The Ocular Hypotensive Efficacy of Topical Fasudil, a Rho-Associated Protein Kinase Inhibitor, in Patients With End-Stage Glaucoma

Laboratory exploration of the use of ripasudil in descemetorhexis with a human ex vivo model

The aim of the study was to investigate the effect of ripasudil on corneal endothelial cell survival and migration after two types of descemetorhexis on a human ex vivo model. Eleven human corneoscleral buttons were incubated in either 50 ml organ culture medium containing 10 μM ripasudil or 50 μl dimethyl sulfoxide (DMSO), the vehicle in ripasudil for 2 days prior to wound creation then for 14 days after. The wound was created with either full trephination scoring or by shallow trephination plus manual peeling. At day 14, immunohistochemistry with vimentin and Na+/K+/ATPase markers was conducted. Tissues were assessed at day 3, 7 and 14 for morphology, cell migration, cell viability and cell density. Full trephination scoring created more damage on tissues compared to shallow trephination with full Descemet membrane peeling. In the full trephination scoring group, no differences in cell viability were noted when ripasudil and DMSO were compared. With the peeling method, Ripasudil could protect the endothelial cell death and maintain the morphology compared to the control. At day 14, no differences in the peripheral cell viability and density were found between ripasudil and DMSO, although the ripasudil group presented significantly increased central cell count and cell viability. Increased cell migration was noted with ripasudil and the initial cell morphology of those migrated cells was similar to that of fibroblasts. In conclusion, ex vivo modelling suggested that peeling resulted in less cell damage than scoring and ripasudil maintained better morphology and promoted migration. These effects might be via transformation of endothelial cells into a more motile spindle-like phenotype.

The Application of Rho Kinase Inhibitors in the Management of Glaucoma

Glaucoma is a chronic neurodegenerative disease that poses a significant threat of irreversible blindness worldwide. Current treatments for glaucoma focus on reducing intraocular pressure (IOP), which is the only modifiable risk factor. Traditional anti-glaucomatous agents, including carbonic anhydrase inhibitors, beta-blockers, alpha-2 agonists, and prostaglandin analogs, work by either improving uveoscleral outflow or reducing aqueous humor production. Rho kinase (ROCK) inhibitors represent a novel class of anti-glaucomatous drugs that have emerged from bench to bedside in the past decade, offering multifunctional characteristics. Unlike conventional medications, ROCK inhibitors directly target the trabecular meshwork outflow pathway. This review aims to discuss the mechanism of ROCK inhibitors in reducing IOP, providing neuroprotection, and preventing fibrosis. We also highlight recent studies and clinical trials evaluating the efficacy and safety of ROCK inhibitors, compare them with other clinical anti-glaucomatous medications, and outline future prospects for ROCK inhibitors in glaucoma treatment.

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.

Exploring the Ocular Absorption Pathway of Fasudil Hydrochloride towards Developing a Nanoparticulate Formulation with Improved Performance

Rho-kinase (ROCK) inhibitors represent a new category of anti-glaucoma medications. Among them, Fasudil hydrochloride, a selective ROCK inhibitor, has demonstrated promising outcomes in glaucoma treatment. It works by inhibiting the ROCK pathway, which plays a crucial role in regulating the trabecular meshwork and canal of Schlemm's aqueous humor outflow. This study aims to investigate the ocular absorption pathway of Fasudil hydrochloride and, subsequently, develop a nanoparticle-based delivery system for enhanced corneal absorption. Employing the ionic gelation method and statistical experimental design, the factors influencing chitosan nanoparticle (Cs NP) characteristics and performance were explored. Fasudil in vitro release and ex vivo permeation studies were performed, and Cs NP ocular tolerability and cytotoxicity on human lens epithelial cells were evaluated. Permeation studies on excised bovine eyes revealed significantly higher Fasudil permeation through the sclera compared to the cornea (370.0 μg/cm2 vs. 96.8 μg/cm2, respectively). The nanoparticle size (144.0 ± 15.6 nm to 835.9 ± 23.4 nm) and entrapment efficiency range achieved (17.2% to 41.4%) were predominantly influenced by chitosan quantity. Cs NPs showed a substantial improvement in the permeation of Fasudil via the cornea, along with slower release compared to the Fasudil aqueous solution. The results from the Hen's Egg Test Chorioallantoic Membrane (HET-CAM) and Bovine Corneal Opacity and Permeability (BCOP) tests indicated good conjunctival and corneal biocompatibility of the formulated chitosan nanoparticles, respectively. Lens epithelial cells displayed excellent tolerance to low concentrations of these nanoparticles (>94% cell viability). To the best of our knowledge, this is the first report on the ocular absorption pathway of topically applied Fasudil hydrochloride where the cornea has been identified as a potential barrier that could be overcome using Cs NPs.

Rho-Kinase Inhibitors as Emerging Targets for Glaucoma Therapy

Glaucoma, the leading cause of irreversible blindness worldwide, is a chronic and progressive optic neuropathy characterized by damage to the optic and retinal nerve fiber layers, which can lead to permanent loss of peripheral or central vision. Reduction of intraocular pressure (IOP) is the only known modifiable risk factor for preventing and treating glaucoma. Rho kinase (ROCK) inhibitors are a new class of glaucoma drugs with a novel mechanism of action and good safety profile. They exert neuroprotective effects, act on the trabecular tissue, increase the outflow of aqueous humor, and reduce intraocular pressure. However, they also cause local adverse reactions, including common conjunctival congestion and subconjunctival bleeding; however, most are self-limiting and temporary. Netarsudil (0.02%), a ROCK inhibitor, relaxes the trabecular meshwork, increases the outflow of aqueous humor, reduces scleral venous pressure, and directly decreases IOP. Conjunctival congestion can be reduced if netarsudil is administered at night. The combination of these medications is always more effective than the single drug. Ripasudil (0.4%), another ROCK inhibitor, also lowers IOP; however, conjunctival hyperemia is the most common adverse drug reaction. The purpose of this review is to summarize the effects and adverse reactions of ROCK inhibitors in the experimental trial stage and in clinical treatment in recent years, providing suggestions for future clinical drug use, and research and development to reduce the side effects of these drugs, maximize the potential for reducing IOP, and improve the therapeutic effect.

ROCK Inhibitors as an Alternative Therapy for Corneal Grafting: A Systematic Review

Currently, corneal blindness is affecting >10 million individuals worldwide, and there is a significant unmet medical need because only 1.5% of transplantation needs are met globally due to a lack of high-quality grafts. In light of this global health disaster, researchers are developing corneal substitutes that can resemble the human cornea in vivo and replace human donor tissue. Thus, this review examines ROCK (Rho-associated coiled-coil containing protein kinases) inhibitors as a potential corneal wound-healing (CWH) therapy by reviewing the existing clinical and nonclinical findings. The systematic review was done from PubMed, Scopus, Web of Science, and Google Scholar for CWH, corneal injury, corneal endothelial wound healing, ROCK inhibitors, Fasudil, Netarsudil, Ripasudil, Y-27632, clinical trial, clinical study, case series, case reports, preclinical study, in vivo, and in vitro studies. After removing duplicates, all downloaded articles were examined. The literature search included the data till January 2023. This review summarized the results of ROCK inhibitors in clinical and preclinical trials. In a clinical trial, various ROCK inhibitors improved CWH in individuals with open-angle glaucoma, cataract, iris cyst, ocular hypertension, and other ocular diseases. ROCK inhibitors also improved ocular wound healing by increasing cell adhesion, migration, and proliferation in vitro and in vivo. ROCK inhibitors have antifibrotic, antiangiogenic, anti-inflammatory, and antiapoptotic characteristics in CWH, according to the existing research. ROCK inhibitors were effective topical treatments for corneal infections. Ripasudil, Y-27632, H-1152, Y-39983, and AMA0526 are a few new ROCK inhibitors that may help CWH and replace human donor tissue.

ROCK inhibitors in ophthalmology: A critical review of the existing clinical evidence

Rho kinase (ROCK) inhibitors have emerged as a key therapeutic class of interest in ophthalmology over the last decade. Promising in vitro studies laid the foundations for the development of novel therapeutic agents that target the ROCK signalling pathway in ocular disease, with subsequent clinical trials supporting their use. Corneal endothelial disease, glaucoma, and vitreoretinal disease are the major pathologies in which ROCK inhibitors have been investigated to date. Ripasudil and netarsudil represent the current leaders in this pharmaceutical group, having been extensively validated and approved for use in glaucoma in some countries. Less substantial evidence exists for fasudil in ophthalmic use. ROCK inhibitors are also increasingly used in cultured endothelial cell grafting and as an adjunct to aid in endothelial cell migration and replication in Descemet's stripping procedures or Descemet's membrane injuries. This review has synthesised both established and emerging research to provide a practical guide to prescribing in this drug class. Drug efficacies, side effect profiles, and the demographic and clinical characteristics of appropriate drug candidates are discussed.

Remodeling of the Lamina Cribrosa: Mechanisms and Potential Therapeutic Approaches for Glaucoma

Glaucomatous optic neuropathy is the leading cause of irreversible blindness in the world. The chronic disease is characterized by optic nerve degeneration and vision field loss. The reduction of intraocular pressure remains the only proven glaucoma treatment, but it does not prevent further neurodegeneration. There are three major classes of cells in the human optic nerve head (ONH): lamina cribrosa (LC) cells, glial cells, and scleral fibroblasts. These cells provide support for the LC which is essential to maintain healthy retinal ganglion cell (RGC) axons. All these cells demonstrate responses to glaucomatous conditions through extracellular matrix remodeling. Therefore, investigations into alternative therapies that alter the characteristic remodeling response of the ONH to enhance the survival of RGC axons are prevalent. Understanding major remodeling pathways in the ONH may be key to developing targeted therapies that reduce deleterious remodeling.

Rho-Kinase Inhibitors for the Treatment of Refractory Diabetic Macular Oedema

Diabetic macular oedema (DMO) is one of the leading causes of vision loss associated with diabetic retinopathy (DR). New insights in managing this condition have changed the paradigm in its treatment, with intravitreal injections of antivascular endothelial growth factor (anti-VEGF) having become the standard therapy for DMO worldwide. However, there is no single standard therapy for all patients DMO refractory to anti-VEGF treatment; thus, further investigation is still needed. The key obstacles in developing suitable therapeutics for refractory DMO lie in its complex pathophysiology; therefore, there is an opportunity for further improvements in the progress and applications of new drugs. Previous studies have indicated that Rho-associated kinase (Rho-kinase/ROCK) is an essential molecule in the pathogenesis of DMO. This is why the Rho/ROCK signalling pathway has been proposed as a possible target for new treatments. The present review focuses on the recent progress on the possible role of ROCK and its therapeutic potential in DMO. A systematic literature search was performed, covering the years 1991 to 2021, using the following keywords: "rho-Associated Kinas-es", "Diabetic Retinopathy", "Macular Edema", "Ripasudil", "Fasudil" and "Netarsudil". Better insight into the pathological role of Rho-kinase/ROCK may lead to the development of new strategies for refractory DMO treatment and prevention.

Evolution of therapies for the corneal endothelium: past, present and future approaches

Corneal endothelial diseases are leading indications for corneal transplantations. With significant advancement in medical science and surgical techniques, corneal transplant surgeries are now increasingly effective at restoring vision in patients with corneal diseases. In the last 15 years, the introduction of endothelial keratoplasty (EK) procedures, where diseased corneal endothelium (CE) are selectively replaced, has significantly transformed the field of corneal transplantation. Compared to traditional penetrating keratoplasty, EK procedures, namely Descemet's stripping automated endothelial keratoplasty (DSAEK) and Descemet membrane endothelial keratoplasty (DMEK), offer faster visual recovery, lower immunological rejection rates, and improved graft survival. Although these modern techniques can achieve high success, there are fundamental impediments to conventional transplantations. A lack of suitable donor corneas worldwide restricts the number of transplants that can be performed. Other barriers include the need for specialized expertise, high cost, and risks of graft rejection or failure. Research is underway to develop alternative treatments for corneal endothelial diseases, which are less dependent on the availability of allogeneic tissues - regenerative medicine and cell-based therapies. In this review, an overview of past and present transplantation procedures used to treat corneal endothelial diseases are described. Potential novel therapies that may be translated into clinical practice will also be presented.

Investigational Rho Kinase Inhibitors for the Treatment of Glaucoma

This review provides a comprehensive update on emerging ROCK inhibitors as an innovative treatment option for lowering intraocular pressure (IOP) in glaucoma and aims to describe the structure, mechanism of action, pharmaceutical characteristics, desirable ocular effects, including side effects for each agent. A literature review was conducted using PubMed, Scopus, clinicaltrials.gov, ARVO journals, Cochrane library and Selleckchem. Databases were searched using "investigational Rho kinase inhibitors," and "glaucoma" as keywords. In addition to this building block strategy, successive fractions were employed to further refine the results. Of the several ROCK inhibitors discovered, only two drugs are currently approved for glaucoma treatment; Netarsudil in the USA and Ripasudil in Japan and China. We identified and reviewed 15 agents currently in laboratory or clinical trials. These agents lower IOP mainly by decreasing outflow resistance through pharmacologic relaxation of the trabecular meshwork (TM) cells and reducing episcleral venous pressure. They have an optimistic safety profile; however, conjunctival hyperemia, conjunctival hemorrhage, pain on instillation, and corneal verticillata are common. Other properties such as neuroprotection (enhancing optic nerve blood flow and promoting axonal regeneration), anti-fibrotic activity, and endothelial cell proliferation may improve the visual prognosis and surgical outcomes in glaucoma. In addition, these agents have the potential to work synergistically with other topical glaucoma medications.

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

The Rho kinase (ROCK) signaling pathway is involved in several cellular events that include cell proliferation and cytoskeleton modulation leading to cell adhesion. The ROCK pathway in the human eye has been hypothesized to play important roles in corneal endothelial cell physiology and pathologic states. In addition, ROCK signaling has been identified as an important regulator of trabecular meshwork (TM) outflow, which is altered in glaucomatous eyes. These roles in corneal and glaucomatous disease states have led to the growing interest in the development of drugs selectively targeting this pathway (ROCK inhibitors). The authors provide a review of the literature on the pathobiology of the ROCK signaling in corneal endothelial disease, glaucoma, and vitreoretinal disease, as well as the clinical usefulness of ROCK inhibitors in Ophthalmology.

Influence of new treatment modalities on adherence in glaucoma

PURPOSE OF REVIEW

It is well known that glaucoma patients are not adherent to their therapeutic regimens. The issue of nonadherence is multifactorial and includes inadequate communication between doctors and patients, resulting in significant costs associated with enhanced disease progression. Therapeutic regimens are risk factors which often influences adherence rates. Thus, alternative treatment modalities, especially those risk factors that do not rely on patients' cooperation, may enable improvements in long-term outcomes of glaucoma in patient.

RECENT FINDINGS

The studies selected for this review were divided into new medications, especially advancements in pharmaceutical approaches to treat glaucoma and new ways of delivering the medication, new surgical methods, especially minimally invasive surgery methods for glaucoma, and new studies about adherence in glaucoma.

SUMMARY

Surprisingly, a very few studies on glaucoma medication or surgery addressed the concept of adherence. However, adherence is discussed in studies which consider psychological aspects of patients or communication issues between doctors and patients. Although these studies were performed in clinical settings, the issue of adherence is not addressed; despite it has significant effect on long-term outpatient care. A combination of both aspects, adherence and miscommunication, should be considered in studies.

Rho Kinase Inhibitors as a Novel Treatment for Glaucoma and Ocular Hypertension

In an elegant example of bench-to-bedside research, a hypothesis that cells in the outflow pathway actively regulate conventional outflow resistance was proposed in the 1990s and systematically pursued, exposing novel cellular and molecular mechanisms of intraocular pressure (IOP) regulation. The critical discovery that pharmacologic manipulation of the cytoskeleton of outflow pathway cells decreased outflow resistance placed a spotlight on the Rho kinase pathway that was known to regulate the cytoskeleton. Ultimately, a search for Rho kinase inhibitors led to the discovery of several molecules of therapeutic interest, leaving us today with 2 new ocular hypotensive agents approved for clinical use: ripasudil in Japan and netarsudil in the United States. These represent members of the first new class of clinically useful ocular hypotensive agents since the US Food and Drug Administration approval of latanoprost in 1996. The development of Rho kinase inhibitors as a class of medications to lower IOP in patients with glaucoma and ocular hypertension represents a triumph in translational research. Rho kinase inhibitors are effective alone or when combined with other known ocular hypotensive medications. They also offer the possibility of neuroprotective activity, a favorable impact on ocular blood flow, and even an antifibrotic effect that may prove useful in conventional glaucoma surgery. Local adverse effects, however, including conjunctival hyperemia, subconjunctival hemorrhages, and cornea verticillata, are common. Development of Rho kinase inhibitors targeted to the cells of the outflow pathway and the retina may allow these agents to have even greater clinical impact. The objectives of this review are to describe the basic science underlying the development of Rho kinase inhibitors as a therapy to lower IOP and to summarize the results of the clinical studies reported to date. The neuroprotective and vasoactive properties of Rho kinase inhibitors, as well as the antifibrotic properties, of these agents are reviewed in the context of their possible role in the medical and surgical treatment of glaucoma.

ROCK inhibitors for the treatment of ocular diseases

The Rho-kinase/ROCK (Rho-associated coiled-coil-containing protein kinase) pathway is involved in the pathogenesis of multiple ocular and systemic disorders. Recently, ROCK inhibitors have been suggested as novel treatments for various ocular diseases. Several in vitro, in vivo and clinical studies have demonstrated the safety and efficacy of ROCK inhibitors in the management of ocular disorders such as corneal epithelial and endothelial damage, glaucoma, retinal and choroidal neovascularisation, diabetic macular oedema and optic nerve disorders. In this review, these studies are explored with focus on the relevant clinical investigations.

Role of the Rho GTPase/Rho kinase signaling pathway in pathogenesis and treatment of glaucoma: Bench to bedside research

Glaucoma is a leading cause of irreversible blindness worldwide. Elevated intraocular pressure (IOP) is considered to be a predominant risk factor for primary open angle glaucoma, the most prevalent form of glaucoma. Although the etiological mechanisms responsible for increased IOP are not completely clear, impairment in aqueous humor (AH) drainage through the conventional or trabecular pathway is recognized to be a primary cause in glaucoma patients. Importantly, lowering of IOP has been demonstrated to reduce progression of vision loss and is a mainstay of treatment for all types of glaucoma. Currently however, there are limited therapeutic options available for lowering IOP especially as it relates to enhancement of AH outflow through the trabecular pathway. Towards addressing this challenge, bench and bedside research conducted over the course of the last decade and a half has identified the significance of inhibiting Rho kinase for lowering IOP. Rho kinase is a downstream effector of Rho GTPase signaling that regulates actomyosin dynamics in numerous cell types. Studies from several laboratories have demonstrated that inhibition of Rho kinase lowers IOP via relaxation of the trabecular meshwork which enhances AH outflow. By contrast, activation of Rho GTPase/Rho kinase signaling in the trabecular outflow pathway increases IOP by altering the contractile, cell adhesive and permeability barrier characteristics of the trabecular meshwork and Schlemm's canal tissues, and by influencing extracellular matrix production and fibrotic activity. This article, written in honor of the late David Epstein, MD, summarizes findings from both basic and clinical studies that have been instrumental for recognition of the importance of the Rho/Rho kinase signaling pathway in regulation of AH outflow, and in the development of Rho kinase inhibitors as promising IOP- lowering agents for glaucoma treatment.