Daylight-Mediated, Passive, and Sustained Release of the Glaucoma Drug Timolol from a Contact Lens.
ABSTRACT: Timolol, a potent inhibitor of ?-adrenergic receptors (?ARs), is a first-line drug for decreasing the intraocular pressure (IOP) of patients with glaucoma. Timolol is administered using 0.5% eye-drop solutions at >3 × 107 times the inhibitory concentration (ki) for ?ARs. This high dose is wasteful and triggers off-target effects that increase medication noncompliance. Here, we introduce contact lenses that release timolol to the eye throughout the day during passive exposures to natural daylight at a more therapeutically relevant concentration (>3000 ki). Timolol is coupled to the polymer of the contact lens via a photocleavable caged cross-linker and is released exclusively to the surrounding fluid after the 400-430 nm mediated cleavage of the cross-linking group. Studies conducted in a preclinical mouse model of glaucoma show photoreleased timolol is effective as authentic timolol in reducing IOP. Our studies highlight several advantages of daylight-mediated release of timolol from lenses compared to eye-drops. First, fitted contact lenses exposed to natural daylight release sufficient timolol to sustain the inhibition of ?ARs over a 10 h period. Second, the contact lenses inhibit ?ARs in the eye using only 5.7% of the timolol within a single eye-drop. Third, the lenses allow the patient to passively control the amount of timolol released from the lens-for example, early morning exposure to outdoor sunlight would release enough timolol to maximally reduce the IOP, whereas subsequent periodic exposures to indoor daylight would release sufficient timolol to overcome the effects of its spontaneous dissociation from ?ARs. Fourth, our lenses are disposable, designed for single day use, and manufactured at a low cost.
Project description:Temporarily implanted devices, such as drug-loaded contact lenses, are emerging as the preferred treatment method for ocular diseases like glaucoma. Localizing the delivery of glaucoma drugs, such as timolol maleate (TM), can minimize adverse effects caused by systemic administration. Although eye drops and drug-soaked lenses allow for local treatment, their utility is limited by burst release and a lack of sustained therapeutic delivery. Additionally, wet transportation and storage of drug-soaked lenses result in drug loss due to elution from the lenses. Here we present a nanodiamond (ND)-embedded contact lens capable of lysozyme-triggered release of TM for sustained therapy. We find that ND-embedded lenses composed of enzyme-cleavable polymers allow for controlled and sustained release of TM in the presence of lysozyme. Retention of drug activity is verified in primary human trabecular meshwork cells. These results demonstrate the translational potential of an ND-embedded lens capable of drug sequestration and enzyme activation.
Project description:Purpose:Continuous monitoring of elevated intraocular pressure and timely drug delivery for successful treatment of glaucoma are necessary to reduce intraocular pressure (IOP), which shows wide variations across the circadian pattern and in response to medication. This in vivo study presents a new contact lens-based method of optical IOP measurement or temperature-triggered drug elution. Methods:A contact lens with moiré patterns of concentric circles measures the changes in eyeball diameter of a rabbit glaucoma model due to changes in IOP by superimposing a camera-captured image onto the micro pattern of the contact lens with a computer-assisted virtual reference image. Drug elution from the nanoporous bicontinuous microemulsion contact lens (BME-CL) into the eye of the rabbit was triggered by a temperature-responsive nanogel drug carrier. Results:The moiré pattern change on the contact lens was proportional to the IOP increase in the rabbit eye either ex vivo or in vivo and was also correlated with imaging-based alterations in the anterior chamber angle at a range of IOP values (3-40 mm Hg). The cumulative drug absorbed reached as high as 10.6 µg/mL aqueous humor until 7 days after wearing the BME-CL, and a 33% decrease in IOP was observed at 3 hours after drug elution. Conclusions:The results suggest that continuous measurement and treatment of elevated IOP are feasible using moiré pattern-inscribed and thermosensitive drug-eluting contact lenses, respectively. Translational Relevance:Pressure-sensing or thermosensitive contact lenses enable monitoring IOP or drug release triggered by body temperature for the treatment of glaucoma patients.
Project description:<h4>Purpose</h4>Medical treatment of glaucoma relies on intraocular pressure (IOP)-lowering medications, typically administered daily by the patient. While these medications are effective when applied correctly, patient adherence is a major obstacle in glaucoma treatment. We have developed a sustained-release formulation of timolol maleate that can be injected subconjunctivally to avoid patient noncompliance.<h4>Methods</h4>A biodegradable microsphere formulation for timolol maleate was injected subconjunctivally in normal rabbits. We measured timolol levels in tears, aqueous humor, vitreous humor, and serum of study rabbits. Furthermore, IOP profiles were recorded longitudinally. Tissue compatibility and side effects were evaluated using histochemistry.<h4>Results</h4>The microsphere formulation led to measureable amounts of timolol in the aqueous humor and the tear film for up to 90 days. Timolol was not detectable in the serum at any time. A significant reduction of IOP was observed in treated eyes. Clinically, the subconjunctival administration of the microspheres was well tolerated with no signs of inflammation or infection. The absence of local inflammation was confirmed by histology.<h4>Conclusions</h4>A single subconjunctival administration of timolol microspheres achieved delivery and IOP reduction in rabbits for up to 90 days without local or systemic inflammation or toxicity. This approach has the potential to improve the management of glaucoma in patient populations, who are challenged to adhere to a regimen of daily eye drops.
Project description:To compare the efficacy and safety of single-dose bimatoprost 0.03%/timolol 0.5% preservative-free (PF) ophthalmic solution with bimatoprost 0.03%/timolol 0.5% ophthalmic solution in patients with open-angle glaucoma or ocular hypertension.In this multicentre, randomised, parallel-group study, patients were randomised to bimatoprost/timolol PF or bimatoprost/timolol once daily in the morning for 12 weeks. Primary efficacy endpoints, reflecting differing regional regulatory requirements, included change from baseline in worse eye intraocular pressure (IOP) in the per-protocol population at week 12, and the average eye IOP at weeks 2, 6 and 12 in the intent-to-treat population.561 patients were randomised (278 to bimatoprost/timolol PF; 283 to bimatoprost/timolol); 96.3% completed the study. Both treatment groups showed statistically and clinically significant mean decreases from baseline in worse eye IOP and in average eye IOP at all follow-up time points (p<0.001). Bimatoprost/timolol PF met all pre-established criteria for non-inferiority and equivalence to bimatoprost/timolol. Ocular adverse events were similar between treatment groups, with conjunctival hyperaemia being the most frequent. Most were mild or moderate in severity.Bimatoprost/timolol PF demonstrated non-inferiority and equivalence in IOP lowering compared with bimatoprost/timolol, with no significant differences in safety and tolerability.NCT01177098.
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 determine the efficacy and safety of fixed-combination travoprost 0.004%/timolol 0.5% preserved with polyquaternium-1 in patients with insufficient response to bimatoprost 0.03%/timolol 0.5% preserved with benzalkonium chloride. PATIENTS AND METHODS:In this open-label nonrandomized study conducted at 13 European sites, patients with primary open-angle glaucoma or ocular hypertension with insufficient intraocular pressure (IOP) reduction during bimatoprost/timolol therapy were transitioned to travoprost/timolol (DuoTrav(®)) administered every evening for 12 weeks. Change in IOP from baseline to week 12 was assessed in patients who transitioned from fixed-combination bimatoprost/timolol (n=57, primary endpoint). Secondary assessments included change in IOP at week 4, percentage of patients with IOP ?18 mmHg at weeks 4 and 12, change in Ocular Surface Disease Index and ocular hyperemia scores at week 12, and patient preference. Adverse events were also reported. RESULTS:IOP change (mean ± SD) from baseline to week 12 was -3.8±1.9 mmHg (P<0.001); results were similar at week 4. Most patients had IOP ?18 mmHg at weeks 4 and 12 (78.6% and 85.5%, respectively). Mean Ocular Surface Disease Index score was significantly reduced (P<0.001); no significant change in ocular hyperemia score was observed (P=0.197). Treatment-related adverse events included dysgeusia, nausea, paresthesia, myalgia, headache, and eye irritation (n=1 each). Most patients (74.5%) preferred travoprost/timolol over bimatoprost/timolol. CONCLUSION:Transition to travoprost/timolol significantly reduced IOP and was well tolerated in patients who had elevated IOP despite bimatoprost/timolol therapy. Polyquaternium-1-preserved travoprost/timolol was preferred over prior treatment with benzalkonium chloride-preserved bimatoprost/timolol.
Project description:OBJECTIVES:Bimatoprost-timolol (bimatoprost 0.03%-timolol 0.5% fixed-dose combination [FDC]) and tafluprost-timolol (tafluprost 0.0015%-timolol 0.5% FDC) eye drops are currently the only topical intraocular pressure (IOP)-reducing therapies available as preservative-free (PF) prostaglandin and timolol FDC. The aim of this study was to investigate changes to ocular signs and symptoms when patients with ocular hypertension (OH) or open-angle glaucoma (OAG) switched from PF or benzalkonium chloride (BAK)-preserved bimatoprost-timolol to PF tafluprost-timolol eye drops. DESIGN:This was a 12-week, open-label, phase IV study. SETTING:Sixteen centres in Finland, Germany, Italy and the UK. PARTICIPANTS:Patients with OH or OAG (IOP on medication ?21?mm Hg), treated with PF or BAK-preserved bimatoprost-timolol for ?4 weeks before screening, and presenting with conjunctival hyperaemia and ?1?ocular symptom. INTERVENTIONS:Patients were switched to PF tafluprost-timolol once daily in the treated eye(s). PRIMARY AND SECONDARY OUTCOME MEASURES:The primary endpoints were change from screening to week 12 in conjunctival hyperaemia and worst ocular symptom. The secondary outcome measures were changes from screening in ocular signs (other than conjunctival hyperaemia) and symptoms at week 12. RESULTS:Of 123 enrolled patients, 121 were included in the intention-to-treat dataset, of which all were Caucasian and 54.5% were female; 76 patients used BAK-preserved bimatoprost-timolol and 45 used PF drops. Conjunctival hyperaemia and severity of worst ocular symptom following switch to PF tafluprost-timolol significantly reduced from screening to week 12 in all patients (p<0.001). The percentage of patients with ocular signs and symptoms was significantly reduced at week 12 compared with screening (p<0.001). IOP was not affected by the change of treatment. CONCLUSIONS:Switching from BAK-preserved or PF bimatoprost-timolol to tafluprost-timolol reduced both signs and symptoms of ocular surface disease with no clinically relevant effect on IOP. TRIAL REGISTRATION NUMBER:EudraCT2014-005273-37; Results.
Project description:The aim of this study is to compare the 24-hour efficacy of dorzolamide/timolol-fixed combination (DTFC) and brimonidine/timolol-fixed combination (BTFC) in primary open-angle glaucoma (POAG).One eye each of 77 POAG patients was included in this prospective, observer-masked, crossover comparison. Following a 2-month timolol run-in period, patients had three intraocular pressure (IOP) measurements at 1000, 1200 and 1400 h while on timolol treatment. Patients showing at least a 20% IOP reduction on timolol were randomised to 3 months of therapy with DTFC or BTFC, and then were crossed over to the opposite therapy.Sixty POAG patients completed the study. The mean 24-hour IOP was significantly reduced with both the fixed combinations compared with the timolol-treated diurnal IOP (P < 0.001). When the two fixed combinations were compared directly, DTFC demonstrated a lower mean 24-hour IOP level as compared with BTFC (mean difference: -0.7 mm Hg, 95% confidence interval (CI): (-1.0, -0.3), P < 0.001). At two individual time points, DTFC significantly reduced IOP more than BTFC: at 1800 h (-1.0 mm Hg, 95% CI (-1.6,-0.5), P = 0.001) and at 0200 (-0.9 mm Hg, 95% CI: (-1.4,-0.5), P = 0.001). No significant difference existed for the other time points.Both the fixed combinations significantly reduce 24-hour IOP in POAG. DTFC provided significantly better 24-hour efficacy.
Project description:PURPOSE:To compare the intraocular pressure- (IOP-) lowering efficacy of fixed combinations travoprost 0.004%/timolol 0.5% and dorzolamide 2%/timolol 0.5% in patients with ocular hypertension or open-angle glaucoma. METHODS:In this prospective, multicenter, double-masked, randomized clinical trial, 319 qualifying patients received either travoprost/timolol once daily in the morning (n = 157) or dorzolamide/timolol twice daily (n = 162). IOP was assessed morning and evening at 2 and 6 weeks. The primary outcome measure was mean diurnal IOP. RESULTS:Baseline mean IOP values were similar between groups. Mean pooled diurnal IOP was significantly lower in the travoprost/timolol group (16.5 mmHg +/- 0.23) than in the dorzolamide/timolol group (17.3 mmHg +/- 0.23; P = 0.011). Mean IOP was significantly lower in the travoprost/timolol group compared to the dorzolamide/timolol group at the 9 AM time point both at Week 2 (P = 0.006) and Week 6 (P = 0.002). The travoprost/timolol combination produced mean IOP reductions from baseline of 35.3% to 38.5%, while the dorzolamide/timolol combination produced mean IOP reductions from baseline of 32.5% to 34.5%. CONCLUSIONS:The fixed combination travoprost 0.004%/timolol 0.5% dosed once daily in the morning demonstrated superior mean diurnal IOP-lowering efficacy compared to dorzolamide 2%/timolol 0.5% dosed twice daily in patients with ocular hypertension or open-angle glaucoma.
Project description:Fixed-combination glaucoma medications are commonly used to achieve target intraocular pressure (IOP) reduction in patients uncontrolled with monotherapy; however, ocular discomfort associated with eye drops can decrease adherence. This study assessed the efficacy and tolerability of twice-daily fixed-combination brinzolamide 1%/timolol 0.5% (BRINZ/TIM-FC) in Latin American patients transitioned from fixed-combination brimonidine 0.2%/timolol 0.5% (BRIM/TIM-FC) because of insufficient IOP control or treatment intolerance.This 8-week, open-label, prospective study was conducted at six sites in Argentina, Chile, and Mexico. Enrolled patients were aged ≥18 years with open-angle glaucoma (including primary, exfoliative, or pigment-dispersion glaucoma) or ocular hypertension with IOP of 19-35 mmHg in ≥1 eye at baseline (on BRIM/TIM-FC). Patients self-administered BRINZ/TIM-FC to both eyes at 8 a.m. and 8 p.m. daily for 8 weeks. The primary and secondary efficacy endpoints were mean IOP change from baseline at week 8 and percentage of patients achieving target IOP (≤18 mmHg) at week 8, respectively. Exploratory endpoints included patient and investigator preference for treatment at week 8. Adverse events (AEs) were assessed as the safety endpoint.Fifty patients (mean ± SD age, 66.7 ± 11.5 years) received BRINZ/TIM-FC, and 49 were included in the intent-to-treat population. Mean ± SD IOP was significantly reduced from baseline after 8 weeks of treatment with BRINZ/TIM-FC (-3.6 ± 3.0 mmHg; P < 0.0001, Wilcoxon signed-rank test; 17.1% reduction). Overall, 55.3% of patients achieved IOP ≤18 mmHg at week 8. Significantly more patients (89.4%) and investigators (95.7%) preferred BRINZ/TIM-FC to BRIM/TIM-FC (both P < 0.0001, exact binomial test). Of the 13 AEs observed, 8 were related to BRINZ/TIM-FC; the most common treatment-related AEs were eye irritation (n = 4) and abnormal sensation in the eye (n = 2).BRINZ/TIM-FC provides an effective and well-tolerated treatment option for patients transitioned from BRIM/TIM-FC.