Medical therapy for glaucoma: what to add after a prostaglandin analogs?

Intraocular Pressure-Lowering and Retina-Protective Effects of Exosome-Rich Conditioned Media from Human Amniotic Membrane Stem Cells in a Rat Model of Glaucoma

Glaucoma is one of the most devastating eye diseases, since the disease can develop into blindness and no effective therapeutics are available. Although the exact mechanisms and causes of glaucoma are unknown, increased intraocular pressure (IOP) has been demonstrated to be an important risk factor. Exosomes are lipid nanoparticles secreted from functional cells, including stem cells, and have been found to contain diverse functional molecules that control body function, inhibit inflammation, protect and regenerate cells, and restore damaged tissues. In the present study, exosome-rich conditioned media (ERCMs) were attained via hypoxic culture (2% O₂) of human amniotic membrane mesenchymal stem cells (AMMSCs) and amniotic membrane epithelial stem cells (AMESCs) containing 50 times more exosome particles than normoxic culture (20% O₂) medium (NCM). The exosome particles in ERCM were confirmed to be 77 nm in mean size and contain much greater amounts of growth factors (GFs) and neurotrophic factors (NFs) than those in NCM. The glaucoma-therapeutic effects of ERCMs were assessed in retinal cells and a hypertonic (1.8 M) saline-induced high-IOP animal model. CM-DiI-labeled AMMSC exosomes were found to readily penetrate the normal and H₂O₂-damaged retinal ganglion cells (RGCs), and AMMSC-ERCM not only facilitated retinal pigment epithelial cell (RPEC) proliferation but also protected against H₂O₂- and hypoxia-induced RPEC insults. The IOP of rats challenged with 1.8 M saline increased twice the normal IOP (12-17 mmHg) in a week. However, intravitreal injection of AMMSC-ERCM or AMESC-ERCM (3.9-4.5 × 10⁸ exosomes in 10 μL/eye) markedly recovered the IOP to normal level in 2 weeks, similar to the effect achieved with platelet-derived growth factor-AB (PDGF-AB, 1.5 μg), a reference material. In addition, AMMSC-ERCM, AMESC-ERCM, and PDGF-AB significantly reversed the shrinkage of retinal layers, preserved RGCs, and prevented neural injury in the glaucoma eyes. It was confirmed that stem cell ERCMs containing large numbers of functional molecules such as GFs and NFs improved glaucoma by protecting retinal cells against oxidative and hypoxic injuries in vitro and by recovering IOP and retinal degeneration in vivo. Therefore, it is suggested that stem cell ERCMs could be a promising candidate for the therapy of glaucoma.

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

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

Effectiveness of Netarsudil versus Brimonidine in Eyes already Being Treated with Glaucoma Medications at a Single Academic Tertiary Care Practice: A Comparative Study

Background

Rho kinase inhibitors, such as netarsudil, are a relatively new class of medications recently introduced into the market for the treatment of glaucoma, the leading cause of irreversible blindness in the world. Previous clinical trials have studied netarsudil's efficacy when used as a first- or second-line agent but limited studies have investigated its effectiveness in the real world where it is more commonly used as a third, fourth, or fifth agent in combination with other topical medications. Equally important, prior studies have not compared its effectiveness to its peer medications in these settings.

Objective

To compare intraocular pressure (IOP) lowering after initiation of netarsudil or brimonidine therapy in patients with glaucoma using >2 medications for IOP management.

Methods

A chart review of 369 eyes from 279 patients followed at a single academic tertiary practice was performed with an institutional review board waiver of consent to compare IOP lowering after prescription of netarsudil (n = 176) versus brimonidine (n = 193) as a third, fourth, or fifth IOP-lowering agent. Patients were identified by querying the electronic medical record for those with a glaucoma-related diagnosis who were prescribed either medication. Five sequential IOP measurements were obtained to determine the mean change in IOP before and after treatment (ΔIOP = mean IOP_4,5 - mean IOP_1,2,3). A multilevel linear mixed-effects model assessed the influence of medication (independent variable) on ΔIOP (dependent variable). Additional independent variables of interest included the number of glaucoma medications at baseline, age, sex, glaucoma type and severity, race, and pretreatment IOP. Bootstrap analysis was performed to remove sampling bias and confirm mixed-effects model findings. Kaplan-Meier survival analysis evaluated the probability of requiring additional intervention within 3 years following the date of medication prescription.

Results

The unadjusted mean (SD) ΔIOP for netarsudil and brimonidine was -2.20 (4.11) mm Hg and -2.21 (3.25) mm Hg, respectively (P = 0.484). The adjusted linear mixed-effects models and bootstrap analysis demonstrated that there was no statistical difference in IOP-lowering effectiveness between the medications. Netarsudil and brimonidine failed to adequately control IOP at similar rates with 42% and 47% probabilities of survival respectively by the 3-year follow-up (P = 0.520).

Conclusions

When escalating pharmacologic therapy, the IOP-lowering effect of netarsudil appeared to be similar to that produced by brimonidine. (Curr Ther Res Clin Exp. 2023; 84:XXX-XXX).

The Additive Effect of ROCK Inhibitor on Prostaglandin-Treated Japanese Patients with Glaucoma Indicating 15 mmHg and Under: ROCK U-15

Introduction

We aimed to evaluate the additional effects and safety of a Rho-associated protein kinase (ROCK) inhibitor, ripasudil hydrochloride hydrate, in Japanese patients with primary open-angle glaucoma (POAG) with an intraocular pressure (IOP) of at most 15 mmHg undergoing prostaglandin F_2α (FP) receptor agonist monotherapy (FP monotherapy).

Methods

In this prospective observational study, 30 Japanese patients with POAG and IOP of at most 15 mmHg (mean age 59.4 years; 10 men) who were undergoing FP monotherapy in both eyes were administered an additional dose of ripasudil hydrochloride hydrate (GLANATEC ophthalmic solution 0.4%: ripasudil) in one eye. The following factors were investigated at 1 and 3 months after the initiation of ripasudil treatment: (1) magnitude of change in IOP between the treated and contralateral untreated eyes, (2) number of treated eyes showing 20% and 30% IOP reduction, (3) IOP difference between treated and contralateral untreated eyes, and (4) safety during the treatment period. Both (1) and (3) were analyzed using the mixed-effect model for repeated measurements.

Results

The treated eyes showed significant reduction in IOP at 1 month (− 1.92 mmHg, P < 0.001) and 3 months (− 1.81 mmHg, P < 0.001). In contrast, contralateral untreated eyes did not show IOP reduction at 1 month (0.53 mmHg, P = 0.016) and 3 months (0.38 mmHg, P = 0.15). IOP reduction of − 20% and − 30% was achieved in 9 (30%) and 3 (10%) treated eyes, respectively. There were significant differences in IOP between the treated and contralateral untreated eyes at 1 month (− 2.46 mmHg, P < 0.001) and 3 months (− 2.20 mmHg, P < 0.001). Two patients experienced local adverse events (facial edema, one patient at week 1; blepharitis, one patient at 1 month); they recovered quickly after stopping ripasudil administration.

Conclusion

In patients with POAG with an IOP of at most 15 mmHg undergoing FP monotherapy, the addition of ripasudil resulted in significant IOP lowering at 1 and 3 months. Ripasudil could be used to enhance the outcome of FP monotherapy.

Trial registration

Registered UMIN ID: UMIN000030742.

A multicenter, open-label study of netarsudil for the reduction of elevated intraocular pressure in patients with open-angle glaucoma or ocular hypertension in a real-world setting

OBJECTIVE

Assess the real-world efficacy of netarsudil, either as monotherapy or concomitant therapy, in patients with open-angle glaucoma (OAG) or ocular hypertension (OHT) requiring modification of intraocular pressure (IOP)-lowering treatment.

METHODS

Multicenter, prospective, interventional, open-label, Phase 4 study, clinical trial registration number: NCT03808688. Netarsudil ophthalmic solution 0.02% was prescribed at the recommended once-daily dosage, with treatment regimens determined by the investigators. Netarsudil could be used alone or in combination with other IOP-lowering medications, consistent with standard clinical practice. Primary efficacy endpoint: percentage reduction from baseline IOP at week 12.

RESULTS

Among 261 enrolled patients, 242 received ≥1 netarsudil dose and had ≥1 follow-up IOP measurement (efficacy population). Mean IOP in patients who were treatment-naïve at baseline and using netarsudil as monotherapy (n = 24) decreased by 16.9%. Netarsudil monotherapy was comparable in efficacy to prior therapy across subgroups, and those who replaced prostaglandin analog (n = 57) monotherapy demonstrated reduction of 2.5% from prostaglandin analog-treated baseline values. Among patients who used netarsudil as concomitant therapy (n = 151), reductions in mean IOP (± standard deviation) to week 12 were seen across subgroups who added netarsudil to a single agent (4.3 ± 2.88 mmHg; 20.5%) or ≥2 classes of concomitant therapy (4.5 ± 4.08 mmHg; 20.9%) and who used netarsudil to replace ≥1 other drug classes (0.4 ± 2.47 mmHg; 1.7%). Of 260 netarsudil-treated patients, 41 (15.8%) discontinued, including 29 (11.2%) due to adverse events.

CONCLUSIONS

In the real-world treatment of patients with OAG or OHT, netarsudil consistently maintained IOP control when it replaced previous IOP-lowering therapies and provided additional IOP-lowering efficacy when added to other treatments.

Comparing glaucoma medications and general demographics in a sample of glaucoma patients treated in private practice with nationwide registry data in Finland

PURPOSE

To investigate the outpatient glaucoma care provided by Finnish private ophthalmologists and to compare this information with the data obtained from national databases.

METHODS

The data were collected by 13 investigators in 27 centres in southern Finland. Patient demography, relevant systemic diseases, possible history of ocular surgery, duration of glaucoma, intraocular pressure (IOP) and type of glaucoma were registered. Ocular hypertensive medication(s) used during the last 6 months were recorded using the generic name coded by the current ATC/DDD index. The data were compared with a dataset obtained from the IMS Health database and the Social Insurance Institution of Finland (Kela).

RESULTS

In total, 568 patients from private ophthalmology clinics were included. Mean age was 70 years (range 30-90 years), and the mean duration of glaucoma was 8.3 years. In general, IOP control was good (mean 16.9 mmHg). The average cost of glaucoma treatment for a single study patient was 336 euros per year. The findings obtained from the survey were similar to those of the nationwide databases, although fewer of the more aggressive glaucoma cases were managed in the private clinics examined during the study.

CONCLUSION

The study patients were treated effectively by private ophthalmologist. Their medication and the cost of medication were the same as in public clinics. Patients with aggressive glaucoma seem to be generally managed by public hospitals.

Matrix Metalloproteinases and Glaucoma Treatment

Matrix metalloproteinases (MMPs) are a family of proteolytic enzymes that degrade extracellular matrix (ECM) components such as collagen and have important roles in multiple biological processes, including development and tissue remodeling, both in health and disease. The activity of MMPs is influenced by the expression of MMPs and tissue inhibitors of metalloproteinase (TIMPs). In the eye, MMP-mediated ECM turnover in the juxtacanalicular region of the trabecular meshwork (TM) reduces outflow resistance in the conventional outflow pathway and helps maintain intraocular pressure (IOP) homeostasis. An imbalance in the MMP/TIMP ratio may be involved in the elevated IOP often associated with glaucoma. The prostaglandin analog/prostamide (PGA) class of topical ocular hypotensive medications used in glaucoma treatment reduces IOP by increasing outflow through both conventional and unconventional (uveoscleral) outflow pathways. Evidence from in vivo and in vitro studies using animal models and anterior segment explant and cell cultures indicates that the mechanism of IOP lowering by PGAs involves increased MMP expression in the TM and ciliary body, leading to tissue remodeling that enhances conventional and unconventional outflow. PGA effects on MMP expression are dependent on the identity and concentration of the PGA. An intracameral sustained-release PGA implant (Bimatoprost SR) in development for glaucoma treatment can reduce IOP for many months after expected intraocular drug bioavailability. We hypothesize that the higher concentrations of bimatoprost achieved in ocular outflow tissues with the implant produce greater MMP upregulation and more extensive, sustained MMP-mediated target tissue remodeling, providing an extended duration of effect.

Nanotechnology for Medical and Surgical Glaucoma Therapy-A Review

Glaucoma is the second leading cause of blindness worldwide. Even though significant advances have been made in its management, currently available antiglaucoma therapies suffer from considerable drawbacks. Typically, the success and efficacy of glaucoma medications are undermined by their limited bioavailability to target tissues and the inadequate adherence demonstrated by patients with glaucoma. The latter is due to a gradual decrease in tolerability of lifelong topical therapies and the significant burden to patients of prescribed stepwise antiglaucoma regimens with frequent dosing which impact quality of life. On the other hand, glaucoma surgery is restricted by the inability of antifibrotic agents to efficiently control the wound healing process without causing severe collateral damage and long-term complications. Evolution of the treatment paradigm for patients with glaucoma will ideally include prevention of retinal ganglion cell degeneration by the successful delivery of neurotrophic factors, anti-inflammatory drugs, and gene therapies. Nanotechnology-based treatments may surpass the limitations of currently available glaucoma therapies through optimized targeted drug delivery, increased bioavailability, and controlled release. This review addresses the recent advances in glaucoma treatment strategies employing nanotechnology, including medical and surgical management, neuroregeneration, and neuroprotection.

Role of 24-Hour Intraocular Pressure Monitoring in Glaucoma Management

Glaucoma is the leading cause of irreversible blindness worldwide and the prevalence is on the rising trend. Intraocular pressure (IOP) reduction is the mainstay of treatment. The current practice of IOP monitoring is based on spot measurements during clinic visits during office hours. However, there are up to 50% of glaucoma patients who had normal initial IOP, while some treated patients continued to have progressive glaucomatous optic nerve damage even with a low IOP. Recent studies have shown that the IOP of glaucoma patients fluctuated during the day with different patterns, and some of them had peak IOP outside office hours. These findings provided us with new insights on the role of 24-hour IOP monitoring in managing normal tension glaucoma and patients with progressive deterioration despite apparently well-controlled IOP. Nevertheless, results to date are rather inconsistent, and there is no consensus yet. In this review, we briefly highlighted the current modalities of 24-hour IOP monitoring and summarized the characteristic 24-hour IOP pattern and the clinical relevance of IOP parameters in predicting glaucomatous progression in different glaucoma subtypes. We also discussed the therapeutic efficacy of current glaucoma treatment modalities with respect to the mentioned 24-hour IOP profiles, so as to strengthen the role of 24-hour IOP monitoring in identifying and stratifying the risks of progression in glaucoma patients, as well as optimizing treatments according to their IOP profiles.

Comparison of Prostaglandin Analog Treatment Patterns in Glaucoma and Ocular Hypertension

BACKGROUND

Prostaglandin analogs (PGAs) are considered an initial therapy to manage increased intraocular pressure (IOP) for patients with glaucoma. When the initial PGA treatment fails to lower IOP adequately, the patient may add or change medications or have surgery/laser treatment.

OBJECTIVE

To compare medication adherence, duration of therapy, and treatment patterns among 3 PGAs-latanoprost, travoprost, and bimatoprost-as initial therapies for patients with glaucoma or ocular hypertension.

METHODS

This was a retrospective cohort study using administrative claims data. The cohort consisted of patients newly diagnosed with glaucoma or ocular hypertension with at least 1 prescription claim for latanoprost, travoprost, or bimatoprost and enrolled in a Medicare Advantage plan between 2007 and 2012. The 24-month medication possession ratio (MPR) was used to measure medication adherence. Discontinuation of first-line PGA therapy was defined as nonpersistence (90-day gap allowance) of the index PGA or a change in therapy during the 24-month follow-up period. Types of second-line therapy (i.e., switch, addition, and surgery) were identified. The 1:1:1 propensity score matching was used.

RESULTS

Patients who met the inclusion criteria were propensity score matched, resulting in 1,296 patients per PGA group. Latanoprost users showed higher adherence (50.1%) than travoprost (48.8%) and bimatoprost (43.0%) users. The latanoprost and travoprost groups had significantly higher MPRs than bimatoprost (P < 0.0001). The latanoprost group showed significantly longer duration of first-line therapy (372 days) than the bimatoprost group (343 days; P = 0.003) but not the travoprost group (361 days). After controlling for demographic and clinical characteristics, a Cox proportional hazards model showed that the travoprost and bimatoprost groups had a higher risk of discontinuation of first-line therapy than the latanoprost group (P < 0.0001). The percentage of patients continuing on the index PGA without treatment pattern change (i.e., switches, additions, and surgery) was higher for latanoprost users (52.9%) compared with travoprost (39.0%) or bimatoprost users (42.1%; P < 0.001).

CONCLUSIONS

Patients who used latanoprost as their initial therapy were more likely to adhere and persist to the index PGA compared with bimatoprost users. The latanoprost group demonstrated a lower risk of discontinuing first-line therapy than the travoprost and bimatoprost groups. The results may assist ophthalmologists in determining the optimal management of this patient population with respect to treatment patterns.

DISCLOSURES

No outside funding supported this study. All authors except Heo and Nair are employed by The University of Texas at Austin College of Pharmacy. Heo was with the Health Outcomes Division, The University of Texas at Austin College of Pharmacy during a portion of this study and is employed by Genesis Research. Nair is employed by Humana. The authors have no financial relationships relevant to this article to disclose. This study was presented as a poster at the 2016 International Society for Pharmacoeconomics and Outcomes Research Annual Meeting, May 2016, Washington, DC.

Stanniocalcin-1 Is an Ocular Hypotensive Agent and a Downstream Effector Molecule That Is Necessary for the Intraocular Pressure-Lowering Effects of Latanoprost

Purpose

To identify downstream signaling molecules through which intraocular pressure (IOP) is lowered following treatment with the prostaglandin analog latanoprost.

Methods

Total RNA and protein isolated from primary human Schlemm's canal cells (n = 3) treated with latanoprost (free acid; 100 nM) were processed for quantitative PCR and Western blot analysis. IOP was evaluated in stanniocalcin-1 (STC-1^−/−) and wild-type mice following treatment with latanoprost or Rho kinase inhibitor Y27632. Human anterior segment pairs (n = 8) were treated with recombinant STC-1 (5, 50, or 500 ng/mL) and pressure was recorded using custom-designed software. The effect of recombinant STC-1 (0.5 mg/mL) on IOP was evaluated in wild-type mice. Tissue morphology was evaluated by light and transmission electron microscopy.

Results

Increased STC-1 mRNA (4.0- to 25.2-fold) and protein expression (1.9- to 5.1-fold) was observed within 12 hours following latanoprost treatment. Latanoprost reduced IOP in wild-type mice (22.0% ± 1.9%), but had no effect on STC-1^−/− mice (0.5% ± 0.7%). In contrast, Y27632 reduced IOP in both wild-type (12.5% ± 1.2%) and in STC-1^−/− mice (13.1% ± 2.8%). Human anterior segments treated with STC-1 (500 ng/mL) showed an increase in outflow facility (0.15 ± 0.03 to 0.27 ± 0.09 μL/min/mm Hg) while no change was observed in paired vehicle-treated controls. Recombinant STC-1 reduced IOP in wild-type mice by 15.2% ± 3.0%. No observable morphologic changes were identified between treatment groups when evaluated by microscopy.

Conclusions

Latanoprost-induced reduction of IOP is mediated through the downstream signaling molecule STC-1. When used by itself, STC-1 exhibits ocular hypotensive properties.

The 24-Hour Effects of Brinzolamide/Brimonidine Fixed Combination and Timolol on Intraocular Pressure and Ocular Perfusion Pressure

PURPOSE

To determine the 24-h effects of brinzolamide/brimonidine tartrate 1%/0.2% fixed combination (BBFC) on intraocular pressure (IOP), ocular perfusion pressure (OPP), blood pressure (BP), and heart rate (HR).

METHODS

Sixty subjects with open angle glaucoma (OAG) or ocular hypertension (OHTN) were admitted overnight for 24-h monitoring of IOP, BP, and HR. All subjects underwent the first, baseline 24-h study after washout of all medications, if necessary. Subjects were then randomized to receive either (1) timolol maleate 0.5% twice daily or (2) BBFC 3 times daily. After 4 weeks of treatment, all subjects completed a follow-up 24-h study visit. At each study visit, IOP, BP, and HR were measured every 2 h in the habitual position. OPP was calculated as 2/3[diastolic BP +1/3(systolic BP-diastolic BP)]-IOP.

RESULTS

Treatment with BBFC significantly lowered IOP during the diurnal period (-2.7 ± 0.4 mmHg; P < 0.01) and nocturnal period (-0.8 ± 0.3 mmHg; P < 0.01). Timolol similarly reduced IOP during the diurnal period, but did not lower IOP overnight. Over a 24-h period, BBFC achieved a significantly greater IOP reduction than timolol (-0.7 ± 0.4 mmHg; P = 0.04). BBFC failed to achieve an increase in OPP during any time period, while timolol increased OPP during the diurnal period only. A significantly greater reduction in HR occurred in the timolol group.

CONCLUSIONS

BBFC significantly lowers IOP during both the diurnal and nocturnal periods, but has no effect on OPP. Timolol only lowers IOP during the diurnal period.