseline best-corrected visual acuity, intraocular pressure, number and location of retinal breaks, location and extension of retinal detachment, duration of symptoms, macula status, presence, and grade of proliferative vitreoretinopathy (PVR) were registered. Follow-up visits were at 1 day, 15 days, 1 month and 3 months. Anatomical and functional outcomes and any adverse event were recorded.

RESULTS

Primary anatomical success was obtained in 82/85 patients (96%). During the postoperative period, PVR was observed in 4/85 cases (4.7%), 3 of whom developed recurrence of retinal detachment. 7/85 (8.2%) patients developed ocular hypertension. We built a model of logistic regression including age, sex, lens status, macula status, number of quadrants involved, number of ruptures and duration of symptoms. None of the variables considered was found to be a predictor of postoperative PVR development. Symptom's duration (β = 0.429; 95% CI = 0.009-0.023; P < 0.001) and preoperative BCVA (β = 0.273; 95% CI = 0.034-0.184; P = 0.005) were predictors for final BCVA.

CONCLUSION

These findings emphasize the safety and efficacy of the use of intraoperative cryotherapy, associated with PPV and gas tamponade, for the management of uncomplicated RRDs.

Risk factors for proliferative vitreoretinopathy after retinal detachment surgery: A systematic review and meta-analysis

BACKGROUND

To comprehensively investigate risk factors for proliferative vitreoretinopathy (PVR) after retinal detachment (RD) surgery.

METHODS

PubMed, Embase, Cochrane Library, and Web of Science were systematically searched until May 22, 2023. Risk factors included demographic and disease-related risk factors. Odds ratios (ORs) and weighted mean differences (WMDs) were used as the effect sizes, and shown with 95% confidence intervals (CIs). Sensitivity analysis was conducted. The protocol was registered with PROSPERO (CRD42022378652).

RESULTS

Twenty-two studies of 13,875 subjects were included in this systematic review and meta-analysis. Increased age was associated with a higher risk of postoperative PVR (pooled WMD = 3.98, 95%CI: 0.21, 7.75, P = 0.038). Smokers had a higher risk of postoperative PVR than non-smokers (pooled OR = 5.07, 95%CI: 2.21-11.61, P<0.001). Presence of preoperative PVR was associated with a greater risk of postoperative PVR (pooled OR = 22.28, 95%CI: 2.54, 195.31, P = 0.005). Presence of vitreous hemorrhage was associated with a greater risk of postoperative PVR (pooled OR = 4.12, 95%CI: 1.62, 10.50, P = 0.003). Individuals with aphakia or pseudophakia had an increased risk of postoperative PVR in contrast to those without (pooled OR = 1.41, 95%CI: 1.02, 1.95, P = 0.040). The risk of postoperative PVR was higher among patients with macula off versus those with macula on (pooled OR = 1.85, 95%CI: 1.24, 2.74, P = 0.002). Extent of RD in patients with postoperative PVR was larger than that in patients without (pooled WMD = 0.31, 95%CI: 0.02, 0.59, P = 0.036). Patients with postoperative PVR had longer duration of RD symptoms than those without (pooled WMD = 10.36, 95%CI: 2.29, 18.43, P = 0.012).

CONCLUSION

Age, smoking, preoperative PVR, vitreous hemorrhage, aphakia or pseudophakia, macula off, extent of RD, and duration of RD symptoms were risk factors for postoperative PVR in patients undergoing RD surgery, which may help better identify high-risk patients, and provide timely interventions.

Endoscopy-assisted pars plana vitrectomy in retinal detachments associated with anterior proliferative vitreoretinopathy and epiciliary membranes

BACKGROUND

Proliferative vitreoretinopathy (PVR) is the leading cause of recurrent retinal detachment. Anterior PVR can contribute to recurrent retinal detachment and is often difficult to remove during conventional pars plana vitrectomy. The purpose of this study is to report surgical outcomes of single endoscopy-assisted pars plana vitrectomy (E-PPV) in patients with tractional retinal detachments associated with anterior proliferative vitreoretinopathy and epiciliary membranes.

METHODS

Retrospective review of E-PPV between 2017 and 2021 at a tertiary referral center. Inclusion criteria involved adult patients who underwent E-PPV for tractional retinal detachment with anterior PVR and epiciliary membranes. Data collection included patients' demographics, ophthalmic exam findings, and surgical outcomes. A series of independent sample tests of proportion were conducted using a p-value of 0.05 as the threshold for statistical significance.

RESULTS

Eighteen out of 55 patients who underwent E-PPV met the inclusion criteria. There were six females (33%) and 12 males (p-value = 0.096). Age ranged between 27 and 82 years old (mean age 52.1 ± 17.3 years). Nine patients (50%) had a history of ipsilateral retinal detachment repair. Single E-PPV success rate was 100% after three months, and 94.4% at the latest follow up visit. Recurrent retinal detachment with posterior PVR occurred in one patient four months after surgery. Cataract progressed in 57% (8/14) of phakic patients, with 63% (5/8) undergoing cataract extraction surgery within the first postoperative year.

CONCLUSION

E-PPV enabled epiciliary membrane and anterior PVR visualization and removal. The single E-PPV success rate remained high at the latest follow up visit. E-PPV enabled the preservation of the phakic lens in all study patients. Larger prospective studies are needed on the role of E-PPV in retina surgeries.

In vitro laboratory models of proliferative vitreoretinopathy

Proliferative vitreoretinopathy (PVR), the most common cause of recurrent retinal detachment, is characterized by the formation and contraction of fibrotic membranes on the surface of the retina. There are no Food and Drug Administration (FDA)-approved drugs to prevent or treat PVR. Therefore, it is necessary to develop accurate in vitro models of the disease that will enable researchers to screen drug candidates and prioritize the most promising candidates for clinical studies. We provide a summary of recent in vitro PVR models, as well as avenues for model improvement. Several in vitro PVR models were identified, including various types of cell cultures. Additionally, novel techniques that have not been used to model PVR were identified, including organoids, hydrogels, and organ-on-a-chip models. Novel ideas for improving in vitro PVR models are highlighted. Researchers may consult this review to help design in vitro models of PVR, which will aid in the development of therapies to treat the disease.

Myo/Nog Cells: The Jekylls and Hydes of the Lens

Herein, we review a unique and versatile lineage composed of Myo/Nog cells that may be beneficial or detrimental depending on their environment and nature of the pathological stimuli they are exposed to. While we will focus on the lens, related Myo/Nog cell behaviors and functions in other tissues are integrated into the narrative of our research that spans over three decades, examines multiple species and progresses from early stages of embryonic development to aging adults. Myo/Nog cells were discovered in the embryonic epiblast by their co-expression of the skeletal muscle-specific transcription factor MyoD, the bone morphogenetic protein inhibitor Noggin and brain-specific angiogenesis inhibitor 1. They were tracked from the epiblast into the developing lens, revealing heterogeneity of cell types within this structure. Depletion of Myo/Nog cells in the epiblast results in eye malformations arising from the absence of Noggin. In the adult lens, Myo/Nog cells are the source of myofibroblasts whose contractions produce wrinkles in the capsule. Eliminating this population within the rabbit lens during cataract surgery reduces posterior capsule opacification to below clinically significant levels. Parallels are drawn between the therapeutic potential of targeting Myo/Nog cells to prevent fibrotic disease in the lens and other ocular tissues.

Applications of Human Amniotic Membrane Patching Assisted Vitrectomy in the Management of Postoperative PVR in Complex Retinal Detachments

Human amniotic membranes (hAMs) are extraembryonic tissues currently employed in the treatment of many ocular and systemic diseases. Several reports indicate that hAMs can suppress the signaling pathway of tissue growth factor beta (TGF-β), a cytokine that plays a major role in the pathogenesis of proliferative vitreoretinopathy (PVR) through the induction of epithelial-mesenchymal transition (EMT) in exposed retinal pigmented epithelium (RPE) cells. The present study was conducted to evaluate the efficacy of a modified vitrectomy procedure (hAMP-V) involving the extensive coverage of exposed RPE with hAM patches to prevent postoperative PVR in a series of 15 cases of retinal detachment complicated by severe preoperatory PVR. The primary outcome was to assess the rate of successful retinal reattachment of a single hAMP-V procedure at 6 months from silicone oil removal. Secondary outcomes included the collection of intraoperative data concerning the quantity, size, and scope of hAM patches, and the assessment of postoperative improvements in mean LogMar BCVA at 3 and 6 months. Successful retinal reattachment was obtained in 14 out of 15 eyes (93.3%). Surgical failure due to major recurrence of PVR occurred in 1 out of 15 eyes (6.7%). Postoperative improvements in mean LogMar BCVA were statistically significant (p < 0.05, paired t-test). No intraoperative and postoperative adverse effects were reported. The study helped to refine the surgical technique while also offering cues for future improvements.

Myo/Nog Cells Give Rise to Myofibroblasts During Epiretinal Membrane Formation in a Mouse Model of Proliferative Vitreoretinopathy

Purpose

Myo/Nog cells are the source of myofibroblasts in the lens and synthesize muscle proteins in human epiretinal membranes (ERMs). In the current study, we examined the response of Myo/Nog cells during ERM formation in a mouse model of proliferative vitreoretinopathy (PVR).

Methods

PVR was induced by intravitreal injections of gas and ARPE-19 cells. PVR grade was scored by fundus imaging, optical coherence tomography, and histology. Double label immunofluorescence localization was performed to quantify Myo/Nog cells, myofibroblasts, and leukocytes.

Results

Myo/Nog cells, identified by co-labeling with antibodies to brain-specific angiogenesis inhibitor 1 (BAI1) and Noggin, increased throughout the eye with induction of PVR and disease progression. They were present on the inner surface of the retina in grades 1/2 PVR and were the largest subpopulation of cells in grades 3 to 6 ERMs. All α-SMA-positive (+) cells and all but one striated myosin+ cell expressed BAI1 in grades 1 to 6 PVR. Folds and areas of retinal detachment were overlain by Myo/Nog cells containing muscle proteins. Low numbers of CD18, CD68, and CD45+ leukocytes were detected throughout the eye. Small subpopulations of BAI1+ cells expressed leukocyte markers. ARPE-19 cells were found in the vitreous but were rare in ERMs. Pigmented cells lacking Myo/Nog and muscle cell markers were present in ERMs and abundant within the retina by grade 5/6.

Conclusions

Myo/Nog cells differentiate into myofibroblasts that appear to contract and produce retinal folds and detachment. Targeting BAI1 for Myo/Nog cell depletion may be a pharmacological approach to preventing and treating PVR.

[Severe contusion of the eyeball as a risk factor for the development of proliferative vitreoretinopathy]

The article is devoted to the problem of proliferative vitreoretinopathy (PVR) developing after severe contusions of the eyeball. Some experts doubt the possibility of developing such a severe complication after a closed eye injury, however, the accumulated literature data and research by scientists demonstrate a high probability of developing PVR in such cases, which could lead to adverse outcomes. The article presents the views of different authors and systematizes information about the frequency and the risk factors of developing PVR after different types of closed eye injury. The main purpose of this review is to demonstrate a high probability of developing PVR after a closed eye injury, which should alert specialists at the first stages of treatment in such patients and stimulate timely prevention and treatment of this complication.

Large inferior retinectomies for proliferative vitreoretinopathy in silicone oil-filled eyes

Background

To describe the anatomical and functional outcomes and late complications in patients who developed inferior proliferative vitreoretinopathy (PVR) in silicone oil-filled eyes and who required reoperation with large inferior retinectomy.

Methods

This is a single-center, retrospective, interventional case series analysis. The study involved 18 individuals with tractional retinal re-detachment due to PVR development inferiorly in eyes who had undergone prior pars plana vitrectomy and silicone oil as a tamponade. All patients included in the study underwent secondary surgery with large inferior retinectomy (from 120° to 270°) and silicone oil filling.

Results

The mean follow-up period was 44.0 ± 31.5 (± SD) months (range: 4 to 96 months. The anatomical success, defined as the complete reattachment of the retina until the last follow-up, was observed in 88.9% of the cases. The postoperative visual acuity ranged from 20/100 to hand motion at 60 cm. Only two cases (11.1%) did not achieve anatomical success at the last follow-up due to recurrent PVR and retinal re-detachment (one including hypotony). All of the patients were pseudophakic. The PVR grade, as well as the presence of PVR prior to primary surgery, showed no statistical correlation with BCVA, the extent of retinectomies, and final macular status. There was a statistically significant correlation between "Final BCVA" and "Initial BCVA" (r = 0.654) and between "Final BCVA" and "Extent of Retinectomy" (r = 0.615).

Conclusions

Reoperation in eyes filled with silicone oil may be required when PVR is developed. Secondary surgery in these cases with large inferior retinectomy and silicone oil implantation may reach good anatomical success with low rates of late complications, besides improving visual acuity. A better BCVA at the time of re-RD diagnosis and cases of retinectomies with greater extensions showed a positive correlation with better functional outcomes.

Trial registration Research Ethics Committee of the Suel Abujamra Institute reviewed and approved this study protocol (approval number, 5.404.961).

Supplementary Information

The online version contains supplementary material available at 10.1186/s40942-022-00420-1.

Long-acting formulation strategies for protein and peptide delivery in the treatment of PSED

The invigoration of protein and peptides in serious eye disease includes age-related macular degeneration, choroidal neovascularization, retinal neovascularization, and diabetic retinopathy. The transportation of macromolecules like aptamers, recombinant proteins, and monoclonal antibodies to the posterior segment of the eye is challenging due to their high molecular weight, rapid degradation, and low solubility. Moreover, it requires frequent administration for prolonged therapy. The long-acting novel formulation strategies are helpful to overcome these issues and provide superior therapy. It avoids frequent administration, improves stability, high retention time, and avoids burst release. This review briefly enlightens posterior segments of eye diseases with their diagnosis techniques and treatments. This article mainly focuses on recent advanced approaches like intravitreal implants and injectables, electrospun injectables, 3D printed drug-loaded implants, nanostructure thin-film polymer devices encapsulated cell technology-based intravitreal implants, injectable and depots, microneedles, PDS with ranibizumab, polymer nanoparticles, inorganic nanoparticles, hydrogels and microparticles for delivering macromolecules in the eye for intended therapy. Furthermore, novel techniques like aptamer, small Interference RNA, and stem cell therapy were also discussed. It is predicted that these systems will make revolutionary changes in treating posterior segment eye diseases in future.

TNF-α and NF-κB signaling play a critical role in cigarette smoke-induced epithelial-mesenchymal transition of retinal pigment epithelial cells in proliferative vitreoretinopathy

Proliferative vitreoretinopathy (PVR) is characterized by the growth and contraction of cellular membranes within the vitreous cavity and on both surfaces of the retina, resulting in recurrent retinal detachments and poor visual outcomes. Proinflammatory cytokines like tumor necrosis factor alpha (TNFα) have been associated with PVR and the epithelial-mesenchymal transition (EMT) of retinal pigment epithelial (RPE) cells. Cigarette smoke is the only known modifiable risk factor for PVR, but the mechanisms are unclear. The purpose of this study was to examine the impact of cigarette smoke on the proinflammatory TNFα/NF-κB/Snail pathway in RPE cells to better understand the mechanisms through which cigarette smoke increases the risk of PVR. Human ARPE-19 cells were exposed to cigarette smoke extract (CSE), for 4 to 24-hours and TNFα, Snail, IL-6, IL-8, and α-SMA levels were analyzed by qPCR and/or Western blot. The severity of PVR formation was assessed in a murine model of PVR after intravitreal injection of ARPE-19 cells pre-treated with CSE or not. Fundus imaging, OCT imaging, and histologic analysis 4 weeks after injection were used to examine PVR severity. ARPE-19 cells exposed to CSE expressed higher levels of TNFα, SNAIL, IL6 and IL8 mRNA as well as SNAIL, Vimentin and α-SMA protein. Inhibition of TNFα and NF-κB pathways blocked the effect of CSE. In vivo, intravitreal injection of ARPE-19 cells treated with CSE resulted in more severe PVR compared to mice injected with untreated RPE cells. These studies suggest that the TNFα pathway is involved in the mechanism whereby cigarette smoke increases PVR. Further investigation into the role of TNFα/NF-κB/Snail in driving PVR and pharmacological targeting of these pathways in disease are warranted.

Incidence of Delayed Vitreous Hemorrhage in Patients With Retinal Tears Associated With Bridging Vessels

BACKGROUND AND OBJECTIVE

The purpose of this article is to determine if outcomes in patients presenting with retinal tears with bridging vessels (BVs) differ from those without BVs.

PATIENTS AND METHODS

A case control study of all patients presenting with retinal tears during a 3-year period was completed. Comparisons were made between patients with and without BVs. Variables included vitreous hemorrhage (VH) at presentation, delayed VH, initial and final visual acuity, need for surgery, and retinal detachment.

RESULTS

There was a significant increase in the number of patients with a VH at presentation (75% vs 28%; P < .0001), delayed VH (31% vs 7.5%; P = .001), and incidence of pars plana vitrectomy (16% vs 1.3%; P = .002) in the BV cohort. There was no significant difference in time to VH (9.4 vs 38.8 days; P = .32) or final visual acuity (20/25 vs 20/25; P = .45) between the two groups.

CONCLUSIONS

The presence of a BV is an important prognostic indicator for risk of delayed VH. Documenting the presence of a BV allows for appropriate patient counseling. [Ophthalmic Surg Lasers Imaging Retina 2022;53:502-505.].

Mini vitrectomy as an alternative technique for intraocular pressure adjustment in non-drainage scleral buckling

Purpose In non-drainage scleral buckling, anterior chamber paracentesis is usually carried out to decrease intraocular pressure. When the buckling is extensive however, this technique may be inefficient and time consuming. In this study, we tried to determine if a mini 25-gauge pars plana vitrectomy could be used as an efficient and safe alternative procedure to anterior chamber paracentesis for adjusting intraocular pressure during a non-drainage scleral buckling. Methods In this case series, 44 patients with rhegmatogenous retinal detachment (proliferative vitreoretinopathy stage < C) were included. In all cases, a mini 25-gauge pars plana vitrectomy was performed before buckle fixation and repeated if necessary. Complete retinal attachment was defined as the anatomical success. Results Forty-four eyes of 44 patients with mean age of 48.1 ± 18.2 years were included. Silicon buckle nº 276, sponge 505, and sponge 507 were utilized for 7, 34, and 3 eyes, respectively. Intravitreal injection of SF6 gas was performed for 54.5% of the eyes. Mean total time of the operation was 61 ± 16 min and the mean time for vitrectomy was 87 ± 31 s. Complete retinal attachment in 37 and incomplete attachment in 4 eyes were achieved after single operation that was a success rate of 93.2%. One had more than usual vitreous leak at the site of scleretomy and one developed a tiny vitreous hemorrhage at the sclerotomy site. Three sclerotomy sites needed suturing. Conclusion The anatomical outcome and the safety observed in this study were comparable to the current methods reported in the literature. Therefore, if anterior chamber paracentesis fails to adjust intraocular pressure during a non-drainage scleral buckling, performing a small gauge mini vitrectomy is safe and helpful.

Utility of Removal of Vitreous Cortex Remnants during Vitrectomy for Primary Rhegmatogenous Retinal Detachment Repair

PURPOSE

To investigate the prevalence of vitreous cortex remnants (VCR) in primary rhegmatogenous retinal detachment (RRD) and the utility of VCR removal using diamond-dusted membrane scrapers (DDMS) during pars plana vitrectomy (PPV).

METHODS

One hundred and eighty-seven eyes (187 consecutive patients) were retrospectively studied. We evaluated the prevalence of VCR on the retinal surface extending from the macula to outside the vascular arcade in eyes that underwent PPV for primary RRD by a single surgeon between July 2014 and February 2021. The VCR outside the vascular arcade was completely removed using a DDMS. Preoperative factors and surgical outcomes were compared between eyes with VCR removed intraoperatively to those without VCR.

RESULTS

VCR was present and removed (group A) in 86 (46%) eyes and absent (group B) in 101 (54%) eyes. Patients with VCR were significantly older than those without (P = 0.006). The preoperative BCVA (logMAR) tended to be worse in group A (1.23 ± 0.92 [Snellen equivalent, 20/340]) than in group B (1.03 ± 0.89 [20/214]), however, the difference was not statistically significant (P = 0.095). There were no between-group differences in postoperative BCVA (group A; 0.44 ± 0.54 [20/55]; group B; 0.42 ± 0.50 [20/53]; P = 0.38). Single surgery anatomic success (group A; 90%, group B; 91%, P = 0.573) and the incidence of postoperative PVR (group A; 9%, group B; 6%, P = 0.554) were comparable between the groups.

CONCLUSIONS

Nearly half of the patients had VCR, which was more likely to occur in older patients. VCR removal resulted in favorable functional and anatomic outcomes similar to those in eyes without any VCR in patients with RRD.

A bio-functional polymer that prevents retinal scarring through modulation of NRF2 signalling pathway

One common cause of vision loss after retinal detachment surgery is the formation of proliferative and contractile fibrocellular membranes. This aberrant wound healing process is mediated by epithelial-mesenchymal transition (EMT) and hyper-proliferation of retinal pigment epithelial (RPE) cells. Current treatment relies primarily on surgical removal of these membranes. Here, we demonstrate that a bio-functional polymer by itself is able to prevent retinal scarring in an experimental rabbit model of proliferative vitreoretinopathy. This is mediated primarily via clathrin-dependent internalisation of polymeric micelles, downstream suppression of canonical EMT transcription factors, reduction of RPE cell hyper-proliferation and migration. Nuclear factor erythroid 2-related factor 2 signalling pathway was identified in a genome-wide transcriptomic profiling as a key sensor and effector. This study highlights the potential of using synthetic bio-functional polymer to modulate RPE cellular behaviour and offers a potential therapy for retinal scarring prevention.

Autofluorescence Imaging in the Long-Term Follow-Up of Scleral Buckling Surgery for Retinal Detachment

Purpose

To analyse fundus autofluorescence (AF) changes in retinal reattachment following primary scleral buckling (SB) surgery for rhegmatogenous retinal detachment (RRD).

Methods

Prospective noninterventional chart review study. AF images were reviewed for peripheral and central changes and compared to clinical and OCT findings.

Results

A total of 73 eyes from 69 patients were included, four presenting with bilateral RRD. Mean age was 55 ± 12 years, male/female ratio 40/29, fovea-on/-off RRD 43/30, and mean follow-up time 376 ± 270 days, with a mean of 5 ± 3 postoperative visits. Preoperatively, RRD was seen as a hypofluorescent area with a hyperfluorescent leading edge. Immediately postoperatively, three types of cryopexy could be differentiated, gradually transforming to scleral hyperfluorescence. Buckle tightening produced alternating hyper-/hypofluorescent streaks, and demarcation lines showed a persistent rugged hyperfluorescent signal. Choroidal detachment led to transient hypofluorescence, whereas vortex vein compression induced persistent hypofluorescence. Peripheral retinal folds were hyperfluorescent and the drainage site was hypofluorescent. AF was highly sensitive in detecting even small amounts of hyperfluorescent persistent subretinal fluid (SRF) that showed a slow resolution during follow-up. A granular “salt-and-pepper-” like pattern in the central macula was seen in 80% of eyes with fovea-off RRD and alternating streaks in 10%. Findings from OCT imaging correlated well with AF regarding SRF, macular oedema, retinal pigment epithelial detachment, and presence of a subretinal scar, but only moderately in epiretinal membrane formation and choroidal folds.

Conclusions

AF is a useful, noninvasive, adjuvant tool in the long-term follow-up after SB surgery.

Early vitrectomy in eyes with non-diabetic vitreous hemorrhage

Background

Optimal management of non-diabetic vitreous hemorrhage (NDVH) is controversial, and reliability of B-scan ultrasonography in detecting retinal tears (RTs) has been reported to be highly variable by previous literature.

Objectives

To report outcomes of conservative versus surgical management of NDVH and reliability of B-scan ultrasonography in detecting RTs and rhegmatogenous retinal detachment (RRD).

Design

Retrospective observational single-center cohort study.

Methods

Ninety-six consecutive NDVH from 96 eyes (96 patients) with minimum follow-up duration of 12 months were included.

Results

Seventy-two eyes (75%) underwent early pars plana vitrectomy (PPV), 19 (20%) were managed conservatively and 5 (5%) underwent late PPV. Initial mean best corrected visual acuities (BCVAs) were 1.95 ± 1.19, 1.19 ± 1.38, and 1.14 ± 1.04 logMAR respectively, the difference was statistically significant (p = 0.039). Mean final BCVAs were 0.92 ± 1.19, 0.59 ± 0.87, and 1.25 ± 1.89 logMAR, respectively, the difference was not significant (p = 0.447). When comparing initial and final BCVAs, the difference was significant only in the early PPV group (p = 0.00001) and was not significant in the conservative group (p = 0.066) and in the late PPV group (p = 0.46). Complications included RRD (n = 2) and re-bleed in vitrectomized cavity (n = 1) in the early surgical group, need for additional laser or cryoretinopexy to RTs (n = 2), retinal detachment (n = 1), neovascular glaucoma (n = 1), persistent vitreous hemorrhage (n = 2) in the conservative group. B-scan ultrasound showed preoperative 11.53% sensitivity and a 60.0% positive predictive value for diagnosing retinal tears (RTs) in NDVH.

Conclusion

The benefit of early PPV in NDVH seems to outweigh the risks of surgery, especially in the context of low sensitivity of B-scan in identifying RTs, and significant improvement in final BCVA following surgery may occur. NDVH should be promptly referred to vitreoretinal services, as surgery may be a safer and more advisable option.

Managing PVR in the Era of Small Gauge Surgery

Proliferative vitreoretinopathy (PVR) is the leading cause of failed rhegmatogenous retinal detachment (RRD) surgery. Based upon the presence of clinical features and due to associated underlying risk factors, it is classified into various grades based upon its severity and extent of involvement. Despite excellent skills, flawless techniques, and high-end technology applied in the management of RRD, PVR still occurs in 5–10% of cases. Due to the advancements in wide angle viewing systems, advance vitrectomy machines and fluidics, early identification, use of long-term heavy silicon oil tamponades, high-speed cutters, small-gauge vitrectomies, use of perfluorocarbon liquid (PFCL), and small-gauge forceps and scissors, the success rate in the management of PVR has increased leading to improved anatomical outcomes. However, functional outcomes do not correlate well with improved anatomical outcomes. Various complications occur after RRD repair that are responsible for re-retinal detachment and recurrence of PVR. This article highlights causes, risk factors, classification, grading, diagnosis, and approach to management of PVR and post-PVR surgery complications.

Systemic Curcumin-Human Serum Albumin in Proliferative Vitreoretinal Retinopathy: A Pilot Study

Objectives The purpose of this study is to compare the risks of novel postoperative curcumin infusion in patients with increased proliferative vitreoretinal retinopathy (PVR) after retinal detachment with steroid infusion or no treatment. Methods This was a prospective, non-randomized pilot study of 15 eyes of 15 patients (mean age 68 ± 7 years) with retinal detachment, macula off, and flare >15 pc/ms. Postoperatively, the patients received either curcumin-HSA (human serum albumin) infusion (C, n=5), prednisolone infusion (P, n=5), or no therapy (N, n=5) for three days. The outcome measures included postoperative PVR rate, the number of vitreoretinal surgeries (VRS) required, epiretinal membrane development, and visual acuity (VA).  Results All patients had a preoperative VA of hand movements, macula-off detachment situation, and two quadrants rhegmatogenous retinal detachment. Patients underwent VRS at a mean time of 5.6 ± 1.5 (C), 4.9 ± 2.0 (P), 4.7 ± 1.2 (N) days after first recognized symptoms. Postoperative PVR developed just in one eye (P) after 16 days and required VRS due to PVR retinal detachment. The remaining 14 patients of group C and N did not develop PVR. BCVA improved six months post surgery to 0.56 ± 0.31 (P), 0.53 ± 0.19 (D), 0.53 ± 0.17 (N) logMAR. There were no side effects nor complications related to the postoperative infusions.  Conclusions In this pilot study, we demonstrated that a postoperative application of curcumin infusion is a safe option in patients with an increased risk of PVR. Whether or not PVR can be reduced by curcumin infusion would require to be investigated in larger, randomized clinical trials.

Vitrectomy vs. Combined Vitrectomy and Scleral Buckle for Repair of Primary Rhegmatogenous Retinal Detachment with Vitreous Hemorrhage

OBJECTIVE

To compare pars plana vitrectomy (PPV) to PPV with scleral buckle (PPV/SB) for repair of primary rhegmatogenous retinal detachment (RRD) with associated vitreous hemorrhage (VH).

DESIGN

Retrospective, observational study.

SUBJECTS

Patients with RRD and associated VH who underwent PPV or PPV/SB from January 1, 2010 through August 31, 2020 were analyzed.

METHODS, INTERVENTION, OR TESTING

We performed a single-institution, retrospective, observational study of 224 eyes with RRD and VH at the time of detachment. We excluded eyes with less than 6 months of follow up, prior history of retinal detachment repair with vitrectomy or scleral buckle, VH that resolved before surgical intervention, tractional or combined tractional and rhegmatogenous detachment.

MAIN OUTCOME MEASURES

Single surgery anatomic success (SSAS) at 6 months, defined as no recurrent retinal detachment requiring surgical intervention.

RESULTS

PPV and PPV/SB were performed on 138 eyes (62%) and 85 eyes (38%), respectively. The mean age was 61.9 years in PPV patients and 60.2 years in PPV/SB patients. Single-surgery anatomic success was achieved in 107 of 138 (77.5%) eyes that underwent PPV and in 78 of 85 (91.7%) eyes that underwent PPV/SB. The difference in SSAS between types of treatment was significant (p = 0.006). Mean visual acuity improvement in the PPV/SB group was 0.54 logMAR units greater than the PPV group (p = 0.126). The incidence of postoperative PVR in the PPV/SB group (11.7%) was lower than in the PPV group (19.5%) (p = 0.128). The rate of repeat PPV for non-RD reasons was similar for both groups (p = 0.437). Final reattachment status was achieved in 137 of 138 and 84 of 85 eyes in the PPV and PPV/SB groups, respectively. Final visual acuity improvement was significantly better in eyes with PPV/SB compared to PPV alone (logMAR 2.12 vs 1.26; p=0.011).

CONCLUSIONS

In RRD with VH patients, SSAS was superior in patients treated with PPV/SB compared with PPV alone. Although not significantly different, the PPV/SB group had better visual outcomes and a lower postoperative PVR rate.

Vitreous M2 Macrophage-Derived Microparticles Promote RPE Cell Proliferation and Migration in Traumatic Proliferative Vitreoretinopathy

Purpose

To characterize vitreous microparticles (MPs) in patients with traumatic proliferative vitreoretinopathy (PVR) and investigate their role in PVR pathogenesis.

Methods

Vitreous MPs were characterized in patients with traumatic PVR, patients with rhegmatogenous retinal detachment (RRD) complicated with PVR, and control subjects by flow cytometry. The presence of M2 macrophages in epiretinal membranes was measured by immunostaining. Vitreous cytokines were quantified by ELISA assay. For in vitro studies, MPs isolated from THP-1 cell differentiated M1 and M2 macrophages, termed M1-MPs and M2-MPs, were used. The effects and mechanisms of M1-MPs and M2-MPs on RPE cell proliferation, migration, and epithelial to mesenchymal transition were analyzed.

Results

Vitreous MPs derived from photoreceptors, microglia, and macrophages were significantly increased in patients with traumatic PVR in comparison with control and patients with RRD (PVR), whereas no significance was identified between the two control groups. M2 macrophages were present in epiretinal membranes, and their signature cytokines were markedly elevated in the vitreous of patients with traumatic PVR. Moreover, MPs from M2 macrophages were increased in the vitreous of patients with traumatic PVR. In vitro analyses showed that M2-MPs promoted the proliferation and migration of RPE cells via activation of the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signaling pathway. However, M2-MPs did not induce the expression of fibrotic proteins, including fibronectin, α-smooth muscle actin, and N-cadherin in RPE cells.

Conclusions

This study demonstrated increased MP shedding in the vitreous of patients with traumatic PVR; specifically, MPs derived from M2 polarized macrophages may contribute to PVR progression by stimulating RPE cell proliferation and migration.

Use of Intravitreal Methotrexate Infusion in Complicated Retinal Detachment for Prevention of Proliferative Vitreoretinopathy in a Pilot Study

Objective

The objective of this pilot study was to evaluate the efficacy and safety of per-operative intravitreal methotrexate (MTX) infusion during vitrectomy in patients of retinal detachment (RD) with advanced grade proliferative vitreoretinopathy (PVR).

Methods

In this prospective interventional case series, we included patients with Grade C PVR, recurrent RD, and open globe trauma. All patients underwent standard single surgeon operated 23-gauge pars plana vitrectomy (PPV) with 80mg of MTX in 1000mL of irrigation fluid. All patients were followed up after four months to assess the final status of retinal attachment and visual acuity. Ethical review board permission was sought for this off-label use of MTX and all patients signed an informed consent form before this intervention.

Results

Thirty eyes of 30 patients with recurrent retinal detachment, open globe trauma, or grade C PVR at initial presentation were included in this study. After PPV, these patients were followed up after four months. A total of 24 (80%) patients maintained retinal attachment at four months. Mean preoperative best-corrected visual acuity (BCVA) was 1.35 logarithm of the minimum angle of resolution (logMAR) (range 0.5-3) and mean four months postoperative BCVA was 1.01 logMAR (range 0.3-3) (Student’s t-test; P-value <0.05). Seventeen (56.6%) eyes had pre-operative BCVA of 1.0 whereas 25 (83.3%) had BCVA of 1.0 at the end of the follow-up period. Six (20%) patients had preoperative BCVA of 0.7 whereas 12 (40%) patients had BCVA of 0.7 at four months postoperatively. Out of six (20%) eyes developing RD after this intervention, four eyes achieved retinal reattachment after a second surgery. We did not observe any MTX-related complications during the follow-up period of this study.

Conclusion

Intravitreal MTX infusion during PPV for complicated RD as an adjunctive therapy showed encouraging results and was found to be safe in its use. We need more rigorous and controlled studies to confirm the possible advantages of MTX and its role in the prevention of PVR.

EXTERNAL DRAINAGE OF SUBRETINAL FLUID DURING RHEGMATOGENOUS RETINAL DETACHMENT REPAIR

PURPOSE

To describe the safety and efficacy of rhegmatogenous retinal detachment (RRD) repair with external drainage of subretinal fluid using a 28-gauge External Drainage and Depression device (Vortex Surgical, Chesterfield, MO).

METHODS

Retrospective review of patients who underwent primary rhegmatogenous retinal detachment repair with scleral buckle, pars plana vitrectomy, or scleral buckle/pars plana vitrectomy using the drainage device from August 2018 through March 2020, performed by four surgeons at two vitreoretinal practices.

RESULTS

Eighty-three eyes of 83 patients were included. At presentation, 28% had proliferative vitreoretinopathy. Surgery included 65% scleral buckle/pars plana vitrectomy, 33% pars plana vitrectomy, and 2% scleral buckle. There were no cases of retinal incarceration and two subretinal hemorrhages at the drainage site (both < 2 DD), 2 cases of recurrent RD with proliferative vitreoretinopathy (1 had proliferative vitreoretinopathy at presentation), and 6 (10%) new epiretinal membranes (3 were mild). There were no other complications. Mean follow-up was 274 days. Single operation success rate for those with ≥ 6-month follow-up was 97% (57/59).

CONCLUSION

External drainage of subretinal fluid during rhegmatogenous retinal detachment repair demonstrated a favorable safety profile with a high single operation success rate. Further study of the role of external drainage in rhegmatogenous retinal detachment repair is warranted.

FHL-1 interacts with human RPE cells through the α5β1 integrin and confers protection against oxidative stress

Retinal pigment epithelial (RPE) cells that underlie the neurosensory retina are essential for the maintenance of photoreceptor cells and hence vision. Interactions between the RPE and their basement membrane, i.e. the inner layer of Bruch's membrane, are essential for RPE cell health and function, but the signals induced by Bruch's membrane engagement, and their contributions to RPE cell fate determination remain poorly defined. Here, we studied the functional role of the soluble complement regulator and component of Bruch's membrane, Factor H-like protein 1 (FHL-1). Human primary RPE cells adhered to FHL-1 in a manner that was eliminated by either mutagenesis of the integrin-binding RGD motif in FHL-1 or by using competing antibodies directed against the α5 and β1 integrin subunits. These short-term experiments reveal an immediate protein-integrin interaction that were obtained from primary RPE cells and replicated using the hTERT-RPE1 cell line. Separate, longer term experiments utilising RNAseq analysis of hTERT-RPE1 cells bound to FHL-1, showed an increased expression of the heat-shock protein genes HSPA6, CRYAB, HSPA1A and HSPA1B when compared to cells bound to fibronectin (FN) or laminin (LA). Pathway analysis implicated changes in EIF2 signalling, the unfolded protein response, and mineralocorticoid receptor signalling as putative pathways. Subsequent cell survival assays using H2O2 to induce oxidative stress-induced cell death suggest hTERT-RPE1 cells had significantly greater protection when bound to FHL-1 or LA compared to plastic or FN. These data show a non-canonical role of FHL-1 in protecting RPE cells against oxidative stress and identifies a novel interaction that has implications for ocular diseases such as age-related macular degeneration.

The risk factors of the progression of rhegmatogenous retinal detachment on patients with the fourteen-day quarantine in the early period of COVID-19 outbreak

Backgrounds

The COVID-19 Pandemic has a great impact on hospitals and patients. The 14-day quarantine caused surgery of rhegmatogenous retinal detachment (RRD) postponed. We aimed to explore the risk factors of RRD progression in a group of patients whose surgery was postponed during the top-level emergency response of COVID-19.

Methods

A retrospective case series. Medical records of all consecutive patients with a diagnosis of RRD who underwent a surgical treatment at Beijing Tongren Hospital’s retina service from February 16, 2020, to April 30, 2020 have been reviewed retrospectively. Medical history, symptoms, and clinical signs of progression of RRD were recorded. RRD progression was defined as the presence of either choroidal detachment or proliferative vitreoretinopathy (PVR) progression during the quarantine period. Risk factors were analyzed using the Cox proportional hazards model, survival analysis, and logistic regression.

Results

Seventy-nine eyes of 79 patients met the inclusion criteria and were included in the study. The median time from the patients’ presentation at the clinic to admission for surgery was 14 days (3–61 days). There were 70 cases (88.6%) who did not present to the hospital within 1 week of the onset of visual symptoms. There were 69 (87.3%) macular-off cases at the presentation and 27 (34.2%) cases combined with choroidal detachment. There were 49 (62.0%) cases with PVR B, 22 (27.8%) cases with PVR C, 4 (5.1%) cases with PVR D, and 4 (5.1%) cases with anterior PVR. After the 14-day quarantine, 21 (26.6%) cases showed RRD progression, and 9 cases showed RRD regression at the time of surgery. Neither the time of onset of the visual symptom (p = 0.46) nor the time between presentation and admission (p = 0.31) was significantly different between the patients with RRD progression and patients without RRD progression. The combination of choroidal detachment (3.07, 1.68-5.60, p<0.001) and retinal breaks located posterior to the equator (3.79, 1.21-11.80, p=0.02) were factors related to the progression of RRD.

Conclusions

In our study during the COVID-19 outbreak, the RRD progression risk factors included a combination of choroidal detachment and retinal breaks posterior to the equator. Ophthalmologists should schedule the surgeries for RRD patients with these signs as soon as possible.

SINGLE NUCLEOTIDE POLYMORPHISMS IN RETINAL DETACHMENT PATIENTS WITH AND WITHOUT PROLIFERATIVE VITREORETINOPATHY

PURPOSE

To investigate differences in genotype distributions of single nucleotide polymorphisms within genes, encoding inflammatory mediators, among patients with rhegmatogenous retinal detachment (RRD) and patients with proliferative vitreoretinopathy (PVR).

METHODS

A genetic association study was performed on 191 Slovenian patients, divided into 2 groups: 113 RRD patients with PVR and 78 RRD patients without PVR. Genotype distributions were investigated within the following 13 single nucleotide polymorphisms: rs3760396 (CCL2), rs9990554 (FGF2), rs17561 (IL1A), rs2069763 (IL2), rs1800795 (IL6), rs1800871 (IL10), rs3008 (JAK3), rs2229094 (LTA), rs1042522 (TP53), rs7656613 (PDGFRA), rs7226855 (SMAD7), rs1800471 (TGFB1), and rs1800629 (TNF).

RESULTS

Differences in genotype distributions between patients with RRD with or without PVR were detected in rs1800795 (IL6) (P = 0.04), rs1800871 (in the vicinity of the IL10) (P = 0.034), and rs1800471 (TGFB1) (P = 0.032). After adjustment none of the 13 analyzed single nucleotide polymorphisms showed statistically significant associations in single nucleotide polymorphism genotype distributions between patients with RRD with and without PVR.

CONCLUSION

Further research is needed, particularly expanded multicentric population-based studies, to clarify the issue of genetic contribution to PVR from different genetic, clinical, and population-based aspects.

Challenges in Management of Rhegmatogenous Retinal Detachment in a Patient With Wilson's Disease: A Case Report and Literature Review

Wilson’s disease (WD) is a rare hepatolenticular inherited disorder affecting copper transport resulting in accumulation of copper, which leads to the induction of apoptosis in different organs. Furthermore, patients with WD have elevated cytokines activity responsible for inflammation of various tissues.

Here, we report our challenges in managing a case of rhegmatogenous retinal detachment (RRD) in a one-eyed 28-year-old male with WD who had a previous history of severe intraocular inflammation that ended with phthisis bulbi after pars plana vitrectomy for RRD. After one year, he developed RRD in the seeing eye.

A decision was made to perform scleral buckling to avoid the risk of postoperative intraocular inflammation. However, a barrage laser was required for shallow retinal detachment in a subsequent follow-up, which was ultimately complicated by severe intraocular inflammation.

We observed that our patient with WD had a tendency for severe intraocular inflammation, even following minor non-surgical ophthalmic procedures. For this reason, ophthalmologists need to be aware of managing similar cases and perhaps other diseases associated with elevated levels of cytokines.

[Proliferative vitreoretinopathy (PVR) surgery: Scar Wars : Five steps to successful treatment of PVR detachment]

BACKGROUND

After initially successful surgery of retinal detachment, proliferative vitreoretinopathy (PVR) is the most common cause of renewed retinal detachment. With an incidence of 5-20% it represents a frequent surgical challenge based on a pronounced epiretinal, subretinal and intraretinal scar formation.

MATERIAL AND METHODS

The five most important steps leading to a successful repair of a PVR retinal detachment are described.

RESULTS

1. The basic prerequisite is the complete removal of the vitreous body in order to remove the substrate for proliferation of pathological cells. 2. Furthermore, the complete removal of all tractional PVR membranes is necessary. Subretinal PVR membranes that show no traction can be left in place. 3. The professional care of the macular is still important. As approximately 12% of all patients who undergo surgery for retinal detachment develop an epiretinal gliosis/macular pucker, peeling of the internal limiting membrane (ILM) is obligatory in cases of PVR. 4. Particularly in PVR detachment the mentioned surgical procedure is facilitated by the selection of suitable modern instruments, including wide-angle optics, such as the binocular indirect ophthalmomicroscope (BIOM), chandelier lights, perfluorocarbons (PFCL) and silicone oil. 5. Last but not least, the credo as much as necessary, as little as possible is of essential importance, as PVR eyes have usually been previously operated on and any further surgical intervention leads to subsequent inflammation and a persisting stimulation of the PVR reaction and further damage.

CONCLUSION

Following a few decisive rules and tips is a prerequisite for a successful reattachment in cases of PVR retinal detachment.

Topical delivery of a small molecule RUNX1 transcription factor inhibitor for the treatment of proliferative vitreoretinopathy

Proliferative vitreoretinopathy (PVR) is the leading cause of retinal detachment surgery failure. Despite significant advances in vitreoretinal surgery, it still remains without an effective prophylactic or therapeutic medical treatment. After ocular injury or retinal detachment, misplaced retinal cells undergo epithelial to mesenchymal transition (EMT) to form contractile membranes within the eye. We identified Runt-related transcription factor 1 (RUNX1) as a gene highly expressed in surgically-removed human PVR specimens. RUNX1 upregulation was a hallmark of EMT in primary cultures derived from human PVR membranes (C-PVR). The inhibition of RUNX1 reduced proliferation of human C-PVR cells in vitro, and curbed growth of freshly isolated human PVR membranes in an explant assay. We formulated Ro5-3335, a lipophilic small molecule RUNX1 inhibitor, into a nanoemulsion that when administered topically curbed the progression of disease in a novel rabbit model of mild PVR developed using C-PVR cells. Mass spectrometry analysis detected 2.67 ng/mL of Ro5-3335 within the vitreous cavity after treatment. This work shows a critical role for RUNX1 in PVR and supports the feasibility of targeting RUNX1 within the eye for the treatment of an EMT-mediated condition using a topical ophthalmic agent.

PREDICTIVE FACTORS FOR PROLIFERATIVE VITREORETINOPATHY FORMATION AFTER UNCOMPLICATED PRIMARY RETINAL DETACHMENT REPAIR

PURPOSE

To determine predictive factors of proliferative vitreoretinopathy (PVR) formation after uncomplicated primary retinal detachment repair.

METHODS

Retrospective, single-center, case-control study of 74 consecutive patients with (37 eyes) and without (37 eyes) PVR formation after undergoing uncomplicated primary surgery for retinal detachment repair. Logistic regression was used to assess factors associated with PVR formation.

RESULTS

Retinal detachment involving the macula was 4.2 times (adjusted odds ratio; 95% confidence interval, 1.4-12.9; P = 0.0119) more likely to have PVR formation compared with those without. Patients who were current or former smokers were 3.6 times (adjusted odds ratio; 95% confidence interval, 1.1-11.7; P = 0.0352) more likely to have PVR formation compared with nonsmokers. Compared with 25-gauge (g) vitrectomy, larger gauge vitrectomy (20 g or 23 g) was 3.6 times (adjusted odds ratio; 95% confidence interval, 1.2-11.3; P = 0.0276) more likely to have PVR formation. Duration of retinal detachment symptoms, high myopia, lens status, lattice degeneration, location of retinal break, number of retinal breaks, and surgical technique (e.g., scleral buckle with or without vitrectomy versus vitrectomy alone) were not found to be predictive of PVR formation.

CONCLUSION

Cigarette smoking and macular involvement are significant risk factors predictive of PVR formation after uncomplicated primary retinal detachment repair.

Epigenomic and Transcriptomic Changes During Human RPE EMT in a Stem Cell Model of Epiretinal Membrane Pathogenesis and Prevention by Nicotinamide

Epithelial to mesenchymal transition (EMT) is a biological process involved in tissue morphogenesis and disease that causes dramatic changes in cell morphology, migration, proliferation, and gene expression. The retinal pigment epithelium (RPE), which supports the neural retina, can undergo EMT, producing fibrous epiretinal membranes (ERMs) associated with vision-impairing clinical conditions, such as macular pucker and proliferative vitreoretinopathy (PVR). We found that co-treatment with TGF-β and TNF-α (TNT) accelerates EMT in adult human RPE stem cell-derived RPE cell cultures. We captured the global epigenomic and transcriptional changes elicited by TNT treatment of RPE and identified putative active enhancers associated with actively transcribed genes, including a set of upregulated transcription factors that are candidate regulators. We found that the vitamin B derivative nicotinamide downregulates these key transcriptional changes, and inhibits and partially reverses RPE EMT, revealing potential therapeutic routes to benefit patients with ERM, macular pucker and PVR.

Comparison of Chemokine CXCL-1 and Interleukin-6 Concentrations in the Subretinal Fluid and Vitreous in Rhegmatogenous Retinal Detachment

Purpose: Comparison of IL-6 and CXCL-1 concentrations and CXCL-1/IL-6 ratio correlations with clinical parameters (RRD extent, duration, and proliferative vitreoretinopathy - PVR-grade) between subretinal fluid (SRF) and vitreous during rhegmatogenous retinal detachment (RRD) complicated with PVR.Methods: A total of 71 eyes of 71 patients with primary RRD possibly complicated with PVR were included; 36 eyes treated with scleral buckling and 35 eyes with pars-plana vitrectomy. Enzyme-Linked Immuno-sorbent Assay was employed for CXCL-1/IL-6 measurement (ng/ml).Results: Correlation analysis between mean CXCL-1/IL-6 ratio and clinical parameters revealed non-significant results. CXCL-1/IL-6 ratio was significantly elevated in phakic eye vitreous. Optimum circumstances for elevated chemokine levels during RRD were considerable extent (2-3-quadrant) and duration (29-60-day) complicated with PVR C.Conclusions: SRF appears to be characterized by greater chemokine concentrations while vitreous retains several structural characteristics that may assist in investigating inflammation and improving understanding of underlying pathophysiological mechanisms during RRD complicated with PVR.

DOUBLE ARCUATE RELAXING RETINOTOMY FOR A LARGE MACULAR HOLE

PURPOSE

To describe double arcuate relaxing retinotomy as an alternative surgical technique in a case with a secondary large macular hole.

METHODS

The management of a patient who developed a large macular hole and macular tractional rhegmatogenous retinal detachment after pars plana vitrectomy for proliferative diabetic retinopathy was retrospectively assessed. Despite surgical procedures, such as dissection of a preretinal membrane from the retina and peeling of the retinal internal limiting membrane, the macular hole could not be closed. In the absence of an alternative method, superior and inferior posterior arcuate, 120° relaxing retinotomies were performed.

RESULTS

At the follow-up, the macular hole closure was confirmed by clinical examination and optical coherence tomography imaging, and visual acuity improved. There were no intraoperative or postoperative complications.

CONCLUSION

In cases of large macular holes, double arcuate relaxing retinotomy can reduce traction, leading to hole closure.

Utility of Induced Pluripotent Stem Cell-Derived Retinal Pigment Epithelium for an In Vitro Model of Proliferative Vitreoretinopathy

The advent of stem cell technology, including the technology to induce pluripotency in somatic cells, and direct differentiation of stem cells into specific somatic cell types, has created an exciting new field of scientific research. Much of the work with pluripotent stem (PS) cells has been focused on the exploration and exploitation of their potential as cells/tissue replacement therapies for personalized medicine. However, PS and stem cell-derived somatic cells are also proving to be valuable tools to study disease pathology and tissue-specific responses to injury. High-throughput drug screening assays using tissue-specific injury models have the potential to identify specific and effective treatments that will promote wound healing. Retinal pigment epithelium (RPE) derived from induced pluripotent stem cells (iPS-RPE) are well characterized cells that exhibit the phenotype and functions of in vivo RPE. In addition to their role as a source of cells to replace damaged or diseased RPE, iPS-RPE provide a robust platform for in vitro drug screening to identify novel therapeutics to promote healing and repair of ocular tissues after injury. Proliferative vitreoretinopathy (PVR) is an abnormal wound healing process that occurs after retinal tears or detachments. In this chapter, the role of iPS-RPE in the development of an in vitro model of PVR is described. Comprehensive analyses of the iPS-RPE response to injury suggests that these cells provide a physiologically relevant tool to investigate the cellular mechanisms of the three phases of PVR pathology: migration, proliferation, and contraction. This in vitro model will provide valuable information regarding cellular wound healing responses specific to RPE and enable the identification of effective therapeutics.

Proliferative Vitreoretinopathy: A Review

Proliferative vitreoretinopathy (PVR) is the most common cause for failure of rhegmatogenous retinal detachment repair and is characterized by the growth and contraction of cellular membranes within the vitreous cavity and on both sides of the retinal surface as well as intraretinal fibrosis. Currently, PVR is thought to be an abnormal wound healing response that is primarily driven by inflammatory, retinal, and RPE cells. At this time, surgery is the only management option for PVR as there is no proven pharmacologic agent for the treatment or prevention of PVR. Laboratory research to better understand PVR pathophysiology and clinical trials of various agents to prevent PVR formation are ongoing.

Microglia Regulate Neuroglia Remodeling in Various Ocular and Retinal Injuries

Reactive microglia and infiltrating peripheral monocytes have been implicated in many neurodegenerative diseases of the retina and CNS. However, their specific contribution in retinal degeneration remains unclear. We recently showed that peripheral monocytes that infiltrate the retina after ocular injury in mice become permanently engrafted into the tissue, establishing a proinflammatory phenotype that promotes neurodegeneration. In this study, we show that microglia regulate the process of neuroglia remodeling during ocular injury, and their depletion results in marked upregulation of inflammatory markers, such as Il17f, Tnfsf11, Ccl4, Il1a, Ccr2, Il4, Il5, and Csf2 in the retina, and abnormal engraftment of peripheral CCR2⁺ CX3CR1⁺ monocytes into the retina, which is associated with increased retinal ganglion cell loss, retinal nerve fiber layer thinning, and pigmentation onto the retinal surface. Furthermore, we show that other types of ocular injuries, such as penetrating corneal trauma and ocular hypertension also cause similar changes. However, optic nerve crush injury-mediated retinal ganglion cell loss evokes neither peripheral monocyte response in the retina nor pigmentation, although peripheral CX3CR1⁺ and CCR2⁺ monocytes infiltrate the optic nerve injury site and remain present for months. Our study suggests that microglia are key regulators of peripheral monocyte infiltration and retinal pigment epithelium migration, and their depletion results in abnormal neuroglia remodeling that exacerbates neuroretinal tissue damage. This mechanism of retinal damage through neuroglia remodeling may be clinically important for the treatment of patients with ocular injuries, including surgical traumas.