A comparison of latanoprost and timolol in primary open-angle glaucoma and ocular hypertension. A 12-week study

The Japan Glaucoma Society guidelines for glaucoma 5th edition

We are pleased to bring you the 5th edition of the Glaucoma Clinical Practice Guidelines. Clinical practice guidelines are based on evidence (scientific grounds). It is a document that presents the treatment that is the most appropriate for the patient. "Glaucoma Clinical Guidelines" was first published in 2003. This was the first guideline for glaucoma treatment in Japan. The principle of glaucoma treatment is to lower intraocular pressure. Means for lowering intraocular pressure includes drugs, lasers, and surgery; Glaucoma is a disease that should be considered as a complex syndrome rather than a single condition. Therefore, the actual medical treatment is not as simple as one word. This time we set the Clinical Questionnaire with a focus on glaucoma treatment. We hope that you will take advantage of the 5th edition.

Omidenepag Isopropyl Versus Latanoprost in Primary Open-Angle Glaucoma and Ocular Hypertension: The Phase 3 AYAME Study

PURPOSE

To evaluate the efficacy and safety of omidenepag isopropyl (OMDI), a selective, non-prostaglandin, prostanoid EP2 receptor agonist, in Japanese patients with primary open-angle glaucoma (POAG) or ocular hypertension (OHT).

DESIGN

Phase III, randomized, investigator-masked, active-controlled, parallel-group, noninferiority study (ClinicalTrials.govNCT02623738).

METHODS

After a washout period of 1-4 weeks, eligible patients were randomized (1:1) to OMDI 0.002% or latanoprost 0.005% once daily for 4 weeks. Intraocular pressure (IOP) was measured at 9:00 AM, 1:00 PM, and 5:00 PM at weeks 1, 2, and 4. The primary endpoint was the change from baseline in mean diurnal IOP at week 4. The noninferiority margin for OMDI versus latanoprost was 1.5 mm Hg. Adverse events (AEs) were recorded.

RESULTS

Of the 190 patients randomized, 189 had at least 1 post-baseline IOP measurement. At baseline, patients who received OMDI or latanoprost had a mean ± SD diurnal IOP of 23.78 ± 1.73 mm Hg and 23.40 ± 1.51 mm Hg, respectively. At week 4, least-squares mean ± SE reduction in IOP from baseline with OMDI (-5.93 ± 0.23 mm Hg) was noninferior to that of latanoprost (-6.56 ± 0.22 mm Hg; 95% confidence interval between groups: 0.01-1.26). The most frequently reported treatment-related ocular AEs (OMDI vs latanoprost) were conjunctival hyperemia (23/94 patients [24.5%] vs 10/96 patients [10.4%]), corneal thickening (11/94 patients [11.7%] vs 1/96 patients [1.0%]), and punctate keratitis (0/94 patients vs 5/96 patients [5.2%]). No serious AEs were observed in either group, and there were no discontinuations related to the study drug.

CONCLUSIONS

OMDI 0.002% was noninferior to latanoprost 0.005% in reducing IOP in patients with OHT or POAG and was well tolerated.

A comparative study on efficacy of fixed combination timolol/brinzolamide versus travoprost monotherapy in drug-naïve open-angle glaucoma patients

Background

Glaucoma is most common irreversible cause of blindness in India. First line management of open-angle glaucoma is either beta blockers or prostaglandin analogs monotherapy. Monotherapy rarely achieves target intraocular pressure within 2 years and patients are shifted to combination medications, usually fixed-dose combination.

Objective

To compare travoprost monotherapy and timolol/brinzolamide fixed-dose combination for their intraocular pressure lowering efficacy, their effects on hemodynamic parameters and cup disc ratio reversibility in newly diagnosed drug-naïve open-angle glaucoma patients.

Material and methods

In a 12-week, prospective, randomised, single-blind study, patients were randomised to receive twice daily 0.5% timolol and 0.2% brinzolamide fixed-dose combination (n = 52) or once daily travoprost 0.004% (n = 52). Intraocular pressure, blood pressure, pulse rate and cup disc ratio were compared across treatment groups over 3 months.

Results

Significant reduction (p < 0.001) in intraocular pressure by 27.99% and 30.49% at 12th-week visit as compared with baseline was observed in monotherapy and fixed-dose combination group, respectively. Significant changes in pulse rate (9 beats/min) and systolic blood pressure (2.35 mmHg) was observed in fixed-dose combination group. No cup disc ratio reversibility was observed at the end of study. Conjunctival hyperaemia (n = 14) and transient blurring of vision (n = 16) were most commonly reported adverse drug reaction in monotherapy and fixed-dose combination, respectively.

Conclusion

The 0.5% timolol and 0.2% brinzolamide fixed-dose combination produced greater reduction in intraocular pressure than those produced by 0.004% travoprost alone in drug-naïve open-angle glaucoma patients.

Efficacy of the combination of carteolol hydrochloride + latanoprost in the treatment of glaucoma and ocular hypertension

INTRODUCTION

The only evidence-based mechanism for prevention and treatment of glaucomatous optic neuropathy is decreasing the intraocular pressure (IOP). Prescribing multiple ocular hypotensive agents, such as the combination of carteolol and latanoprost, may synergistically improve IOP; however, doing so may increase the complexity of a medication regimen, in turn, impairing patient adherence. Fixed-combination glaucoma medications offer convenience and effectiveness. New to this class of glaucoma medication is fixed combination carteolol-latanoprost (FCCL). Area covered: This review intends to give the reader a better understanding of the efficacy of the combination of carteolol and latanoprost separately, and where FCCL fits into the vast medical arsenal of IOP drops. Furthermore, it outlines the particular pharmacologic mechanisms targeted, the pharmacokinetics, effectiveness, the advantages of fixed-combination administration, and tolerability. Expert opinion: The combination of carteolol and latanoprost, separately or in a fixed-combination, is more effective than either drug alone. Given the early stage in development of FCCL, it has yet to be determined how FCCL compares to other fixed-combination medications. However, pending further approval, fixed-combination carteolol-latanoprost may represent a reasonable alternative for a patient whose IOP is inadequately controlled on a prostaglandin analog alone and for whom a simplified combination is preferred.

Washout Duration of Prostaglandin Analogues: A Systematic Review and Meta-analysis

TOPIC

Prostaglandin analogues (PGAs) are first-line medical therapy for primary open angle glaucoma (POAG) and ocular hypertension (OHT). Intraocular pressure (IOP) lowering effects in full responders are known to be 25-33% for this class; however, partial responders and nonresponders do exist. In clinical trials or prospective series, discontinuation and washout of PGAs is necessary to evaluate true change in IOP from novel surgeries and medical therapies.

CLINICAL RELEVANCE

To identify all relevant papers with pertinent data on washout of PGAs and quantify the duration and long-term effect of reported PGA washout periods in glaucoma and OHT patients.

METHODS

A systematic review and meta-analysis was conducted to investigate the long-term effects on IOP after discontinuation of topical PGAs POAG and OHT patients. The main search was conducted in MEDLINE/PubMed, EMBASE, Cochrane Library, CINAHL, Web of Science, and BIOSIS Previews and conference proceedings.

RESULTS

1055 papers were identified, 548 were independently screened by two physicians., and 56 papers were analyzed for washout durations. The mean washout was found to be 4.56 weeks (±1.25), with the mode and median being 5 weeks. Five studies were analyzed as randomized control trials in which latanoprost was discontinued for 4 weeks prior to restarting another intraocular pressure-lowering drug. Meta-analysis revealed a 4-week discontinuation of latanoprost, on average, subjects returned to their baseline IOP.

CONCLUSION

A significant IOP-lowering effect of latanoprost was not observed beyond 4 weeks, suggesting this may be an appropriate washout period for latanoprost. We could not identify appropriate washout periods for either travoprost or bimatoprost, although a majority of articles had 4-week washout durations for the two drugs. Despite the widespread use of this class of medication, there is a paucity of literature on the effects of PGA washout in patients that are treatment naïve to other topical medications.

Intraocular Pressure Lowering Effect of Latanoprost as First-line Treatment for Glaucoma

PURPOSE

The purpose of this study was to assess the intraocular pressure (IOP) - reducing effect of latanoprost in treatment-naïve patients with newly detected open-angle glaucoma with no restriction of the level of untreated IOP.

METHODS

Eighty-six patients (105 eyes) with a diagnosis of open-angle glaucoma received IOP-lowering therapy with latanoprost. The IOP reduction 1 and 3 months after initiation of treatment was recorded.

RESULTS

Mean untreated IOP for all eyes was 26.2 mm Hg (ranging from 10 to 51 mm Hg). The mean pressure reduction was 7.9 mm Hg (28%), with equivalent average levels at 1 and 3 months. The reduction in IOP ranged from -2.3 to 25.3 mm Hg after 1 month, and from -1.3 to 33.3 mm Hg after 3 months. The pressure-lowering effect was considerably more pronounced in eyes with higher untreated IOP; the reduction increased by 0.55 mm Hg per mm Hg higher untreated IOP. Four eyes, with untreated IOP within statistically normal limits, had no or negative IOP-reduction. A regression model predicted that IOP reduction ended at untreated IOP≤16 mm Hg. Multiple regression analysis showed that an additional IOP-lowering effect of 1.28 mm Hg was achieved in eyes with pseudoexfoliation glaucoma.

CONCLUSIONS

To the best of our knowledge, this paper is the first to report the IOP-reducing effect of latanoprost treatment at all untreated IOP levels in newly detected glaucoma patients. The effect was proportional to the untreated IOP at all levels above 16 mm Hg and better at higher untreated IOP levels, also in relative terms. Our results further confirm the indication of latanoprost as a first-line therapy for glaucoma.

The Effect of Latanaprost on Intraocular Inflammation and Macular Edema

There is debate concerning whether the use of Latanoprost in early postoperative period of cataract surgery and in glaucoma patients with uveitis as it may aggravate the inflammation and results in macular edema (ME), because of blood-ocular barrier disruption. However, there is no solid evidence for disruption of blood-ocular barrier with Latanoprost and aggravation of uveitis or ME formation. Similar to pseudophakic ME, the imaging ME in cases claimed to be secondary to Latanoprost is greater than clinical ME, happens mostly in complicated surgeries, and the vast majority resolve within weeks to months with using a non-steroidal anti-inflammatory drug. The current literature suggests that Latanoprost can be used in patients with uveitis and early after cataract surgery with or without concomitant topical non-steroidal anti-inflammatory drugs that are currently used by many ophthalmologists as a preventive measure for ME even in non-glaucoma uncomplicated cataract surgeries.

Association between glaucoma eye drops and hyperemia

PURPOSE

We used an image analysis software program to quantitatively investigate conjunctival injection in patients treated with eye drops for glaucoma.

METHODS

We compared 169 patients (89 men and 80 women) with a diagnosis of glaucoma. Photographs of the conjunctiva were taken on the temporal side of each patient's right eye using a slit lamp. We determined the mean pixel frequencies of the conjunctival blood vessels from the photographs.

RESULTS

The ocular hyperemia of the patients being treated with prostaglandins was more severe than that of the patients being treated with beta-blockers or no eye drops. In multiple comparisons of each of the eye drops, the control group had a significantly lower degree of hyperemia than did the patients being treated with each of the various prostaglandin analogs (latanoprost, travoprost, tafluprost, and bimatoprost). Among the patients receiving prostaglandin, the percentage of those with hyperemia was highest in the bimatoprost users, followed in order by the travoprost, latanoprost, and tafluprost users. However, no significant differences were found among the different prostaglandin analogs in terms of the percentage of patients with hyperemia.

CONCLUSION

Our software program may be useful for evaluating the hyperemic effects of eye drops used for glaucoma. The particular type of prostaglandin analog seems to determine the level of conjunctival hyperemia during ocular hypotensive medical treatment.

Comparative Efficacy and Tolerability of Topical Prostaglandin Analogues for Primary Open-Angle Glaucoma and Ocular Hypertension

Objective: To systematically review the efficacy and tolerability of 4 prostaglandin analogues (PGAs) as first-line monotherapies for intraocular pressure (IOP) lowering in adult patients with primary open-angle glaucoma or ocular hypertension. Data Sources: A literature search was performed in PubMed (1965-June 2013) and the Cochrane Library (1980-June 2013) using the search terms ocular hypertension, open-angle glaucoma, prostaglandin analogues, bimatoprost, latanoprost, tafluprost, and travoprost. Additional studies were searched from the reference lists of identified publications. Study Selection and Data Extraction: In all, 32 randomized controlled trials comparing between PGAs (bimatoprost 0.03%, latanoprost 0.005%, tafluprost 0.0015%, and travoprost 0.004%) or PGA with timolol were selected. Data Synthesis: A network meta-analysis was conducted. Using timolol as reference, the relative risks (RRs) of achieving treatment success, defined as the proportion of patients achieving at least 30% IOP reduction, with 95% CIs, were as follows: bimatoprost, 1.59 (1.28-1.98); latanoprost, 1.32 (1.00-1.74); travoprost, 1.33 (1.03-1.72); and tafluprost, 1.10 (0.85-1.42). The mean IOP reductions after 1 month were 1.98 (1.50-2.47), 1.01 (0.55-1.46), 1.08 (0.59-1.57), and 0.46 (−0.41 to 1.33) mm Hg, respectively, and the results were sustained at 3 months. Bimatoprost was associated with the highest risk of developing hyperemia, whereas latanoprost had the lowest risk, with RRs (95% CI) of 4.66 (3.49-6.23) and 2.30 (1.76-3.00), respectively. Conclusions: Bimatoprost achieved the highest efficacy in terms of IOP reduction, whereas latanoprost had the most favorable tolerability profile. This review serves to guide selection of the optimal PGA agent for individual patient care in clinical practice.

Long-term medical management of primary open-angle glaucoma and ocular hypertension in the UK: optimizing cost-effectiveness and clinic resources by minimizing therapy switches

PURPOSE

The objective was to assess the long-term economic consequences of the medical management of glaucoma in the UK.

METHODS

The economic evaluation was conducted using the results from a 10-year Markov model based around 3 key triggers for a switch in medical therapy for glaucoma, namely: lack of tolerance (using hyperemia as a proxy); intraocular pressure (IOP) not meeting treatment benchmark; and glaucoma progression. Clinical data from a comprehensive systematic literature review and meta-analysis were used. Direct costs associated with glaucoma treatment are considered (at 2008/9 prices) from the perspective of the UK NHS as payer (outpatient/secondary care setting). Using this model, the economic consequences of 3 prostaglandin-based treatment sequences were compared.

RESULTS

Drug acquisition costs account for around 8% to 13% of the total cost of glaucoma and, if ophthalmologist visits are included, amount to approximately £0.80 to £0.90 per day of medical therapy. The total long-term costs of all prostaglandin strategies are similar because of a shift in resources: increased drug costs are offset by fewer clinic visits to instigate treatment switches, and by avoiding surgery or costs associated with managing low vision. Under the latanoprost-based strategy, patients would have longer intervals between the need to switch therapies, which is largely due to a reduction in hyperemia, seen as a proxy for tolerance. This leads to a delay in glaucoma progression of 12 to 13 months. For every 1000 clinic appointments, 719 patients can be managed for 1 year with a latanoprost-based strategy compared with 586 or 568 with a bimatoprost or travoprost-based strategy.

CONCLUSIONS

Drug acquisition costs are not a key driver of the total cost of glaucoma management and the cost of medical therapy is offset by avoiding the cost of managing low vision. Economic models of glaucoma should include the long-term consequences of treatment as these will affect cost-effectiveness. This analysis supports the hypothesis that the economic and clinical benefits can be optimized by minimizing therapy switches.

Randomized clinical trial of the efficacy and safety of preservative-free tafluprost and timolol in patients with open-angle glaucoma or ocular hypertension

PURPOSE

To compare the efficacy and safety of tafluprost, a preservative-free (PF) prostaglandin analogue, with PF timolol in patients with open-angle glaucoma or ocular hypertension.

DESIGN

Randomized, double-masked, multicenter clinical trial.

METHODS

After discontinuation and washout of existing ocular hypotensive treatment, patients who had intraocular pressure (IOP) ≥23 and ≤36 mm Hg in at least 1 eye at the 08:00 hour time point were randomized 1:1 to 12 weeks of treatment with either PF tafluprost 0.0015% or PF timolol 0.5%. IOP was measured 3 times during the day (08:00, 10:00, 16:00 hours) at baseline and at weeks 2, 6, and 12. It was hypothesized that PF tafluprost would be noninferior to PF timolol over 12 weeks with regard to change from baseline IOP. The trial was powered for a noninferiority margin of 1.5 mm Hg at each of the 9 time points assessed.

RESULTS

A total of 643 patients were randomized and 618 completed (PF tafluprost = 306, PF timolol = 312). IOPs at the 3 time points assessed during the baseline visit ranged from 23.8 to 26.1 mm Hg in the PF tafluprost group and 23.5 to 26.0 mm Hg in the PF timolol group. IOPs at the 3 time points assessed during the 12-week visit ranged from 17.4 to 18.6 mm Hg for PF tafluprost and 17.9 to 18.5 mm Hg for PF timolol. At all 9 time points, the upper limits of the 2-sided 95% confidence intervals for the difference between treatments in IOP lowering were less than the prespecified noninferiority margin. Similar percentages of PF tafluprost and PF timolol patients reported ocular pain/stinging/irritation (4.4% vs 4.6%) and pruritus (2.5% vs 1.5%). The percentages of PF tafluprost and PF timolol patients reporting conjunctival hyperemia were 4.4% vs 1.2% (nominal P = .016).

CONCLUSIONS

The IOP-lowering effect of PF tafluprost was noninferior to that of PF timolol. PF tafluprost is an efficacious and generally well-tolerated ocular hypotensive agent.

A review of the use of latanoprost for glaucoma since its launch

INTRODUCTION

Prostaglandins are increasingly used as first choice treatment for glaucoma because they are highly effective, lack relevant systemic side effects and require just once-daily administration. Latanoprost is an ester prodrug analog of prostaglandin F2α, which reduces intraocular pressure (IOP) by increasing uveoscleral outflow. Latanoprost 0.005% has received European and US approval as the first-line drug for reducing IOP in patients with open-angle glaucoma or ocular hypertension. Following the recent patent expiry for Xalatan®, a number of latanoprost generics have entered the glaucoma market.

AREAS COVERED

This review, achieved through PubMed and Medline research methods, describes the composition, pharmacokinetics, mode of action, efficacy, side effects and safety profile of latanoprost.

EXPERT OPINION

Latanoprost was the first prostaglandin analog introduced in glaucoma management and it dramatically changed the market of the disease thanks to its efficacy and safety. Conjunctival hyperemia, which is commonly found after latanoprost use, is associated with a minor efficacy and duration of trabeculectomy; yet, from the ophthalmologist's perspective, this side effect seems largely counterbalanced by the high efficacy and safety of this compound. It is always advisable to consider the pro-inflammatory mode of action of latanoprost because this may have negative effects in particular patients (i.e., those with uveitis and cystoid macular edema) for whom caution and close follow-up is necessary.

Recent advances in pharmacotherapy of glaucoma

Glaucoma is a slow progressive degeneration of the retinal ganglion cells (RGCs) and the optic nerve axons, leading to irreversible blindness if left undiagnosed and untreated. Although increased intraocular pressure is a major risk factor of glaucoma, other factors include increased glutamate levels, alterations in nitric oxide (NO) metabolism, vascular alterations and oxidative damage caused by reactive oxygen species. Glaucoma is the second leading cause of blindness globally, accounting for 12.3% of the total blindness. Glaucoma has been broadly classified as primary or secondary open-angle or angle-closure glaucoma. The primary goal in management of glaucoma is to prevent the risk factor, especially elevated intraocular pressure (IOP), using medications, laser therapy or conventional surgery. The first-line treatment of glaucoma usually begins with the use of a topical selective or nonselective blocker or a prostaglandin analog. Second-line drugs of choice include alpha-agonists and topical carbonic anhydrase inhibitors. Cholinergic agonists are considered third-line treatment options. When a single therapy is not sufficient to lower the IOP, a combination therapy is indicated. To enhance the patient compliance, drug delivery systems like electronic devices, ocular inserts, tansdermal and mechanical drug delivery systems have been developed. Use of viscoelastic agents in ophthalmic formulations, emulsions and soluble ophthalmic drug inserts (SODI) enhance patience compliance and ocular drug delivery in patients in long-term glaucoma therapy. For patients who do not respond to antiglaucoma medications, laser trabeculoplasty and incisional surgery are recommended. Several nutrients and botanicals hold promise for the treatment of glaucoma, but most studies are preliminary, and larger, controlled studies are required. Future directions for the development of a novel therapy glaucoma may target glutamate inhibition, NMDA receptor blockade, exogenously applied neurotrophins, open channel blockers, antioxidants, protease inhibitors and gene therapy.

The management of glaucoma and intraocular hypertension: current approaches and recent advances

In the last decade, numerous novel ocular hypotensive agents have been introduced for the control of intraocular pressure (IOP). Clinicians now have more options than ever in the selection of medical therapy for the treatment of glaucoma and ocular hypertension. When selecting an ocular hypotensive medication for their patients, clinicians should consider not only the IOP-lowering efficacy of an agent, but also the ability of the drug to allow patients to achieve target levels of IOP that are low enough to stop the progression of glaucomatous damage. Other considerations should include how well the drug controls diurnal IOP, the likelihood of serious adverse events, the versatility of the medication for use as an adjunctive agent, as well as other potential attributes (ie, neuroprotection).

Mixed treatment comparison of repeated measurements of a continuous endpoint: an example using topical treatments for primary open-angle glaucoma and ocular hypertension

Mixed treatment comparison (MTC) meta-analyses estimate relative treatment effects from networks of evidence while preserving randomisation. We extend the MTC framework to allow for repeated measurements of a continuous endpoint that varies over time. We used, as a case study, a systematic review and meta-analysis of intraocular pressure (IOP) measurements from randomised controlled trials evaluating topical ocular hypotensives in primary open-angle glaucoma or ocular hypertension because IOP varies over the day and over the treatment course, and repeated measurements are frequently reported. We adopted models for conducting MTC in WinBUGS (The BUGS Project, Cambridge, UK) to allow for repeated IOP measurements and to impute missing standard deviations of the raw data using the predictive distribution from observations with standard deviations. A flexible model with an unconstrained baseline for IOP variations over time and time-invariant random treatment effects fitted the data well. We also adopted repeated measures models to allow for class effects; assuming treatment effects to be exchangeable within classes slightly improved model fit but could bias estimated treatment effects if exchangeability assumptions were not valid. We enabled all timepoints to be included in the analysis, allowing for repeated measures to increase precision around treatment effects and avoid bias associated with selecting timepoints for meta-analysis.The methods we developed for modelling repeated measures and allowing for missing data may be adapted for use in other MTC meta-analyses.

Fixed combination of topical brimonidine 0.2% and timolol 0.5% for glaucoma and uncontrolled intraocular pressure

Lowering IOP is the most readily modifiable risk factor to delay the development and progression of glaucoma (POAG). The fixed combination of brimonidine tartrate 0.2% and timolol maleate 0.5% (FCBT) combines a highly selective α2-adrenergic agonist (brimonidine) with a non-selective β-blocker (timolol). FCBT reduces aqueous production and enhances uveoscleral outflow. Concomitant brimonidine and timolol have additive effects on reducing intraocular pressure (IOP). Multi-center randomized control trials have documented superiority of FCBT twice daily on IOP control compared with monotherapy with the individual components, and equal efficacy compared with concomitant therapy. IOP reduction with FCBT versus fixed combination dorzolamide 2% and timolol 0.5% (FCDT) was similar in a small study. Other studies (n > 293) evaluating concomitant brimonidine and timolol have shown that it is not inferior to FCDT. However, concomitant brimonidine and timolol administered twice daily was significantly less efficacious in IOP reduction than fixed combination latanoprost 0.005% and timolol 0.5% (FCLT). There are no published studies comparing FCBT with FCLT. The side effect profile for FCBT reflects that of its individual components. FCBT was generally well tolerated, with less ocular side effects than brimondine alone, but more than timolol alone. Documented systemic effects were few, although this could be confounded by selection bias. FCBT is a safe and effective IOP lowering agent for POAG and ocular hypertension.

Clinical utility and differential effects of prostaglandin analogs in the management of raised intraocular pressure and ocular hypertension

Prostaglandin analogs (PGA) are powerful topical ocular hypotensive agents available for the treatment of elevated intraocular pressure (IOP). Latanoprost 0.005% and travoprost 0.004% are prodrugs and analogs of prostaglandin F2α. Bimatoprost 0.03% is regarded as a prostamide, and debate continues as to whether it is a prodrug. The free acids of all 3 PGAs reduce IOP by enhancing uveoscleral and trabecular outflow via direct effects on ciliary muscle relaxation and remodeling of extracellular matrix. The vast majority of clinical trials demonstrate IOP-lowering superiority of latanoprost, bimatoprost and travoprost compared with timolol 0.5%, brimonidine 0.2%, or dorzolamide 2% monotherapy. Bimatoprost appears to be more efficacious in IOP-lowering compared with latanoprost, with weighted mean difference in IOP reduction documented in one meta-analysis of 2.59% to 5.60% from 1- to 6-months study duration. PGAs reduce IOP further when used as adjunctive therapy. Fixed combinations of latanoprost, bimatoprost or travoprost formulated with timolol 0.5% and administered once daily are superior to monotherapy of its constituent parts. PGA have near absence of systemic side effects, although do have other commonly encountered ocular adverse effects. The adverse effects of PGA, and also those found more frequently with bimatoprost use include ocular hyperemia, eyelash growth, and peri-ocular pigmentary changes. Iris pigmentary change is unique to PGA treatment. Once daily administration and near absence of systemic side effects enhances tolerance and compliance. PGAs are often prescribed as first-line treatment for ocular hypertension and open-angle glaucoma.

Mixed treatment comparison and meta-regression of the efficacy and safety of prostaglandin analogues and comparators for primary open-angle glaucoma and ocular hypertension

OBJECTIVES

Primary open-angle glaucoma (POAG) is a chronic condition characterised by optic neuropathy and vision loss. Elevated intraocular pressure (IOP) can damage the optic nerve and is a risk factor for glaucoma, thus treatment usually comprises topical hypotensives. This analysis aims to address methodological issues associated with the synthesis of glaucoma clinical trial data, given variations in study methodology and IOP measurement.

METHODS

Meta-regression was used to estimate how IOP varies over time for patients receiving treatment. Relative treatment effects were assessed using a random-effects mixed treatment comparison (MTC) in order to preserve randomisation and avoid selection bias. To produce clinically meaningful outputs, these analyses were combined to obtain the mean on-treatment IOP and the proportion of patients achieving different IOP targets at different time points. A further MTC estimated the probability of hyperaemia events.

RESULTS

The analysis showed that after 3 months' treatment, between 58 and 83% of patients will have a > or =20% reduction in IOP and 70-93% of patients will have an absolute IOP <20 mmHg. Latanoprost and bimatoprost were found to produce significantly lower on-treatment IOP compared with timolol (p < 0.05); the difference between latanoprost and bimatoprost was not significant. Travoprost produced a lower mean IOP compared with timolol (not significant). Latanoprost-timolol was found to produce significantly lower IOP than latanoprost alone or beta-blockers. The probability of hyperaemia-type events varied between treatments from 14.8 to 63.03%. Latanoprost had significantly lower odds of hyperaemia than travoprost, bimatoprost, travoprost-timolol, or bimatoprost-timolol.

CONCLUSION

This analysis suggests that latanoprost and bimatoprost produce a statistically significant reduction in IOP compared with timolol, but are associated with a higher risk of hyperaemia. Out of all the prostaglandins, latanoprost may achieve a good balance between tolerability and IOP efficacy. As with all forms of meta-analysis, the results are based on the assumption that the studies and intervention groupings are sufficiently similar to be compared.

Latanoprost in pediatric glaucoma--pediatric exposure over a decade

BACKGROUND

Although numerous studies of latanoprost in adult glaucoma have shown it to be an effective hypotensive agent with a low incidence of side effects, these issues have not been well studied in pediatric glaucomas. The purpose of the current study is to evaluate the safety and intraocular pressure (IOP) lowering effect of latanoprost in various pediatric glaucomas over a long period.

SUBJECTS AND METHODS

This retrospective study included all children treated with latanoprost at our institution from 1996 to 2007. Demographic, glaucoma-related, and side-effect information was recorded for each subject. Duration of latanoprost exposure was calculated in child-months (1 child exposed for 1 month). If interpretable IOP data were available, the presence or absence of a treatment response (IOP reduction > or =15% from baseline) was determined for each subject.

RESULTS

A total of 115 subjects with latanoprost exposure were identified, with a collective exposure of 2,325 child-months. Exposure for > or =1 year occurred in 52 subjects. Side effects were mild and infrequently reported. Of the 115 subjects, 63 had interpretable IOP data, and 22 (35%) were treatment responders. Predictors of a response included a diagnosis of juvenile open-angle glaucoma, monotherapy, and older age.

CONCLUSIONS

This large study of latanoprost-treated children confirms the excellent safety profile of the drug in the treatment of pediatric glaucoma. The study also confirms latanoprost's IOP-lowering ability in older children with juvenile open-angle glaucoma and in some children with aphakic glaucoma. Prospective studies are needed to better define the optimal role of latanoprost in the treatment of pediatric glaucoma, especially congenital glaucoma.

The additive effects on intraocular pressure of combining nipradilol 0.25% and latanoprost 0.005% ophthalmic solutions: a prospective, randomized, multicenter study

PURPOSE

To investigate the effectiveness of combining nipradilol 0.25% and latanoprost 0.005% ophthalmic solutions in improving the intraocular pressures (IOPs) in glaucoma patients.

METHODS

We divided the 53 patients into two groups, those who had been treated with latanoprost and those who had been treated with nipradilol. We administered to the first group one dose of latanoprost daily for 12 weeks and to the second group one dose of nipradilol daily for 12 weeks. Each group then received both solutions for another 12 weeks; the latanoprost group received nipradilol and the nipradilol group received latanoprost. IOPs were measured at each 4-week visit.

RESULTS

In the patients previously treated with latanoprost, the mean IOP was 19.6+/-2.5 mmHg at baseline, and 14.9+/-2.4 mmHg (23.7% reduction) after 12 weeks of latanoprost monotherapy. The addition of nipradilol decreased the IOP to 13.8+/-1.9 mmHg (29.0% reduction). In the group previously treated with nipradilol, the mean IOP was 20.2+/-3.1 mmHg at baseline, and 16.7+/-3.5 mmHg (17.1% reduction) after 12 weeks of nipradilol monotherapy. Addition of latanoprost decreased the IOP to 14.2+/-3.2 mmHg (29.5% reduction).

CONCLUSION

Latanoprost and nipradilol are more effective as a combination therapy than each one by itself.

Performing meta-analysis with incomplete statistical information in clinical trials

BACKGROUND

Results from clinical trials are usually summarized in the form of sampling distributions. When full information (mean, SEM) about these distributions is given, performing meta-analysis is straightforward. However, when some of the sampling distributions only have mean values, a challenging issue is to decide how to use such distributions in meta-analysis. Currently, the most common approaches are either ignoring such trials or for each trial with a missing SEM, finding a similar trial and taking its SEM value as the missing SEM. Both approaches have drawbacks. As an alternative, this paper develops and tests two new methods, the first being the prognostic method and the second being the interval method, to estimate any missing SEMs from a set of sampling distributions with full information. A merging method is also proposed to handle clinical trials with partial information to simulate meta-analysis.

METHODS

Both of our methods use the assumption that the samples for which the sampling distributions will be merged are randomly selected from the same population. In the prognostic method, we predict the missing SEMs from the given SEMs. In the interval method, we define intervals that we believe will contain the missing SEMs and then we use these intervals in the merging process.

RESULTS

Two sets of clinical trials are used to verify our methods. One family of trials is on comparing different drugs for reduction of low density lipprotein cholesterol (LDL) for Type-2 diabetes, and the other is about the effectiveness of drugs for lowering intraocular pressure (IOP). Both methods are shown to be useful for approximating the conventional meta-analysis including trials with incomplete information. For example, the meta-analysis result of Latanoprost versus Timolol on IOP reduction for six months provided in 1 was 5.05 +/- 1.15 (Mean +/- SEM) with full information. If the last trial in this study is assumed to be with partial information, the traditional analysis method for dealing with incomplete information that ignores this trial would give 6.49 +/- 1.36 while our prognostic method gives 5.02 +/- 1.15, and our interval method provides two intervals as Mean in [4.25, 5.63] and SEM in [1.01, 1.24].

CONCLUSION

Both the prognostic and the interval methods are useful alternatives for dealing with missing data in meta-analysis. We recommend clinicians to use the prognostic method to predict the missing SEMs in order to perform meta-analysis and the interval method for obtaining a more cautious result.

Topical WIN55212-2 alleviates intraocular hypertension in rats through a CB1 receptor mediated mechanism of action

INTRODUCTION

Systemically administered cannabinoids can reduce intraocular pressure (IOP), but produce undesirable cardiovascular and central nervous system effects. In a chronic model of ocular hypertension, we examined the efficacy of acute topical administration of WIN55212-2 (WIN) in a novel commercially available vehicle and in combination with timolol.

METHODS

IOP was chronically elevated by the surgical ligature of vortex veins in Sprague Dawley rats. IOP was measured by using Goldmann applanation tonometry. IOP, blood pressure (BP), and heart rate (HR) were measured at baseline and 30, 60, 90, and 120 min after the topical administration of WIN 1.0%, 0.25%, 0.06%, or 0.015%, the commercially available vehicle, timolol 0.5%, or a combination of WIN and timolol. SR141716 (CB1 antagonist) or SR144528 (CB2 antagonist) was administered topically 30 min before WIN to determine receptor specificity. To determine ocular and systemic penetration, 3H WIN 55212-2 was administered topically and tissues were collected at 60 and 120 min. Ocular irritation was evaluated by slit-lamp examination (SLE) at baseline and 120 min.

RESULTS

WIN significantly decreased IOP in the hypertensive eye, with no BP or HR effects. SR141716 pretreatment significantly inhibited the IOP effects of WIN 1.0% in a dose-dependent manner, while SR 144528 was not as effective. No significant additive effects were observed by combining WIN (0.5% or 1.0%) with timolol 0.5%. WIN was retained in ocular tissue with a t1/2 of 80-100 min. SLE at 120 min revealed no solvent or drug-related toxic effects.

CONCLUSIONS

In a chronic ocular hypertensive rat model, topically applied WIN is an effective, nontoxic ocular hypotensive agent with no hemodynamic side-effects. This effect was predominantly CB1 receptor mediated, but some CB2 contribution could not be ruled out.

Topical latanoprost causes posterior movement of lens in a patient with exfoliation syndrome and subluxated lens: a case report

Introduction

To report the effect of topical latanoprost on the position of a subluxated lens.

Case presentation

After 0.005% latanoprost was administered topically to a patient with ocular hypertension due to a pseudoexfoliation syndrome and a subluxated lens, the position of the lens was examined by slit-lamp biomicroscopy, and the ciliary body thickness by ultrasound biomicroscopy. The lens had moved posteriorly, and the thickness of the ciliary body had decreased after the latanoprost.

Conclusion

We suggest that the decrease in the thickness of the ciliary body resulted in an increase in the tension of the zonule of Zinn fibers, thus pulling the subluxated lens posteriorly.

Effect of Latanoprost Acid and Pilocarpine on Cultured Rabbit Ciliary Muscle Cells

OBJECTIVE

To study the interaction between latanoprost and pilocarpine on cultured rabbit ciliary muscle (RCM) cells, and investigate the time courses of the two drugs, when given alone or in combination.

METHODS

Cultured RCM cells were treated for 24 h with different concentrations of latanoprost acid, pilocarpine and mixtures of latanoprost acid and pilocarpine. RNA was extracted, expressions of matrix metalloproteinase 1 (MMP-1), tissue inhibitor of metalloproteinase 1 (TIMP-1) and TIMP-2 were detected by reverse transcription-polymerase chain reaction (RT-PCR), and the optimum concentrations of those drugs were found. Then the cells were treated with the optimum concentrations of those drugs for various periods. RNA was extracted after the treatment and expressions of MMP-1, TIMP-1 and TIMP-2 were detected by RT-PCR again. Changes in [Ca(2+)](i) were estimated by fluorescence measurement using the Ca(2+) indicator Fluo-3 AM with a laser scanning confocal microscope. [Ca(2+)](i) of each cell was monitored continually after administration of the drugs. Gray values at 5 s and 2, 4, 6, 8 and 10 min were chosen for statistical analysis, and the influence and time-effect relationship of those drugs on [Ca(2+)](i) of the cultured cells were evaluated.

RESULTS

Exposure of the cells to increasing concentrations of latanoprost acid induced increased MMP-1 mRNA and decreased TIMP-1 and TIMP-2 mRNA in a dose-dependent manner. After 24 h of treatment, the optimum concentration of latanoprost acid for maximal changes in MMP-1 and TIMP-2 expression was 2 x 10(-7)M, and for maximal changes in TIMP-1 expression, the optimum concentration was 5 x 10(-7)M. When the optimum concentrations of latanoprost acid were chosen to treat the cells for various periods, the optimum time of the peak MMP-1 expression and trough TIMP-1 expression was 24 h, and of the trough TIMP-2 expression, it was 36 h after initiation of treatment. No significant expression changes of MMP-1, TIMP-1 and TIMP-2 mRNA were found when the cells were treated with pilocarpine at any concentration or at any time. Exposure of the cells to the mixtures of latanoprost acid and pilocarpine induced the same changes and time course of MMP-1, TIMP-1, and TIMP-2 mRNA expression as exposure of the cells to latanoprost acid alone. Exposure of ciliary muscle cells to pilocarpine induced an increase in [Ca(2+)](i), with the peak of increase observed at 5 s after initiation of treatment; then [Ca(2+)](i) gradually decreased near to baseline level within 10 min. Exposure of the cells to latanoprost acid did not significantly change [Ca(2+)](i). Exposure of the cells to the mixtures of latanoprost acid and pilocarpine induced the same [Ca(2+)](i) change as exposure to pilocarpine alone.

CONCLUSION

Latanoprost and pilocarpine have no interaction in their various effects on the cultured RCM cells.

Predictive value of the efficacy of glaucoma medications in regulatory trials: Phase I-III to post-marketing studies

PURPOSE

To determine the predictive value of early Phase trials (I-II) for the ocular hypotensive efficacy observed in Phases III and IV.

DESIGN

A review of published literature.

METHODS

This study evaluated 12 medicines in 65 articles in the literature with at least two phases available.

RESULTS

For medicines with Phase I results available (n=3), the average reduction in intraocular pressure (IOP) from untreated baseline was 16%, 26% for Phase II, 26% for Phase III, and 24% for Phase IV. For medicines with Phase II results available (n=6), the average reduction in IOP was 23%, 24% for Phase III, and 23% for Phase IV. For medicines with Phase III results available (n=11), the average reduction in IOP was 25% and 24% for Phase IV.

CONCLUSION

This study indicates that early phase trials usually approximated the results of later regulatory studies and post-commercialization trials.

Circadian Intraocular Pressure Control with Dorzolamide versus Timolol Maleate Add-On Treatments in Primary Open-Angle Glaucoma Patients Using Latanoprost

PURPOSE

To compare the 24-hour efficacy of dorzolamide and timolol maleate administered twice daily to primary open-angle glaucoma patients whose intraocular pressure (IOP) could not be adequately controlled with latanoprost monotherapy.

METHODS

In this double-blind prospective crossover clinical comparison trial, 36 primary open-angle glaucoma patients with uncontrolled IOP despite treatment with latanoprost applied once daily were administered timolol and dorzolamide twice daily. The treatment sequence was randomized. All patients underwent measurements for four 24-hour tonometric curves: at baseline and after each 4-week period of treatment. The IOP measurements were taken at 06:00, 09:00, 12:00, 15:00, 18:00, 21:00, 24:00 and 03:00 h. The between-group differences were tested for significance by means of parametric analysis of variance at each time point and circadian curve. The peak values within circadian curve were defined. The mean of the exact amount and percentage of additional IOP reductions from baseline were evaluated and success rates (a minimum of 10% reduction) were determined for both drug regimens.

RESULTS

The mean peak/circadian curve IOPs were 23.4 +/- 2.2/21.8 +/- 2.2 mm Hg at dorzolamide baseline, 23.3 +/- 2.2/21.7 +/- 2.1 mm Hg at timolol baseline, and reduced to 20.2 +/- 1.7/18.7 +/- 1.7 mm Hg and 20.7 +/- 2.4/19.4 +/- 1.6 mm Hg, respectively. When added to latanoprost, both dorzolamide and timolol lowered IOP at circadian curve significantly (p < 0.05). Dorzolamide reduced baseline IOP values at each time point. Timolol also significantly reduced baseline IOP values at all time points except at 03:00. The mean of the exact amount and percentage of reduction in IOP at circadian curve and 5 out of 8 time points were significantly greater with dorzolamide add-on treatment (p < 0.05). The successful reduction rates were 86% for the dorzolamide group and 61% for the timolol group (p = 0.016; chi(2) test).

CONCLUSION

Both of the combinations are effective in lowering IOP, the exact amount and percentage of reduction is greater with the latanoprost + dorzolamide regimen, especially at night-time.

Prostanoids in the therapy of glaucoma

Elevated intraocular pressure (IOP) is one of the most important risk factors for the development of glaucoma, which is a progressive optic neuropathy. Lowering IOP is currently the only therapeutic approach to the therapy of glaucoma. Since the use of pilocarpine eye drops for glaucoma treatment was reported in the late 1870s, academic researchers and pharmaceutical companies attempted to discover new drugs with more potent, prolonged, and safer IOP-reducing effects. These persistent efforts finally paid off, and prostanoids with FP-receptor agonist activity were found to be very potent IOP-lowering agents. To date, three prostanoids (latanoprost, travoprost and bimatoprost) have been launched in many countries, and now a new FP-receptor agonist, tafluprost, is entering clinical development. All of these prostanoids are superior to the beta-adrenoceptor antagonists in their IOP-lowering efficacy, and no severe side effects have been reported in their long-term clinical use. In addition, tafluprost may be expected to improve ocular blood flow. Hence, prostanoids currently occupy center stage among glaucoma medications. It cannot be denied that in terms of efficacy, safety, patient compliance, and medical economy prostanoids are currently the first-line medicines among ocular antihypertensive drugs.

Additional reduction in intraocular pressure achieved with latanoprost in normal-tension glaucoma patients previously treated with unoprostone

PURPOSE

To determine whether treatment with latanoprost eye drops is able to further reduce intraocular pressure (IOP) in normal-tension glaucoma (NTG) patients whose IOP has been well controlled with unoprostone.

PATIENTS AND METHODS

A total of 34 eyes (34 individuals) with NTG that had been treated with 0.12% unoprostone eye drops twice daily for >or=3 months were switched to treatment once daily with eye drops containing 0.005% latanoprost. IOP was measured before and 1, 2, and 3 months after the switch to latanoprost.

RESULTS

The mean IOP of all eyes was decreased significantly by 1.8, 2.9, and 2.3 mmHg at 1, 2, and 3 months after the switch from unoprostone to latanoprost treatment. The IOP of patients with an initial IOP of <or=12 or >12 mmHg was reduced by 11.0 or 19.9%, respectively, after 3 months on latanoprost. The IOP of 30 (88.2%) of the 34 eyes was further reduced by the switch from unoprostone to latanoprost.

CONCLUSIONS

Latanoprost reduced the IOP of NTG patients who had already been treated with unoprostone, even though both drugs are prostaglandin-related. Switching to latanoprost might thus achieve a maximal decrease in IOP and thereby better prevent damage to the optic nerve and loss of visual field in NTG patients.

The Outcome of Mitomycin C Trabeculectomy and Laser Suture Lysis Depends on Postoperative Management

PURPOSE

To verify that postoperative management affects the outcome of mitomycin C (MMC) trabeculectomy and suture lysis.

METHODS

A total of 108 eyes in 108 Japanese patients were treated with MMC trabeculectomy. They were divided into two groups based on when the operation was performed: group A, 57 eyes in 1998, and group B, 51 eyes in 2001. The results, including postoperative intraocular pressure (IOP), complications, and postoperative management, were compared between groups. In addition, they were evaluated by a Kaplan-Meier life-table analysis.

RESULTS

Postoperative IOP was lower and the probability of success by life-table analysis was higher in group B than in group A. Postoperative management, including laser suture lysis and subconjunctival injection of 5-fluorouracil, was started significantly earlier in group B than in group A patients. Although more postoperative complications occurred in group B, none were severe and all were adequately managed.

CONCLUSIONS

Starting postoperative management earlier, particularly laser suture lysis, may be necessary to achieve lower and longer IOP control in MMC trabeculectomy.

Additive Effect of Dorzolamide or Carteolol to Latanoprost in Primary Open-angle Glaucoma

PURPOSE

To compare the additive effect of dorzolamide or carteolol to latanoprost on intraocular pressure (IOP) in glaucoma patients.

DESIGN

Prospective open-label randomized crossover clinical study.

METHODS

A total of 64 patients with primary open-angle glaucoma were treated with latanoprost 0.005% once daily for 3 months then randomized to receive latanoprost plus dorzolamide 1% 3 times daily (dorzolamide preceding group; n=32) or carteolol hydrochloride 2% twice daily (carteolol preceding group; n=32) for a further 3 months. Then, all patients were crossed over to the opposite treatment arm for a further 3 months. IOP was recorded each month at around the time same as on the baseline day.

RESULTS

Sixty-one patients (95%) completed this trial. In the dorzolamide preceding group, mean (+/-SD) IOP was 19.0+/-2.1 mm Hg at baseline and 16.0+/-2.1 mm Hg at the end of latanoprost monotherapy (P<0.01). Addition of dorzolamide reduced IOP to 15.0+/-1.3 mm Hg and this was not changed by switching to carteolol (15.1+/-1.7 mm Hg). In the carteolol preceding group, IOP was 19.1+/-1.9 mm Hg at baseline and 16.2+/-1.2 mm Hg at the end of latanoprost monotherapy (P<0.01). Addition of carteolol reduced IOP to 14.9+/-1.5 mm Hg, and after switching to dorzolamide IOP was 15.2+/-1.5 mm Hg. Mean additional IOP reduction was 0.9+/-1.2 mm Hg (5.6%) for the latanoprost-dorzolamide combination and 1.1+/-1.5 mm Hg (6.8%) for the latanoprost-carteolol combination. Hence, IOP reduction by carteolol and dorzolamide additionally to latanoprost was not different.

CONCLUSIONS

Both dorzolamide and carteolol reduce IOP additively when used in combination with latanoprost, and the additive effect of these drugs is equal.

Efficacité du latanoprost, donné en première ou deuxième intention, sur la pression intra-oculaire et la symptomatologie oculaire chez des patients présentant un glaucome à angle ouvert ou une hypertension oculaire simple

OBJECTIVES

The aim of this study was to assess the changes in intraocular pressure (IOP) and ophthalmic symptoms with the Glaucoma Symptom Scale in patients suffering from open-angle glaucoma (OAG) or ocular hypertension (OHT) after 3 months of treatment with latanoprost.

MATERIALS AND METHODS

This multicentric open study was carried out in adult patients suffering from OAG or simple OHT (naive or previously treated with monotherapy) and needing a change or initiation of anti-glaucomatous treatment. One drop of latanoprost 0.005% was instilled every evening for 12 weeks in each affected eye. Efficacy was assessed by the variation in IOP and ophthalmic symptomatology at the end of treatment. Prognosis factors associated with a relative IOP reduction of at least 30% were sought (using a logistic regression model).

RESULTS

A total of 920 patients suffering from OAG (54%) or OHT (44%), either previously treated (69%) or naive (31%), were included. The male:female ratio was 0.78 and the mean age was 63+/-13 years. At inclusion, the mean IOP was 22.1+/-3.8 mmHg. After treatment, IOP was significantly decreased by 5.1+/-4 mmHg, corresponding to a 22% reduction. IOP reduction was 7.1+/-4 mmHg, corresponding to 29% in naive patients and 4.2+/-4 mmHg, corresponding to 19% in previously treated patients. A relative IOP reduction of at least 30% was reached by 47% of naive patients and 21% of previously treated patients. In previously treated patients, a relative IOP reduction of at least 30% had a greater chance of being reached in men with previous ophthalmic history and high IOP at inclusion (above 21 mmHg). IOP reduction was similar in patients with OAG and OHT. A significant improvement in ophthalmic symptoms was observed after treatment in previously treated patients. A total of 7% of the patients presented an adverse event affecting the visual system: eye irritation (2%), eye pain (2%), or eye hyperemia (1%). Compliance was good for 94% of the patients.

CONCLUSION

Latanoprost given as first or second-line treatment at the recommended dose effectively decreases IOP in patients with OAG or OHT. This treatment also improves visual and nonvisual symptoms in previously treated patients and presents a good safety profile.

Correlation between individual differences in intraocular pressure reduction and outflow facility due to latanoprost in normal-tension glaucoma patients

PURPOSE

The amount of intraocular pressure (IOP) reduction achieved by the use of latanoprost eyedrops varies among patients, and there are even nonresponders. This report examines whether there is any correlation between the amount of individual variability in IOP reduction and the uveoscleral outflow facility after latanoprost eyedrop instillation in normal-tension glaucoma patients.

METHODS

Sixteen normal-tension glaucoma patients (mean age, 56.4 years) were enrolled in the study to investigate the relationship between the amount of IOP reduction and outflow facility. Before treatment, subjects underwent circadian IOP measurement and then tonography, and the outflow facility was calculated. Subsequently, patients began treatment once daily with latanoprost instillation in one eye. After 4 weeks of daily latanoprost treatment, circadian IOP was measured again.

RESULTS

Mean pretreatment outflow facility was 0.23 +/- 0.05 microl/min per mmHg. On average, latanoprost instillation decreased IOP by 2.8 mmHg, but the reduction varied among individuals from -0.3 mmHg to 5.8 mmHg. No significant correlation was noted between the outflow facility and the IOP decline associated with latanoprost.

CONCLUSION

Because there was no significant correlation between individual IOP reduction by latanoprost and outflow facility, the differences in substantial change in uveoscleral outflow after latanoprost administration may be one explanation for the individual variation in IOP reduction after treatment with this drug.

Efficacy of latanoprost or fixed-combination latanoprost-timolol in patients switched from a combination of timolol and a nonprostaglandin medication

PURPOSE

To compare latanoprost with the fixed-combination latanoprost-timolol in glaucoma or ocular hypertension patients switched from a combination glaucoma therapy with timolol and another nonprostaglandin medication.

DESIGN

Prospective randomized clinical trial.

METHODS

Glaucoma or ocular hypertension patients receiving a combined treatment of timolol 0.5% and another nonprostaglandin medication (pilocarpine 4%, alpha-agonist, or a topical carbonic anhydrase inhibitor) underwent a 30-day washout of their medications. A masked observer then measured their intraocular pressure (IOP). The subjects were randomized to either latanoprost or fixed-combination latanoprost-timolol eyedrops to use once daily at 7 am. The IOP was measured again 30 days after the patients started using one of the study drugs by the same examiner at the same time.

MAIN OUTCOME MEASURE

Comparison of the study medications' hypotensive effect.

RESULTS

Fifty-three eyes (28 in the latanoprost group and 25 in the latanoprost-timolol group) from 28 patients were included in the study. The IOP reduction was greater in both study groups compared with the previous combination therapy with timolol and another nonprostaglandin medication in millimeters of mercury (7.7+/-2.3 vs. 5.5+/-2.3, P<0.001, for the latanoprost group; 8.5+/-3.5 vs. 6.3+/-2.7, P<0.001, for the latanoprost-timolol group) and percentage (35.8+/-8.2% vs. 25.6+/-8.9%, P<0.001, for the latanoprost group; 38.6+/-8.7% vs. 28.6+/-9.0%, P<0.001, for the latanoprost-timolol group). There was no statistical difference between latanoprost and fixed-combination latanoprost-timolol in reducing IOP, in either millimeters of mercury (P = 0.3) or percentage (P = 0.2).

CONCLUSIONS

Both latanoprost and fixed-combination latanoprost-timolol may be viable substitutes for timolol and another nonprostaglandin medication in glaucoma or ocular hypertension patients.

Cost-effectiveness of monotherapy treatment of glaucoma and ocular hypertension with the lipid class of medications

PURPOSE

Cost-effectiveness evaluation of monotherapy with the newer lipid class of intraocular pressure (IOP)-lowering medications in glaucoma and ocular hypertension.

DESIGN

Retrospective pharmacoeconomic analysis.

METHODS

Analysis included all published studies measuring IOP reduction from untreated baseline with once-daily bimatoprost (Lumigan), latanoprost (Xalatan), or travoprost (Travatan) monotherapy in patients with elevated IOP. Percentage IOP reduction at the final study visit was calculated using the early morning IOP measurement to control for diurnal variation in IOP. Patient-weighted average percentage IOP reductions were computed for each medication. Cost per 2.5-ml bottle was determined using PriceAlert 2005 (February). Cost-effectiveness was defined as monthly cost of medication per patient-weighted average 1% reduction in IOP.

RESULTS

Studies included 951 bimatoprost, 1598 latanoprost, and 765 travoprost patients. The AWP in February, 2005 for a 2.5-ml bottle was 62.10 dollars for bimatoprost, 61.29 dollars for latanoprost, and 62.19 dollars for travoprost. Patient-weighted average IOP reduction was 32.4% for bimatoprost, 29.6% for latanoprost, and 29.0% for travoprost. Calculated cost-effectiveness was 1.92 dollars for bimatoprost, 2.07 dollars for latanoprost, and 2.14 dollars for travoprost. Incremental cost-effectiveness ratio (ICER) analysis showed an incremental cost of 0.29 dollars for each additional 1% IOP reduction provided by bimatoprost over latanoprost. The rank order of the cost-effectiveness of the drugs (bimatoprost > latanoprost > travoprost) was robust in sensitivity analyses to cost and efficacy.

CONCLUSIONS

On the basis of AWP and patient-weighted average percentage IOP reduction in published studies, bimatoprost had the most favorable cost-effectiveness among the drugs compared. Cost-effectiveness should be considered along with traditional clinical safety and efficacy measures to make individual and group healthcare decisions.

Analytic review of bimatoprost, latanoprost and travoprost in primary open angle glaucoma

OBJECTIVE

The objective of this review was to evaluate different measures of efficacy of the intraocular pressure (IOP) lowering lipid class agents bimatoprost, latanoprost and travoprost in the treatment of primary open angle glaucoma. Study arms of timolol in trials including the above mentioned lipid class drugs were also included.

METHODS

MEDLINE and EMBASE were searched for randomized clinical trials including one or more of the lipid class drugs bimatoprost, latanoprost and travoprost. The study results were pooled, and the simple, weighted IOP-lowering efficacy was compared among the lipid class drugs and timolol, where data were available. Efficacy parameters were reviewed, including mean reduction of IOP and percentage of patients achieving different levels of IOP.

RESULTS

161 articles were identified of which 42 were included in the analysis. A total of 9295 patients participated in the included trials. Based on all studies, timolol on average had a weighted mean IOP reduction of 22.2%, while latanoprost, travoprost and bimatoprost had a weighted mean IOP reduction of 26.7%, 28.7% and 30.3%, respectively. Analysis of target achievement to various IOP levels shows that bimatoprost seems more efficacious than latanoprost. The direct comparisons (head-to-head studies) also show that bimatoprost is the most efficacious treatment, however it is not conclusive whether latanoprost or travoprost is better in reducing IOP.

CONCLUSIONS

This review shows that bimatoprost seems to be the most efficacious treatment in lowering IOP. Head-to-head studies confirm this.

Water-drinking test in patients with primary open-angle glaucoma while treated with different topical medications

OBJECTIVE

Reduction and diurnal stabilization of the intra-ocular pressure (IOP) is the mainstay of treatment for glaucoma. Fluctuations of IOP in glaucomatous patients can also be induced by the osmotic variations caused by water ingestion. Such influence can be studied by means of the water-drinking test (WDT). The aim of this study was to perform the WDT in patients with primary open-angle glaucoma (POAG) while they were being treated with different IOP-lowering medications, to test the effect of drugs with different mechanisms of action on the ability to maintain a stable IOP.

METHODS

A total of 280 POAG patients were enrolled, 40 patients per group for each of the tested medications (timolol, dorzolamide, brinzolamide, travoprost,latanoprost, bimatoprost, and brimonidine). After baseline IOP measurement, all patients underwent WDT (1000 mL of water in 10 min). The IOP was measured at 15-min intervals until the return of IOP to baseline values. The main outcomes measured were mean IOP peak, mean IOP percentage increase, and mean time for returning to baseline IOP value.

RESULTS

The highest mean IOP peak was found with timolol, whereas no difference was found among the other drugs. The highest mean IOP percentage increase was found with timolol, whereas bimatoprost showed an IOP percentage increase significantly lower than latanoprost, dorzolamide, and brinzolamide. The duration of IOP increase was shortest for bimatoprost and longest for timolol.

CONCLUSION

This study suggests that topical medications that enhance outflow (e.g., bimatoprost, latanoprost, travoprost, and brimonidine) may provide, under stressful conditions such as the WDT, better IOP stabilization than medications that decrease aqueous humor inflow, such as timolol and topical carbonic anhydrase inhibitors.

How to control measurement variation in estimating the mean intraocular pressure reducing effect at a specific point in time

OBJECTIVE

To clarify how to control measurement variation in estimating the mean intraocular pressure reducing effect at a specific point in time.

METHODS

A set of 629 open-angle glaucoma or ocular hypertensive patients, eligible for treatment in both eyes, previously untreated, were reanalyzed at 3 or 6 months of intraocular pressure (IOP) reducing treatment. The trial design had parallel treatment groups; one group receives treatment A and the other group receives treatment B. The standard deviation (SD) of the IOP response variable was calculated based on a single eye per patient, mean of right and left eye (bilaterally identical treatment within each group) or difference between right and left eye (paired-eye difference within each group; one eye receives active treatment and the other eye receives placebo). The effect of using mean of replicated recordings on the SD of the patient group mean IOP was also studied. The results were generalized by applying a measurement variation model.

RESULTS

The "paired-eye difference within each group" design was clearly most effective; the SD of the IOP response variable was 2.2 mm Hg. Using mean of the right and left eye in a "design with bilaterally identical treatment in each group" was the next best solution; the SD of the IOP was 3.0 mm Hg. The SD of the IOP was 3.2 to 3.4 mm Hg when based on a single eye per patient. The minimization of the SD gave important reduction of number of patients required to enroll in a new trial. Using a single IOP recording per patient produced similar SD of the patient group mean IOP as using mean of replicated IOP recordings when measured with Goldmann tonometry.

CONCLUSION

Calculating the mean IOP by using measurements from both eyes of the patient gives important reduction of the variability.

Management of glaucoma: focus on pharmacological therapy

Glaucoma represents a major cause of vision loss throughout the world. Primary open-angle glaucoma, the most common form of glaucoma, is a chronic, progressive disease often, though not always, accompanied by elevated intraocular pressure (IOP). In this disorder, retinal ganglion cell loss and excavation of the optic nerve head produce characteristic peripheral visual field deficits. Patients with normal-tension glaucoma present with typical visual field and optic nerve head changes, without a documented history of elevated IOP. A variety of secondary causes, such as pigment dispersion syndrome and ocular trauma, can result in glaucoma as well. Treatment of all forms of glaucoma consists of reducing IOP. With proper treatment, progression of this disease can often be delayed or prevented. Treatment options for glaucoma include medications, laser therapy and incisional surgery. Laser techniques for the reduction of IOP include argon laser trabeculoplasty and selective laser trabeculoplasty. Both techniques work by increasing outflow of aqueous humour through the trabecular meshwork. Surgical options for glaucoma treatment include trabeculectomy, glaucoma drainage tube implantation and ciliary body cyclodestruction. While each of these types of procedures is effective at lowering IOP, therapy usually begins with medications. Medications lower IOP either by reducing the production or by increasing the rate of outflow of aqueous humour within the eye. Currently, there are five major classes of drugs used for the treatment of glaucoma: (i) cholinergics (acetylcholine receptor agonists); (ii) adrenoceptor agonists; (iii) carbonic anhydrase inhibitors (CAIs); (iv) beta-adrenoceptor antagonists; and (v) prostaglandin analogues (PGAs). Treatment typically begins with the selection of an agent for IOP reduction. Although beta-adrenoceptor antagonists are still commonly used by many clinicians, the PGAs are playing an increasingly important role in the first-line therapy of glaucoma. Adjunctive agents, such as alpha-adrenoceptor agonists and CAIs are often effective at providing additional reduction in IOP for patients not controlled on monotherapy. As with any chronic disease, effective treatment depends on minimising the adverse effects of therapy and maximising patient compliance. The introduction of a variety of well tolerated and potent medications over the past few years now allows the clinician to choose a treatment regimen on an individual patient basis and thereby treat this disorder more effectively.

Latanoprost or Brimonidine as Treatment for Elevated Intraocular Pressure

PURPOSE

To compare the efficacy and tolerability of latanoprost or brimonidine in patients with elevated intraocular pressure (IOP).

MATERIALS AND METHODS

This prospective, randomized, masked-evaluator, parallel-group, multicenter study in the United States included patients with primary open angle glaucoma or ocular hypertension. Patients received latanoprost 0.005% once daily (8:00 AM; n = 152) or brimonidine tartrate 0.2% twice daily (8:00 AM and 8:00 PM; n = 151). Patients underwent evaluation at screening, baseline (randomization), and after 0.5, 3, and 6 months of treatment. IOP was measured at 8:00 AM, 10:00 AM, noon, and 4:00 PM at baseline and the months 3 and 6 visits, and at 8:00 AM only at week 2. The main outcome measure was the difference in diurnal IOP change from baseline to month 6 between treatment groups. Adverse events were recorded at each visit.

RESULTS

Baseline mean diurnal IOP levels were similar between groups. At month 6, the adjusted mean (+/- SEM) diurnal IOP reduction was 5.7 +/- 0.3 mm Hg in the latanoprost group and 3.1 +/- 0.3 mm Hg in patients receiving brimonidine (P < 0.001). The mean difference in diurnal IOP reduction was 2.5 +/- 0.3 mm Hg (95% CI: 1.9, 3.2; P < 0.001). Five times more patients receiving brimonidine than latanoprost were withdrawn from the study due to adverse events.

CONCLUSION

Latanoprost instilled once daily is more effective and better tolerated than brimonidine administered twice daily for the treatment of patients with glaucoma or ocular hypertension. During therapy, the range of daily fluctuation of IOP is less for latanoprost compared with brimonidine.

Degree of angle closure and the intraocular pressure–lowering effect of latanoprost in subjects with chronic angle-closure glaucoma

OBJECTIVE

To examine the relationship between the configuration of the drainage angle and intraocular pressure (IOP)-lowering efficacy of latanoprost in subjects with chronic angle-closure glaucoma (CACG).

DESIGN

Prospective observational case series.

PARTICIPANTS

One hundred thirty-seven Asian subjects with CACG.

METHODS

Study subjects had participated in a 12-week, randomized, double-masked study that assessed the IOP-reducing effect of latanoprost. Chronic angle-closure glaucoma was defined as optic neuropathy with or without a visual field defect, an anterior chamber angle in which the trabecular meshwork was not visible for at least 180 degrees on gonioscopy, and evidence of peripheral anterior synechiae (PAS) in association with a chronically elevated IOP. Static and dynamic gonioscopy was performed at baseline. The angles were graded in each quadrant according to the Shaffer scheme, and the number of clock hours of PAS was recorded. The change in daily IOP (defined as the mean of the 9:00 am and 5:00 pm IOP time point values) from baseline to week 12 was analyzed and correlated with mean angle width and extent of PAS.

RESULTS

One hundred thirty-seven Asian subjects with CACG completed the study in the latanoprost-treated group. Most subjects were female (75%), and the mean age was 62.6+/-9.4 years. At baseline, the mean angle width was 0.84+/-0.55, and the mean number of clock hours of PAS was 4.67+/-2.95. After 12 weeks of treatment, latanoprost reduced IOP from 25.0+/-5.5 mmHg to 17.5+/-5.0 mmHg (P<0.001). The percent change in IOP produced by latanoprost was not associated with mean angle width (Spearman's r = 0.04, P = 0.64) or the number of clock hours of PAS (Spearman's r = -0.15, P = 0.08).

CONCLUSIONS

In subjects with CACG, the IOP-reducing efficacy of latanoprost was not affected by the degree of angle narrowing or extent of synechial angle closure.

Efficacy of Latanoprost in Patients with Chronic Angle-Closure Glaucoma and No Visible Ciliary-Body Face: A Preliminary Study

The aim of this study was to evaluate the efficacy of 0.005% latanoprost in lowering intraocular pressure (IOP) in patients with chronic angle-closure glaucoma (CACG) and no visible ciliary-body face. Fourteen eyes of 14 Korean patients with CACG with 360 degrees of peripheral anterior synechiae (PAS) and an IOP greater than 21 mmHg without medication were treated with 0.005% latanoprost once-daily. All patients completed 3 months of treatment with latanoprost. The IOP, which was 30.3 +/- 4.5 (mean +/- standard deviation) mmHg at baseline, decreased to 22.6 +/- 4.9 mmHg after 1 week, 19.6 +/- 5.5 mmHg after 1 month, 19.4 +/- 4.9 mmHg after 2 months, and 21.5 +/- 5.9 mmHg after 3 months of treatment with latanoprost (P < 0.01 for each). Ultrasound biomicroscopy of the anterior chamber angle showed anterior bowing of the iris with total occlusion of the angle by PAS, except for 5 eyes with focal microscopic openings to the ciliary-body face at various angles. Adverse ocular events were well-tolerated and transient. In this preliminary study, treatment with 0.005% latanoprost once-daily resulted in a significant reduction in IOP in CACG patients with 360 degrees of PAS on gonioscopy. Our results suggest that latanoprost may be considered as a therapy of choice in these rare cases.

New fluoroprostaglandin F(2alpha) derivatives with prostanoid FP-receptor agonistic activity as potent ocular-hypotensive agents

To find new prostanoid FP-receptor agonists possessing potent ocular-hypotensive effects with minimal side effects, we evaluated the agonistic activities of newly synthesized prostaglandin F(2alpha) derivatives for the prostanoid FP-receptor both in vitro and in vivo. The iris constrictions induced by the derivatives and their effects on melanin content were examined using cat isolated iris sphincters and cultured B16 melanoma cells, respectively. The effects of derivative ester forms on miosis and intraocular pressure (IOP) were evaluated in cats and cynomolgus monkeys, respectively. Of these derivatives, 6 out of 12 compounds were more potent iris constrictors, with EC(50) values of 0.6 to 9.4 nM, than a carboxylic acid of latanoprost (EC(50)=13.6 nM). A carboxylic acid of latanoprost (100 microM) significantly increased the melanin content of cultured B16 melanoma cells, but some 15,15-difluoro derivatives, such as AFP-157 and AFP-172, did not. Topically applied AFP-168, AFP-169 and AFP-175 (isopropyl ester, methyl ester and ethyl ester forms, respectively, of AFP-172) induced miosis in cats more potently than latanoprost. AFP-168 (0.0005%) reduced IOP to the same extent as 0.005% latanoprost (for at least 8 h). These findings indicate that 15,15-difluoroprostaglandin F(2alpha) derivatives, especially AFP-168, have more potent prostanoid FP-receptor agonistic activities than latanoprost. Hence, AFP-168 may be worthy of further evaluation as an ocular-hypotensive agent.

A three-year prospective, randomized and open comparison between latanoprost and timolol in Japanese normal-tension glaucoma patients

PURPOSE

To compare the longitudinal effects of treatment on intraocular pressure (IOP) and visual field performance in Japanese normal-tension glaucoma (NTG) between latanoprost and timolol.

PATIENTS AND METHODS

This is an open-label, randomized, study. A total of 62 NTG patients were prospectively, consecutively enrolled. All study subjects were randomly assigned to 0.005% latanoprost instillation once daily in the morning or 0.5% timolol instillation twice daily for a prospective 3-year follow-up, and underwent a routine ocular examination every month. Automated perimetry was performed every 6 months using Humphrey field analysers. Stereophotographs of optic discs were also obtained every 6 months.

RESULTS

Percentage of IOP reduction or the magnitude of IOP reduction showed no intergroup differences either at any time point (13-15%). In the visual field, the estimated rate of change in the MD value (dB/year) was -0.34+/-0.17 (SE) for the latanoprost group, and -0.10+/-0.18 (SE) for the timolol group. The estimated rate of change in MD showed no significant difference from zero in both groups, and there were no statistical intergroup differences. No changes in the optic nerve head topography in the vertical cup-to-disc ratio and rim area measured by image-analysis techniques were observed in either group. There were no patients who dropped out due to the side effects of treatment regimens.

CONCLUSION

Both latanoprost and timolol single treatments reduced IOP by 13-15% at their trough effects for 3 years in Japanese NTG patients; both showed similar effects on visual field performance.

Comparison of latanoprost with fixed-combination dorzolamide and timolol in adult patients with elevated intraocular pressure: an eight-week, randomized, open-label, parallel-group, multicenter study in Latin America

BACKGROUND

The newer ocular hypotensive agents available to treat glaucoma and ocular hypertension (OHT) include latanoprost, a prostaglandin F(2alpha) analogue, and the fixed combination of dorzolamide hydrochloride, a carbonic anhydrase inhibitor, and timolol maleate, a beta-blocker.

OBJECTIVE

The aim of this study was to compare the efficacy and tolerability of latanoprost with that of the fixed combination of dorzolamide and timolol over 8 weeks.

METHODS

This interventional, 8-week, randomized, open-label, parallel-group study was conducted at 18 centers in 6 Latin American countries. Patients with unilateral or bilateral primary open-angle, pigmentary, or exfoliative glaucoma or OHT were randomized to receive latanoprost, 1 drop in the affected eye QD (evening), or fixed-combination dorzolamide/timolol, 1 drop in the affected eye BID (morning and evening). Medications were self-administered, 1 drop per affected eye. At baseline and week 8, intraocular pressure (IOP) was measured 3 times each at 8:30 am, 10:00 am, 2:00 pm, and 5:00 pm and after the water-drinking test, which estimates the IOP peak of diurnal tension curve, performed following the 5:00 pm IOP assessment. The primary efficacy outcome was change in diurnal IOP (the mean of IOP measurements) from baseline to week 8. Adverse effect (AE) data were recorded at each visit.

RESULTS

A total of 229 patients were randomized (latanoprost, n = 112; dorzolamide/timolol, n = 117). Mean baseline diurnal IOP values were similar between the 2 groups. Mean (SD) diurnal IOP reductions at week 8 before the water-drinking test were 6.9 (3.0) mm Hg for the latanoprost group and 6.4 (3.2) mm Hg for the dorzolamide/timolol group. Mean IOP values were similar at all time points except at 5:00 pm, when levels were significantly lower in latanoprost-treated patients (P = 0.025). After the water-drinking test, the increase in IOP values was similar between groups at baseline but lower in latanoprost-treated patients at week 8 (adjusted difference, 1.08 mm Hg; P = 0.012). Fewer patients treated with latanoprost reported ocular or systemic AEs (P = 0.025 and P < 0.001, respectively).

CONCLUSIONS

In this study of patients with unilateral or bilateral primary open-angle, pigmentary, or exfoliative glaucoma or OHT IOP reductions generally were similar between treatment groups, except at 5:00 pm, when the mean IOP level was significantly lower in latanoprost-treated patients. Latanoprost was better tolerated than fixed-combination dorzolamide and timolol.