Microbead-induced ocular hypertensive mouse model for screening and testing of aqueous production suppressants for glaucoma.
ABSTRACT: To characterize the microbead-induced ocular hypertension (OHT) mouse model and investigate its potential use for preclinical screening and evaluation of ocular hypotensive agents, we tested the model's responses to major antiglaucoma drugs.Adult C57BL/6J mice were induced to develop OHT unilaterally by intracameral injection of microbeads. The effects of the most commonly used ocular hypotensive drugs, including timolol, brimonidine, brinzolamide, pilocarpine, and latanoprost, on IOP and glaucomatous neural damage were evaluated. Degeneration of retinal ganglion cells (RGCs) and optic nerve axons were quantitatively assessed using immunofluorescence labeling and histochemistry. Thickness of the ganglion cell complex (GCC) was also assessed with spectral-domain optical coherence tomography (SD-OCT).A microbead-induced OHT model promptly responded to drugs, such as timolol, brimonidine, and brinzolamide, that lower IOP through suppressing aqueous humor production and showed improved RGC and axon survival as compared to vehicle controls. Accordingly, SD-OCT detected significantly less reduction of GCC thickness in mice treated with all three aqueous production suppressants as compared to the vehicle contol-treated group. In contrast, drugs that increase aqueous outflow, such as pilocarpine and latanoprost, failed to decrease IOP in the microbead-induced OHT mice.Microbead-induced OHT mice carry dysfunctional aqueous outflow facility and therefore offer a unique model that allows selective screening of aqueous production suppressant antiglaucoma drugs or for studying the mechanisms regulating aqueous humor production. Our data set the stage for using GCC thickness assessed by SD-OCT as an imaging biomarker for noninvasive tracking of neuronal benefits of glaucoma therapy in this model.
Project description:<b>Background:</b> Brinzolamide as a carbonic anhydrase inhibitor could be combined with other intraocular pressure (IOP) lowering drugs for glaucoma and ocular hypertension (OHT), but the efficacy was controversial. So, this study was used to assess the efficacy and safety of brinzolamide as add-on to prostaglandin analogues (PGAs) or ?-blocker in treating patients with glaucoma or OHT who fail to adequately control IOP. <b>Methods:</b> We searched PubMed, Embase, MEDLINE, Cochrane Library, and clinicaltrials.gov from inception to October 4, 2018. Randomized controlled trials of brinzolamide as add-on to PGAs or ?-blocker for glaucoma and OHT were included. Meta-analysis was conducted by RevMan 5.3 software. <b>Results:</b> A total of 26 trials including 5,583 patients were analyzed. Brinzolamide produced absolute reductions of IOP as an adjunctive therapy for patients with glaucoma or OHT. Brinzolamide and timolol were not significantly different in lowering IOP as add-on to PGAs (9 am: <i>P</i> = 0.07; 12 am: <i>P</i> = 0.66; 4 pm: <i>P</i> = 0.66). Likewise, brinzolamide was as effective as dorzolamide in depressing IOP (9 am: <i>P</i> = 0.59; 12 am: <i>P</i> = 0.94; 4 pm: <i>P</i> = 0.95). For the mean diurnal IOP at the end of treatment duration, there were no statistical differences in above comparisons (<i>P</i> > 0.05). Compared with brimonidine (b.i.d.), there was a significant reduction of IOP in brinzolamide (b.i.d.) at 9 am (<i>P</i> < 0.0001); however, the difference was cloudy in thrice daily subgroup (<i>P</i> = 0.44); at 12 am, brinzolamide (b.i.d.) was similar to brimonidine (b.i.d.) in IOP-lowering effect (<i>P</i> = 0.23), whereas brimonidine (t.i.d.) led to a greater effect than brinzolamide (t.i.d.) (<i>P</i> = 0.02). At 4 pm, brinzolamide (b.i.d.) was superior IOP-lowering effect compared with brimonidine (b.i.d.) (<i>P</i> = 0.0003); conversely, the effect in brinzolamide (t.i.d.) was lower than brimonidine (t.i.d.) (<i>P</i> < 0.0001). For the mean diurnal IOP, brinzolamide was lower in twice daily subgroup (<i>P</i> < 0.00001); brimonidine was lower in thrice daily subgroup (<i>P</i> < 0.00001). With regard to the safety, brinzolamide and dorzolamide had a higher incidence of taste abnormality; moreover, brinzolamide resulted in more frequent blurred vision; dorzolamide resulted in more frequent ocular discomfort and eye pain. Timolol resulted in more frequent blurred vision and less conjunctival hyperemia. Brimonidine resulted in more frequent ocular hyperemia. As to other adverse events (AEs) (conjunctivitis, eye pruritus, foreign body sensation in eyes, and treatment-related AEs), brinzolamide was similar to other three active comparators. <b>Conclusions:</b> Brinzolamide, as add-on to PGAs or ?-blocker, significantly decreased IOP of patients with refractory glaucoma or OHT and the AEs were tolerable.
Project description:This study compared the intraocular pressure (IOP)-lowering efficacy of fixed-combination brinzolamide 1%/brimonidine 0.2% (BBFC) with that of its component medications, brinzolamide and brimonidine, in patients with open-angle glaucoma or ocular hypertension.In this phase 3, multicenter, double-masked, parallel-group, 3-month study with a 3-month safety extension, eligible patients were randomized 1:1:1 to treatment with BBFC, brinzolamide, or brimonidine thrice daily after a washout period, during which any IOP-lowering medications were discontinued. The primary objectives of this study were to determine whether the IOP-lowering efficacy of BBFC was superior to that of brinzolamide alone and, separately, of brimonidine alone. IOP was assessed at 8:00 AM, 10:00 AM, 3:00 PM, and 5:00 PM at 2 weeks, 6 weeks, and 3 months after study drug initiation.A total of 690 patients were enrolled in the study, and 615 completed the 3-month visit. Baseline mean IOP levels were similar among the 3 treatment groups at each of the 4 time points assessed. At the 3-month primary endpoint, mean IOP of the BBFC group was significantly lower than that of either the brinzolamide group or the brimonidine group (P?0.005) across all time points. At the 2- and 6-week supportive endpoints, mean IOP of the BBFC group was significantly lower at all time points than the mean IOP of either the brinzolamide group (P?0.01) or the brimonidine group (P<0.0001). A total of 143 patients experienced at least 1 treatment-related adverse event (AE; BBFC group, n=58, 26.2%; brinzolamide group, n=44, 18.8%; brimonidine group, n=41, 17.4%), the majority of which were ocular AEs.This study demonstrated that BBFC has significantly superior IOP-lowering activity compared with either brinzolamide 1% or brimonidine 0.2% in patients with open-angle glaucoma or ocular hypertension while providing a safety profile which is consistent with that of the individual components.
Project description:AIM: To evaluate the existing evidence on relative efficacy and tolerability of topical mono-compound intraocular pressure (IOP)-lowering drugs in treatment of primary open angle glaucoma (POAG) and ocular hypertension (OHT). METHODS: In this systematic review of systematic reviews/meta-analyses of randomized controlled trials a thorough and sensitive search of PubMed, Embase and Cochrane Databases was performed. Individual study methodological quality and quality of evidence were assessed using the AMSTAR checklist and the GRADE system, respectively. The relationships between individual drugs were evaluated based on the best available evidence. RESULTS: Of the 133 initial non-duplicate records, 16 studies met the inclusion criteria. Five achieved an overall "moderate" (none achieved "high") quality of evidence and evaluated prostaglandin analogues (PGAs) - latanoprost, travoprost, and bimatoprost; timolol; "other beta-blockers;" carbonic anhydrase inhibitors (CAI) as a group or dorzolamide separately; and brimonidine. "Moderate quality" refers to efficacy and incidence of conjunctival hyperemia. Quality of evidence regarding other tolerability aspects was low. PGAs should be considered equivalent regarding efficacy, but latanoprost was relevantly better tolerated than the other two. Non-PGA compounds did not relevantly differ between each other in either efficacy or safety. Timolol and brimonidine were relevantly less effective than all PGAs. The same was true for CAI vs bimatoprost. Regarding tolerability, timolol was superior to all PGAs and brimonidine and CAI were superior to bimatoprost. CONCLUSION: No high quality evidence on relative efficacy and tolerability of the most commonly used mono-compound IOP-lowering drugs for POAG/OHT exists. Moderate quality evidence indicates latanoprost as a treatment with the most favorable trade-off between benefits and harms.
Project description:OBJECTIVE:To evaluate the additive intraocular pressure (IOP)-lowering efficacy and safety of fixed-combination brimonidine 0.2%/timolol 0.5% compared with timolol 0.5% at peak and trough effect when used as therapy adjunctive to latanoprost 0.005% in patients with glaucoma or ocular hypertension who require additional IOP lowering. METHODS:In this prospective, randomized, multicenter, investigator-masked, parallel-group study, patients were treated with latanoprost monotherapy for at least four weeks prior to baseline. At baseline on latanoprost, patients with IOP ?21 mmHg in at least one eye were randomized to twice-daily fixed brimonidine-timolol (n = 102) or timolol (n = 102), each adjunctive to latanoprost for 12 weeks. IOP was measured at 8 am and 10 am at baseline, week 6, and week 12 and evaluated in the per protocol population. The primary efficacy endpoint was peak IOP lowering at 10 am, week 12. Safety measures included adverse events. RESULTS:Baseline mean IOP was similar at 10 am in the treatment groups (brimonidine-timolol 23.4 mmHg; timolol 23.0 mmHg). The mean additional reduction from latanoprost-treated baseline IOP was 8.3 mmHg (35.5%) with fixed brimonidine-timolol and 6.2 mmHg (27.0%) with timolol at 10 am, week 12 (P < 0.001). Patients treated with fixed brimonidine-timolol adjunctive to latanoprost were significantly more likely than patients treated with adjunctive timolol to achieve an IOP <18 mmHg (P = 0.028) and a ?20% reduction in IOP from baseline (P = 0.047) at both 8 am and 10 am in week 12. Adverse events occurred in 14.7% of fixed brimonidine-timolol patients and 12.7% of timolol patients. Biomicroscopy findings were similar between the treatment groups after 12 weeks of treatment. CONCLUSION:Fixed-combination brimonidine-timolol reduced IOP significantly more effectively than timolol when used as adjunctive therapy to latanoprost in patients with glaucoma and ocular hypertension. Both fixed brimonidine-timolol and timolol were well tolerated as agents adjunctive to latanoprost.
Project description:PURPOSE: To describe pooled efficacy and safety data from two phase 3 studies comparing brinzolamide 1%/brimonidine 0.2% fixed combination (BBFC) with its component medications, brinzolamide and brimonidine, in patients with open-angle glaucoma or ocular hypertension. METHODS: Data were pooled from two nearly identical clinical trials comparing BBFC with its component medications, each given three times daily. The 3-month efficacy outcome was mean intraocular pressure (IOP) at 0800, 1000, 1500, and 1700 hours. Safety outcomes included adverse events (AEs), best-corrected visual acuity, examination of ocular structures, pachymetry, perimetry, and vital signs. RESULTS: A total of 1350 patients were enrolled and included in this analysis (BBFC, n=437; brinzolamide, n=458; brimonidine, n=455). Baseline mean IOP levels were similar among the three treatment groups. At 3 months, mean IOP of the BBFC group was significantly lower than that of either monotherapy group (P<0.0001) at all the four time points. A total of 272 patients (20.1%) experienced at least one treatment-related AE (BBFC, 24.6%; brinzolamide, 18.7%; brimonidine, 17.4%), the majority of which were ocular AEs. One serious AE, moderate intensity chest pain, was considered related to brinzolamide treatment and resulted in study discontinuation. CONCLUSIONS: This analysis strengthens the conclusions drawn from the two individual phase 3 studies showing that, in patients with open-angle glaucoma or ocular hypertension, BBFC had significantly superior IOP-lowering activity compared with either brinzolamide or brimonidine alone and a safety profile consistent with that of its individual components.
Project description:In humans, the longitudinal characterisation of early optic nerve head (ONH) damage in ocular hypertension (OHT) is difficult as patients with glaucoma usually have structural ONH damage at the time of diagnosis. Previous studies assessed glaucomatous ONH cupping by measuring the anterior lamina cribrosa depth (LCD) and minimal rim width (MRW) using optical coherence tomography (OCT). In this study, we induced OHT by repeated intracameral microbead injections in 16 cynomolgus primates (10 unilateral; 6 bilateral) and assessed the structural changes of the ONH longitudinally to observe early changes. Elevated intraocular pressure (IOP) in OHT eyes was maintained for 7 months and serial OCT measurements were performed during this period. The mean IOP was significantly elevated in OHT eyes when compared to baseline and compared to the control eyes. Thinner MRW and deeper LCD values from baseline were observed in OHT eyes with the greatest changes seen between month 1 and month 2 of OHT. Both the mean and maximum IOP values were significant predictors of MRW and LCD changes, although the maximum IOP was a slightly better predictor. We believe that this model could be useful to study IOP-induced early ONH structural damage which is important for understanding glaucoma pathogenesis.
Project description:BACKGROUND:The purpose of this study was to evaluate the intraocular pressure (IOP)-lowering efficacy and safety of bimatoprost 0.01% or 0.03% as monotherapy in patients treated with latanoprost 0.005% monotherapy who require additional IOP lowering for their ocular hypertension or open-angle glaucoma. METHODS:Two prospective, investigator-masked, randomized, parallel-group, multicenter studies enrolled patients with baseline IOP ?20 mmHg after ?30 days of latanoprost 0.005% monotherapy. Patients were randomized to 12 weeks of study treatment (study 1, bimatoprost 0.01% once daily or bimatoprost 0.01% once daily plus brimonidine 0.1% three times daily; study 2, bimatoprost 0.03% once daily or bimatoprost 0.03% once daily plus fixed-combination brimonidine 0.2%/timolol 0.5% twice daily). Patient evaluations at weeks 4 and 12 included IOP at 8 am, 10 am, and 4 pm and safety assessments. Results in the monotherapy study arms (bimatoprost 0.01% or 0.03%) are presented. RESULTS:Latanoprost-treated baseline mean diurnal IOP (± standard error of the mean) was 22.2±0.3 mmHg and 22.1±0.4 mmHg in the bimatoprost 0.01% and bimatoprost 0.03% treatment arms, respectively (P=0.957). In both treatment arms, mean (± standard error of the mean) reduction in IOP from latanoprost-treated baseline was statistically significant at each time point at both follow-up visits (P<0.001), ranging from 3.7±0.4 (17.0%) mmHg to 4.4±0.4 (19.9%) mmHg with bimatoprost 0.01% and from 2.8±0.5 (12.8%) mmHg to 3.9±0.5 (16.7%) mmHg with bimatoprost 0.03%. Mean percentage IOP reduction from latanoprost-treated baseline was numerically greater with bimatoprost 0.01% than with bimatoprost 0.03% throughout follow-up. The incidence of conjunctival hyperemia of mild or greater severity increased from latanoprost baseline after 12 weeks of treatment only in the bimatoprost 0.03% treatment arm. CONCLUSION:Many patients who do not reach their target IOP on latanoprost can achieve additional IOP lowering and maintain monotherapy by replacing latanoprost with bimatoprost. Reductions in IOP from latanoprost baseline were larger with bimatoprost 0.01% than with bimatoprost 0.03%, and bimatoprost 0.01% had a more favorable tolerability profile.
Project description:INTRODUCTION:New open-angle glaucoma (OAG) and ocular hypertension (OHT) therapies that reduce treatment burden and improve outcomes relative to currently available agents are needed. Netarsudil, a novel Rho kinase inhibitor approved by the US Food and Drug Administration, reduces intraocular pressure (IOP) by increasing trabecular outflow. Two phase 3 superiority studies compared a fixed-dose combination (FDC) of netarsudil and the prostaglandin latanoprost with each active component for IOP-lowering efficacy. METHODS:Pooled efficacy and safety data were analyzed from MERCURY-1 and -2 studies in patients with OAG or OHT. Patients instilled one drop of netarsudil (0.02%)/latanoprost (0.005%) FDC (n?=?483), netarsudil (0.02%, n?=?499), or latanoprost (0.005%, n?=?486) into each eye once-daily between 20:00 and 22:00. IOP was measured at 08:00, 10:00, and 16:00 at weeks 2, 6, and the primary endpoint at month 3. RESULTS:Baseline mean diurnal IOP was 23.6, 23.6, and 23.5 mmHg in netarsudil/latanoprost FDC, netarsudil, and latanoprost groups, respectively. Mean diurnal IOP in each group was 15.3, 18.1, and 17.5 mmHg at week 2, 15.7, 18.4, and 17.4 mmHg at week 6, and 15.8, 18.4, and 17.3 mmHg at week 12. The netarsudil/latanoprost FDC met criteria for superiority compared with each active component (p?<?0.0001 for all nine time points). At month 3, among patients randomized to netarsudil/latanoprost FDC or latanoprost, 58.4% vs 37.3% (p?<?0.0001) achieved IOP???16 mmHg. Among patients randomized to netarsudil/latanoprost FDC or netarsudil or latanoprost, 30.9% vs 5.9% (p?<?0.0001) vs 8.5% (p?<?0.0001) achieved at least a 40% reduction from baseline in mean diurnal IOP. Pooled safety results were consistent with individual MERCURY studies. CONCLUSION:Once-daily netarsudil/latanoprost FDC produced statistically significant and clinically relevant reductions in mean IOP that were statistically superior to IOP reductions achieved by netarsudil and latanoprost monotherapy. Results of the pooled efficacy and safety analyses were consistent with the individual studies. TRIAL REGISTRATION:ClinicalTrials.gov identifiers, NCT02558400 and NCT02674854.
Project description:Introduction:Maximal medical therapy (MMT) is the use of ?3 classes of topical anti-glaucoma agents to achieve maximal intraocular pressure (IOP) reduction while minimizing adverse effects and compliance challenges. Purpose:To evaluate the additive IOP-lowering effect of twice-daily brinzolamide 1%/brimonidine 0.2% fixed-dose combination (BBFC) used adjunctively with once daily travoprost 0.004%/timolol 0.5% fixed-dose combination (TTFC) in patients with open-angle glaucoma (OAG)/ocular hypertension (OHT). Methods:In this phase IV, double-masked study, patients on TTFC for ?28 days, aged ?18 years, with mean IOP ?19 and ?28 mmHg in at least 1 eye were randomized to receive BBFC+TTFC (n=67) or vehicle+TTFC (n=67) for 6 weeks. The primary endpoint was mean change in diurnal IOP from baseline (BL, averaged over 09:00 and 11:00) at Week 6. Results:The study was terminated prematurely due to recruitment challenges. BL mean IOP was similar in both groups (BBFC+TTFC: 21.6±1.78 mmHg; vehicle+TTFC: 21.8±1.90 mmHg). Mean change in diurnal IOP from BL at Week 6 was greater with BBFC+TTFC (-4.25 mmHg, 95% confidence interval [CI]: -4.7, -3.8) than with vehicle+TTFC (-2.11 mmHg, 95% CI: -2.6, -1.6, treatment difference, -2.15 mmHg (95% CI: -2.8, -1.5; P<0.001). Ocular adverse events (AEs) were reported in 11.9% of patients given BBFC+TTFC and 7.5% of patients given vehicle+TTFC. The AE with highest frequency was punctate keratitis (3%) in the BBFC+TTFC group; eye irritation (3%) in the vehicle+TTFC group. Conclusion:BBFC+TTFC as MMT demonstrated clinically relevant and statistically significant reductions in mean diurnal IOP in patients with OAG/OHT. AEs were consistent with known safety profiles of individual medications.
Project description:The main first-line treatment strategy for glaucoma is to reduce intraocular pressure (IOP) by topical ocular hypotensive medications, but many patients require multiple medications for adequate IOP control. Fixed-combination therapies provide several benefits, including simplified treatment regimens, theoretical improved treatment adherence, elimination of the potential for washout of the first drug by the second, and the reduction in ocular exposure to preservatives. ?-Adrenoceptor antagonists (particularly 0.5% timolol) are the most commonly used agents in combination with other classes of drugs as fixed-combination eyedrops, but they are contraindicated in many patients, owing to local allergy or systemic side effects. A fixed-combination preparation without a ?-blocker is therefore warranted. This paper reviews the clinical effectiveness of brinzolamide 1% and brimonidine 0.2% fixed combination (BBFC) for use in patients with primary open-angle glaucoma and ocular hypertension. We searched PubMed and the ClinicalTrials.gov registry, and identified three randomized controlled trials comparing BBFC vs its constituents (brimonidine vs brinzolamide), and one comparing BBFC with unfixed brimonidine and brinzolamide. All of the studies demonstrated mean diurnal IOP to be statistically significantly lower in the BBFC group compared with constituent groups and noninferior to that with the concomitant group using two separate bottles. The safety profile of BBFC was consistent with that of its individual components, the most common ocular adverse events being ocular hyperemia, visual disturbances, and ocular allergic reactions. Common systemic adverse effects included altered taste sensation, oral dryness, fatigue, somnolence, and decreased alertness. BBFC seems to be a promising new fixed combination for use in glaucoma patients. However, long-term effects of BBFC on IOP, treatment adherence, and safety need to be determined.