Rho kinase inhibitors-a review on the physiology and clinical use in Ophthalmology

Effectiveness of netarsudil 0.02% in lowering intraocular pressure in patients with secondary glaucoma

OBJECTIVE

To determine the effectiveness of netarsudil, 0.02% in lowering intraocular pressure (IOP) in patients with secondary forms of glaucoma.

METHODS

A total of 77 patients (98 eyes) with either primary open-angle glaucoma (POAG) or secondary glaucoma were reviewed retrospectively over the course of 1 year after starting netarsudil. The secondary glaucoma group was comprised of patients with uveitic, pseudoexfoliative, neovascular, congenital, and other forms of secondary glaucoma. Patient IOP measurements were collected at baseline and at 1-, 3-, 6-, and 12-month intervals. Two sample t tests and 1-way analysis of variance were used to determine differences in IOP reductions following netarsudil treatment.

RESULTS

Patients with POAG or secondary glaucomas were matched for age (mean ± SD: 69.1 ± 16.0 years vs. 64.5 ± 21.2 years; p = 0.30). Both the POAG and secondary glaucoma patients exhibited significant decreases in IOP at each time point (1, 3, 6, and 12 months) when compared with baseline (p < 0.05). Both groups showed similar overall decreases in IOP from baseline after 1 year of treatment (6.0 ± 4.5 mm Hg vs. 6.6 ± 8.4 mm Hg; p = 0.70). Forty-sex percent of POAG patients achieved an IOP of <14 mm Hg compared with 17% of secondary glaucoma patients. Among the secondary glaucoma subtypes, netarsudil was found to be most effective for treating uveitic glaucoma, showing a decrease in IOP of 9.5 mm Hg after 12 months (p = 0.02).

CONCLUSION

Netarsudil is effective in lowering IOP in patients with certain forms of secondary glaucoma and should be considered for IOP management in those with uveitic glaucoma.

Rho-kinase inhibitor alleviates CD4+T cell mediated corneal graft rejection by modulating its STAT3 and STAT5 activation

Penetrating keratoplasty remains the most common treatment to restore vision for corneal diseases. Immune rejection after corneal transplantation is one of the major causes of graft failure. In recent years, Rho-associated protein kinase (ROCK) inhibitors have been found to be associated with the activation of the STATs pathway and are widely studied in autoimmune diseases. Therefore, it may be possible that the ROCK inhibitors also participate in the local and systemic immune regulation in corneal transplantation through activation of the STATs pathway and affect the CD4+ T cell differentiation. This study aimed to explore the role of ROCK-STATs pathway in the occurrence of immune rejection in corneal transplantation by applying Y27632, a ROCK inhibitor, to the recipient mice and peripheral CD4+ T cells. We found that Y27632 significantly up-regulated the phosphorylation level of STAT5 in both spleen and lymph nodes, down-regulated the phosphorylation level of STAT3 in the CD4+ T cells in the spleen. It also increased the proportion of CD4+CD25+Foxp3+Helios+ Tregs while decreased CD4+IL17A+ -Th17 cells. Moreover, Y27632 also reduced the proportion of dendritic cells in both spleen and lymph nodes, as well as the expression level of CD86 on their surfaces in the spleen, while the proportion of macrophages was not affected. The expression levels of ROCK1, ROCK2, CD11c and IL-17A mRNA were also found to be low in the graft tissue while the expression of Helios was upregulated. Rho-kinase inhibitor can modulate the balance of Tregs/Th17 by regulating the phosphorylation levels of both STAT3 and STAT5, thereby inhibiting the occurrence of immune rejection in allogeneic corneal transplantation.

The Role of Rho Kinase Inhibitors in Corneal Diseases

The cornea, as the outermost layer of the eye, plays a crucial role in vision by focusing light onto the retina. Various diseases and injuries can compromise its clarity, leading to impaired vision. This review aims to provide a thorough overview of the pharmacological properties, therapeutic potential and associated risks of Rho-associated protein kinase (ROCK) inhibitors in the management of corneal diseases. The article focuses on four key ROCK inhibitors: Y-27632, fasudil, ripasudil, and netarsudil, providing a comparative examination. Studies supporting the use of ROCK inhibitors highlight their efficacy across diverse corneal conditions. In Fuchs' endothelial corneal dystrophy, studies on the application of Y-27632, ripasudil, and netarsudil demonstrated noteworthy enhancements in corneal clarity, endothelial cell density, and visual acuity. In pseudophakic bullous keratopathy, the injection of Y-27632 together with cultured corneal endothelial cells into the anterior chamber lead to enhanced corneal endothelial cell density and improved visual acuity. Animal models simulating chemical injury to the cornea showed a reduction of neovascularization and epithelial defects after application of fasudil and in a case of iridocorneal endothelial syndrome netarsudil improved corneal edema. Addressing safety considerations, netarsudil and ripasudil, both clinically approved, exhibit adverse events such as conjunctival hyperemia, conjunctival hemorrhage, cornea verticillata, conjunctivitis, and blepharitis. Monitoring patients during treatment becomes crucial to balancing the potential therapeutic benefits with these associated risks. In conclusion, ROCK inhibitors, particularly netarsudil and ripasudil, offer promise in managing corneal diseases. The comparative analysis of their pharmacological properties and studies supporting their efficacy underscore their potential therapeutic significance. However, ongoing research is paramount to comprehensively understand their safety profiles and long-term outcomes in diverse corneal conditions, guiding their optimal application in clinical practice.

MERCURY-3: a randomized comparison of netarsudil/latanoprost and bimatoprost/timolol in open-angle glaucoma and ocular hypertension

PURPOSE   : To compare the efficacy and safety of the fixed-dose combination (FDC) of netarsudil 0.02%/latanoprost 0.005% ophthalmic solution (NET/LAT; Roclanda®) with bimatoprost 0.03%/timolol maleate 0.5% (BIM/TIM; Ganfort®) ophthalmic solution in the treatment of open-angle glaucoma (OAG) and ocular hypertension (OHT).

METHODS

MERCURY-3 was a 6-month prospective, double-masked, randomized, multicenter, active-controlled, parallel-group, non-inferiority study. Patients (≥ 18 years) with a diagnosis of OAG or OHT in both eyes that was insufficiently controlled with topical medication (IOP ≥ 17 mmHg in ≥ 1 eye and < 28 mmHg in both eyes) were included. Following washout, patients were randomized to once-daily NET/LAT or BIM/TIM for up to 6 months; efficacy was assessed at Week 2, Week 4, and Month 3; safety was evaluated for 6 months. Comparison of NET/LAT relative to BIM/TIM for mean IOP at 08:00, 10:00, and 16:00 h was assessed at Week 2, Week 6, and Month 3. Non-inferiority of NET/LAT to BIM/TIM was defined as a difference of ≤ 1.5 mmHg at all nine time points through Month 3 and ≤ 1.0 mmHg at five or more of nine time points through Month 3.

RESULTS

Overall, 430 patients were randomized (NET/LAT, n = 218; BIM/TIM, n = 212), and all received at least one dose of study medication. Efficacy analyses were performed at Month 3 on 388 patients (NET/LAT, n = 184; BIM/TIM, n = 204). NET/LAT demonstrated non-inferiority to BIM/TIM, with a between-treatment difference in IOP of ≤ 1.5 mmHg achieved at all time points and ≤ 1.0 mmHg at the majority of time points (six of nine) through Month 3. Mean diurnal IOP during the study ranged from 15.4 to 15.6 mmHg and 15.2 to 15.6 mmHg in the NET/LAT and BIM/TIM groups respectively, with no between-group statistically significant difference. No significant differences were observed in key secondary endpoints. No serious, treatment-related adverse events (AEs) were observed, and AEs were typically mild/moderate in severity. The most common treatment-related AEs were conjunctival hyperemia (NET/LAT, 30.7%; BIM/TIM, 9.0%) and cornea verticillata (NET/LAT, 11.0%; BIM/TIM, 0%).

CONCLUSIONS

Once-daily NET/LAT was non-inferior to BIM/TIM in IOP reduction in OAG and OHT, with AEs consistent with previous findings. NET/LAT offers a compelling alternative FDC treatment option for OAG and OHT.

ROCK Inhibitors in Corneal Diseases and Glaucoma-A Comprehensive Review of These Emerging Drugs

Rho kinase (ROCK) inhibitors have gained significant attention as emerging novel treatment options in the field of ophthalmology in recent years. The evidence supporting their efficacy in glaucoma and corneal pathology includes both in vitro and clinical studies. Among the available options, ripasudil and netarsudil have emerged as the leading ROCK inhibitors, and some countries have approved these therapeutic options as treatments for glaucoma. Various dosing regimens have been studied, including monotherapy and combination therapy, especially for patients with secondary glaucoma who are already on multiple medications. Another rising application of ROCK inhibitors includes their use as an adjunct in surgical procedures such as Descemetorhexis Without Endothelial Keratoplasty (DWEK), Descemet Stripping Only (DSO) to accelerate visual recovery, glaucoma surgeries to reduce scarring process and allow better intraocular pressure (IOP) control, or after complicated anterior segment surgery to treat corneal oedema. This article provides a comprehensive overview of the existing literature in the field, offering recommendations for prescribing ROCK inhibitors and also discussing patient selection, drug efficacy, and possible adverse effects.

Gomes J, Güell JL, Casaroli-Marano RP. Corneal Endothelial Cell Cultures from Organotypic Preservation of Older Donor Corneas Are Suitable for Advanced Cell Therapy

INTRODUCTION

The purpose of this work was to evaluate the in vitro growth capacity and functionality of human corneal endothelial cells (hCEC) expanded from corneas of elderly (>60 years) donors that were preserved using an organotypic culture method (>15 days, 31°C) and did not meet the clinical criteria for keratoplasty.

METHODS

Cell cultures were obtained from prior descemetorhexis (≥10 mm) and a controlled incubation with collagenase type I followed by recombinant trypsin. Cells were seeded on coated plates (fibronectin-albumin-collagen I) and cultures were expanded using the dual supplemented medium approach (maintenance medium and growth medium), in the presence of a 10 μm Rho-associated protein kinase inhibitor (Y-27632). Cell passages were obtained at culture confluency (∼2 weeks). A quantitative colorimetric WST-1 cell growth assay was performed at different time points of the culture. Morphometric analysis (area assessment and circularity), immunocytochemistry (ZO-1, Na+/K+-ATPase α, Ki67), and transendothelial electrical resistance (TEER) were performed on confluent monolayers.

RESULTS

There was no difference between the cell growth profiles of hCEC cultures obtained from corneas older than 60 years, whether preserved cold or cultivated organotypic corneas. Primary cultures were able to maintain a certain cell circularity index (around 0.8) and morphology (hexagonal) similar to corneal endothelial mosaic. The ZO-1 and Na+/K+-ATPase pump markers were highly positive in confluent cell monolayers at 21 days after isolation (passage 0; P0), but significantly decreased in confluent monolayers after the first passage (P1). A weak expression of Ki67 was observed in both P0 and P1 monolayers. The P0 monolayers showed a progressive increase in TEER values between days 6 and 11 and remained stable until day 18 of culture, indicating a state of controlled permeability in monolayers. The P1 monolayers also showed some functional ability but with decreased TEER values compared to monolayers at P0.

CONCLUSIONS

Our results indicate that it is possible to obtain functional hCEC cultures in eye banks, using simplified and standardized protocols, from older donor corneas (>60 years of age), previously preserved under organotypic culture conditions. This tissue is more readily available in our setting, due to the profile of the donor population or due to the low endothelial count (<2,000 cells/mm2) of the donated cornea.

Ocular surface disease: a known yet overlooked side effect of topical glaucoma therapy

Ocular surface disease (OSD), a disorder affecting the lacrimal and meibomian glands and the corneal and conjunctival epithelium, is a well-known complication of topical glaucoma therapy. OSD can present as a new or pre-existing condition that virtually any anti-glaucoma formulation can exacerbate. As such, both glaucoma and OSD frequently coexist. Typical OSD symptoms include ocular discomfort, redness, burning, and dryness, whereas signs include periorbital and eyelid skin pigmentation, conjunctival scarring, and superficial punctate keratitis. Pressure-lowering eyedrops can cause toxic, allergic, and inflammatory reactions on the ocular surface. The latter can result from either preservatives or direct toxicity from the active molecule. Although usually mild, OSD can cause significant symptoms that lead to poor quality of life, decreased compliance to therapy, glaucoma progression, and worse visual outcomes. Given the chronic nature of glaucoma, lack of curative therapy, and subsequent lifelong treatment, addressing OSD is necessary. This manuscript aims to provide an up-to-date overview of OSD's signs, symptoms, and pathogenic mechanisms from glaucoma therapy toxicity.

The Multifarious Effects of Various Glaucoma Pharmacotherapy on Corneal Endothelium: A Narrative Review

Corneal endothelium is a single cell layer that is mainly responsible for maintaining corneal clarity. Endothelial damage secondary to toxicity, stress, or genetic predisposition are common and in conjunction with the low regenerative ability of the cells, making their preservation critical for maintaining visual acuity. Patients with glaucoma, who are estimated to be close to 80 million worldwide, have a plethora of reasons for developing endothelial damage, being exposed to a spectrum that extends from various medical and surgical interventions to the disease itself. The wide spectrum of glaucoma pharmacotherapy that has been recently extended by addition of newer classes of medications has been the focus of extensive research on its effects on corneal endothelium. Both basic and clinical research have attempted to shine a light on the complex mechanisms associated with the effects of glaucoma medication on corneal endothelium and to answer the important question as to whether these findings are clinically significant. The aim of this review is to summarize and present current literature of the various findings, both from in vivo and in vitro studies that have focused on the complex relationship between different classes of glaucoma medication and their effect on corneal endothelium.

A novel fixed-combination timolol-netarsudil-latanoprost ophthalmic solution for the treatment of glaucoma and ocular hypertension

Currently commercial fixed-concomitant three agents have multiple problems such as multiple dosing administration, poor efficacy and side effects. Once-daily fixed-combination timolol-netarsudil-latanoprost ophthalmic solution (FC-TNL) has the ability to treat glaucoma by lowering the intraocular pressure (IOP) with great efficacy and improving patient compliance. However, the commercialized netarsudil dimesylate precipitated when the pH of the solution was above 5.4, or when maleic acid, the salt of commercial timolol maleate, was mixed with netarsudil dimesylate. Consequently, the homologous salt engineering strategy was used to make netarsudil dimesylate soluble in pH 4.8-5.2 solution by synthesizing timolol mesylate. Next, the morphology of timolol mesylate was observed by scanning electron microscopy, differential scanning calorimetry, thermogravimetric analysis, and powder X-ray diffraction. The prepared FC-TNL showed good stability during refrigeration storage. Additionally, FC-TNL exerted no influence on the intraocular penetration of each active compounds in the pharmacokinetic study. Importantly, once-daily FC-TNL exerted potent IOP-lowering effect and protective effect on retinal ganglion cells. The FC-TNL was stable, safe and effective, being a promising glaucoma therapeutic.

Combined intravitreal injection of bevacizumab and a ROCK inhibitor (fasudil) for refractory macular edema secondary to retinal vein occlusion: a pilot study

Background

To investigate the adjunctive effect of an intravitreal ROCK inhibitor (fasudil) in combination with intravitreal bevacizumab (IVB) on refractory macular edema secondary to retinal vein occlusion (RVO).

Methods

In this prospective interventional case series, 17 eyes of 17 patients (10 men, 7 women) with refractory RVO-related macular edema underwent three consecutive intravitreal injections of bevacizumab plus fasudil. Monthly evaluation was continued up to 12 months and IVB injection was performed if needed during the follow-up. Changes in the best corrected visual acuity (BCVA) was the primary outcome measure. The secondary outcome measures included central macular thickness (CMT) changes and any adverse events.

Results

BCVA significantly improved (mean change: −0.15 LogMAR; P = 0.017) after 3 consecutive intravitreal injections of fasudil in combination with bevacizumab. CMT significantly decreased (mean change: −206 µm; P = 0.028). The anatomical and functional improvement was maintained during the 12 month follow-up. No adverse effects were noticed.

Conclusion

Intravitreal ROCK inhibitors may break the resistance to anti-VEGF therapy and improve the RVO induced macular edema via affecting the VEGF-independent pathways.

Rho kinase inhibitor for primary open-angle glaucoma and ocular hypertension

BACKGROUND

Glaucoma is a group of optic neuropathies characterized by progressive degeneration of the retinal ganglion cells, axonal loss and irreversible visual field defects. Glaucoma is classified as primary or secondary, and worldwide, primary glaucoma is a leading cause of irreversible blindness. Several subtypes of glaucoma exist, and primary open-angle glaucoma (POAG) is the most common. The etiology of POAG is unknown, but current treatments aim to reduce intraocular pressure (IOP), thus preventing the onset and progression of the disease. Compared with traditional antiglaucomatous treatments, rho kinase inhibitors (ROKi) have a different pharmacodynamic. ROKi is the only current treatment that effectively lowers IOP by modulating the drainage of aqueous humor through the trabecular meshwork and Schlemm's canal. As ROKi are introduced into the market more widely, it is important to assess the efficacy and potential AEs of the treatment.

OBJECTIVES

To compare the efficacy and safety of ROKi with placebo or other glaucoma medication in people diagnosed with open-angle glaucoma (OAG), primary open-angle glaucoma (POAG) or ocular hypertension (OHT).

SEARCH METHODS

We used standard Cochrane methods and searched databases on 11 December 2020.

SELECTION CRITERIA

We included randomized clinical trials examining commercially available ROKi-based monotherapy or combination therapy compared with placebo or other IOP-lowering medical treatments in people diagnosed with (P)OAG or OHT. We included trials where ROKi were administered according to official glaucoma guidelines. There were no restrictions regarding type, year or status of the publication.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Two review authors independently screened studies, extracted data, and evaluated risk of bias by using Cochrane's RoB 2 tool.  MAIN RESULTS: We included 17 trials with 4953 participants diagnosed with (P)OAG or OHT. Fifteen were multicenter trials and 15 were masked trials. All participants were aged above 18 years. Trial duration varied from 24 hours to 12 months. Trials were conducted in the USA, Canada and Japan. Sixteen trials were funded by pharmaceutical companies, and one trial provided no information about funding sources. The trials compared ROKi monotherapy (netarsudil or ripasudil) or combination therapy with latanoprost (prostaglandin analog) or timolol (beta-blocker) with placebo, timolol, latanoprost or netarsudil. Reported outcomes were IOP and safety. Meta-analyses were applied to 13 trials (IOP reduction from baseline) and 15 trials (ocular AEs).  Of the trials evaluating IOP, seven were at low risk, three had some concerns, and three were at high risk of bias. Three trials found that netarsudil monotherapy may be superior to placebo (mean difference [MD] 3.11 mmHg, 95% confidence interval [CI] 2.59 to 3.62; I² = 0%; 155 participants; low-certainty evidence). Evidence from three trials found that timolol may be superior to netarsudil with an MD of 0.66 mmHg (95% CI 0.41 to 0.91; I² = 0%; 1415 participants; low-certainty evidence). Evidence from four trials found that latanoprost may be superior to netarsudil with an MD of 0.97 mmHg (95% CI 0.67 to 1.27; I² = 4%; 1283 participants; moderate-certainty evidence).  Evidence from three trials showed that, compared with monotherapy with latanoprost, combination therapy with netarsudil and latanoprost probably led to an additional pooled mean IOP reduction from baseline of 1.64 mmHg (95% CI -2.16 to -1.11; 1114 participants). Evidence from three trials showed that, compared with monotherapy with netarsudil, combination therapy with netarsudil and latanoprost probably led to an additional pooled mean IOP reduction from baseline of 2.66 mmHg (95% CI -2.98 to -2.35; 1132 participants). The certainty of evidence was moderate. One trial showed that,  compared with timolol monotherapy, combination therapy with ripasudil and timolol may lead to an IOP reduction from baseline of 0.75 mmHg (95% -1.29 to -CI 0.21; 208 participants). The certainty of evidence was moderate. Of the trials assessing total ocular AEs, three were at low risk, four had some concerns, and eight were at high risk of bias.  We found very low-certainty evidence that netarsudil may lead to more ocular AEs compared with placebo, with 66 more ocular AEs per 100 person-months (95% CI 28 to 103; I² = 86%; 4 trials, 188 participants). We found low-certainty evidence that netarsudil may lead to more ocular AEs compared with latanoprost, with 29 more ocular AEs per 100 person-months (95% CI 17 to 42; I² = 95%; 4 trials, 1286 participants).  We found moderate-certainty evidence that, compared with timolol, netarsudil probably led to 21 additional ocular AEs (95% CI 14 to 27; I² = 93%; 4 trials, 1678 participants). Data from three trials (1132 participants) showed no evidence of differences in the incidence rate of AEs between combination therapy with netarsudil and latanoprost and netarsudil monotherapy (1 more event per 100 person-months, 95% CI 0 to 3); however, the certainty of evidence was low. Similarly, we found low-certainty evidence that, compared with latanoprost, combination therapy with netarsudil and latanoprost may cause 29 more ocular events per 100 person-months (95% CI 11 to 47; 3 trials, 1116 participants). We found moderate-certainty evidence that, compared with timolol monotherapy, combination therapy with ripasudil and timolol probably causes 35 more ocular events per 100 person-months (95% CI 25 to 45; 1 trial, 208 participants). In all included trials, ROKi was reportedly not associated with any particular serious AEs.

AUTHORS' CONCLUSIONS

The current evidence suggests that in people diagnosed with OHT or (P)OAG, the hypotensive effect of netarsudil may be inferior to latanoprost and slightly inferior to timolol. Combining netarsudil and latanoprost probably further reduces IOP compared with monotherapy. Netarsudil as mono- or combination therapy may result in more ocular AEs. However, the certainty of evidence was very low or low for all comparisons except timolol. In general, AEs were described as mild, transient, and reversible upon treatment discontinuation. ROKi was not associated with any particular serious AEs. Future trials of sufficient size and follow-up should be conducted to provide reliable information about glaucoma progression, relevant IOP measurements and a detailed description of AEs using similar terminology. This would ensure the robustness and confidence of the results and assess the intermediate- and long-term efficacy and safety of ROKi.

A 20-year bibliometric analysis of Fuchs endothelial corneal dystrophy: from 2001 to 2020

PURPOSE

The aim of this study was to identify trends and focuses in the field of Fuchs endothelial corneal dystrophy (FECD) research.

METHODS

A bibliometric analysis based on the Web of Science Core Collection was conducted. All publications related to FECD from 2001 to 2020 were extracted and analyzed. VOSviewer v.1.6.17 was used to construct a visualization map and evaluate the trends and focuses in FECD research.

RESULTS

A total of 1,041 publications were extracted. The rate of global publications has steadily increased. The United States produced the highest number of publications (461), the highest number of citations (18,757), and the highest H index (69). Melles GRJ published the highest number of papers (60), and Price FW had the highest number of citations (4,154) in the FECD research field. The highest number of publications came from the journal Cornea (279). Keywords were classified into four clusters: (1) corneal transplantation surgery, (2) surgical techniques and instruments, (3) corneal parameter measurement, and (4) genetic and molecular pathomechanisms. The average appearing years (AAYs) of the keywords were evaluated. Recently appearing keywords included "Tcf4 gene" (AAY of 2018.3), "ctg18.1" (AAY of 2017.2), "trinucleotide repeat expansion" (AAY of 2018.3), "rock inhibitor" (AAY of 2017.4), and "descemetorhexis" (AAY of 2017.4).

CONCLUSIONS

The United States has a dominant position in FECD research. Although corneal transplantation surgery has been the most mainstream area of FECD research field for a long time, gene mutations such as the TCF4 CTG trinucleotide repeat expansion, nonsurgical interventions such as rho-associated kinase inhibitors, and newer surgical methods such as descemetorhexis without endothelial keratoplasty are potential research hotspots.

Topical Medication Therapy for Glaucoma and Ocular Hypertension

Glaucoma is one of the most common causes of blindness, thus seriously affecting people’s health and quality of life. The topical medical therapy is as the first line treatment in the management of glaucoma since it is inexpensive, convenient, effective, and safe. This review summarizes and compares extensive clinical trials on the topical medications for the treatment of glaucoma, including topical monotherapy agents, topical fixed-combination agents, topical non-fixed combination agents, and their composition, mechanism of action, efficacy, and adverse effects, which will provide reference for optimal choice of clinical medication. Fixed-combination therapeutics offer greater efficacy, reliable security, clinical compliance, and tolerance than non-fixed combination agents and monotherapy agents, which will become a prefer option for the treatment of glaucoma. Meanwhile, we also discuss new trends in the field of new fixed combinations of medications, which may better control IOP and treat glaucoma.

Secondary Endothelial Keratoplasty-A Narrative Review of the Outcomes of Secondary Corneal Endothelial Allografts

BACKGROUND

We review the literature on the efficacy and safety outcomes of secondary Descemet stripping endothelial keratoplasty (DSEK) and Descemet membrane endothelial keratoplasty (DMEK).

METHODS

Literature search of English-written publications up to September 27, 2020 in PubMed database, using the terms "endothelial keratoplasty" in combination with keywords "secondary" or "repeat." In addition, we manually searched the references of the primary articles.

RESULTS

Twenty-seven studies (n = 651 eyes) were retained and reviewed, including 10 studies on repeat DSEK, 8 studies on repeat DMEK, 6 studies of DMEK following DSEK, and 3 studies of DSEK after failed DMEK. All studies reported significant improvement in visual acuity after secondary endothelial keratoplasty (EK). Twelve studies compared visual outcomes between primary and secondary EK, reporting conflicting findings. Sixteen studies reported endothelial cell loss rates after secondary EK, and only 1 study reported significantly increased endothelial cell loss rates compared with primary EK. Allograft rejection episodes occurred in 1.8% of eyes (range, 0%-50%). Six studies compared complication rates between primary and secondary EK eyes, and only 1 study found a higher median number of complications. However, 2 studies reported higher regraft failure rates compared with primary EK eyes.

CONCLUSIONS

Secondary EK is surgically feasible and renders significant visual improvement after failed primary EK, although it is not clear whether visual outcomes and allograft survival are comparable with primary EK, raising the question of whether secondary EK eyes are "low risk" as primary EK eyes. Further larger, prospective studies are encouraged to obtain additional quality data on secondary corneal endothelial allotransplantation.

Genetic Risk and Phenotype Correlation of Primary Open-Angle Glaucoma Based on Rho-Kinase Gene Polymorphisms

Rho-associated coiled-coil kinase (ROCK) signaling can affect glaucoma risk by regulating trabecular meshwork outflow. We investigated the effect of ROCK gene polymorphism on the risks of primary open-angle glaucoma (POAG) and POAG-related phenotypes including intraocular pressure (IOP) in a Korean population. A total of 24 single-nucleotide polymorphisms (SNPs) from ROCK1 and ROCK2 were selected and genotyped for 363 POAG patients and 213 healthy controls. Among the 363 POAG patients, 282 were normal-tension glaucoma (NTG, baseline IOP ≤ 21 mmHg) and 81 were high-tension glaucoma (HTG, baseline IOP > 21 mmHg). The SNPs rs288979, rs1006881, rs35996865, rs10083915, and rs11873284 in ROCK1 (tagged to each other, r² = 1) were nominally associated with risk of HTG (OR = 0.52, p = 0.045). However, there were no SNPs that were significantly associated with the risk of NTG. In the genotype-phenotype correlation analysis, the SNPs rs2230773 and rs3771106 in ROCK2 were significantly correlated with central corneal thickness (CCT)-adjusted IOP (p = 0.024) and axial length (AXL; p = 0.024), respectively. The present data implicated the role of ROCK in POAG development, and as such, can serve as a good reference for upcoming Rho/ROCK-pathway-related studies on POAG.

AR12286 Alleviates TGF-β-Related Myofibroblast Transdifferentiation and Reduces Fibrosis after Glaucoma Filtration Surgery

Scar formation can cause the failure of glaucoma filtration surgery. We investigated the effect of AR12286, a selective Rho-associated kinase inhibitor, on myofibroblast transdifferentiation and intraocular pressure assessment in rabbit glaucoma filtration surgery models. Cell migration and collagen contraction were used to demonstrate the functionality of AR12286-modulated human conjunctival fibroblasts (HConFs). Polymerase chain reaction quantitative analysis was used to determine the effect of AR12286 on the production of collagen Type 1A1 and fibronectin 1. Cell migration and collagen contraction in HConFs were activated by TGF-β1. However, compared with the control group, rabbit models treated with AR12286 exhibited higher reduction in intraocular pressure after filtration surgery, and decreased collagen levels at the wound site in vivo. Therefore, increased α-SMA expression in HConFs induced by TGF-β1 could be inhibited by AR12286, and the production of Type 1A1 collagen and fibronectin 1 in TGF-β1-treated HConFs was inhibited by AR12286. Overall, the stimulation of HConFs by TGF-β1 was alleviated by AR12286, and this effect was mediated by the downregulation of TGF-β receptor-related SMAD signaling pathways. In vivo results indicated that AR12286 thus improves the outcome of filtration surgery as a result of its antifibrotic action in the bleb tissue because AR12286 inhibited the TGF-β receptor-related signaling pathway, suppressing several downstream reactions in myofibroblast transdifferentiation.

Improving outcomes in retinal detachment: the potential role of rho-kinase inhibitors

PURPOSE OF REVIEW

Retinal detachment initiates a series of events that lead to degenerative changes in retinal synaptic architecture as well as the well-known phenomena of gliosis and photoreceptor apoptosis. Retinal reattachment does not always result in complete visual recovery, even if the fovea is not directly involved in the detachment. Rho-kinase (ROCK) inhibitors may mitigate some of these deleterious changes including disruption of synaptic architecture, photoreceptor apoptosis, and initiation of the epithelial-mesenchymal transition that characterizes proliferative vitreoretinopathy (PVR). This review focuses on the use of ROCK inhibitors to modulate synaptic disjunction.

RECENT FINDINGS

ROCK inhibition prevents retinal detachment-induced photoreceptor synaptic terminal retraction (i.e., synaptic disjunction), thereby diminishing the damage of the first synapse in the visual pathway. ROCK inhibition also reduces retinal detachment-induced photoreceptor apoptosis and suppresses PVR progression in preclinical models.

SUMMARY

Inhibition of ROCK may help to optimize visual recovery after retinal detachment surgery or iatrogenic detachments during cell transplantation or viral subretinal injection and might play a role in reducing the risk of PVR after retinal detachment surgery.

Simvastatin and ROCK Inhibitor Y-27632 Inhibit Myofibroblast Differentiation of Graves' Ophthalmopathy-Derived Orbital Fibroblasts via RhoA-Mediated ERK and p38 Signaling Pathways

Transforming growth factor-β (TGF-β)-induced differentiation of orbital fibroblasts into myofibroblasts is an important pathogenesis of Graves' ophthalmopathy (GO) and leads to orbital tissue fibrosis. In the present study, we explored the antifibrotic effects of simvastatin and ROCK inhibitor Y-27632 in primary cultured GO orbital fibroblasts and tried to explain the molecular mechanisms behind these effects. Both simvastatin and Y-27632 inhibited TGF-β-induced α-smooth muscle actin (α-SMA) expression, which serves as a marker of fibrosis. The inhibitory effect of simvastatin on TGF-β-induced RhoA, ROCK1, and α-SMA expression could be reversed by geranylgeranyl pyrophosphate, an intermediate in the biosynthesis of cholesterol. This suggested that the mechanism of simvastatin-mediated antifibrotic effects may involve RhoA/ROCK signaling. Furthermore, simvastatin and Y-27632 suppressed TGF-β-induced phosphorylation of ERK and p38. The TGF-β-mediated α-SMA expression was suppressed by pharmacological inhibitors of p38 and ERK. These results suggested that simvastatin inhibits TGF-β-induced myofibroblast differentiation via suppression of the RhoA/ROCK/ERK and p38 MAPK signaling pathways. Thus, our study provides evidence that simvastatin and ROCK inhibitors may be potential therapeutic drugs for the prevention and treatment of orbital fibrosis in GO.

Rho-kinase inhibitors in the management of glaucoma

Introduction: Glaucoma is a group of progressive optic neuropathies in which elevated intraocular pressure (IOP) as a consequence of an increased aqueous humor (AH) outflow resistance, is the main and only clinically modifiable risk factor for its development and progression. Relaxing Trabecular meshwork (TM) tissue, Rho-Kinase (ROCK) inhibitors directly decrease resistance in the conventional AH outflow, thus resulting in a significant IOP-lowering effect. Areas covered: The progress made in the field of ROCK inhibitors for glaucoma treatment will be discussed, referring to the recent patent literature published mainly in the last 3 years. Development and last studies conducted on the recently approved ripasudil and netarsudil will be described, along with newly reported combinations with other antiglaucoma agents. New molecular entities as ROCK inhibitors will be reported as well as new biological approaches to affect the Rho/ROCK pathway. Expert opinion: With three drugs currently available on the market belonging to this class, ROCK inhibitors have been definitely validated as therapeutic agents for glaucoma treatment. The literature of the last 3 years confirmed the success of the soft-drug and bis-functional approaches in the design of ROCK inhibitors. However, few completely new molecular scaffolds have been reported.

Prostaglandin receptor agonists as antiglaucoma agents (a patent review 2013 - 2018)

Introduction: Elevated intraocular pressure (IOP) is the most prevalent risk factor for glaucoma. Prostaglandin analogs are a first-line therapy for glaucoma due to their ability to reduce IOP, once-daily dosing, efficacy, and minimal side-effect profile. Many compounds targeting different PG receptors have been developed in the last years, some of them being in clinical use. Latanoprost, Bimatoprost, Travoprost, and Tafluprost are clinically used as antiglaucoma drugs and act as agonists of the PGF2α receptor. The inability to fully understand the mechanism of action of clinically used PGF2α analogs is thus a strong driver for additional research into the mechanism of action of ocular hypotensive drugs belonging to this class of pharmacological agents. Areas covered: This review explores the last 5 years (2013-2018), where many patents describing new compounds acting on different prostaglandin receptors, and mainly targeting EP1-4 and FP receptors, were released. Expert opinion: To date, there has been a growing awareness over recent years of the therapeutic use of novel derivatives as new antiglaucoma pharmaceutical products. Patents involved in discovering new approaches and new molecules for the treatment of glaucoma diseases encouraged the scientific community to increase the variety of drugs available for the treatment of ocular diseases.