Current Medical Therapy and Future Trends in the Management of Glaucoma Treatment

Molecular Mechanisms of Glaucoma Pathogenesis with Implications to Caveolin Adaptor Protein and Caveolin-Shp2 Axis

Glaucoma is a common retinal disorder characterized by progressive optic nerve damage, resulting in visual impairment and potential blindness. Elevated intraocular pressure (IOP) is a major risk factor, but some patients still experience disease progression despite IOP-lowering treatments. Genome-wide association studies have linked variations in the Caveolin1/2 (CAV-1/2) gene loci to glaucoma risk. Cav-1, a key protein in caveolae membrane invaginations, is involved in signaling pathways and its absence impairs retinal function. Recent research suggests that Cav-1 is implicated in modulating the BDNF/TrkB signaling pathway in retinal ganglion cells, which plays a critical role in retinal ganglion cell (RGC) health and protection against apoptosis. Understanding the interplay between these proteins could shed light on glaucoma pathogenesis and provide potential therapeutic targets.

Real-Life Study on the Efficacy and Tolerance of a Preservative-Free Surfactant-Free Latanoprost Eye Drop in Patients with Glaucoma

INTRODUCTION

The purpose of this study is to assess the real-life efficacy and tolerance of a new preservative-free, surfactant-free latanoprost (PFSF-LAT) formulation.

METHODS

Retrospective, multicentre, non-comparative, observational study in patients with ocular hypertension or open angle glaucoma, naïve or non-naïve to previous intraocular pressure (IOP)-lowering treatment, and treated for at least 3 months with the study eye drop. IOP for worse eye, ocular signs and symptoms, and concomitant use of artificial tears were collected at study drug initiation and at last visit under treatment. Reasons for discontinuing the study eye drop (if relevant) and investigators' satisfaction were also assessed.

RESULTS

In the per protocol population (103 eyes; 63 naïve, 39 switched, 1 not classified because of missing data), IOP decreased significantly (p < 0.001) from 21.6 ± 5.0 mmHg at baseline to 16.1 ± 3.5 mmHg at the end of the study (mean reduction of - 5.5 ± 4.6 mmHg; - 25.5%). IOP in naïve patients was significantly improved, with a mean reduction of 7.1 mmHg (- 30.7%), which was within expected latanoprost IOP-lowering effect. Interestingly, in previously treated patients, switching to PFSF-LAT also allowed for a further 2.9 mmHg decrease in IOP (p < 0.001). The incidence of ocular side effects at study initiation was significantly (p < 0.001) reduced from 31.1% to 11.3% in the overall population, and from 65.0% to 7.5% in switched patients. This included conjunctival hyperaemia and superficial punctate keratitis (from 42.5% to 2.5% and from 37.5% to 2.5% in switched patients, respectively). According to investigators, tolerance and efficacy of the study eye drop were satisfactory or very satisfactory in 98.1% and 83.2% of patients, respectively.

CONCLUSION

PFSF-LAT is an efficient treatment for patients with glaucoma with an improved tolerance profile. It can be considered as initial therapy in naïve patients or in patients with poor ocular tolerance to previous IOP-lowering eye drops.

Nanomedicine in glaucoma treatment; Current challenges and future perspectives

Glaucoma presents a significant global health concern and affects millions of individuals worldwide and predicted a high increase in prevalence of about 111 million by 2040. The current standard treatment involves hypotensive eye drops; however, challenges such as patient adherence and limited drug bioavailability hinder the treatment effectiveness. Nanopharmaceuticals or nanomedicines offer promising solutions to overcome these obstacles. In this manuscript, we summarized the current limitations of conventional antiglaucoma treatment, role of nanomedicine in glaucoma treatment, rational design, factors effecting the performance of nanomedicine and different types of nanocarriers in designing of nanomedicine along with their applications in glaucoma treatment from recent literature. Current clinical challenges that hinder real-time application of antiglaucoma nanomedicine are highlighted. Lastly, future directions are identified for improving the therapeutic potential and translation of antiglaucoma nanomedicine into clinic.

Near Add Power of Glaucoma Patients with Early Presbyopia

Purpose: Glaucoma medication may accelerate the progression of presbyopia. The aim of this study was to compare presbyopia between controls and patients with glaucoma in their 40s. Methods: This was a cross-sectional study of bilateral phakic participants aged between 40 and 49, which included controls (n = 114, mean age 46.1 ± 2.7 y) and patients with primary open-angle glaucoma (n = 105, 46.4 ± 2.7 y) who had been using FP receptor agonists, beta blockers, and carbonic anhydrase inhibitors for at least six months. We compared the near add power between the two groups. Results: The mean near add power and the prevalence of symptomatic presbyopia (near add power ≥ 1.50 D) were 1.16 ± 0.74 D and 42.1% for controls and 1.77 ± 0.71 D (p < 0.01) and 79.0% (p < 0.01) for glaucoma patients, respectively. The odds ratio (OR) and confidence interval for symptomatic presbyopia were associated with age (1.36, 1.21-1.52), ganglion cell complex thickness (0.96, 0.94-0.99), presence of glaucoma (6.19, 3.13-12.23), and number of glaucoma medications (4.26, 2.42-7.43). Among medications, only FP receptor agonists (5.79, 2.68-12.32) produced significant results. Survival analysis showed that glaucoma patients reached the threshold of a near add power of +1.50 D significantly sooner than controls (p < 0.05; log-rank test). Conclusions: Glaucoma patients, especially those using FP receptor agonists, had higher near add power than controls.

Secondary Glaucoma Following Corneal Transplantation: A Comprehensive Review of Pathophysiology and Therapeutic Approaches

Corneal transplantation is a critical surgical procedure aimed at restoring vision in patients with corneal blindness or severe damage. This review focuses on secondary glaucoma, a significant postoperative complication, with the primary objective of providing a comprehensive analysis of its pathophysiology, risk factors, diagnostic challenges, and therapeutic approaches. Unlike other reviews, this work emphasizes the interplay between inflammatory responses, corticosteroid use, and structural changes in the eye that lead to elevated intraocular pressure (IOP) after transplantation. A comprehensive review of the literature was conducted, including studies on postcorneal transplantation glaucoma, to highlight both clinical outcomes and the efficacy of current management strategies. Key findings indicate that medical treatments, such as prostaglandin analogs and beta-blockers, are effective for IOP control in the early stages, while surgical interventions, like trabeculectomy, are often necessary for more advanced cases. Diagnostic challenges, such as the difficulty of accurate IOP measurement posttransplant, are underscored, along with the importance of advanced imaging techniques for the early detection of optic nerve damage. The pathophysiology of secondary glaucoma involves a complex interaction of postsurgical inflammation, steroid-induced complications, and anatomical changes that hinder aqueous humor outflow. Diagnosis requires a combination of tonometry, gonioscopy, and imaging technologies. Management strategies range from pharmacological treatments to surgical options, with a critical focus on balancing IOP control and minimizing risks to graft survival. Clinically, these findings highlight the need for proactive and tailored management of IOP in corneal transplant patients to preserve both graft function and long-term visual outcomes. Future research should focus on improving diagnostic accuracy, developing less invasive surgical techniques, and exploring personalized medicine approaches, including genetic profiling and targeted therapies.

Remyelination-oriented clemastine treatment attenuates neuropathies of optic nerve and retina in glaucoma

As one of the top causes of blindness worldwide, glaucoma leads to diverse optic neuropathies such as degeneration of retinal ganglion cells (RGCs). It is widely accepted that the level of intraocular pressure (IOP) is a major risk factor in human glaucoma, and reduction of IOP level is the principally most well-known method to prevent cell death of RGCs. However, clinical studies show that lowering IOP fails to prevent RGC degeneration in the progression of glaucoma. Thus, a comprehensive understanding of glaucoma pathological process is required for developing new therapeutic strategies. In this study, we provide functional and histological evidence showing that optic nerve defects occurred before retina damage in an ocular hypertension glaucoma mouse model, in which oligodendroglial lineage cells were responsible for the subsequent neuropathology. By treatment with clemastine, an Food and Drug Administration (FDA)-approved first-generation antihistamine medicine, we demonstrate that the optic nerve and retina damages were attenuated via promoting oligodendrocyte precursor cell (OPC) differentiation and enhancing remyelination. Taken together, our results reveal the timeline of the optic neuropathies in glaucoma and highlight the potential role of oligodendroglial lineage cells playing in its treatment. Clemastine may be used in future clinical applications for demyelination-associated glaucoma.

Association between Glucagon-like Peptide-1 Receptor Agonists and the Risk of Glaucoma in Individuals with Type 2 Diabetes

PURPOSE

To examine the association between glucagon-like peptide-1 receptor agonist (GLP-1RA) use and the development of glaucoma in individuals with type 2 diabetes.

DESIGN

Nationwide, nested case-control study.

PARTICIPANTS

From a nationwide cohort of 264 708 individuals, we identified 1737 incident glaucoma cases and matched them to 8685 glaucoma-free controls, all aged more than 21 years and treated with metformin and a second-line antihyperglycemic drug formulation, with no history of glaucoma, eye trauma, or eye surgery.

METHODS

Cases were incidence-density-matched to 5 controls by birth year, sex, and date of second-line treatment initiation.

MAIN OUTCOME MEASURES

Conditional logistic regression was used to calculate adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) for glaucoma, defined by first-time diagnosis, first-time use of glaucoma-specific medication, or first-time glaucoma-specific surgical intervention.

RESULTS

Compared with the reference group, who received treatments other than GLP-1RA, individuals who were exposed to GLP-1RA treatment exhibited a lower risk of incident glaucoma (HR, 0.81; CI, 0.70-0.94; P = 0.006). Prolonged treatment extending beyond 3 years lowered the risk even further (HR, 0.71; CI, 0.55-0.91; P = 0.007). Treatment with GLP-1RA for 0 to 1 year (HR, 0.89; CI, 0.70-1.14; P = 0.35) and 1 to 3 years (HR, 0.85; CI, 0.67-1.06; P = 0.15) was not significant.

CONCLUSIONS

Exposure to GLP-1RA was associated with a lower risk of developing glaucoma compared with receiving other second-line antihyperglycemic medication.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

The TGFβ Induced MicroRNAome of the Trabecular Meshwork

Primary open-angle glaucoma (POAG) is a progressive optic neuropathy with a complex, multifactorial aetiology. Raised intraocular pressure (IOP) is the most important clinically modifiable risk factor for POAG. All current pharmacological agents target aqueous humour dynamics to lower IOP. Newer therapeutic agents are required as some patients with POAG show a limited therapeutic response or develop ocular and systemic side effects to topical medication. Elevated IOP in POAG results from cellular and molecular changes in the trabecular meshwork driven by increased levels of transforming growth factor β (TGFβ) in the anterior segment of the eye. Understanding how TGFβ affects both the structural and functional changes in the outflow pathway and IOP is required to develop new glaucoma therapies that target the molecular pathology in the trabecular meshwork. In this study, we evaluated the effects of TGF-β1 and -β2 treatment on miRNA expression in cultured human primary trabecular meshwork cells. Our findings are presented in terms of specific miRNAs (miRNA-centric), but given miRNAs work in networks to control cellular pathways and processes, a pathway-centric view of miRNA action is also reported. Evaluating TGFβ-responsive miRNA expression in trabecular meshwork cells will further our understanding of the important pathways and changes involved in the pathogenesis of glaucoma and could lead to the development of miRNAs as new therapeutic modalities in glaucoma.

Predictors and long-term patterns of medication adherence to glaucoma treatment in Denmark-an observational registry study of 30 100 Danish patients with glaucoma

BACKGROUND

Self-treatment with glaucoma medication (eye drops) has been associated with adherence challenges. Poor adherence results in worse outcomes in terms of visual field loss.

OBJECTIVE

To investigate patterns in medication adherence among Danish patients with glaucoma in relation to selected predictors of adherence, long-term adherence patterns, and long-term societal economic consequences of poor adherence.

METHODS AND ANALYSIS

This register-based study included 30 100 glaucoma patients followed for 10 years between 2000 and 2018. Glaucoma was identified from the Danish national registers by diagnosis of Open Angle Glaucoma and/or by redeemed prescriptions of glaucoma medication. Logistic regression models were applied to estimate patient characteristics related to medical adherence. Diagnosis-related group fees were applied to estimate healthcare costs.

RESULTS

High adherence in the first year(s) of treatment was less likely among men (ORfirst year: 0.78, 95% CI: 0.75 to 0.82), younger individuals and among those with a positive Charlson Comorbidity Index (CCI) score (ORfirst year/CCI≥3: 0.71, 95% CI: 0.63 to 0.80). Adherence in the first year and in the first two years was associated with adherence in the fifth (ORfirst year: 4.55, 95% CI: 4.30 to 4.82/ORfirst two years: 6.47, 95% CI: 6.10 to 6.86) as with adherence in the 10th year with slightly lower estimates. Being medical adherent was related to higher costs related to glaucoma medication after 5 and 10 years comparing with poor adherence, whereas poor adherence was associated with a marked increase in long-term costs for hospital contacts.

CONCLUSION

Increasing age, female sex and low comorbidity score are correlated with better adherence to glaucoma treatment. Adherence in the first years of treatment may be a good predictor for future adherence. In the long term, patients with poor adherence are overall more expensive to society in terms of hospital contacts.

How latanoprost changed glaucoma management

Glaucoma is currently considered one of the leading causes of severe visual impairment and blindness worldwide. Topical medical therapy represents the treatment of choice for many glaucoma patients. Introduction of latanoprost, 25 years ago, with an entirely new mechanism of action from that of the antiglaucoma drugs used up to that time was a very important milestone. Since then, due mainly to their efficacy, limited systemic side effects and once daily dosing, prostaglandin analogues (PGAs) have become as the first-choice treatment for primary open-angle glaucoma. PGAs are in general terms well tolerated, although they are associated with several mild to moderate ocular and periocular adverse events. Among them, conjunctival hyperemia, eyelash changes, eyelid pigmentation, iris pigmentation and hypertrichosis around the eyes are the most prevalent. The objective of this paper is to review the role of PGAs in the treatment of glaucoma over the 25 years since the launch of Latanoprost and their impact on clinical practice outcomes.

Loss of Sarm1 reduces retinal ganglion cell loss in chronic glaucoma

Glaucoma is one of the leading causes of irreversible blindness worldwide and vision loss in the disease results from the deterioration of retinal ganglion cells (RGC) and their axons. Metabolic dysfunction of RGC plays a significant role in the onset and progression of the disease in both human patients and rodent models, highlighting the need to better define the mechanisms regulating cellular energy metabolism in glaucoma. This study sought to determine if Sarm1, a gene involved in axonal degeneration and NAD+ metabolism, contributes to glaucomatous RGC loss in a mouse model with chronic elevated intraocular pressure (IOP). Our data demonstrate that after 16 weeks of elevated IOP, Sarm1 knockout (KO) mice retain significantly more RGC than control animals. Sarm1 KO mice also performed significantly better when compared to control mice during optomotor testing, indicating that visual function is preserved in this group. Our findings also indicate that Sarm1 KO mice display mild ocular developmental abnormalities, including reduced optic nerve axon diameter and lower visual acuity than controls. Finally, we present data to indicate that SARM1 expression in the optic nerve is most prominently associated with oligodendrocytes. Taken together, these data suggest that attenuating Sarm1 activity through gene therapy, pharmacologic inhibition, or NAD+ supplementation, may be a novel therapeutic approach for patients with glaucoma.

The Anti-Inflammatory and Antioxidant Properties of Acebuche Oil Exert a Retinoprotective Effect in a Murine Model of High-Tension Glaucoma

Glaucoma is characterized by cupping of the optic disc, apoptotic degeneration of retinal ganglion cells (RGCs) and their axons, and thinning of the retinal nerve fiber layer, with patchy loss of vision. Elevated intraocular pressure (IOP) is a major risk factor for hypertensive glaucoma and the only modifiable one. There is a need to find novel compounds that counteract other risk factors contributing to RGC degeneration. The oil derived from the wild olive tree (Olea europaea var. sylvestris), also called Acebuche (ACE), shows powerful anti-inflammatory, antioxidant and retinoprotective effects. We evaluated whether ACE oil could counteract glaucoma-related detrimental effects. To this aim, we fed mice either a regular or an ACE oil-enriched diet and then induced IOP elevation through intraocular injection of methylcellulose. An ACE oil-enriched diet suppressed glaucoma-dependent retinal glia reactivity and inflammation. The redox status of the glaucomatous retinas was restored to a control-like situation, and ischemia was alleviated by an ACE oil-enriched diet. Notably, retinal apoptosis was suppressed in the glaucomatous animals fed ACE oil. Furthermore, as shown by electroretinogram analyses, RGC electrophysiological functions were almost completely preserved by the ACE oil-enriched diet. These ameliorative effects were IOP-independent and might depend on ACE oil's peculiar composition. Although additional studies are needed, nutritional supplementation with ACE oil might represent an adjuvant in the management of glaucoma.

Oxymatrine impedes the progression of endotoxin-induced glaucoma via redox system modulations

This study aimed to provide irrefutable evidence of the preventive effects of oxymatine (OMT) on a model of endotoxin induced glaucoma in Wistar rats which can be attributed to its anti-inflammatory, antioxidant, and TNF-α antagonistic properties. To assess the impact of OMT on uveitic glaucoma, the normal group received 100 μL distilled water topically for 15 days, while the glaucoma control group was induced with uveitic glaucoma by applying 10 μL of 10 μg/mL lipopolysaccharide (LPS) topically for 3 consecutive days. The treatment groups were then given OMT solution at a volume of 50 μL with varying doses of 0.25%, 0.5%, and 1% once a day via topical administration for 15 days. In addition, as a standard, the animals were also given 100 μL of 1% dorzolamide topically for 15 days. All ophthalmic dosing was carried out by pulling the lower eye-lid of the experimental animals and administration of the respective solutions. The study uses cutting-edge real-time imaging of the retinal vasculature in anesthetized animals, postsacrifice lenticular picturization and biochemical evidence to support the changes in the retinal layers. LPS induced animals demonstrated increased IOP, disrupted antioxidant systems, massive lipid damage, enhanced TNF-α activity and changes in intracellular ATPase and ionic activities. The damaged retinal vasculature and lenticular opacification further supported the biochemical evidence. However, using OMT at a 1% dosage effectively enhanced the antioxidant levels, regulated intracellular ion concentration and ATPases, decreased TNF-α activity, and counteracted mechanobiological changes in the visual front and retina. Moreover, OMT can successfully normalize intraocular pressure, making it a highly beneficial treatment option for glaucoma.

Efficacy of Continuous-Wave Transscleral Cyclophotocoagulation Post-Pars Plana Vitrectomy in Glaucoma Patients: A Retrospective Study from Poland

BACKGROUND Glaucoma, a vision-threatening condition, results from optic nerve damage and affects millions of people worldwide. Often asymptomatic, it is hereditary, with risk factors like hypertension, diabetes, and steroid use. Despite its link with intraocular pressure (IOP), not everyone with high IOP develops glaucoma. After pars plana vitrectomy (PPV), patients face increased IOP risks. Traditional treatment includes pharmacotherapy, and, when ineffective, surgical interventions. Continuous-wave transscleral cyclophotocoagulation (CW-TSCPC) is an alternative for refractory glaucoma but can have complications. Our study compares the efficacy and safety of CW-TSCPC after PPV. MATERIAL AND METHODS The study group consisted of 18 patients diagnosed with glaucoma who underwent the CW-TSCP procedure as the first-choice therapy after conservative treatment of glaucoma proved ineffective. The comparison group consisted of 12 patients who underwent the CW-TSCP procedure after conservative drug treatment and in whom surgical treatment of glaucoma had been unsuccessful. All patients had inadequate control of IOP after PPV. RESULTS Study and comparison group patients showed a decrease in IOP during the follow-up, independent of the type of endotamponade used (P<0.05). When the indication for PPV was retinal detachment hemorrhage into the vitreous chamber, a significant decrease in IOP between 0 days and 180 days was only found in the study group (P<0.05). In contrast, when the indication for PPV was the state after uveitis or proliferative diabetic retinopathy, a significant decrease in IOP was found at 180 days in the study and comparison groups (P<0.05). CONCLUSIONS The analysis showed that the CW-TSCPC procedure can be recommended as the first-choice invasive treatment in patients with increased IOP after PPV.

Glaucoma: now and beyond

The glaucomas are a group of conditions leading to irreversible sight loss and characterised by progressive loss of retinal ganglion cells. Although not always elevated, intraocular pressure is the only modifiable risk factor demonstrated by large clinical trials. It remains the leading cause of irreversible blindness, but timely treatment to lower intraocular pressure is effective at slowing the rate of vision loss from glaucoma. Methods for lowering intraocular pressure include laser treatments, topical medications, and surgery. Although modern surgical innovations aim to be less invasive, many have been introduced with little supporting evidence from randomised controlled trials. Many cases remain undiagnosed until the advanced stages of disease due to the limitations of screening and poor access to opportunistic case finding. Future research aims to generate evidence for intraocular pressure-independent neuroprotective treatments, personalised treatment through genetic risk profiling, and exploration of potential advanced cellular and gene therapies.

Cell-based Therapies for Corneal and Retinal Disorders

Maintenance of the visual function is the desired outcome of ophthalmologic therapies. The shortcomings of the current treatment options, like partial recovery, post-operation failure, rigorous post-operative care, complications, etc., which are usually encountered with the conventional treatment options has warranted newer treatment options that may eliminate the root cause of diseases and minimize the side effects. Cell therapies, a class of regenerative medicines, have emerged as cutting-edge treatment option. The corneal and retinal dystrophies during the ocular disorders are the major cause of blindness, worldwide. Corneal disorders are mainly categorized mainly into corneal epithelial, stromal, and endothelial disorders. On the other hand, glaucoma, retinitis pigmentosa, age-related macular degeneration, diabetic retinopathy, Stargardt Disease, choroideremia, Leber congenital amaurosis are then major retinal degenerative disorders. In this manuscript, we have presented a detailed overview of the development of cell-based therapies, using embryonic stem cells, bone marrow stem cells, mesenchymal stem cells, dental pulp stem cells, induced pluripotent stem cells, limbal stem cells, corneal epithelial, stromal and endothelial, embryonic stem cell-derived differentiated cells (like retinal pigment epithelium or RPE), neural progenitor cells, photoreceptor precursors, and bone marrow-derived hematopoietic stem/progenitor cells etc. The manuscript highlights their efficiency, drawbacks and the strategies that have been explored to regain visual function in the preclinical and clinical state associated with them which can be considered for their potential application in the development of treatment.

An insight on ophthalmic drug delivery systems: Focus on polymeric biomaterials-based carriers

Presently, different types of eye diseases, such as glaucoma, myopia, infection, and dry eyes are treated with topical eye drops. However, due to ocular surface barriers, eye drops require multiple administrations, which may cause several risks, thereby necessitating additional strategies. Some of the key characteristics of an ideal ocular drug delivery system are as follows: (a) good penetration into cornea, (b) high drug retention in the ocular tissues, (c) targetability to the desired regions of the eye, and (d) good bioavailability. It is worthy to note that the corneal epithelial tight junctions hinder the permeation of therapeutics through the cornea. Therefore, it is necessary to design nanocarriers that can overcome these barriers and enhance drug penetration into the inner parts of the eye. Moreover, intelligent multifunctional nanocarriers can be designed to include cavities, which may help encapsulate sufficient amount of the drug. In addition, nanocarriers can be modified with the targeting moieties. Different types of nanocarriers have been developed for ocular drug delivery applications, including emulsions, liposomes, micelles, and nanoparticles. However, these formulations may be rapidly cleared from the eye. The therapeutic use of the nanoparticles (NPs) is also hindered by the non-specific adsorption of proteins on NPs, which may limit their interaction with the cellular moieties or other targeted biological factors. Functional drug delivery systems (DDS), which can offer targeted ocular drug delivery while avoiding the non-specific protein adsorption could exhibit great potential. This could be further realized by the on-demand DDS, which can respond to the stimuli in a spatio-temporal fashion. The cell-mediated DDS offer another valuable platform for ophthalmological drug delivery.

Topical netarsudil for treatment of glaucoma with elevated episcleral venous pressure: A pilot investigation in sturge-weber syndrome

PURPOSE

Topical netarsudil 0.02% may reduce intraocular pressure (IOP) by decreasing episcleral venous pressure (EVP), which carries theoretical utility for glaucoma associated with elevated EVP. A role for netarsudil in patients with elevated EVP is evaluated in a pilot investigation using a cohort of individuals with Sturge-Weber syndrome (SWS).

METHODS

Retrospective study of patients with SWS and glaucoma who were treated with netarsudil. Five patients (six eyes) were identified. Data collected included demographics, visual acuity, IOP, glaucoma medical and surgical treatments, and adverse effects of netarsudil.

RESULTS

Mean age was 13.6  ±  8.5 years. EVP elevation was presumed based on clinical stigmata and/or historical features. Mean number of baseline glaucoma medications was 3.3  ±  1.2. There was a significant reduction in the IOP at netarsudil initiation (mean 26.2  ±  4.5 mmHg) to 1 month of netarsudil therapy (mean 20.2  ±  3.8 mmHg, p  =  0.0283) and latest IOP on netarsudil (mean 17.6  ±  1.4 mmHg, p  =  0.0034). Mean duration of netarsudil therapy was 18.7  ±  11.8 months. Three patients required additional glaucoma procedures; one patient required an additional glaucoma medication. Three eyes (50%) developed conjunctival hyperemia. One patient discontinued netarsudil at 29 months, to reduce drop burden.

CONCLUSIONS

Netarsudil can effectively reduce IOP in patients with SWS, even when used as a fourth or fifth glaucoma medication. A possible role for netarsudil in the management of patients with elevated EVP is suggested pending further future investigations.

Untargeted metabolomics in the aqueous humor reveals the involvement of TAAR pathway in glaucoma

Understanding the metabolic dysfunctions and underlying complex pathological mechanisms of neurodegeneration in glaucoma could help discover disease pathways, identify novel biomarkers, and rationalize newer therapeutics. Therefore, we aimed to investigate the local metabolomic alterations in the aqueous humor and plasma of primary glaucomatous patients. This study cohort comprised primary open-angle glaucoma (POAG), primary angle-closure glaucoma (PACG), and cataract control groups. Aqueous humor and plasma samples were collected from patients undergoing trabeculectomy or cataract surgery and subjected to high-resolution mass spectrometry (HRMS) analysis. Spectral information was processed, and the acquired data were subjected to uni-variate as well as multi-variate statistical analyses using MetaboAnalyst ver5.0. To further understand the localized metabolic abnormalities in glaucoma, metabolites affected in aqueous humor were distinguished from metabolites altered in plasma in this study. Nine and twelve metabolites were found to be significantly altered (p < 0.05, variable importance of projection >1 and log2 fold change ≥0.58/≤ -0.58) in the aqueous humor of PACG and POAG patients, respectively. The galactose and amino acid metabolic pathways were locally affected in the PACG and POAG groups, respectively. Based on the observation of the previous findings, gene expression profiles of trace amine-associated receptor-1 (TAAR-1) were studied in rat ocular tissues. The pharmacodynamics of TAAR-1 were explored in rabbits using topical administration of its agonist, β-phenyl-ethylamine (β-PEA). TAAR-1 was expressed in the rat's iris-ciliary body, optic nerve, lens, and cornea. β-PEA elicited a mydriatic response in rabbit eyes, without altering intraocular pressure. Targeted analysis of β-PEA levels in the aqueous humor of POAG patients showed an insignificant elevation. This study provides new insights regarding alterations in both localized and systemic metabolites in primary glaucomatous patients. This study also demonstrated the propensity of β-PEA to cause an adrenergic response through the TAAR-1 pathway.

Exploring Early-Stage Retinal Neurodegeneration in Murine Pigmentary Glaucoma: Insights From Gene Networks and miRNA Regulation Analyses

Purpose

Glaucoma is a group of heterogeneous optic neuropathies characterized by the progressive degeneration of retinal ganglion cells. However, the underlying mechanisms have not been understood completely. We aimed to elucidate the genetic network associated with the development of pigmentary glaucoma with DBA/2J (D2) mouse model of glaucoma and corresponding genetic control D2-Gpnmb (D2G) mice carrying the wild type (WT) Gpnmb allele.

Methods

Retinas isolated from 13 D2 and 12 D2G mice were subdivided into 2 age groups: pre-onset (1-6 months: samples were collected at approximately 1-2, 2-4, and 5-6 months) and post-onset (7-15 months: samples were collected at approximately 7-9, 10-12, and 13-15 months) glaucoma were compared. Differential gene expression (DEG) analysis and gene-set enrichment analyses were performed. To identify micro-RNAs (miRNAs) that target Gpnmb, miRNA expression levels were correlated with time point matched mRNA expression levels. A weighted gene co-expression network analysis (WGCNA) was performed using the reference BXD mouse population. Quantitative real-time PCR (qRT-PCR) was used to validate Gpnmb and miRNA expression levels.

Results

A total of 314 and 86 DEGs were identified in the pre-onset and post-onset glaucoma groups, respectively. DEGs in the pre-onset glaucoma group were associated with the crystallin gene family, whereas those in the post-onset group were related to innate immune system response. Of 1329 miRNAs predicted to target Gpnmb, 3 miRNAs (miR-125a-3p, miR-3076-5p, and miR-214-5p) were selected. A total of 47 genes demonstrated overlapping with the identified DEGs between D2 and D2G, segregated into their time-relevant stages. Gpnmb was significantly downregulated, whereas 2 out of 3 miRNAs were significantly upregulated (P < 0.05) in D2 mice at both 3-and 10-month time points.

Conclusions

These findings suggest distinct gene-sets involved in pre-and post-glaucoma in the D2 mouse. We identified three miRNAs regulating Gpnmb in the development of murine pigmentary glaucoma.

Carteolol triggers senescence via activation of β-arrestin-ERK-NOX4-ROS pathway in human corneal endothelial cells in vitro

Carteolol is a commonly-used topical medication for primary open-angle glaucoma. However, long-term and frequent ocular application of carteolol entails its residuals at low concentration in the aqueous humor for a long duration and may exert latent toxicity in the human corneal endothelial cells (HCEnCs). Here, we treated the HCEnCs in vitro with 0.0117% carteolol for 10 days. Thereafter, we removed the cartelolol and normally cultured the cells for 25 days to investigate the chronical toxicity of carteolol and the underlying mechanism. The results exhibited that 0.0117% carteolol induces senescent features in the HCEnCs, such as increased senescence-associated β-galactosidase positive rates, enlarged relative cell area and upregulated p16^INK4A and senescence-associated secretory phenotypes, including IL-1α, TGF-β1, IL-10, TNF-α, CCL-27, IL-6 and IL-8, as well as decreased Lamin B1 expression and cell viability and proliferation. Thereby, further exploration demonstrated that the carteolol activates β-arrestin-ERK-NOX4 pathway to increase reactive oxygen species (ROS) production that imposes oxidative stress on energetic metabolism causing a vicious cycle between declining ATP and increasing ROS production and downregulation of NAD⁺ resulting in metabolic disturbance-mediated senescence of the HCEnCs. The excess ROS also impair DNA to activate the DNA damage response (DDR) pathway of ATM-p53-p21^WAF1/CIP1 with diminished poly(ADP-Ribose) polymerase (PARP) 1, a NAD⁺-dependent enzyme for DNA damage repair, resulting in cell cycle arrest and subsequent DDR-mediated senescence. Taken together, carteolol induces excess ROS to trigger HCEnC senescence via metabolic disturbance and DDR pathway.

Is fat the future for saving sight? Bioactive lipids and their impact on glaucoma

Glaucoma is characterized by a continuous loss of retinal ganglion cells. The cause of glaucoma is associated with an increase in intraocular pressure (IOP), but the underlying pathophysiology is diverse and, in most cases, unknown. There is an indisputable unmet need to identify new pathways involved in glaucoma pathogenesis. Increasing evidence suggests that bioactive lipids may be critical in the development and progression of glaucoma. Preclinical and clinical bioactive lipid targets exist and are being developed. In this review, we aim to shed light on the potential of bioactive lipids for the prevention, diagnosis, prognosis, and treatment of glaucoma by asking the question "is fat the future for saving sight".

Nanocarriers for the Delivery of Neuroprotective Agents in the Treatment of Ocular Neurodegenerative Diseases

Retinal neurodegeneration is considered an early event in the pathogenesis of several ocular diseases, such as diabetic retinopathy, age-related macular degeneration, and glaucoma. At present, there is no definitive treatment to prevent the progression or reversal of vision loss caused by photoreceptor degeneration and the death of retinal ganglion cells. Neuroprotective approaches are being developed to increase the life expectancy of neurons by maintaining their shape/function and thus prevent the loss of vision and blindness. A successful neuroprotective approach could prolong patients' vision functioning and quality of life. Conventional pharmaceutical technologies have been investigated for delivering ocular medications; however, the distinctive structural characteristics of the eye and the physiological ocular barriers restrict the efficient delivery of drugs. Recent developments in bio-adhesive in situ gelling systems and nanotechnology-based targeted/sustained drug delivery systems are receiving a lot of attention. This review summarizes the putative mechanism, pharmacokinetics, and mode of administration of neuroprotective drugs used to treat ocular disorders. Additionally, this review focuses on cutting-edge nanocarriers that demonstrated promising results in treating ocular neurodegenerative diseases.

Assessment of the Effectiveness of Glaucoma Treatment Using MicroPulse Transscleral Cyclophotocoagulation in Patients with Glaucoma Who Have Previously Undergone Vitreoretinal Surgery

INTRODUCTION

This retrospective study aimed to assess the effectiveness of using MicroPulse transscleral cyclophotocoagulation (µP-TSCPC) in patients who had previously undergone pars plana vitrectomy (PPV), depending on the endotamponade used.

METHODS

For the study, a total of 60 patients were enrolled who underwent PPV followed by tμP-TSCPC as a result of an increase in intraocular pressure (IOP) over the norm of 21 mmHg. In this group of patients, 20 received silicone oil endotamponade during PPV, 20 received sulfur hexafluoride gas SF6, and in another 20 a differentiated balanced salt solution (BSS) was used.

RESULTS

The main indications for conducting PPV were (1) retinal detachment (silicone oil endotamponade was used; n = 12); (2) dislocation/subluxation of the patient's own or artificial intraocular lens (balanced salt solution (BSS) endotamponade was used; n = 11); (3) the presence of an epiretinal membrane and/or a macular hole (BSS endotamponade was used; n = 9, or SF6; n = 20); and (4) hemorrhage into the vitreous chamber (silicone oil endotamponade was used; n = 8).

CONCLUSION

The choice of endotamponade used during PPV was not found to determine the effectiveness of µP-TSCPC treatment. The effectiveness of µP-TSCPC in patients after PPV depended, above all, on the etiology of the disease, for which PPV was previously performed. The lowest effectiveness of µP-TSCPC was noted in cases where the reason for conducting PPV was hemorrhage into the vitreous chamber and silicone oil endotamponade was used, while the highest effectiveness was noted in cases where PPV was conducted owing to the presence of an epiretinal membrane and/or a macular hole and SF6 endotamponade was used.

Success rate in micropulse diode laser treatment with regard to lens status, refractive errors, and glaucoma subtypes

PURPOSE

To evaluate the efficacy of micropulse transscleral cyclophotocoagulation (MP-TSCPC) considering different characteristics: glaucoma subtypes and lens status.

METHODS

A retrospective case-series study was designed to evaluate intraocular pressure (IOP), and the number of IOP-lowering medications, used by glaucoma patients treated with MP-TSCPC between 2016 and 2019. Cases had a follow-up period of 12 months. Achieving an IOP reduction higher than 20%, or the decrease of at least one IOP-lowering medication, was considered a successful outcome. The same population was analyzed by classifying them in two groups as: glaucoma subtypes and lens status. The baseline spherical equivalent (SE) was also calculated for considering association with the achieved IOP.

RESULTS

A total of 86 eyes were included. In most cases, IOP and IOP-lowering medications were decreased with a statistically significant difference (p < 0.0001), and all of them had a successful outcome. The percentage of IOP drop oscillated between 25.9% (open-angle glaucoma sub-group) and 37.5% (pseudoexfoliative glaucoma sub-group), 12 months after surgery. The difference between the groups was not statistically significant (p 0.20 and 0.32 for glaucoma subtypes and lens status, respectively). The Pearson's coefficient obtained was low for the SE and IOP association, at the 12 -month postoperative mark (- 0.009; p < 0.001).

CONCLUSIONS

The MP-TSCPC treatment was successful in decreasing IOP and IOP-lowering medications, in different glaucoma subtypes. Differences between groups (glaucoma subtypes, phakic and pseudophakic eyes) were not statistically significant. No association was found between the SE and the IOP achieved value after MS-TSCPC treatment.

S1PR1 signaling attenuates apoptosis of retinal ganglion cells via modulation of cJun/Bim cascade and Bad phosphorylation in a mouse model of glaucoma

Glaucoma is a complex neurodegenerative disease characterized by optic nerve damage and apoptotic retinal ganglion cell (RGC) death, and is the leading cause of irreversible blindness worldwide. Among the sphingosine 1-phosphate receptors (S1PRs) family, S1PR1 is a highly expressed subtype in the central nervous system and has gained rapid attention as an important mediator of pathophysiological processes in the brain and the retina. Our recent study showed that mice treated orally with siponimod drug exerted neuroprotection via modulation of neuronal S1PR1 in experimental glaucoma. This study identified the molecular signaling pathway modulated by S1PR1 activation with siponimod treatment in RGCs in glaucomatous injury. We investigated the critical neuroprotective signaling pathway in vivo using mice deleted for S1PR1 in RGCs. Our results showed marked upregulation of the apoptotic pathway was associated with decreased Akt and Erk1/2 activation levels in the retina in glaucoma conditions. Activation of S1PR1 with siponimod treatment significantly increased neuroprotective Akt and Erk1/2 activation and attenuated the apoptotic signaling via suppression of c-Jun/Bim cascade and by increasing Bad phosphorylation. Conversely, deletion of S1PR1 in RGCs significantly increased the apoptotic cells in the ganglion cell layer in glaucoma and diminished the neuroprotective effects of siponimod treatment on Akt/Erk1/2 activation, c-Jun/Bim cascade, and Bad phosphorylation. Our data demonstrated that activation of S1PR1 in RGCs induces crucial neuroprotective signaling that suppresses the proapoptotic c-Jun/Bim cascade and increases antiapoptotic Bad phosphorylation. Our findings suggest that S1PR1 is a potential therapeutic target for neuroprotection of RGCs in glaucoma.

Analysis of the Readability and Accountability of Online Patient Education Materials Related to Glaucoma Diagnosis and Treatment

Purpose

To assess the readability and accountability of online patient education materials related to glaucoma diagnosis and treatment.

Methods

We conducted a Google search for 10 search terms related to glaucoma diagnosis and 10 search terms related to glaucoma treatment. For each search term, the first 10 patient education websites populated after Google search were assessed for readability and accountability. Readability was assessed using five validated measures: Flesch Reading Ease (FRE), Gunning Fog Index (GFI), Flesch-Kincaid Grade Level (FKGL), Simple Measure of Gobbledygook (SMOG), and New Dale-Chall (NDC). Accountability was assessed using the Journal of the American Medical Association (JAMA) benchmarks. The source of information for each article analyzed was recorded.

Results

Of the 200 total websites analyzed, only 11% were written at or below the recommended 6th grade reading level. The average FRE and grade level for 100 glaucoma diagnosis-related articles were 42.02 ± 1.08 and 10.53 ± 1.30, respectively. The average FRE and grade level for 100 glaucoma treatment-related articles were 43.86 ± 1.01 and 11.29 ± 1.54, respectively. Crowdsourced articles were written at the highest average grade level (12.32 ± 0.78), followed by articles written by private practice/independent users (11.22 ± 1.74), national organizations (10.92 ± 1.24), and educational institutions (10.33 ± 1.35). Websites averaged 1.12 ± 1.15 of 4 JAMA accountability metrics.

Conclusion

Despite wide variation in the readability and accountability of online patient education materials related to glaucoma diagnosis and treatment, patient education materials are consistently written at levels above the recommended reading level and often lack accountability. Articles from educational institutions and national organizations were often written at lower reading levels but are less frequently encountered after Google search. There is a need for accurate and understandable online information that glaucoma patients can use to inform decisions about their eye health.

Glaucoma and Ocular Surface Disease: More than Meets the Eye

Understanding the association between ocular surface disease and glaucoma is important for improving adherence to treatment and introducing practical solutions. While topical antihypertensive medications for glaucoma are well tolerated according to short-term studies, there is little evidence on their long-term effects. Since they are often required for many years, the effects of these drops on the ocular surface become important in regard to quality of life and adherence. In this nonsystematic review performed in April 2022, we summarize what is known about the relationship between glaucoma and ocular surface disease. Specifically, we examine how each class of topical glaucoma drops affects the ocular surface. We then review the treatment of ocular surface disease for patients on topical glaucoma therapy. Finally, we discuss treatments that may reduce or eliminate the burden of topical medications.

Neuroprotection in neurodegenerations of the brain and eye: Lessons from the past and directions for the future

Background

Neurological and ophthalmological neurodegenerative diseases in large part share underlying biology and pathophysiology. Despite extensive preclinical research on neuroprotection that in many cases bridges and unifies both fields, only a handful of neuroprotective therapies have succeeded clinically in either.

Main body

Understanding the commonalities among brain and neuroretinal neurodegenerations can help develop innovative ways to improve translational success in neuroprotection research and emerging therapies. To do this, analysis of why translational research in neuroprotection fails necessitates addressing roadblocks at basic research and clinical trial levels. These include optimizing translational approaches with respect to biomarkers, therapeutic targets, treatments, animal models, and regulatory pathways.

Conclusion

The common features of neurological and ophthalmological neurodegenerations are useful for outlining a path forward that should increase the likelihood of translational success in neuroprotective therapies.

Latanoprostene Bunod 0.024% in the Treatment of Open-Angle Glaucoma and Ocular Hypertension: A Meta-Analysis

Latanoprostene bunod (LBN) 0.024%, a newly approved glaucoma eye drop, is metabolized into latanoprost acid and a nitric oxide (NO)-donating moiety, thus increasing the outflow of aqueous humor through the uveoscleral and trabecular routes, respectively. This study aimed to evaluate the intraocular pressure (IOP)-lowering effect of LBN among patients with open-angle glaucoma (OAG) and ocular hypertension (OHT). The effectiveness of LBN was also compared with timolol maleate 0.5% and latanoprost 0.005%. We searched PubMed and Embase between 1 January 2010, and 31 March 2022 and adopted only peer-reviewed clinical studies in our meta-analysis. A total of nine studies (2389 patients with OAG or OHT) assessing the IOP-reduction effect of LBN were included. Standardized mean differences (SMDs) of IOP between post-treatment time points (2 weeks, 6 weeks, 3 months, 6 months, 9 months, and 12 months) and baseline were calculated. The pooled analysis according to each time point revealed a significant IOP drop after LBN treatment (all p values for SMD < 0.05). In addition, LBN revealed a significantly stronger efficacy in decreasing IOP than timolol maleate 0.5% and latanoprost 0.005% during the follow-up period of three months. No serious side effects of LBN 0.024% were reported. Our study concluded that LBN could achieve good performance for IOP reduction in patients with OAG and OHT. The safety was favorable with no severe side effects.

Comparison of the Effect on Vessel Density and RNFL between Carteolol and Latanoprost

The aim of the study was to compare the treatment of hypertensive glaucoma (HTG) in the early stages with carteolol and latanoprost by assessing the change in vessel density (VD) and retinal nerve fibre layer (RNFL). Methods: The first group with diagnosed HTG consisted of 46 eyes treated with carteolol; the second group consisted of 52 eyes treated with latanoprost. The following examinations were evaluated in all patients: intraocular pressure (IOP), retinal nerve fibre layer (RNFL), vessel density (VD) and visual field examination (glaucoma fast threshold test). The results were compared before treatment and 3 months after treatment. Results: There was no difference in the overall visual field defect (OD) between groups before treatment. After treatment, there was a decrease in IOP in both groups (carteolol-treated group had a mean decrease of 5.8 mmHg and latanoprost-treated eyes had a mean decrease of 7 mmHg). This difference was not statistically significant (p = 0.133). No similar difference was observed for RNFL (p = 0.161). In contrast, the change in the VD parameter was statistically significant between groups (p < 0.05), with a greater difference observed in the carteolol-treated group of eyes. Carteolol had a better effect on the VD.

Hub Gene Screening Associated with Early Glaucoma: An Integrated Bioinformatics Analysis

Background

Primary open-angle glaucoma (POAG) is the most common type of glaucoma. The potential influence of some DEGs on the progression of POAG was still incomplete. In this study, we integrated transcriptome data with clinical data to investigate the relationship between them in POAG patients.

Methods

The gene expression profile (GSE27276) from Gene Expression Omnibus (GEO) was used to identify DEGs. The LIMMA package of R was used to identify the DEGs (Diboun et al., 2006). The adjusted P values (adj P value) were calculated instead to avoid the appearance of false-positive results. Genes with |log₂ fold change (FC)| larger than 1 and adj P value < 0.01 were taken as DEGs between PH and PC samples. GO (Gene Ontology) function and KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway enrichment analyses of the DEGs were performed. Protein-protein interactions (PPIs) of the DEGs were constructed.

Results

A total of 182 DEGs were identified through our analysis, of which 119 genes were upregulated and 63 genes were downregulated. GO enrichment analysis illustrated that these DEGs were mostly enriched into haptoglobin binding, antioxidant activity, and organic acid binding. KEGG enrichment analysis illustrated that these DEGs were mostly enriched into Staphylococcus aureus infection. The most significant module was identified by MCODE consists of 8 DEGs, and BCL11A is the seeded gene. The second most significant module consists of 5 DEGs, and IL1RN is the seeded gene.

Conclusion

Our results demonstrate the potential influence of some DEGs on the progression of POAG, providing a comprehensive bioinformatics analysis of the pathogenesis, which may contribute to future investigation into the molecular mechanisms and biomarkers.

Prevention of Cell Death by Activation of Hydroxycarboxylic Acid Receptor 1 (GPR81) in Retinal Explants

Background: Progressive retinal ganglion cell (RGC) dysfunction and death are common characteristics of retinal neurodegenerative diseases. Recently, hydroxycarboxylic acid receptor 1 (HCA1R, GPR81) was identified as a key modulator of mitochondrial function and cell survival. Thus, we aimed to test whether activation of HCA1R with 3,5-Dihydroxybenzoic acid (DHBA) also promotes RGC survival and improves energy metabolism in mouse retinas. Methods: Retinal explants were treated with 5 mM of the HCA1R agonist, 3,5-DHBA, for 2, 4, 24, and 72 h. Additionally, explants were also treated with 15 mM of L-glutamate to induce toxicity. Tissue survival was assessed through lactate dehydrogenase (LDH) viability assays. RGC survival was measured through immunohistochemical (IHC) staining. Total ATP levels were quantified through bioluminescence assays. Energy metabolism was investigated through stable isotope labeling and gas chromatography-mass spectrometry (GC-MS). Lactate and nitric oxide levels were measured through colorimetric assays. Results: HCA1R activation with 3,5-DHBAincreased retinal explant survival. During glutamate-induced death, 3,5-DHBA treatment also increased survival. IHC analysis revealed that 3,5-DHBA treatment promoted RGC survival in retinal wholemounts. 3,5-DHBA treatment also enhanced ATP levels in retinal explants, whereas lactate levels decreased. No effects on glucose metabolism were observed, but small changes in lactate metabolism were found. Nitric oxide levels remained unaltered in response to 3,5-DHBA treatment. Conclusion: The present study reveals that activation of HCA1R with 3,5-DHBA treatment has a neuroprotective effect specifically on RGCs and on glutamate-induced retinal degeneration. Hence, HCA1R agonist administration may be a potential new strategy for rescuing RGCs, ultimately preventing visual disability.

Brain-Derived Neurotrophic Factor-Mediated Neuroprotection in Glaucoma: A Review of Current State of the Art

Retinal ganglion cells (RGCs) are neurons of the visual system that are responsible for transmitting signals from the retina to the brain via the optic nerve. Glaucoma is an optic neuropathy characterized by apoptotic loss of RGCs and degeneration of optic nerve fibers. Risk factors such as elevated intraocular pressure and vascular dysregulation trigger the injury that culminates in RGC apoptosis. In the event of injury, the survival of RGCs is facilitated by neurotrophic factors (NTFs), the most widely studied of which is brain-derived neurotrophic factor (BDNF). Its production is regulated locally in the retina, but transport of BDNF retrogradely from the brain to retina is also crucial. Not only that the interruption of this retrograde transport has been detected in the early stages of glaucoma, but significantly low levels of BDNF have also been detected in the sera and ocular fluids of glaucoma patients, supporting the notion that neurotrophic deprivation is a likely mechanism of glaucomatous optic neuropathy. Moreover, exogenous NTF including BDNF administration was shown reduce neuronal loss in animal models of various neurodegenerative diseases, indicating the possibility that exogenous BDNF may be a treatment option in glaucoma. Current literature provides an extensive insight not only into the sources, transport, and target sites of BDNF but also the intracellular signaling pathways, other pathways that influence BDNF signaling and a wide range of its functions. In this review, the authors discuss the neuroprotective role of BDNF in promoting the survival of RGCs and its possible application as a therapeutic tool to meet the challenges in glaucoma management. We also highlight the possibility of using BDNF as a biomarker in neurodegenerative disease such as glaucoma. Further we discuss the challenges and future strategies to explore the utility of BDNF in the management of glaucoma.

Adverse effects and Safety in Glaucoma Patients - Agreement on Clinical Trial Outcomes for Reports on Eye Drops (ASGARD) - A Delphi Consensus Statement

PURPOSE

The purpose of this study is to establish consensus among experts on outcomes and methods to be used in clinical trials to assess adverse effects of anti-glaucomatous eye drops.

DESIGN

Modified Delphi method.

METHODS

Clinical experts from Europe, North America, South America, the Middle East, and Asia were invited to participate in two sequential web-based surveys administered from June 27 to August 29, 2021. A total of 91 clinical experts were invited to participate. Of these, 71 (78%) experts from 23 different countries accepted the invitation and answered the first questionnaire. The importance of items was ranked using a 10-point scale (1 as not important, 10 as very important).

RESULTS

A total of 84 items were rated in round one by 71 participants. Of these, 68 (81%) reached consensus. In round two, 19 items, including three additional items, were rated by 53 (75%) participants. Consensus was reached in 98% of investigated items. Eight outcomes were agreed as important to assess when conducting future trials: ocular surface, dryness, epithelial damage, local adverse effects related to eye drops as reported by patients, periocular surroundings and eyelids, quality of life questionnaires, hyperemia, visual acuity, tear film, and anterior chamber inflammation.

CONCLUSION

We propose a consensus-based series of outcomes and assessment methods to be used in clinical trials assessing adverse effects of anti-glaucomatous eye drops. This will hopefully improve the comparability of results from future trials and thus facilitate meta-analyses and progress in this field.

Long-Term Intraocular Pressure-Lowering Effects and Adverse Events of Ripasudil in Patients with Glaucoma or Ocular Hypertension over 24 Months

INTRODUCTION

Glaucoma is a leading cause of irreversible blindness and ripasudil was the first Rho kinase inhibitor approved as antiglaucoma medication. Here we present the final analysis of the ROCK-J study, a large-scale post-marketing surveillance study to evaluate the long-term safety and effectiveness of ripasudil in Japanese patients with glaucoma or ocular hypertension in a real-word clinical setting.

METHODS

ROCK-J was a 24-month, prospective, open-label, observational study that included ripasudil-naïve patients with glaucoma or ocular hypertension who were initiating treatment with ripasudil according to the Japanese approved indication between June 1, 2015 and April 30, 2017. The primary safety endpoint was the incidence of adverse drug reactions (ADRs) (including blepharitis, plus assessment of its background factors); the primary efficacy endpoint was change in intraocular pressure (IOP) from baseline to 24 months.

RESULTS

A total of 3374 Japanese patients with glaucoma or ocular hypertension were evaluated for safety and 3178 for effectiveness of ripasudil over a mean 524.5-day observational period. Overall, 853 (25.3%) patients experienced adverse drug reactions; the most common were blepharitis (8.6%), conjunctival hyperemia (8.5%), and conjunctivitis (6.3%). Multivariate analyses demonstrated that patients were more likely to experience the ADR blepharitis with ripasudil treatment if they were female (hazard ratio [HR] 1.307; p = 0.040), had comorbid or a previous history of blepharitis (HR 2.178; p = 0.001), or had a history of allergy to pollen (HR 1.645; p = 0.003) or medication (HR 2.276; p < 0.001). IOP decreased significantly from baseline with ripasudil; the least-squares mean ± standard error change in IOP from baseline to 24 months was - 2.6 ± 0.1 mmHg (p < 0.001). Significant IOP changes were seen in four types of glaucoma, namely primary open-angle glaucoma, normal-tension glaucoma, primary angle-closure glaucoma, and secondary glaucoma, and ocular hypertension.

CONCLUSION

Ripasudil was safe and effective as an antiglaucoma medication with no new safety signals identified and significant reductions in IOP maintained over 24 months of treatment.

Effects of Ethanol Extract of Propolis on Repair Optic Nerve Damage in a Rat Model for Diabetes Mellitus (Study of MDA, CRP, Caspase-3, and TGF-β Expression and Histopathological Changes on Optic Nerve Damage)

Purpose Hyperglycemia in diabetes increases oxidative stress in the body. It causes optic nerve damage and risk of glaucoma. In this study, we evaluated and analyzed the effect of propolis ethanol extract on repair of optic nerve damage in a rat model for Diabetes Mellitus. Study Design Laboratory experimental using the posttest only control group design was used in this study. Methods A total of 28 male Wistar rat were randomly divided into the following four groups namely control (K1), diabetes mellitus (K2), diabetes mellitus with propolis treatment (100 mg/kg) (P1) and diabetes mellitus with propolis treatment (200 mg/kg) (P2). Statistical analysis used ANOVA and Kruskal Wallis with a significance of p < 0.05. Results The results showed that Gunung Lawu propolis significantly reduced serum glucose levels, malondialdehyde levels and C-reactive protein levels (p<0.01). Furthermore, propolis extract significantly decreased caspase-3 expression and TGF-β expression (p<0.05) in the optic nerve. Propolis can significantly repair optic nerve damage (optic nerve necrosis, thinning of the retinal nerve fiber layer and retinal ganglion cell apoptosis (p < 0.01). Conclusion The final results showed that most of the beneficial effects of propolis were mediated by the reduction of blood glucose levels in diabetic rat.

Neuroprotection Against NMDA-Induced Retinal Damage by Philanthotoxin-343 Involves Reduced Nitrosative Stress

N-methyl-D-aspartate receptor (NMDAR) overstimulation is known to mediate neurodegeneration, and hence represents a relevant therapeutic target for neurodegenerative disorders including glaucoma. This study examined the neuroprotective effects of philanthotoxin (PhTX)-343 against NMDA-induced retinal injury in rats. Male Sprague Dawley rats were divided into three groups; group 1 received phosphate buffer saline as the negative control, group 2 was injected with NMDA (160 nM) to induce retinal excitotoxic injury, and group 3 was pre-treated with PhTX-343 (160 nM) 24 h before NMDA exposure. All treatments were given intravitreally and bilaterally. Seven days post-treatment, rats were subjected to visual behaviour assessments using open field and colour recognition tests. Rats were then euthanized, and the retinas were harvested and subjected to haematoxylin and eosin (H&E) staining for morphometric analysis and 3-nitrotyrosine (3-NT) ELISA protocol as the nitrosative stress biomarker. PhTX-343 treatment prior to NMDA exposure improved the ability of rats to recognize visual cues and preserved visual functions (i.e., recognition of objects with different colours). Morphological examination of retinal tissues showed that the fractional ganglion cell layer thickness within the inner retina (IR) in the PhTX-343 treated group was greater by 1.28-fold as compared to NMDA-treated rats (p < 0.05) and was comparable to control rats (p > 0.05). Additionally, the number of retinal cell nuclei/100 μm² in IR for the PhTX-343-treated group was greater by 1.82-fold compared to NMDA-treated rats (p < 0.05) and was comparable to control group (p > 0.05). PhTX-343 also reduced the retinal 3-NT levels by 1.74-fold compared to NMDA-treated rats (p < 0.05). In conclusion, PhTX-343 pretreatment protects against NMDA-induced retinal morphological changes and visual impairment by suppressing nitrosative stress as reflected by the reduced retinal 3-NT level.

Cytotoxicity and Mitochondrial Effects of Phenolic and Quinone-Based Mitochondria-Targeted and Untargeted Antioxidants on Human Neuronal and Hepatic Cell Lines: A Comparative Analysis

Mitochondriotropic antioxidants (MC3, MC6.2, MC4 and MC7.2) based on dietary antioxidants and analogs (caffeic, hydrocaffeic, trihydroxyphenylpropanoic and trihydroxycinnamic acids) were developed. In this study, we evaluate and compare the cytotoxicity profile of novel mitochondria-targeted molecules (generally known as MitoCINs) on human HepG2 and differentiated SH-SY5Y cells with the quinone-based mitochondria-targeted antioxidants MitoQ and SkQ1 and with two non-targeted antioxidants, resveratrol and coenzyme Q10 (CoQ10). We further evaluate their effects on mitochondrial membrane potential, cellular oxygen consumption and extracellular acidification rates. Overall, MitoCINs derivatives reduced cell viability at concentrations about six times higher than those observed with MitoQ and SkQ1. A toxicity ranking for both cell lines was produced: MC4 < MC7.2 < MC3 < MC6.2. These results suggest that C-6 carbon linker and the presence of a pyrogallol group result in lower cytotoxicity. MC3 and MC6.2 affected the mitochondrial function more significantly relative to MitoQ, SkQ1, resveratrol and CoQ10, while MC4 and MC7.2 displayed around 100-1000 times less cytotoxicity than SkQ1 and MitoQ. Based on the mitochondrial and cytotoxicity cellular data, MC4 and MC7.2 are proposed as leads that can be optimized to develop safe drug candidates with therapeutic application in mitochondrial oxidative stress-related diseases.

Latanoprost eye drops induce conjunctival lymphatic vessel development

AIM

To investigate the effect of latanoprost eye drops on the conjunctival lymphatics.

METHODS

Twenty-four healthy New Zealand White rabbits weighing 1.5 to 2.0 kg were randomly divided into three groups: latanoprost group (n=8) administered with latanoprost eye drops once a day for 2mo, carteolol group (n=8) administered with carteolol eye drops once a day for 2mo, and control group (n=8) without any treatment. The conjunctival tissues in the three groups were extracted to investigate the expression levels of 5'-nucleotidase (5'-Nase) by Western blot, reverse transcription-polymerase chain reaction (RT-PCR), and immunofluorescence staining, respectively.

RESULTS

The protein expression level of 5'-Nase was significantly higher in latanoprost group than carteolol group (F=231.175, P<0.001) and control group (P<0.001), while there was no significant difference between the carteolol group and the control group (P>0.05). The mRNA expression level of 5'-Nase in the latanoprost group was also significantly higher than carteolol group (F=71.169 P<0.005) and control group (P<0.005). The conjunctival lymphatics were positive immunofluorescence stained with the 5'-Nase antibodies in the latanoprost group and not stained in the control group.

CONCLUSION

Latanoprost eye drops can induce conjunctival lymphangiogenesis which may be concerned in clinical implications.

Glaucoma Clinical Research: Trends in Treatment Strategies and Drug Development

Purpose: To investigate the trends and progresses in glaucoma research by searching two major clinical trial registries; clinicaltrials.gov, and Australianclinicaltrials.gov.au. Methods: All clinical trials with glaucoma covered by Clinicaltrials.gov, and Australianclinicaltrials.gov.au starting the study before 1 January 2021 were included. Trials evaluating glaucoma treatment were separated from non-treatment trials and divided into three major categories: "laser treatment," "surgical treatment," and "medical treatment." In the category of "medical treatment," new compounds and their individual targets were identified and subcategorized according to treatment strategy; intraocular pressure (IOP)-lowering, neuroprotective or vascular. The phase transition success rates were calculated. Results: One-thousand five hundred and thirty-seven trials were identified. Sixty-three percent (n = 971) evaluated glaucoma treatment, of which medical treatment accounted for the largest proportion (53%). The majority of medical trials evaluated IOP-lowering compounds, while trials with neuroprotective or vascular compounds accounted for only 5 and 3%, respectively. Eighty-eight new compounds were identified. Phase I, II, and III transition success rates were 63, 26, and 47%, respectively. Conclusion: The number of clinical trials in glaucoma research has increased significantly over the last 30 years. Among the most recently evaluated compounds, all three main treatment strategies were represented, but clinical trials in neuroprotection and vascular modalities are still sparse. In addition to traditional medicines, dietary supplements and growth factors are assessed for a potential anti-glaucomatous effect. Phase II and III success rates were below previously reported success rates for all diseases and ophthalmology in general. A stricter phenotyping of patients can improve the success rates in glaucoma and ophthalmological research and gain a better understanding of responders and non-responders.

Inhibitory and Agonistic Autoantibodies Directed Against the β2-Adrenergic Receptor in Pseudoexfoliation Syndrome and Glaucoma

Pseudoexfoliation syndrome (PEXS) and glaucoma (PEXG) are assumed to be caused by a generalized elastosis leading to the accumulation of PEX material in ocular as well as in extraocular tissues. The exact pathophysiology of PEXS is still elusive. PEXG, the most common type of secondary open-angle glaucoma (OAG), is characterized by large peaks of intraocular pressure (IOP) with a progressive loss of the visual field. Agonistic autoantibodies (agAAbs) against the β₂-adrenergic receptor (AR) have been shown to be present in sera of patients with primary and secondary OAG and ocular hypertension and are seemingly linked to IOP. In the present study, we investigated the autoantibodies directed against the β₂-AR in sera of patients with PEXS and PEXG. We recruited 15, 10, and 15 patients with PEXG, PEXS, and primary OAG, respectively. Ten healthy individuals served as controls. All patients underwent standard ophthalmological examination with Octopus G1 perimetry. agAAbs prepared from serum samples were analyzed in a rat cardiomyocyte-based bioassay for the presence of agAAbs. We identified the interacting loop of the β₂-AR and the immunoglobulin G (IgG) subclasses using synthetic peptides corresponding to the extracellular loops of the receptors and enzyme-linked immunosorbent assay, respectively. None of the controls were β₂-agAAb-positive (0.2 ± 0.5 U). No β₂-agAAbs (0.2 ± 0.4 U), but inhibitory β₂-AAbs were observed in 80% of the patients that partially blocked the drug-induced β₂-adrenergic stimulation; 5.8 ± 1.7 U vs. 11.1 ± 0.9 U for clenbuterol in the absence and the presence of sera from patients with PEXS, respectively. Epitope analyses identified the third extracellular loop of the β₂-AR as the target of the inhibitory β₂-AAbs, being of IgG3 subtype in PEXS patients. In contrast, patients with PEXG showed β₂-agAAbs (5.6 ± 0.9 U), but no inhibitory ones. The β₂-agAAbs levels of patients with PEXG and primary OAG patients (3.9 ± 2.8 U; p > 0.05) were at a similar level. In two cases of PEXG, the β₂-agAAbs exert synergistic effects with clenbuterol. The activity increased from 11.5 ± 0.3 (clenbuterol only) to 16.3 ± 0.9 U. As autoimmune mechanisms were reportedly involved in the pathogenesis of glaucoma, agonistic and inhibitory β₂-AAbs seem to be a part of this multifactorial interplay.

Targeting the NLRP3 Inflammasome in Glaucoma

Glaucoma is a group of optic neuropathies characterised by the degeneration of retinal ganglion cells, resulting in damage to the optic nerve head (ONH) and loss of vision in one or both eyes. Increased intraocular pressure (IOP) is one of the major aetiological risk factors in glaucoma, and is currently the only modifiable risk factor. However, 30–40% of glaucoma patients do not present with elevated IOP and still proceed to lose vision. The pathophysiology of glaucoma is therefore not completely understood, and there is a need for the development of IOP-independent neuroprotective therapies to preserve vision. Neuroinflammation has been shown to play a key role in glaucoma and, specifically, the NLRP3 inflammasome, a key driver of inflammation, has recently been implicated. The NLRP3 inflammasome is expressed in the eye and its activation is reported in pre-clinical studies of glaucoma. Activation of the NLRP3 inflammasome results in IL-1β processing. This pro inflammatory cytokine is elevated in the blood of glaucoma patients and is believed to drive neurotoxic inflammation, resulting in axon degeneration and the death of retinal ganglion cells (RGCs). This review discusses glaucoma as an inflammatory disease and evaluates targeting the NLRP3 inflammasome as a therapeutic strategy. A hypothetical mechanism for the action of the NLRP3 inflammasome in glaucoma is presented.

One-year outcomes of microhook trabeculotomy versus suture trabeculotomy ab interno

Purpose

To compare clinical success rates and reductions in intraocular pressure (IOP) and IOP-lowering medication use following suture trabeculotomy ab interno (S group) or microhook trabeculotomy (μ group).

Methods

This retrospective review collected data from S (n = 104, 122 eyes) and μ (n = 42, 47 eyes) groups who underwent treatment between June 1, 2016, and October 31, 2019, and had 12-month follow-up data including IOP, glaucoma medications, complications, and additional IOP-lowering procedures. The Kaplan–Meier survival analysis was used to evaluate treatment success rates defined as normal IOP (> 5 to ≤ 18 mm Hg), ≥ 20% reduction of IOP from baseline at two consecutive visits, and no further glaucoma surgery.

Results

Schlemm’s canal opening was longer in the S group than in the μ group (P < 0.0001). The Kaplan–Meier survival analysis of all eyes showed cumulative clinical success rates in S and µ groups were 71.1% and 61.7% (P = 0.230). The Kaplan–Meier survival analysis of eyes with preoperative IOP ≥ 21 mmHg showed cumulative clinical success rates in S and μ groups were 80.4% and 60.0% (P = 0.0192). There were no significant differences in postoperative IOP at 1, 3, and 6 months (S group, 14.9 ± 5.6, 14.6 ± 4.5, 14.6 ± 3.9 mmHg; μ group, 15.8 ± 5.9, 15.2 ± 4.4, 14.7 ± 3.7 mmHg; P = 0.364, 0.443, 0.823), but postoperative IOP was significantly lower in the S group at 12 months (S group, 14.1 ± 3.1 mmHg; μ group, 15.6 ± 4.1 mmHg; P = 0.0361). There were no significant differences in postoperative numbers of glaucoma medications at 1, 3, 6, and 12 months (S group, 1.8 ± 1.6, 1.8 ± 1.5, 2.0 ± 1.6, 1.8 ± 1.5; μ group, 2.0 ± 1.6, 2.0 ± 1.6, 2.1 ± 1.6, 2.2 ± 1.7; P = 0.699, 0.420, 0.737, 0.198).

Conclusion

S and µ group eyes achieved IOP reduction, but μ group eyes had lower clinical success rates among patients with high preoperative IOP at 12 months.

Cyclodextrin-based formulation of carbonic anhydrase inhibitors for ocular delivery - A review

Carbonic anhydrase inhibitors (CAIs) are used as systemic and topical agents for lowering intraocular pressure (IOP) in patients with glaucoma. Owing to the wide distribution of CAs and their physiological functions in various tissues, systemic administration of CAIs may lead to unwanted side effects. Thus, exploration of drugs targeting the specific CA isoenzyme in ocular tissues and application of the same as topical eye drops would be desirable. However, the anatomical and physiological barriers of the eyes can limit drug availability at the site. The very low aqueous solubility of CAI agents can further hamper drug bioavailability, consequently resulting in insufficient therapeutic efficacy. Solubilization of drugs using cyclodextrin (CD) complexes can enhance both solubility and permeability of the drugs. The use of CD for such purposes and development and testing of topical CAI eye drops containing CD have been discussed in detail. Further, pharmaceutical nanotechnology platforms were discussed in terms of investigation of their IOP-lowering efficacies. Future prospects in drug discovery and the use of CD nanoparticles and CD-based nanocarriers to develop potential topical CAI formulations have also been described here.

Discovery of a Biased Allosteric Modulator for Cannabinoid 1 Receptor: Preclinical Anti-Glaucoma Efficacy

We apply the magic methyl effect to improve the potency/efficacy of GAT211, the prototypic 2-phenylindole-based cannabinoid type-1 receptor (CB1R) agonist-positive allosteric modulator (ago-PAM). Introducing a methyl group at the α-position of nitro group generated two diastereomers, the greater potency and efficacy of erythro, (±)-9 vs threo, (±)-10 constitutes the first demonstration of diastereoselective CB1R-allosteric modulator interaction. Of the (±)-9 enantiomers, (-)-(S,R)-13 evidenced improved potency over GAT211 as a CB1R ago-PAM, whereas (+)-(R,S)-14 was a CB1R allosteric agonist biased toward G protein- vs β-arrestin1/2-dependent signaling. (-)-(S,R)-13 and (+)-(R,S)-14 were devoid of undesirable side effects (triad test), and (+)-(R,S)-14 reduced intraocular pressure with an unprecedentedly long duration of action in a murine glaucoma model. (-)-(S,R)-13 docked into both a CB1R extracellular PAM and intracellular allosteric-agonist site(s), whereas (+)-(R,S)-14 preferentially engaged only the latter. Exploiting G-protein biased CB1R-allosteric modulation can offer safer therapeutic candidates for glaucoma and, potentially, other diseases.

Cerebral Modifications in Glaucoma and Macular Degeneration: Analysis of Current Evidence in Literature and Their Implications on Therapeutic Perspectives

Glaucoma and macular degeneration are leading causes of irreversible blindness, significantly compromising the quality of life and having a high economic and social impact. Promising therapeutic approaches aimed at regenerating or bypassing the damaged anatomical-functional components are currently under development: these approaches have generated great expectations, but to be effective require a visual network that, despite the pathology, maintains its integrity up to the higher brain areas. In the light of this, the existing findings concerning how the central nervous system modifies its connections following the pathological damage caused by glaucoma and macular degeneration acquire great interest. This review aims to examine the scientific literature concerning the morphological and functional changes affecting the central nervous system in these pathological conditions, summarizing the evidence in an analytical way, discussing their possible causes and highlighting the potential repercussions on the current therapeutic perspectives.

Advances in the discovery of novel agents for the treatment of glaucoma

INTRODUCTION

Glaucoma, a neuropathy characterized by increased intraocular pressure (IOP), is the major cause of blindness worldwide and its treatment aims at reducing IOP.

AREAS COVERED

The authors review the design of the main classes of anti-glaucoma agents. Drugs which interfere with the aqueous humor secretion (adrenergic agonists/antagonists, carbonic anhydrase inhibitors) and with its outflow, by means of both conventional and non-conventional pathways (prostaglandin (PG) analogs, rho kinase inhibitors, nitric oxide (NO) donors) as well as new agents (adenosine receptors modulators, melatonin - fatty acid amide hydrolase hybrids, tyrosine kinase activators, natriuretic peptide analogs) are considered.

EXPERT OPINION

The anti-glaucoma drug field has undergone several developments in recent years with the approval of at least three new drugs belonging to novel pharmacological classes, the rho kinase inhibitors ripasudil and netarsudil, and the PG-NO donor hybrid latanoprostene bunod. Eye drops with combinations of two different drugs are also available, allowing for effective IOP control, with once daily administration for some of them, which assures a better patient compliance and ease of administration. Overall, after more than a decade without new anti-glaucoma drugs, the last year afforded interesting new pharmacological opportunities for the management of this disease.