Proliferative Vitreoretinopathy: A Review

Complications of Silicone Oil as Vitreous Tamponade in Pars Plana Vitrectomy: A Mini Review

PURPOSE

Silicone oil (SO) has been used as a vitreous tamponade for decades. Surgical complications such as glaucoma, cataract, or emulsification are well known. Despite that, increasing case reports of unexplained visual loss after SO removal is concerning because there is no treatment available. This article describes practical complications related to SO use and advantages/disadvantages for consideration regarding the choice of a vitreous substitute in practice.

METHODS

A literature review was conducted for publications related to silicone oil, heavy silicone oil, and vitreous substitutes.

RESULTS

This article summarizes the SO chemical and physical properties including both SO and heavy SO and postoperative complications such as corneal decompensation, glaucoma, hypotony, cataract, optic neuropathy. Surgical complications such as over/underfilling, SO migration/emulsification, sticky SO and proliferative vitreoretinopathy (PVR) simulating epiretinal membranes formation, recurrent retinal detachments, SO unexplained visual loss, and permanent SO, are described. A brief overview on potential vitreous substitutes is presented.

CONCLUSION

The decision to use SO as vitreous substitute in daily practice is based on the severity of retinal diseases and surgeon experience. SO potential complications must not be underestimated. The pursuit of novel safer vitreous substitutes is imperative.

Effect of Preoperative Glucocorticoid Application on Vitreous Parthanatos-Related Protein Expression in Patients with Rhegmatogenous Retinal Detachment Associated with Choroidal Detachment

PURPOSE

The protein concentrations of apoptosis inducing factor (AIF), macrophage migration inhibitory factor (MIF), interleukin-1β (IL-1β), poly ADP ribose polymerase-1 (PARP-1), poly (ADP-ribose) (PAR), α-synuclein (α-SYN), monocyte chemotactic protein‑1 (MCP-1) and tumor necrosis factor-α (TNF-α) in the vitreous of eyes with rhegmatogenous retinal detachment associated with choroidal detachment (RRDCD) were observed and analyzed.

METHODS

A total of 57 patients' samples were included. 30 patients with RRD were set as the control group, 27 patients with RRDCD were set as the experimental group (16 patients with preoperative glucocorticosteroid (GC+) and 11 patients without preoperative glucocorticosteroid (GC-)). The levels of AIF, MIF, IL-1β, PARP-1, PAR, α-SYN, MCP-1 and TNF-α in vitreous of patients in the control and experimental groups were detected by enzyme-linked immunosorbent assay (ELISA).

RESULTS

The concentration of AIF in the vitreous was higher in the RRD group (9.96 ± 2.78 ng/ml) than in the RRDCD (GC+) group (7.65 ± 2.13 ng/ml, p = 0.006),the RRDCD (GC+) group was lower than the RRDCD (GC-) group (10.28 ± 2.81 ng/ml) (p = 0.013). The concentration of MIF in vitreous fluid was lower in the RRDCD (GC+) group (61.21 ± 17.56 ng/ml) than in the RRDCD (GC-) group (74.30 ± 9.66 ng/ml, p = 0.039). In the experimental group, the protein concentration of MCP-1 in the RRDCD (GC+) group was higher in the preoperative PVR grading C (284.93 ± 54.96 ng/ml) grade than in the D grade (225.94 ± 24.05 ng/ml) (p = 0.050); The protein concentration of MIF was lower in the RRDCD (GC+) group of patients with an ocular axis of <26 mm (56.19 ± 6.99 ng/ml) than in those with an ocular axis of ≥26 mm (76.26 ± 26.60 ng/ml, p = 0.043).

CONCLUSION

Low expression of Parthanatos-related proteins is present in the vitreous of patients with RRDCD (GC+), and preoperative treatment with glucocorticoids may reduce the expression of Parthanatos-related proteins.

ORAL CURCUMIN TO REDUCE RISK OF PROLIFERATIVE VITREORETINOPATHY FOLLOWING RHEGMATOGENOUS RETINAL DETACHMENT REPAIR

PURPOSE

To evaluate outcomes of patients who underwent rhegmatogenous retinal detachment repair and were started on oral curcumin for proliferative vitreoretinopathy (PVR) prevention.

METHODS

Retrospective, observational case series of eyes of patients undergoing high-risk rhegmatogenous retinal detachment repair that was started on curcumin postoperatively. Recommended dosage was 500 mg twice daily for 30 days followed by 500 mg daily for 60 days. The primary outcome was recurrent PVR-related rhegmatogenous retinal detachment within 6 months and a single-surgery retinal reattachment rate. Secondary outcomes included epiretinal membrane formation, visual acuity, and curcumin safety profile.

RESULTS

Thirty-two eyes of 31 patients met the study inclusion criteria. Postoperatively, 2 eyes developed a PVR-related detachment (6.3%), and 2 eyes redetached due to new breaks without PVR (6.3%). Overall, single-surgery retinal reattachment rate was 87.5%. Single-surgery retinal reattachment rate without silicone oil was 92.6% (25/27). Of the 12 cases with Grade C PVR-related retinal detachment, the single-surgery retinal reattachment rate was 91.7%. Postoperatively, 7 eyes developed an epiretinal membrane (21.9%), of which 3 underwent epiretinal membrane removal (9.4%). No patient had gastrointestinal upset or anemia.

CONCLUSION

This proof-of-concept clinical study suggests that oral curcumin is well tolerated and warrants further investigation for its potential to reduce the risk of PVR after rhegmatogenous retinal detachment repair in eyes at higher risk of PVR.

Proliferative vitreoretinopathy and its relationship with inflammatory serum biomarkers

AIM

To analyze if a relationship between levels of inflammatory serum biomarkers and severity of primary proliferative vitreoretinopathy (PVR) exists.

METHODS

A retrospective case-control study. The healthy adult patients with rhegmatogenous retinal detachment and primary PVR were included in the PVR group. For the control group, healthy adults who underwent cataract surgery were included. The grade of PVR was classified according to the Retinal Society Terminology Committee. Blood samples were obtained before surgery, and processed in MYTHIC 18. Measures of interest were neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and lymphocyte-to-monocyte ratio (LMR), the time between the decrease in visual acuity and surgery, PVR grade, type of surgery, final best corrected visual acuity, and rate of re-detachment.

RESULTS

Totally 240 patients were included, 120 in each group, 79 (65.8%) and 56 (46.7%) were male in the PVR and control group, respectively. PVR A had greater levels of monocytes (0.28±0.18 vs 0.12±0.32, P=0.002), neutrophils (4.59±1.51 vs 3.92±1.27, P=0.006), and LMR (9.32±4.42 vs 7.43±3.90, P=0.01). PVR B had a greater monocyte count (0.30±0.13 vs 0.12±0.32, P=0.001), and PVR C demonstrated higher levels in monocytes (0.27±0.12 vs 0.12±0.32, P=0.004), neutrophils (4.39±1.13 vs 3.92±1.27, P=0.004), and LMR (9.63±3.24 vs 7.43±3.90, P=0.002) compared to control, respectively. An LMR cut-off value of 9.38 predicted PVR with a sensibility of 54.2% and specificity of 77.5% and NLR cut-off of 1.70 predicted PVR with a sensibility of 62% and specificity of 54.2%.

CONCLUSION

Patients with primary PVR demonstrate greater neutrophil, monocyte, and LMR levels than the control group. Cut-off values obtained from ratios could be useful in a clinical setting when no posterior view of the fundus is possible due to media opacity.

Knockdown of HSPA13 Inhibits TGFβ1-Induced Epithelial-Mesenchymal Transition of RPE by Suppressing the PI3K/Akt Signaling Pathway

Purpose

This study aimed to explore the impact of HSPA13 on epithelial-mesenchymal transition (EMT) in retinal pigment epithelial (RPE) cells and proliferative vitreoretinopathy (PVR) development, along with its associated molecular mechanisms.

Methods

HSPA13 expression was evaluated in epiretinal membranes (ERMs) from patients with PVR using immunohistochemistry. The effects of HSPA13 knockdown on TGFβ1-induced EMT in hESC-RPE cells were studied through quantitative PCR (qPCR), Western blot, and wound healing assays. Intracellular Ca2+ levels were measured using Fluo-8/AM incubation. A rat PVR model was induced by the intravitreal injection of RPE cells combined with platelet-rich plasma (PRP). RNA-seq was applied to study the molecular mechanism of HSPA13 knockdown-mediated EMT inhibition.

Results

HSPA13 was found in human ERMs and its expression increased with TGFβ1 treatment in hESC-RPE cells. Knockdown of HSPA13 inhibited TGFβ1-induced EMT and migration. In the PVR rat model, HSPA13 was expressed in the ERMs and its knockdown in RPE cells reduced the development of PVR. Consistent with these observations, RNA-seq showed a global suppression of TGFβ1-induced EMT and migration by shHSPA13 in RPE cells. Mechanistically, TGFβ1 treatment increased intracellular Ca2+ levels, leading to an upregulation of HSPA13 expression. Downregulation of HSPA13 hindered the phosphorylation of PI3K/Akt in TGFβ1-induced RPE cells.

Conclusions

Our study revealed the involvement of HSPA13 in PVR development, as well as in TGFβ1-induced EMT of RPE through the PI3K/Akt signaling pathway. Targeting HSPA13-related pathways involved in regulating EMT in RPE cells could serve as a novel therapeutic approach for patients with PVR.

Rhegmatogenous Retinal Detachment in Syphilitic Uveitis: A Case Series and Comprehensive Review of the Literature

PURPOSE

Uveitis is the most common ocular manifestation of syphilis. However, an association between syphilitic uveitis and rhegmatogenous retinal detachment (RRD) is not widely recognized. We report a consecutive series of six new cases of syphilitic uveitis complicated by RRD and describe the typical characteristics, clinical course, and surgical management of such cases.

METHODS

Consecutive case series and comprehensive review of the literature.

RESULTS

We identified a total of 19 cases (23 eyes) with syphilitic uveitis subsequently complicated by RRD, including six new cases (seven eyes) reported here and 13 cases (16 eyes) previously reported in the literature. Fifteen patients (79%) were positive for human immunodeficiency virus (HIV) and not on combination antiretroviral therapy. Most retinal detachments developed within two months of uveitis presentation; retinal breaks were often found in areas of previous retinitis. Sixteen eyes (70%) were complicated by early proliferative vitreoretinopathy. Twenty-one eyes underwent surgical repair, of which six (26%) suffered re-detachment. Surgical management commonly involved pars-plana vitrectomy and silicone oil tamponade, with or without scleral buckling. Visual outcomes were generally poor: only six eyes (26%) attained visual acuity of 20/40 or better and 11 eyes (48%) remained 20/200 or worse.

CONCLUSIONS

Patients with syphilitic uveitis, as with viral retinitis, should be monitored closely for the development of retinal tears and RRD. A combination of pars plana vitrectomy with silicone oil tamponade and/or scleral buckle placement is a prudent surgical approach to most cases of syphilitic RRD, although visual prognosis remains guarded.

Survey of Dopamine Receptor D2 Antagonists as Retinal Antifibrotics

Purpose: To evaluate the potency and efficacy of a library of dopamine receptor D2 (D2R) antagonists in the mitigation of fibrotic activation in retinal pigment epithelial (RPE) cells. Methods: ARPE-19 cells were cultured and treated with methotrexate or 27 district D2R antagonists using a fibronectin deposition assay. The most potent compounds were then further assessed in assays measuring cellular proliferation, cellular migration, and profibrotic gene expression. Results: The previously established antifibrotic D2R antagonist loxapine exerted a robust and dose-dependent inhibition of fibronectin deposition, whereas methotrexate exerted minimal inhibition. The most potent D2R antagonist identified, fluphenazine, effectively blocked in vitro models of fibrosis at 300-1,000 nM concentrations. Conclusions: Here we found multiple FDA-approved D2R antagonists that potently block RPE cell fibrogenesis. These findings further support the potential of D2R antagonism as a potential therapeutic for retinal fibrotic disease.

Nano-Based Drug Approaches to Proliferative Vitreoretinopathy Instead of Standard Vitreoretinal Surgery

Proliferative vitreoretinopathy (PVR) has traditionally been managed with vitreoretinal surgery. Although there have been several recent innovations in this surgery to make the retinal approach as uninvasive as possible, the outcomes remain unsatisfactory. Significant complications remain and the complexity of the surgical approach is challenging. The focus of this review was to investigate and discuss the effectiveness of nanomedicine, featuring a wide range of drugs and molecules, as a novel potential treatment for PVR. To date, ocular drug delivery remains a significant issue due to the physiological and anatomical barriers, dynamic or static, which prevent the entry of exogenous molecules. We tried to summarize the nanotechnology-based ophthalmic drugs and new nanoparticles currently under research, with the intention of tackling the onset and development of PVR. The purpose of this review was to thoroughly and analytically examine and assess the potential of nano-based techniques as innovative strategies to treat proliferative vitreoretinopathy (PVR). This study aimed to emphasize the breakthroughs in nanomedicine that provide promising therapeutic options to enhance the results of vitreoretinal surgery and halt disease progression, considering the complexity and difficulty of PVR treatment. The future directions of the nanoparticles and nanotherapies applied to PVR highlight the importance of investing in the development of better designs and novel ophthalmic formulations in order to accomplish a mini-invasive ocular approach, replacing the standard-of-care vitreoretinal surgery.

Prognostic Factors for Recurrent Rhegmatogenous Retinal Detachment after Silicone Oil Removal

PURPOSE

To investigate the prognostic factors for recurrent rhegmatogenous retinal detachment following silicone oil removal.

METHODS

This retrospective review included 147 consecutive patients with rhegmatogenous retinal detachment treated with silicone oil tamponade at a high-volume referral-based tertiary hospital between January 2012 and May 2022. All patients underwent follow-up for a minimum of 6 months after subsequent silicone oil removal. The primary outcome measure was the rate of recurrent retinal detachment following silicone oil removal, and the secondary outcome was best-corrected visual acuity after silicone oil removal.

RESULTS

The mean silicone oil tamponade duration was 4.7 ± 5.01 months (range, 1-38 months; median, 3 months), and the recurrent retinal detachment rate after silicone oil removal was 15.6%. Logistic regression analysis revealed that argon endolaser photocoagulation during silicone oil removal (odds ratio [OR], 0.309; 95% confidence interval [CI], 0.106-0.898; p = 0.031) was associated with a lower rate of anatomical success after silicone oil removal. Demographics, preoperative ocular characteristics, proliferative vitreoretinopathy, previous scleral encircling or buckling, previous retinectomy, concomitant phacoemulsification, duration of silicone oil tamponade, and gas tamponade after silicone oil removal were not significantly associated with recurrent retinal redetachment after silicone oil removal. Duration of silicone oil tamponade (OR, 1.226; 95% CI, 1.073-1.402; p = 0.003) and recurrent retinal detachment after silicone oil removal (OR, 3.400; 95% CI, 1.311-8.817; p = 0.012) were associated with poor visual outcomes after silicone oil removal.

CONCLUSIONS

Among all factors examined in this study, including the duration of silicone oil tamponade, laser retinopexy was the only significant prognostic factor for recurrent retinal detachment after silicone oil removal. A longer duration of silicone oil tamponade was associated with worse visual outcomes and a lower rate of visual improvement after silicone oil removal.

Biodegradable microspheres come into sight: A promising biomaterial for delivering drug to the posterior segment of the eyeball

Posterior segment disease acts as a major cause of irreversible visual impairments. Successful treatment of posterior segment disease requires the efficient delivery of therapeutic substances to the targeted lesion. However, the complex ocular architecture makes the bioavailability of topically applied drugs extremely low. Invasive delivery approaches like intravitreal injection may cause adverse complications. To enhance the efficiency, several biomedical engineering systems have been developed to increase the penetration efficiency and improve the bioavailability of drugs at the posterior segments. Advantageously, biodegradable microspheres are found to deliver the therapeutic agents in a controlled fashion. The microspheres prepared from novel biomaterials can realize the prolonged release at the posterior segment with minimum side effects. Moreover, it will be degraded automatically into products that are non-toxic to the human body without the necessity of secondary operation to remove the residual polymer matrix. Additionally, biodegradable microspheres have decent thermoplasticity, adjustable hydrophilicity, controlled crystallinity, and high tensile strength, which make them suitable for intraocular delivery. In this review, we introduce the latest advancements in microsphere production technology and elaborate on the biomaterials that are used to prepare microspheres. We discuss systematically the pharmacological characteristics of biodegradable microspheres and compare their potential advantages and limitations in the treatment of posterior segment diseases. These findings would enrich our knowledge of biodegradable microspheres and cast light into the discovery of effective biomaterials for ocular drug delivery.

Association of Cutaneous Keloids, Hypertrophic Scarring, and Fibrosis with Risk of Postoperative Proliferative Vitreoretinopathy

PURPOSE

To assess an association between cutaneous keloids, hypertrophic scarring, and fibrosis (KHF) and risk of postoperative proliferative vitreoretinopathy (PVR) after rhegmatogenous retinal detachment (RRD) repair.

DESIGN

Retrospective, population-based cohort study.

PARTICIPANTS

Patients aged ≥ 18 years who underwent initial retinal detachment (RD) repair with pars plana vitrectomy with or without scleral buckle (SB) (Current Procedural Terminology [CPT] 67108), pneumatic retinopexy (67110), and primary SB (67107) from January 1, 2003, to March 1, 2023.

METHODS

A de-identified electronic health record database through TriNetX, a global health research network, was used to analyze patients. Patients were queried for International Classification of Diseases, 10th Revision (ICD-10) codes L91.0 (hypertrophic scar) and L90.5 (scar conditions and fibrosis of skin). Frequency of subsequent diagnosis of PVR (H35.2) and CPT codes for secondary surgery including complex RD repair (67113) were determined. Patients with proliferative diabetic retinopathy (PDR) (ICD-10 H10.35/H11.35) were excluded. Descriptive statistics (Z-test) and propensity score matching (PSM) were used to match for age, sex, and race.

MAIN OUTCOME MEASURES

Prevalence of H35.2 and CPT 67113 within 180 days after RRD repair in the KHF cohort versus the non-KHF cohort.

RESULTS

Among patients with CPT 67108, 1061 in each cohort (KHF and non-KHF) were analyzed after PSM. The mean (standard deviation) age was 60.7 (15.2) years. Within 180 days, 10.1% of patients in the KHF cohort and 3.4% in the non-KHF cohort had a diagnosis of PVR (H35.2) (P < 0.001, odds ratio [OR], 3.2; 95% confidence interval [CI], 2.13-4.71). A total of 8.3% of patients in the KHF cohort and 5.4% of patients in the non-KHF cohort underwent complex RD repair (CPT 67113) (P = 0.008; OR, 3.2; 95% CI, 1.13-2.25). When including all RD repair types (CPT 67108, 67110, 67107), the rate of PVR diagnosis was still significantly greater in the KHF cohort than in the non-KHF cohort (9.0% vs 4.2%, P < 0.01; OR, 2.28; 95% CI, 1.64-3.16).

CONCLUSIONS

A dermatologic history of KHF may be a risk factor for PVR after RD repair.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

Tricetin suppresses the cell migration and BMP-6 expression through p38 signaling pathways in human retinal pigment epithelium cells

Proliferative vitreoretinopathy (PVR) is a visual-threatening disease, which cause from the migration of retinal pigment epithelium (RPE). Tricetin, a family of flavonoids, can inhibit the metastasis of several cancers. Herein, we aim to evaluate the possible effect of tricetin on inhibiting ARPE-19 cells migration. The Boyden chamber assay, wound healing assay, RNA sequencing, and Western blot analysis were applied in our experiment. The results revealed that tricetin inhibited the cell migration abilities of ARPE-19 cells. Moreover, using RNA sequencing technology, we revealed that tricetin repressed bone morphogenetic protein-6 (BMP-6) gene expressions in ARPE-19 cells. Overexpression of BMP-6 resulted in significant restoration of cell migration capabilities of tricetin-treated ARPE-19 cells. Furthermore, tricetin suppressed the phosphorylation of the p38 signaling pathway. Moreover, blocking the p38 pathway also inhibits BMP-6 expression and migration in the ARPE-19 cells. In conclusion, this study revealed that tricetin inhibits the ARPE-19 cell migration mainly via the suppression of BMP-6 expression and p38 signaling pathway.

Risk factors and management of primary giant retinal tears

PURPOSE

To describe clinical characteristics and management in a large cohort of patients with retinal detachment due to a giant retinal tear (GRT).

METHODS

We performed a retrospective cohort study with 222 eyes of 206 patients with a primary and non-traumatic GRTs between 2005 and 2022. We analysed the relevant clinical and surgical data from these patients.

RESULTS

Eighty-six per cent (n = 177) of patients were male. We observed no relation between refractive error and GRT size (Spearman's rho: r = -0.018, p = 0.83). We achieved a primary and final treatment success in 77%, respectively 92%, of eyes. The final visual outcome was 20/40 or better in 65% and 36% of eyes in fovea-on and fovea-off GRTs respectively. Thirty-five per cent (n = 73) of patients developed a retinal detachment in the fellow eye. The median time until a retinal detachment in the fellow eye occurred after GRT was 20 months, and 10% developed within 1 month. A prediction model for the development of retinal detachment in the fellow eye resulted in a receiver operating characteristics curve with an area under the curve of 0.68 (95% CI: 0.57-0.78, p = 0.001).

CONCLUSION

We observed a highly significant gender imbalance in patients with a non-traumatic GRT. One third of patients developed a retinal detachment bilaterally. Ten per cent of fellow eye's retinal detachment that develop after GRT, occur within 1 month. Clinical parameters showed limited predictive value for a retinal detachment in the fellow eye. These findings suggest an underlying genetic factor.

Initial Characterization of WDR5B Reveals a Role in the Proliferation of Retinal Pigment Epithelial Cells

The chromatin-associated protein WDR5 has been widely studied due to its role in histone modification and its potential as a pharmacological target for the treatment of cancer. In humans, the protein with highest sequence homology to WDR5 is encoded by the retrogene WDR5B, which remains unexplored. Here, we used CRISPR-Cas9 genome editing to generate WDR5B knockout and WDR5B-FLAG knock-in cell lines for further characterization. In contrast to WDR5, WDR5B exhibits low expression in pluripotent cells and is upregulated upon neural differentiation. Loss or shRNA depletion of WDR5B impairs cell growth and increases the fraction of non-viable cells in proliferating retinal pigment epithelial (RPE) cultures. CUT&RUN chromatin profiling in RPE and neural progenitors indicates minimal WDR5B enrichment at established WDR5 binding sites. These results suggest that WDR5 and WDR5B exhibit several divergent biological properties despite sharing a high degree of sequence homology.

Application of Silicone in Ophthalmology: A Review

This paper reviews the latest trends and applications of silicone in ophthalmology, especially related to intraocular lenses (IOLs). Silicone, or siloxane elastomer, as a synthetic polymer, has excellent biocompatibility, high chemical inertness, and hydrophobicity, enabling wide biomedical applications. The physicochemical properties of silicone are reviewed. A review of methods for mechanical and in vivo characterization of IOLs is presented as a prospective research area, since there are only a few available technologies, even though these properties are vital to ensure medical safety and suitability for clinical use, especially if long-term function is considered. IOLs represent permanent implants to replace the natural lens or for correcting vision, with the first commercial foldable lens made of silicone. Biological aspects of posterior capsular opacification have been reviewed, including the effects of the implanted silicone IOL. However, certain issues with silicone IOLs are still challenging and some conditions can prevent its application in all patients. The latest trends in nanotechnology solutions have been reviewed. Surface modifications of silicone IOLs are an efficient approach to further improve biocompatibility or to enable drug-eluting function. Different surface modifications, including coatings, can provide long-term treatments for various medical conditions or medical diagnoses through the incorporation of sensory functions. It is essential that IOL optical characteristics remain unchanged in case of drug incorporation and the application of nanoparticles can enable it. However, clinical trials related to these advanced technologies are still missing, thus preventing their clinical applications at this moment.

Interventions for Proliferative Vitreoretinopathy

Clinical Question

What is the efficacy of pharmacologic interventions in preventing proliferative vitreoretinopathy?

Bottom Line

There is limited high-quality evidence to support currently available pharmacological options for prevention of proliferative vitreoretinopathy.

Advancements in Therapeutic Approaches for Proliferative Vitreoretinopathy: A Comprehensive Review

Proliferative vitreoretinopathy (PVR) is a significant complication of retinal detachment surgery, characterized by the growth of fibrous membranes that can lead to recurrent retinal detachment and vision loss. This comprehensive review aims to summarize the latest advancements in the therapeutic approaches for PVR, encompassing historical perspectives, current surgical techniques, pharmacological interventions, biological and genetic therapies, and novel experimental treatments. Traditional surgical methods, such as vitrectomy, have been refined with advanced instrumentation and techniques to improve outcomes. Pharmacological treatments, including anti-inflammatory and anti-proliferative agents, are being explored to prevent and manage PVR. Emerging therapies, such as stem cell and gene therapy, offer promising new avenues for treatment. Despite these advancements, challenges remain in preventing recurrence and improving long-term outcomes. This review highlights the progress made and identifies areas for future research, emphasizing the importance of continued innovation to enhance patient care and reduce the burden of PVR.

FUNCTIONAL AND ANATOMICAL OUTCOMES AFTER SHORT-TERM HEAVY SILICONE OIL ENDOTAMPONADE FOR INFERIOR RHEGMATOGENOUS RETINAL REDETACHMENT: A Pilot Study

PURPOSE

To assess the success of the short-term location of the heavy silicone oil (Densiron 68, HSO) as endotamponade after pars plana vitrectomy for rhegmatogenous complex retinal redetachment.

METHODS

Consecutive, retrospective, nonrandomized, pilot study was conducted. Twenty-two eyes of 22 patients with complex inferior retinal redetachment previously tamponade with gas (SF6 or C3F8) or 1000 cSt standard silicone oil (SSO) were selected. All were treated with HSO endotamponade, and its removal was performed after 1 month. The main outcomes were best-corrected visual acuity and postoperative complications after the HSO removal.

RESULTS

Of the 22 eyes, 10 were treated with SSO endotamponade, 3 with fluorinated gas 14% C3F8, and 9 with 20% SF6 at first surgery. In all eyes, a complex inferior retinal redetachment was observed after the first surgery, in 1 month to 3 months after silicone oil removal or gas endotamponade introduction. In 10 eyes, the proliferative vitreoretinopathy (Grade B or C 1-3) was found. The main best-corrected visual acuity before HSO removal was 0.55 ± 0.20 the logarithm of the minimum angle of resolution (range 0.4-0.7) and after the HSO removal, it was 0.32 ± 0.29 the logarithm of the minimum angle of resolution (0.1-0.4). Among the postoperative complications, only in four eyes the macular edema was found (medically resolved), in four eyes an increase of intraocular pressure, and none of these developed the epiretinal membrane.

CONCLUSION

The main purpose of this study is to establish a short-term HSO endotamponade in eyes with complex retinal detachment recurrences, reducing the possible postoperative complications and having a better prognosis for visual acuity outcomes.

Epithelial-mesenchymal Transition (EMT) and the Effect of Atorvastatin on it in ARPE-19 cells

Proliferative vitreoretinopathy (PVR) develops after an unsuccessful or complicated recovery from rhegmatogenous retinal detachment (RRD) surgery. Intraocular scar formation with the contribution of epithelial-mesenchymal transition (EMT) in RPE cells is prominent in the pathology of PVR. In the present study, the EMT process was experimentally induced in human retinal pigment epithelium (RPE; ARPE-19) cells, and the effect of atorvastatin on the process was studied. The mRNA and protein levels of mesenchymal markers actin alpha 2 (ACTA2) / alpha-smooth muscle actin (α-SMA) and fibronectin (FN), and epithelial markers occludin (OCLN) and zonula occludens-1 (ZO-1) were measured using quantitative real-time PCR (qRT-PCR) and western blot methods, respectively. In addition, α-SMA and FN were visualized using immunofluorescence staining. Cells were photographed under a phase contrast light microscope. Changes in the functionality of cells following the EMT process were studied using the IncuCyte scratch wound cell migration assay and the collagen cell invasion assay with confocal microscopy. The induction of EMT in ARPE-19 cells increased the expression of mesenchymal markers ACTA2/α-SMA and fibronectin and reduced the expression of epithelial marker OCLN both at mRNA and protein levels. The mRNA levels of ZO-1 were lower after EMT, as well. Increased levels of α-SMA and FN were confirmed by immunofluorescence staining. Atorvastatin further increased the mRNA levels of mesenchymal markers ACTA2 and FN as well as the protein levels of α-SMA and reduced the mRNA levels of epithelial markers OCLN and ZO-1 under the EMT process. EMT promoted wound closure and cell invasion into the 3D collagen matrix when compared to untreated control cells. These data present cellular changes upon the induction of the EMT process in ARPE-19 cells and the propensity of atorvastatin to complement the effect. More studies are needed to confirm the exact influence of the EMT process and atorvastatin treatment on the PVR development after RRD surgery.

THE ROLE OF INTRAVITREAL METHOTREXATE AS AN ADJUNCT TO LOCAL OR SYSTEMIC CORTICOSTEROIDS IN VITRECTOMY FOR RHEGMATOGENOUS RETINAL DETACHMENT AND CHOROIDAL DETACHMENT: A Pilot Study

PURPOSE

To evaluate the role of repeated intravitreal methotrexate as an adjunct to pars plana vitrectomy in the management of rhegmatogenous retinal detachment with choroidal detachment.

METHOD

The authors compared anatomical and visual outcomes of rhegmatogenous retinal detachment with choroidal detachment eyes that underwent pars plana vitrectomy with (Group B) or without repeated intravitreal methotrexate (Group A).

RESULTS

The study included 25 eyes of 25 patients, 16 eyes in Group A and nine in Group B. Both groups had similar baseline characteristics. In Group A, successful retinal attachment was achieved in 50% as compared with 89% in Group B; however, the difference was not statistically significant ( P = 0.08). Also, Group B had a significantly greater change in visual acuity from baseline to the last follow-up visit (1.6 + 1.5 logMAR units) compared with Group A (1.18 + 1 logMAR units) ( P = 0.05). There were no significant safety concerns with the use of intravitreal methotrexate.

CONCLUSION

Repeated intravitreal methotrexate after vitrectomy for rhegmatogenous retinal detachment with choroidal detachment improves outcomes without posing major safety concerns. Nonetheless, further investigation is necessary to establish the optimal intravitreal methotrexate dosage and duration to prevent recurrence effectively.

Vitreomacular interface abnormalities in type 2 macular telangiectasia (MacTel)

PURPOSE

To describe the different types of vitreomacular interface abnormalities (VMIA) seen on optical coherence tomography (OCT) in type 2 macular telangiectasia (MacTel) and explain the possible reasons for its development.

METHODS

In this retrospective cross-sectional study, type 2 MacTel eyes with macular volumetric OCT imaging protocol were included to identify different types of VMIA such as abnormal PVD, vitreomacular traction (VMT), ERM, and lamellar and full-thickness macular hole. The VMIA findings were then correlated with different MacTel disease stages and visual acuity.

RESULTS

One thousand forty-three OCTs of 332 type 2 MacTel eyes from 169 patients at different visits were examined. VMIA was detected in 709 (68%) of those OCT scans in 216 (65%) eyes. There were 273 (39%), 31 (4%), 89 (13%), 7 (1%), and 381 (54%) OCT scans with vitreomacular adhesion, VMT, ERM, and inner and outer lamellar macular holes discovered respectively. VMIA eyes had a high frequency of abnormal PVD (p = 0.001) and retinal pigment clumps (RPCs) [p = 0.032]. Eyes with abnormal PVD (p = 0.034) and RPC (p = 0.000) had a higher rate of ERM development. RPC was linked to an increased risk of developing ERM (odd ratio 2.472; 95% CI 1.488-4.052). RPC and ERM contributed significantly to poor visual acuity (0.661 ± 0.416, 20/92).

CONCLUSION

OCT reveals a high frequency of VMIA in advanced type 2 MacTel eyes. RPC could be responsible for the development of anomalous PVD, as well as subsequent VMIAs and ERM. Additional work is required to examine the long-term changes and surgical outcomes of these eyes.

ADDITIONAL PNEUMATIC RETINOPEXY IN PATIENTS WITH PERSISTENT RETINAL DETACHMENT AFTER SCLERAL BUCKLING

PURPOSE

To investigate the efficacy, safety, and indications for additional pneumatic retinopexy (PR) in patients with persistent retinal detachment after scleral buckling.

METHODS

This retrospective study included patients who underwent additional PR after scleral buckling for primary rhegmatogenous retinal detachment (n = 78). We defined "inadequate buckle" as retinal detachment persistence because of low buckle height despite accurate buckle placement and "buckle misplacement" as an uncovered tear because of incorrect buckle placement.

RESULTS

The anatomical success rate after additional PR was 52.6%. Development of proliferative vitreoretinopathy Grade B (hazard ratio, 5.73; P < 0.001) and inferior retinal tears (hazard ratio, 2.12; P = 0.040) were significant risk factors for anatomical failure. The most common cause of anatomical failure was proliferative vitreoretinopathy (19 of 37; 51.4%), and epiretinal membrane formation was a common complication after additional PR (22 of 78; 28.2%). The anatomical success rate with additional PR was significantly higher in the inadequate buckle group than in the misplacement group (8 of 9 [88.9%] vs. 1228 [42.9%]; P = 0.023).

CONCLUSION

Development of proliferative vitreoretinopathy Grade B and inferior retinal tears were significantly associated with anatomical failure after additional PR. Additional PR may benefit patients with superior retinal tears or low buckle height and those without proliferative vitreoretinopathy.

Management, risk factors and treatment outcomes of rhegmatogenous retinal detachment associated with giant retinal tears: scoping review

BACKGROUND

Rhegmatogenous retinal detachment (RRD) is a serious condition that occurs when the retina detaches from its underlying retinal pigment epithelium. RRDs associated with giant retinal tears (GRTs) are caused by retinal tears at least 90° or one-quarter of the circumferential extent. This scoping review systematically identifies and summarizes clinical studies evaluating surgical techniques for the management of GRT-related RRDs, discusses functional and visual outcomes and the risk factors affecting treatment outcomes.

METHODS

This study was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. PubMed, Scopus, Google Scholar, and Springer Link databases were searched for relevant papers (from January 2001 to March 2023). Studies that were published in the English language and reported the risk factors, management, and treatment outcomes of GRT-related RRDs were included in the review. The outcome measures included anatomic success rates, changes in BCVA (logMAR) from baseline to the final follow-up, and adverse events.

RESULTS

A total of 11,982 articles were identified. After the title and abstract review, 71 studies were deemed eligible for full-text review. Thirty-six studies that met the eligibility criteria were included in the final review. Four surgical techniques were identified: pars plana vitrectomy (PPV), combined PPV and scleral buckling, scleral buckling alone, and pneumatic retinopexy. Various types of tamponades, including gas, silicone oil, and air, have been used. PPV was the most commonly used surgical technique in 33.1-100% of patients. Among the 20 studies that used PPV alone, 17 were associated with preoperative PVR. In addition, scleral buckling alone or in combination with PPV was reported as a treatment option in 10 studies, with 2-100% of patients experiencing scleral buckling alone and 13.6-100% experiencing combined PPV and complementary scleral buckling. Primary anatomic success (PAS) was achieved with retinal reattachment via a single operation with no residual tamponade, whereas final anatomic success (FAS) was achieved via more than one operation with no residual tamponade. Reported single surgery anatomic success (SSAS) rates range from 65.51 to 100%. The preoperative best-corrected visual acuity (BCVA) ranged from 0.067 to 2.47 logMAR, whereas the postoperative BCVA ranged from 0.08 to 2.3 logMAR. An improvement in visual acuity was observed in 29 studies. Cataracts (3.9-28.3%) were the most common postoperative complication, followed by high IOP (0.01-51.2%) and PVR (0.8-31.57%).

CONCLUSION

PPV is the most common surgical technique, and currently microincision vitrectomy surgery (MIVS) systems are commonly employed. Silicone oil is the most frequently used tamponade in RRD repair. Risk factors for GRT-related RRD include age, sex, lens status, high myopia status, proliferative vitreoretinopathy (PVR), presenting visual acuity, the extent of the GRT and retinal detachment, and macular involvement. Future research areas include guidelines to reduce variability in the reporting of surgical methodology, choice of tamponades, and reporting of functional and visual outcomes to inform the best therapeutic interventions in GRT-related RRD.

ABCA4 mediated traumatic proliferative vitreoretinopathy associated with PI3K/Akt signaling pathway

Background

Proliferative vitreoretinopathy (PVR) is the main cause of retinal detachment. However, the underlying mechanism of PVR is complex and has not yet been fully elucidated. The PI3K/Akt/mTOR signaling pathway is involved in angiogenesis and plays an important role in cell proliferation and tumor formation. Therefore, our study was designed to investigate the potential biological mechanisms of alleviating ARPE-19 cell and traumatic PVR model involving PI3K/Akt signaling pathway by targeting ABCA4.

Materials and methods

ARPE-19 cell model was induced by ABCA4 overexpression vector and si-ABCA4, then the ABCA4 overexpression vector and si-ABCA4 were constructed, the plasmids were expanded for cell transfection and verification. In addition, OE-ABCA4, shRNA NC and si-ABCA4 were transfected into ARPE-19 cells. Cell viability was detected by CCK-8 assay, cell cycle was determined by flow cytometry. The expression level and location of ABCA4 were detected by immunofluorescence. Finally, rabbit traumatic PVR model was induced by surgery, the adenovirus was injected into the vitreous body respectively, and the fundus observation was performed by direct ophthalmoscope observation combined with fundus photography, and the retinal routine histopathology HE staining was performed. Analysis of P21, CDK4, Cyclin D1, BAX, BAD, and ABCA4 was used by quantitative RT-PCR and Western blot. Besides, the expression level of ABCA4, AKT, p-AKT, PI3K, p-PI3K, P38, p-P38, JNK, p-JNK, ERK, and p-ERK was detected by Western blot.

Results

All results indicated that the viability of cells with high expression of ABC4A increased, while the viability of cells with inhibition of ABC4A decreased, the number of cells with high ABC4A expression was significantly higher, and the migration level of cells was significantly reduced after ABC4A inhibition (P < 0.05). ABC4A could affect cell apoptosis by affecting G1/G2 phase. The cell proliferation level was significantly increased with high expression of ABC4A. High expression of ABC4A increased phosphorylation levels, including p-AKT, p-PIK3, and p-P38, while inhibition of ABC4A decreased the expression levels of these proteins (P < 0.05). Inhibition of ABC4A could significantly improve retinopathy, indicating that the proliferation ability of cells was restored after inhibition of ABC4A.

Conclusions

Our finding suggested that inhibition of ABC4A ameliorated the injury degree of traumatic PVR and performed the potential anti-PVR effect via inhibiting PI3K/Akt signaling pathway, while promoting cell proliferation in both rabbit and ARPE-19 cells PVR model. The study has a certain innovation by building a traumatic PVR model to explore whether the ABCA4 participates in the regulation of the PI3K/AKT signaling pathway and the pathological mechanism of PVR regulation. At the same time, ABCA4's participation in the regulation of PI3K/Akt signaling pathway can prevent and delay the occurrence and development of PVR, which has positive significance for improving the survival rate and quality of life of patients, and also provides an important basis for its therapeutic mechanism. Therefore, our study demonstrated a significant strategy for inhibiting traumatic PVR via targeting PI3K/Akt/ABCA4 pathway.

Microfluidic Fabricated Liposomes for Nutlin-3a Ocular Delivery as Potential Candidate for Proliferative Vitreoretinal Diseases Treatment

Purpose

Proliferative vitreoretinal diseases (PVDs) represent a heterogeneous group of pathologies characterized by the presence of retinal proliferative membranes, in whose development retinal pigment epithelium (RPE) is deeply involved. As the only effective treatment for PVDs at present is surgery, we aimed to investigate the potential therapeutic activity of Nutlin-3a, a small non-genotoxic inhibitor of the MDM2/p53 interaction, on ARPE-19 cell line and on human RPE primary cells, as in vitro models of RPE and, more importantly, to formulate and evaluate Nutlin-3a loaded liposomes designed for ophthalmic administration.

Methods

Liposomes were produced using an innovative approach by a microfluidic device under selection of different conditions. Liposome size distribution was evaluated by photon correlation spectroscopy and centrifugal field flow fractionation, while the liposome structure was studied by transmission electron microscopy and Fourier-transform infrared spectroscopy. The Nutlin-3a entrapment capacity was evaluated by ultrafiltration and HPLC. Nutlin-3a biological effectiveness as a solution or loaded in liposomes was evaluated by viability, proliferation, apoptosis and migration assays and by morphological analysis.

Results

The microfluidic formulative study enabled the selection of liposomes composed of phosphatidylcholine (PC) 5.4 or 8.2 mg/mL and 10% ethanol, characterized by roundish vesicular structures with 150-250 nm mean diameters. Particularly, liposomes based on the lower PC concentration were characterized by higher stability. Nutlin-3a was effectively encapsulated in liposomes and was able to induce a significant reduction of viability and migration in RPE cell models.

Conclusion

Our results lay the basis for a possible use of liposomes for the ocular delivery of Nutlin-3a.

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.

TGF-β2-induced alterations of m6A methylation in hTERT RPE-1 cells

N6-methyladenosine (m6A) is a major type of RNA modification implicated in various pathophysiological processes. Transforming growth factor β2 (TGF-β2) induces epithelial-mesenchymal transition (EMT) in retinal pigmental epithelial (RPE) cells and promotes the progression of proliferative vitreoretinopathy (PVR). However, the role of m6A methylation in the EMT of human telomerase reverse transcriptase (hTERT) retinal pigmental epithelium (RPE)-1 cells has not been clarified. Here, we extracted RNA from RPE cells subjected to 0 or 20 ng/mL TGF-β2 for 72 h and identified differentially methylated genes (DMGs) by m6A-Seq and differentially expressed genes (DEGs) by RNA-Seq. We selected the genes related to EMT by conjoint m6A-Seq/RNA-Seq analysis and verified them by qRT-PCR. We then confirmed the function of m6A methylation in the EMT of RPE cells by knocking down the methyltransferase METTL3 and the m6A reading protein YTHDF1. Sequencing yielded 5814 DMGs and 1607 DEGs. Conjoint analysis selected 467 genes altered at the m6A and RNA levels that are closely associated with the EMT-related TGF-β, AGE-RAGE, PI3K-Akt, P53, and Wnt signaling pathways. We also identified ten core EMT genes ACTG2, BMP6, CDH2, LOXL2, SNAIL1, SPARC, BMP4, EMP3, FOXM1, and MYC. Their RNA levels were evaluated by qRT-PCR and were consistent with the sequencing results. We observed that METTL3 knockdown enhanced RPE cell migration and significantly upregulated the EMT markers N-cadherin (encoded by CDH2), fibronectin (FN), Snail family transcription repressor (SLUG), and vimentin. However, YTHDF1 knockdown had the opposite effects and decreased both cell migration and the N-cadherin, FN, and SLUG expression levels. The present study clarified TGF-β2-induced m6A- and RNA-level differences in RPE cells, indicated that m6A methylation might regulate EMT marker expression, and showed that m6A could regulate TGF-β2-induced EMT.

Bone morphogenetic protein 6 (BMP6) antagonises experimental proliferative vitreoretinopathy established by TGF-β2 stimulation in retinal pigment epithelial cells through modulation of the p38 and JNK MAPK pathways

The formation of the epiretinal fibrotic membrane by retinal pigment epithelial (RPE) cells is a primary pathological change for proliferative vitreoretinopathy (PVR). Bone morphogenetic protein 6 (BMP6) is an antifibrogenic factor in various cells. To date, it is still unknown whether BMP6 can interfere with the fibrogenesis of RPE cells during the progression of PVR. This work aimed to address the relationship between BMP6 and transforming growth factor-β2 (TGF-β2)-elicited fibrogenesis of RPE cells, an experimental model for studying PVR in vitro. The BMP6 level was down-regulated, while the TGF-β2 level was up-regulated in the vitreous humor of PVR patients. The BMP6 level was down-regulated in human RPE cells challenged with TGF-β2. The treatment of RPE cells with TGF-β2 resulted in significant increases in proliferation, migration, epithelial-to-mesenchymal transition (EMT), and extracellular matrix (ECM) remodelling. These effects were found to be inhibited by the overexpression of BMP6 or exacerbated by the knockdown of BMP6. BMP6 overexpression reduced the phosphorylation of p38 and JNK in TGF-β2-stimulated RPE cells, while BMP6 knockdown showed the opposite effects. The inhibition of p38 or JNK partially reversed the BMP6-silencing-induced promoting effects on TGF-β2-elicited fibrogenesis in RPE cells. Taken together, BMP6 demonstrates the ability to counteract the proliferation, migration, EMT, and ECM remodelling of RPE cells induced by TGF-β2. This is achieved through the regulation of the p38 and JNK MAPK pathways. These findings imply a potential connection between BMP6 and PVR, and highlight the potential application of BMP6 in therapeutic interventions for PVR.

Anti-inflammatory potential of simvastatin and amfenac in ARPE-19 cells; insights in preventing re-detachment and proliferative vitreoretinopathy after rhegmatogenous retinal detachment surgery

PURPOSE

Rhegmatogenous retinal detachment is a severe vision-threatening complication that can result into proliferative vitreoretinopathy (PVR) and re-detachment of the retina if recovery from surgery fails. Inflammation and changes in retinal pigment epithelial (RPE) cells are important contributors to the disease. Here, we studied the effects of simvastatin and amfenac on ARPE-19 cells under inflammatory conditions.

METHODS

ARPE-19 cells were pre-treated with simvastatin and/or amfenac for 24 h after which interleukin (IL)-1α or IL-1β was added for another 24 h. After treatments, lactate dehydrogenase release, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) processing, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) activity, prostaglandin E2 (PGE2) level, and extracellular levels of IL-6, IL-8, monocytic chemoattractant protein (MCP-1), vascular endothelial growth factor (VEGF), and pigment epithelium-derived factor, as well as the production of reactive oxygen species (ROS) were determined.

RESULTS

Pre-treatment of human ARPE-19 cells with simvastatin reduced the production of IL-6, IL-8, and MCP-1 cytokines, PGE2 levels, as well as NF-κB activity upon inflammation, whereas amfenac reduced IL-8 and MCP-1 release but increased ROS production. Together, simvastatin and amfenac reduced the release of IL-6, IL-8, and MCP-1 cytokines as well as NF-κB activity but increased the VEGF release upon inflammation in ARPE-19 cells.

CONCLUSION

Our present study supports the anti-inflammatory capacity of simvastatin as pre-treatment against inflammation in human RPE cells, and the addition of amfenac complements the effect. The early modulation of local conditions in the retina can prevent inflammation induced PVR formation and subsequent retinal re-detachment.

Retinal complications post posterior chamber phakic intraocular lens implantation at a tertiary eye hospital in the Eastern Province of Saudi Arabia

PURPOSE

Phakic intraocular lenses treat higher degrees of myopia not possible previously with conventional refractive surgery. The aim of this study is to report the incidence and risk factors of retinal complications after posterior chamber PIOL implantation and assess the differences in biometric parameters between patients who developed such complications versus those who did not.

METHODS

This retrospective study recruited 514 patients who underwent ICL implantation to correct myopia at a tertiary eye hospital center in the Eastern province of Saudi Arabia. Follow up period was at least one year. Medical records of the patients were reviewed to obtain the required data. Associations between respondents' characteristics and retinal complications were evaluated using the Chi-squared test.

RESULTS

The mean (SD) age was 27.7 (± 6.5) years ranging from 18 to 47. Laser treatment was performed in 14 cases (2.7%). Retinal complications occurred in six cases (1.2%). The risk of retinal complication was significantly higher among patients with high axial length (OR = 1.3, 95% CI 1.2, 1.4) and patients with high pre-spherical equivalent before ICL (OR = 1.09, 95% CI 1.03, 1.4).

CONCLUSION

Patients with higher axial length and higher pre-spherical equivalent before ICL implantation are at high risk of retinal complications.

Retinal detachment

Retinal detachment (RD) occurs when the neurosensory retina, the neurovascular tissue responsible for phototransduction, is separated from the underlying retinal pigment epithelium (RPE). Given the importance of the RPE for optimal retinal function, RD invariably leads to decreased vision. There are three main types of RD: rhegmatogenous, tractional and exudative (also termed serous) RD. In rhegmatogenous RD, one or more retinal breaks enable vitreous fluid to enter the subretinal space and separate the neurosensory retina from the RPE. In tractional RD, preretinal, intraretinal or subretinal membranes contract and exert tangential forces and elevate the retina from the underlying RPE. Finally, in exudative RD, an underlying inflammatory condition, vascular abnormality or the presence of a tumour causes exudative fluid to accumulate in the subretinal space, exceeding the osmotic pump function of the RPE. The surgical management of RD usually involves pars plana vitrectomy, scleral buckling or pneumatic retinopexy. The approach taken often depends on patient characteristics as well as on practitioner experience and clinical judgement. Advances in surgical technology and continued innovation have improved outcomes for many patients. However, even if retinal re-attachment is achieved, some patients still experience decreased vision or other visual symptoms, such as metamorphopsia, that diminish their quality of life. Continued research in the areas of neuroprotection and retinal biology as well as continued surgical innovation are necessary to enhance therapeutic options and outcomes for these patients.

Proliferative vitreoretinopathy: an update on the current and emerging treatment options

Proliferative vitreoretinopathy (PVR) remains the main cause of failure in retinal detachment (RD) surgery and a demanding challenge for vitreoretinal surgeons. Despite the large improvements in surgical techniques and a better understanding of PVR pathogenesis in the last years, satisfactory anatomical and visual outcomes have not been provided yet. For this reason, several different adjunctive pharmacological agents have been investigated in combination with surgery. In this review, we analyze the current and emerging adjunctive treatment options for the management of PVR and we discuss their possible clinical application and beneficial role in this subgroup of patients.

Effect of Oral Prednisone on the Prevention and Management of Proliferative Vitreoretinopathy After Open-Globe Injury

Purpose: To determine the impact of oral prednisone on the final visual acuity (VA) and prevention of proliferative vitreoretinopathy (PVR) in patients having pars plana vitrectomy (PPV) for globe injuries. Methods: A retrospective chart review was performed of all globe injuries with an initial repair and subsequent PPV between 2009 and 2018. Data included the initial VA, zones of injury, initial closure date, time to secondary intervention (PPV), oral prednisone (1 mg/kg/day) use, the final VA, and enucleation rate. Multivariable regression models were used to assess the impact of oral prednisone use on anatomic and functional outcomes. Results: The mean (±SD) patient age was 46.25 ±18.56 years (range, 13-92); 131 (83.9%) were men. Oral prednisone intake was recorded in 81 patients (52.3%). The prednisone group had significantly more zone 3 involvement (P = .001), worse initial VA (2.28 vs 1.92 logMAR; P = .003), and a greater mean number of surgeries (P = .020) than the no-steroids (control) group but an equivalent final logMAR VA (1.57 vs 1.52; P = .881). The prednisone group had significant VA improvement (P = .025); however, oral prednisone use did not predict the development of PVR (29.23% vs 12.90%; odds ratio [OR], 2.81; 95% CI, 0.89-8.85) or retinal detachment (27.27% vs 29.58%; OR, 0.59; 95% CI, 0.23-1.56). Conclusions: Despite a worse initial clinical presentation, patients who received oral prednisone had significant visual improvement compared with the control group. However, oral prednisone (1 mg/kg/day) use at the time of injury did not decrease the PVR rate.

Characteristics and surgery outcomes of macular hole diagnosed after rhegmatogenous retinal detachment repair

PURPOSE

To report the characteristics and the visual and anatomical outcomes of secondary macular holes (SMHs) diagnosed after rhegmatogenous retinal detachment (RRD) repair and their associated factors.

METHODS

Retrospective, interventional case series. All consecutive patients who were diagnosed with SMH after RRD repair at Beijing Tongren eye center from January 2016 to April 2021 were included. Patients who had their primary RRD repair in other hospitals and were referred to our center after diagnosis of SMH were also included. The minimum follow-up time after RRD repair was 6 months.

RESULTS

37 SMHs were diagnosed within a series of 5696 RRDs. Including 24 eyes referred from other hospitals after the diagnosis of SMH, 61 eyes were included. The type of primary RRD repair surgery included 22/61 (36%) eyes with scleral buckling procedure (SBP) and 39/61 (64%) eyes with pars plana vitrectomy (PPV). 21/61 (34%) eyes had recurrent RD. The median time to SMH diagnosis was 150 days (range, 7 ~ 4380 days). Macular hole (MH) closure was achieved in 77% eyes. Visual acuity (VA) improvement of at least 2 lines of Snellen's visual acuity was observed in 51% eyes. Final MH closure status was associated with preoperative MH diameter (for every 50 μm increment) (P = 0.046, OR = 0.875, 95%CI: 0.767 ~ 0.998). VA improvement was associated with final MH closure status (P = 0.009, OR = 8.742, 95%CI: 1.711 ~ 44.672). Final VA (logMAR) was associated with recurrent RD (P < 0.001, B = 0.663, 95%CI: 0.390 ~ 0.935), preoperative MH diameter (P = 0.001, B = 0.038, 95%CI: 0.017 ~ 0.058), VA at the time of SMH diagnosis (P < 0.001, B = 0.783, 95%CI: 0.557 ~ 1.009) and final MH closure status (P = 0.024, B = -0.345, 95%CI: -0.644 ~ -0.046). For patients without recurrent RD, VA improvement and final VA was associated with final MH closure status (P = 0.016 and P < 0.001, respectively), while for patients with recurrent RD, VA improvement or final VA did not associate with final MH closure status (P > 0.05).

CONCLUSION

For SMH diagnosed after RRD repair, final MH closure status was associated with preoperative MH diameter. Recurrent RD, larger preoperative MH diameter, worse VA at the time of SMH diagnosis and failed MH closure are predictive factors for worse final VA. Visual outcome is associated with final MH closure status in patients without recurrent RD, but not as so in patients with recurrent RD.

[Methods for predicting the risks of development, course and recurrence of rhegmatogenous retinal detachment]

Rhegmatogenous retinal detachment (RRD) is a severe disease of the visual organ that is one of the leading causes of blindness worldwide. Without surgical treatment, RRD almost always leads to vision loss and blindness. Surgical treatment in the early stages of the disease reduces the risk of blindness. This article analyzes scientific publications reflecting the issues of prognosis and prevention of RRD. Literature analysis showed that there are few prognostic matrices in ophthalmology in general, and specifically related to RRD. Most prognostic matrices for RRD are aimed at preventing its recurrence and predicting the development or progression of peripheral vitreochorioretinal dystrophy in the operated or fellow eye. Building a prognostic matrix for the risk of occurrence and development of such a serious disease as RRD in adults will allow early prediction, enabling surgical treatment in the shortest possible time and positively influencing the functional outcome of treatment.

Antioxidant therapy against TGF-β/SMAD pathway involved in organ fibrosis

Fibrosis refers to excessive build-up of scar tissue and extracellular matrix components in different organs. In recent years, it has been revealed that different cytokines and chemokines, especially Transforming growth factor beta (TGF-β) is involved in the pathogenesis of fibrosis. It has been shown that TGF-β is upregulated in fibrotic tissues, and contributes to fibrosis by mediating pathways that are related to matrix preservation and fibroblasts differentiation. There is no doubt that antioxidants protect against different inflammatory conditions by reversing the effects of nitrogen, oxygen and sulfur-based reactive elements. Oxidative stress has a direct impact on chronic inflammation, and as results, prolonged inflammation ultimately results in fibrosis. Different types of antioxidants, in the forms of vitamins, natural compounds or synthetic ones, have been proven to be beneficial in the protection against fibrotic conditions both in vitro and in vivo. In this study, we reviewed the role of different compounds with antioxidant activity in induction or inhibition of TGF-β/SMAD signalling pathway, with regard to different fibrotic conditions such as gastro-intestinal fibrosis, cardiac fibrosis, pulmonary fibrosis, skin fibrosis, renal fibrosis and also some rare cases of fibrosis, both in animal models and cell lines.

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.

Vitreous Cortex Remnants Removal With Beveled Vitrectomy Probe During Vitrectomy For Primary Rhegmatogenous Retinal Detachment

PURPOSE

To introduce a new surgical technique with a beveled vitrectomy probe for the removal of peripheral vitreous cortex remnants (VCR) in primary rhegmatogenous retinal detachment (RRD).

METHODS

This study was a retrospective case series. From September 2019 to June 2022, 54 patients with complete or partial posterior vitreous detachment who underwent vitrectomy for primary RRD by a single surgeon were enrolled.

RESULTS

After staining the vitreous with triamcinolone acetonide, the presence of VCR was assessed in detail. If VCR were present, the macular VCR were removed using surgical forceps, and then, a free flap of peripheral VCR was used as a handle for removing peripheral VCR using the beveled vitrectomy probe. Of the total patients, the presence of VCR was confirmed in 16 patients (29.6%). There were no intraoperative or postoperative complications, except for retinal redetachment caused by proliferative vitreoretinopathy, that occurred in only one eye (1.9%).

CONCLUSION

Using a beveled vitrectomy probe was a practical solution for removing VCR during RRD vitrectomy because additional instruments were not needed and risk of iatrogenic retinal damage was low.

Molecular Signatures Integral to Natural Reprogramming in the Pigment Epithelium Cells after Retinal Detachment in Pleurodeles waltl

The reprogramming of retinal pigment epithelium (RPE) cells into retinal cells (transdifferentiation) lies in the bases of retinal regeneration in several Urodela. The identification of the key genes involved in this process helps with looking for approaches to the prevention and treatment of RPE-related degenerative diseases of the human retina. The purpose of our study was to examine the transcriptome changes at initial stages of RPE cell reprogramming in adult newt Pleurodeles waltl. RPE was isolated from the eye samples of day 0, 4, and 7 after experimental surgical detachment of the neural retina and was used for a de novo transcriptome assembly through the RNA-Seq method. A total of 1019 transcripts corresponding to the differently expressed genes have been revealed in silico: the 83 increased the expression at an early stage, and 168 increased the expression at a late stage of RPE reprogramming. We have identified up-regulation of classical early response genes, chaperones and co-chaperones, genes involved in the regulation of protein biosynthesis, suppressors of oncogenes, and EMT-related genes. We revealed the growth in the proportion of down-regulated ribosomal and translation-associated genes. Our findings contribute to revealing the molecular mechanism of RPE reprogramming in Urodela.

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.

TRANSSCLERAL INCISION FOR PEELING SUBRETINAL PROLIFERATION TISSUE IN GRADE C PROLIFERATIVE VITREORETINOPATHY

PURPOSE

The purpose of this study was to investigate the clinical outcomes of an optimized method to clearly remove the subretinal proliferative tissue by transscleral puncture into the subretinal space in patients with grade C proliferative vitreoretinopathy without inducing retinal injury.

METHODS

This was a prospective clinical observation study. Eight consecutive patients who had undergone optimized vitrectomy surgery for retinal detachment complicated by grade C proliferative vitreoretinopathy were investigated. Subretinal proliferation was cleared by adding one additional scleral 23-gauge trocar under the detached retina at 9 mm to 10 mm from the limbus. After the sclera is pierced, the puncture knife changed its direction without touching the retina. 23-G intraocular forceps were used to remove the proliferation strand or membrane through the puncture channel.

RESULTS

Retinal reattachment was achieved in each case without a retinotomy. The mean best-corrected visual acuity was improved within the first 1 month ( P = 0.039) and remained stable at the following phase. There were no postoperative complications, such as reoccurrence of retinal detachment or proliferative vitreoretinopathy. No postoperative hemorrhage or hypotension was observed.

CONCLUSION

The satisfying results demonstrated the feasibility of this cost-effective, easy-to-follow, transscleral vitrectomy method in treating retinal detachment with grade C proliferative vitreoretinopathy.

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.

Evolution of demarcation line after pneumatic retinopexy-a case report

BACKGROUND

Demarcation line in a rhegmatogenous retinal detachment (RD) is a classic finding noted in chronic cases. In this case report, we describe a case of evolution of post-operative demarcation line after pneumatic retinopexy (PnR) in a subtotal rhegmatogenous RD.

CASE DESCRIPTION

A 31-year-old male diagnosed with acute, subtotal, macula-off rhegmatogenous RD in the left eye of 15-day duration underwent PnR on the same day. His presenting visual acuity was 6/48 in the left eye. Transconjunctival cryopexy was performed to the retinal break at the same sitting and 0.5 cc of 100% perfluoroproprane (C3F8) gas was injected in the vitreous cavity and right lateral position was advised to the patient.

RESULT

A pigmentary demarcation line was noted extending the nasal part of the macula along the most dependent part of the detachment on the immediate post-operative day and was more obviously visible on the 2nd and then on the 11th post-operative day. The visual acuity at the last follow-up visit improved to 6/18. Successful reattachment of the retina was noted on the last follow-up visit.

CONCLUSION

Post-operative demarcation lines after RD surgery could develop due to subretinal migration of pigments and along the most-dependent part depending upon post-operative positioning of the patient. Careful post-operative positioning, particularly in macula splitting RDs could be important to avoid pigment accumulation along the foveal area.

Silibinin Prevents TGFβ-Induced EMT of RPE in Proliferative Vitreoretinopathy by Inhibiting Stat3 and Smad3 Phosphorylation

Purpose

The purpose of this study was to investigate the effects of silibinin on epithelial-mesenchymal transition (EMT) of retinal pigment epithelial (RPE) and proliferative vitreoretinopathy (PVR) formation, as well as its underlying molecular mechanism.

Methods

Cellular morphological change and EMT molecular markers were evaluated by using phase contrast imaging, qPCR, and Western blot (WB) to investigate the impact of silibinin on the EMT of ARPE-19 cells. Scratch assay and transwell assay were used to study the effect of silibinin on cell migration. An intravitreally injected RPE-induced rat PVR model was used to assess the effect of silibinin on PVR in vivo. RNA-seq was applied to study the molecular mechanism of silibinin-mediated PVR prevention.

Results

Silibinin inhibited TGFβ1-induced EMT and migration of RPE in a dose-dependent manner in vitro. Moreover, silibinin prevented proliferative membrane formation in an intravitreal injected RPE-induced rat PVR model. In line with these findings, RNA-seq revealed a global suppression of TGFβ1-induced EMT and migration-related genes by silibinin in RPEs. Mechanistically, silibinin reduced TGFβ1-induced phosphorylation levels of Smad3 and Stat3, and Smad3 nuclear translocation in RPE.

Conclusions

Silibinin inhibits the EMT of RPE cells in vitro and prevents the formation of PVR membranes in vivo. Mechanistically, silibinin inhibits Smad3 phosphorylation and suppresses Smad3 nuclear translocation through the inhibition of Stat3 phosphorylation. These findings suggest that silibinin may serve as a potential treatment for PVR.

Cellular and Molecular Triggers of Retinal Regeneration in Amphibians

Understanding the mechanisms triggering the initiation of retinal regeneration in amphibians may advance the quest for prevention and treatment options for degenerating human retina diseases. Natural retinal regeneration in amphibians requires two cell sources, namely retinal pigment epithelium (RPE) and ciliary marginal zone. The disruption of RPE interaction with photoreceptors through surgery or injury triggers local and systemic responses for retinal protection. In mammals, disease-induced damage to the retina results in the shutdown of the function, cellular or oxidative stress, pronounced immune response, cell death and retinal degeneration. In contrast to retinal pathology in mammals, regenerative responses in amphibians have taxon-specific features ensuring efficient regeneration. These include rapid hemostasis, the recruitment of cells and factors of endogenous defense systems, activities of the immature immune system, high cell viability, and the efficiency of the extracellular matrix, cytoskeleton, and cell surface remodeling. These reactions are controlled by specific signaling pathways, transcription factors, and the epigenome, which are insufficiently studied. This review provides a summary of the mechanisms initiating retinal regeneration in amphibians and reveals its features collectively directed at recruiting universal responses to trauma to activate the cell sources of retinal regeneration. This study of the integrated molecular network of these processes is a prospect for future research in demand biomedicine.