Occipital Proton Magnetic Resonance Spectroscopy ((1)H-MRS) Reveals Normal Metabolite Concentrations in Retinal Visual Field Defects

BACKGROUND: Progressive visual field defects, such as age-related macular degeneration and glaucoma, prevent normal stimulation of visual cortex. We investigated whether in the case of visual field defects, concentrations of metabolites such as N-acetylaspartate (NAA), a marker for degenerative processes, are reduced in the occipital brain region. METHODOLOGY/PRINCIPAL FINDINGS: Participants known with glaucoma, age-related macular degeneration (the two leading causes of visual impairment in the developed world), and controls were examined by proton MR spectroscopic ((1)H-MRS) imaging. Absolute NAA, Creatine and Choline concentrations were derived from a single-voxel in the occipital region of each brain hemisphere. No significant differences in metabolites concentrations were found between the three groups. CONCLUSIONS/SIGNIFICANCE: We conclude that progressive retinal visual field defects do not affect metabolite concentration in visual brain areas suggesting that there is no ongoing occipital degeneration. We discuss the possibility that metabolite change is too slow to be detectable

A 6-Month Study Comparing Efficacy, Safety, and Tolerability of the Preservative-free Fixed Combination of Tafluprost 0.0015% and Timolol 0.5% versus Each of Its Individual Preservative-Free Components

The efficacy, safety and tolerability of the preservative-free (PF) fixed combination (FC) of tafluprost 0.0015\% and timolol 0.5\% (once daily) were compared to those of the individual components (PF tafluprost 0.0015\% once daily and PF timolol 0.5\% twice daily) in patients with open-angle glaucoma or ocular hypertension inadequately controlled on prior timolol or prostaglandin monotherapy for 6\ua0months.A stratified, double-masked, randomized, multicenter phase III study was conducted. A total of 189 prior timolol users were randomized within the timolol stratum (TS) to receive either FC (n\ua0=\ua095) or timolol 0.5\% (TIM; n\ua0=\ua094). Furthermore, a total of 375 prior prostaglandin analog (PGA) users were randomized within the prostaglandin stratum (PS) to receive either FC (n\ua0=\ua0188) or tafluprost 0.0015\% (TAF; n\ua0=\ua0187). To be eligible for participation in the study, the patients were required to have an intraocular pressure (IOP) of\ua0 6522\ua0mmHg when on timolol (TIM) or of\ua0 6520\ua0mmHg when on PGA in either treated eye at the screening and end-of-run-in visits. In addition to these, the study included visits at baseline, 2 and 6\ua0weeks, 3 and 6\ua0months and at a post-study visit. IOP was measured at 8 a.m., 10 a.m., 4 p.m., and 8 p.m.In the TS, a significant reduction from baseline IOP was seen with FC and TIM throughout the study. Average diurnal IOP change from baseline at month 3 was -8.55\ua0mmHg (32\%) for FC and -7.35\ua0mmHg (28\%) for TIM. The model-based treatment difference (FC-TIM) was -0.885\ua0mmHg [95\% confidence interval (CI) -1.745 to -0.024; p\ua0=\ua00.044] demonstrating the superiority of FC over TIM. In the PS, a significant reduction in IOP was seen with both FC and TAF throughout the study. The average diurnal IOP change from baseline at month 3 was -8.61\ua0mmHg (33\%) for FC and -7.23\ua0mmHg (28\%) for TAF. The model-based treatment difference (FC-TAF) was -1.516\ua0mmHg (95\% CI -2.044 to -0.988; p\ua0<\ua00.001) demonstrating the superiority of FC over TAF. In the TS, related ocular adverse events (AEs) were more frequent for patients treated with FC compared to TIM (16.8\% versus 6.4\%), whereas related non-ocular AEs were more frequent with TIM compared to FC (2.1\% versus 0.0\%). In the PS, AEs were similarly distributed between FC and TAF. The frequency of conjunctival hyperemia of FC was low (6.4\%).The preservative-free fixed combination of tafluprost and timolol provided a substantial and significant IOP reduction in both strata. The IOP reduction was superior to both tafluprost 0.0015\% and timolol 0.5\% when given as monotherapies. Overall, the study treatments were safe and well tolerated.Santen Oy, Tampere, Finland

Twelve-week, randomized, multicenter study comparing a fixed combination of brimonidine-timolol with timolol as therapy adjunctive to latanoprost

Robert D Fechtner1, Paul Harasymowycz2, Donald R Nixon3, Steven D Vold4, Fiaz Zaman5, Julia M Williams6, David A Hollander61Glaucoma Division, University of Medicine and Dentistry New Jersey, Newark, NJ, USA; 2University of Montreal, Montreal, QC, Canada; 3Royal Victoria Hospital, Barrie, ON, Canada; 4Boozman-Hof Regional Eye Clinic, Rogers, AR, USA; 5Houston Eye Associates, Houston, TX, USA; 6Allergan Inc, Irvine, CA, USAObjective: 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 &amp;ge;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 &amp;lt; 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 &amp;lt;18 mmHg (P = 0.028) and a &amp;ge;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.Keywords: brimonidine, drug combinations, glaucoma, intraocular pressure, ocular hypertension, timolo