A double-masked randomized comparison of the efficacy and safety of unoprostone with timolol and betaxolol in patients with primary open-angle glaucoma including pseudoexfoliation glaucoma or ocular hypertension. 6 month data

Clinical Study of the IOPTx™ System - an Electroceutical Wearable to Lower Intraocular Pressure

Purpose: To investigate the safety and efficacy of the IOPTx™ system - a novel wearable, electroceutical treatment to lower intraocular pressure. Methods: Patients wear the customized contact lens and spectacles of the IOPTx™ system and undergo three 15-minute randomized stimulation trials at different stimulus amplitudes with 15 minutes of rest in between. The parameters for the stimulation trials include a frequency of 50 Hz, a pulse width of 100 µs, and current amplitudes between 90-150 µA. The optometrist measures the intraocular pressure (IOP) before, immediately after, and 15 minutes after the trial, and performs topography, a slit eye examination, and specular microscopy before and after the entire study to check the health of the eye and confirm the safety of the system. Results: The IOPTx™ system successfully modulates a patient's IOP. By testing various currents, we create individual tuning curves examining the effect of the stimulation amplitude on the change in IOP. Each patient may have an optimal dose-response curve and by normalizing to this value, the IOPTx™ system decreased IOP by an average of 17.7% with fifteen minutes of therapy. No Adverse Events or Adverse Device Effects occurred.Conclusions: The results of this clinical case series provide preliminary evidence of efficacy and safety of the IOPTx™ system and its potential usefulness to lower IOP in glaucoma and ocular hypertension.

Progression patterns of normal-tension glaucoma groups classified by hierarchical cluster analysis

OBJECTIVES

To investigate differences in progression patterns of normal-tension glaucoma (NTG) patients in three clusters classified by hierarchical cluster analysis (HCA).

MATERIALS AND METHODS

In a retrospective study, 200 eyes of NTG patients classified by HCA in 2015 who were followed up to the current date were evaluated. Peripapillary retinal nerve fibre layer (RNFL) thicknesses were measured by Cirrus HD-OCT and progression rate was calculated by trend analysis (Guided Progression Analysis [GPA]). VF progression rate was evaluated by linear regression analysis of mean deviation (MD). Progression patterns of three clusters were compared by histograms.

RESULTS

In total, 153 eyes of 153 patients were followed up. Mean observation period was 5 years. RNFL reduction rate was -0.83 μm/year in cluster 1, which showed early glaucomatous damage in previous reports; -0.45 μm/year in cluster 2, which showed moderate glaucomatous damage; and -0.36 μm/year in cluster 3, which showed young and myopic glaucomatous damage. The progression pattern of cluster 3 showed a double-peak distribution; RNFL reduction rate was 0.11 μm/year in the non-progressive group and -1.07 μm/year in the progressive group.

CONCLUSION

The progression patterns were different among three NTG groups that were divided by HCA. In particular, the group of young and myopic eyes showed a mixture of two different patterns.

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.

Update on the Medical Treatment of Primary Open-Angle Glaucoma

Glaucoma comprises a group of progressive, neurodegenerative disorders characterized by retinal ganglion cell death and nerve fiber layer atrophy. Several randomized controlled trials have consistently demonstrated the efficacy of intraocular pressure lowering to slow or halt the measurable progression of the disease. Medical therapy, in places where it is easily accessible, is often the primary method to lower intraocular pressure. We review the medical options currently available and possible future options currently in development. The 5 contemporary classes of topical agents in use include prostaglandin analogs, beta blockers, carbonic anhydrase inhibitors, alpha agonists, and cholinergics. In addition, several fixed combination agents are commercially available. Agents from each of these classes have unique mechanisms of action, adverse effects, and other characteristics that impact how they are used in clinical practice. Despite the plethora of medical options available, there are limitations to topical ophthalmic therapy such as the high rate of noncompliance and local and systemic adverse effects. Alternate and sustained drug delivery models, such as injectable agents and punctal plug delivery systems, may in the future alleviate some such concerns and lead to increased efficacy of treatment while minimizing adverse effects.

Effect of topical anti-glaucoma medications on late pupillary light reflex, as evaluated by pupillometry

Purpose

The late post-illumination pupillary response (PIPR_10–30s) to blue light is reduced in glaucoma, suggesting that pupillometry can be used in clinical glaucoma evaluation. Since animal studies have indicated that common anti-glaucomatous agents affect the iris muscle, we investigated the short-term effect of the anti-glaucoma drugs on the pupillary light reflex and in particular on the PIPR_10–30s.

Methods

In this randomized, double-masked, crossover trial, pupillometry was performed before and after topical administration of latanoprost, dorzolamide, and timolol in 20 healthy subjects. Stimulus was blue (463 nm) and red light (633 nm) of 2 log (lux). Main outcome was the PIPR_10–30s to blue light. Additionally, pupil size, maximal contraction, and the early post-illumination pupillary response (PIPR_0–10s) to blue and red light were investigated. Pupil response variations between 8 a.m. and 2 p.m. were also assessed. Intraocular pressure (IOP) was measured before and 3.5 h after drug instillation.

Results

We found no drug effect on the blue light PIPR_10–30s or any other blue light pupil parameters. During the control day, the only significant variation over time was observed for the red light PIPR_0–10s (p = 0.02). Pupillary size decreased slightly with timolol (0.1 mm, p = 0.03) and dorzolamide (0.2 mm, p < 0.001), but not with latanoprost. Timolol also reduced the maximal contraction amplitude significantly during red light (p = 0.02). Intraocular pressure was significantly reduced by all three drugs after 3.5 h (p < 0.01), while it remained unchanged during the control day (p = 0.3).

Conclusion

Anti-glaucoma medications did not interfere with the blue light elicited PIPR. Dorzolamide reduced pupil size, while timolol reduced both pupil size and maximal contraction to red light, but the effect was minute and not of clinical importance.

Glaucoma management: relative value and place in therapy of available drug treatments

Lowering intraocular pressure (IOP) is the only proven therapeutic intervention for glaucomatous optic neuropathy. Despite advances in laser and microsurgical techniques, medical IOP reduction remains the first-line treatment option for the majority of patients with open-angle glaucoma. Prostaglandin analogs are the most efficacious topical agents and carry a remarkable safety profile. Topical beta-blockers, alpha-agonists, and carbonic anhydrase inhibitors are often employed as adjunctive agents for further IOP control. Newer preserved and nonpreserved formulations are available and appear to be less toxic to the ocular surface. Oral carbonic anhydrase inhibitors, miotic agents, and hyperosmotics are infrequently used due to a host of potentially serious adverse events. Medical therapies on the horizon include rho-kinase inhibitors, neuroprotective interventions, and gene therapies.

An evidence-based review of unoprostone isopropyl ophthalmic solution 0.15% for glaucoma: place in therapy

Glaucoma is a progressive, neurodegenerative optic nerve disease that can cause significant visual morbidity and affects over 60 million people worldwide. The only known modifiable risk factor for glaucoma at this time is elevated intraocular pressure (IOP), which may be treated with medications, laser therapy, and/or incisional surgery. Topical ocular medications are commonly used as first-line therapy for glaucoma, although side effects may limit their use. Unoprostone is a novel 22-carbon ocular hypotensive agent that may be advantageous in treating some patients with open angle glaucoma or ocular hypertension. Unlike the 20-carbon prostanoids, such as latanoprost, that lower IOP primarily through an increase in uveoscleral outflow, unoprostone may lower IOP through increased aqueous outflow via the conventional trabecular meshwork pathway. Although not as efficacious as other prostanoids, unoprostone is effective for IOP reduction both as monotherapy and adjunctive therapy with timolol. Unoprostone has decreased affinity for the prostaglandin F2α receptor, which may explain its well tolerated ocular and systemic side effect profile compared with other prostanoids.

Clinical options for the reduction of elevated intraocular pressure

Elevated IOP in clinical practice is usually seen in glaucoma or ocular hypertension. Glaucoma affects 60 million people worldwide and 8.4 million are bilaterally blind from this chronic disease.1 Options for reducing IOP rely on pharmacological agents, laser treatments and surgery which may be penetrating or non-penetrating. The last twenty years has seen significant changes in all of these strategies. This review aims to cover these clinical options and introduce some of the new technologies currently in development for the clinical lowering of IOP.

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).

Effects of some ophthalmic medications on pupil size: a literature review

Ophthalmological pharmacology is a rapidly expanding field aimed at achieving the safest and most effective treatment results. Physicians must be aware of the side-effect profiles, both beneficial and harmful, of medications currently used. This review highlights the available data on the effect of some ophthalmic medications on pupil size; it was limited to all reports or studies describing topical ophthalmic agents not originally designed or indicated to alter pupil diameter. This awareness will protect patients from unwanted drug-induced side effects and will improve clinical management and patient care.

Commercially available prostaglandin analogs for the reduction of intraocular pressure: similarities and differences

Over the last 12 years, the pharmacological management of glaucoma and ocular hypertension has significantly changed with the introduction of the prostaglandin analogs, specifically, latanoprost, bimatoprost, and travoprost. Their ability to effectively reduce intraocular pressure with once-per-day dosing, their comparable ocular tolerability with timolol, and their general lack of systemic side effects have made them the mainstay of pharmacological therapy for glaucoma and ocular hypertension in most parts of the world. A review of their pharmacology reveals that they are all prodrugs that are converted to their respective free acids within the eye to activate the prostanoid FP receptor and to reduce intraocular pressure by enhancing the uveoscleral and the trabecular meshwork outflow pathways. A review of numerous prospective, randomized comparative studies indicates that no clinically significant differences exist among these agents regarding their ability to lower intraocular pressure.

The side effects of the prostaglandin analogues

In the last decade topically applied prostaglandin F2alpha analogues (bimatoprost, latanoprost, travoprost and unoprostone) have become widely used as a means to reduce elevated intraocular pressure in patients with glaucoma and ocular hypertension. These molecules all have similar side-effect profiles, which include both side effects that occur frequently (e.g., conjunctiva hyperaemia, increase of iris pigmentation and eyelash changes) and rare adverse reactions (e.g., periocular pigmentation, damage to the blood-aqueous barrier and cystoid macular oedema). Conjunctiva hyperaemia, eyelash changes and cystoid macular oedema are reversible, but certain other side effects, such as increased iris pigmentation, are not. However, the systemic side-effect profile is favourable for all the prostaglandin analogues, and some of the local side effects are only of cosmetic significance. Numerous clinical studies suggest that discontinuing treatment with prostaglandin analogues on account of their side effects is rare in clinical practice.

A 3-month clinical trial comparing the IOP-lowering efficacy of bimatoprost and latanoprost in patients with normal-tension glaucoma

This multicenter, randomized, double-blind clinical trial was undertaken to compare the intraocular pressure (IOP)-lowering efficacy and safety of topical bimatoprost 0.03% with that of latanoprost 0.005% for the treatment of patients with normal-tension glaucoma. After washout of all ocular hypotensive medications, patients with normal-tension glaucoma (n=60) were randomly assigned to oncedaily bimatoprost 0.03% or latanoprost 0.005% for 3 mo. Diurnal IOP measurements were taken at each study visit. Primary outcome measures consisted of mean change from baseline IOP (8 AM, Noon, 4 PM) and change in visual field. Secondary measures included mean IOP, ophthalmologic examination findings, results of clinical evaluation, and adverse events. Mean change from baseline IOP at each study visit was statistically significant at all diurnal measurements for patients taking bimatoprost and for those taking latanoprost (P<.001). The 8 AM mean change from baseline IOP measurement showed a significant between-group difference (P< or =.033) in favor of bimatoprost at both follow-up visits. After 3 mo of treatment, mean IOP reductions from baseline ranged from 2.8 to 3.8 mm Hg (17.5%-21.6%) with bimatoprost and from 2.1 to 2.6 mm Hg (12.7%-16.2%) with latanoprost. Overall mean reduction in IOP after 3 mo of treatment was 3.4 mm Hg (19.9% rpar; with bimatoprost and 2.3 mm Hg (14.6%) with latanoprost (P=.035). No significant between-group differences were observed in incidence of adverse events, clinical success, or demographic variables. Bimatoprost was found to be more effective than latanoprost in lowering IOP in the patient with normal-tension glaucoma. Both drugs were efficacious and well tolerated.

Entry order as a consideration for innovation strategies

Prior studies have defined an effect of market entry order on commercial success that depends on attributes of the underlying technology, the rate of change in technology improvement, consumer expectations of these attributes and the degree of unmet demand. Analyses of pharmaceutical sales data suggest that the commercial success of drugs is subject to similar forces. These findings have important implications for innovation strategies.

Evolving Paradigms in the Medical Treatment of Glaucoma

In the last 5 years, numerous novel ocular hypotensive agents have been introduced for the control of intraocular pressure (IOP). Clinicians now have more options than ever in 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 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 (e.g., neuroprotection).

Glaucoma Medications

As with many diseases, glaucoma increases in frequency in older populations, and is very often encountered in patients taking multiple medications. While the exact mechanism of glaucomatous optic neuropathy (GON) is not known, intraocular pressure (IOP) is thought to be central to the process, and reducing IOP is the only known effective treatment. The newer definition of glaucoma is an IOP-sensitive optic neuropathy. While large, controlled studies have indicated that reducing IOP will slow the progression of disease, the contributions of other conditions and medications have not been adequately studied. As the adverse effect profiles of medical therapies for glaucoma have improved, use of these agents has increased greatly. This has resulted in a large number of older patients taking glaucoma medications. Since topical medications can easily be overlooked in a medical history, and are for the most part well tolerated, systemic complications from these agents can be missed. In addition to being a common disease requiring treatment, glaucoma is also a model system for other degenerative diseases, and many of the concepts originally developed in relation to neurodegenerative diseases such as Alzheimer's disease are under investigation for glaucoma. These include approaches targeted towards neuroprotection and excitotoxicity.

Feasibility and Efficacy of a Mass Switch from Latanoprost to Bimatoprost in Glaucoma Patients in a Prepaid Health Maintenance Organization

OBJECTIVE

To assess the feasibility of an automatic switch of a large number of patients with glaucoma or suspicion of glaucoma from latanoprost to bimatoprost, and to compare the efficacy of the 2 prostaglandin analogs before and after the switch.

DESIGN

Retrospective nonrandomized comparison.

PARTICIPANTS

Forty-three thousand four hundred forty-one California patients and 538 patients at one Southern California clinical facility of a nationwide prepaid health maintenance organization (HMO) who were on either prostaglandin between March 2002 and December 2003 (21 months).

METHODS

Beginning in April 2002, patients on latanoprost were systemically switched to bimatoprost by the HMO pharmacy service after obtaining approval from the entire ophthalmology staff. PART 1: computerized dispensing records of California patients were retrieved. PART 2: medical records of patients at one clinical facility were reviewed.

MAIN OUTCOME MEASURES

Rates of switching or switching back from one prostaglandin to another, intraocular pressure (IOP) control, and intolerability.

RESULTS

PART 1: 17847 patients initially received latanoprost. Of them, 84.8% were switched from latanoprost to bimatoprost, and 13.0% were switched back to latanoprost. Twenty-five thousand five hundred ninety-four patients were started on bimatoprost without previous experience with latanoprost. Of them, 8.6% were later switched to latanoprost use instead. Patients who had previous experience with latanoprost had a statistically significantly higher rate of switching back to latanoprost after a period of bimatoprost use when compared with those who had no prior experience with latanoprost (13.0% vs. 8.6%, respectively; P<0.0001). PART 2: 309 patients were switched from latanoprost to bimatoprost. The mean IOP reduction of 0.51+/-2.77 mmHg (95% confidence interval, 0.20-0.82) after the switch was statistically significant (P = 0.001). Forty-one patients (13.3%) had a decrease of >3 mmHg of IOP. The statistical significance of the IOP reduction after the switch remains in the monotherapy group (P = 0.005) but not in the multitherapy group (P = 0.058). Thirty-three patients (10.7%) who were switched from latanoprost to bimatoprost discontinued bimatoprost and resumed latanoprost.

CONCLUSION

A systematic pharmacy-level switch from latanoprost to bimatoprost in a nationwide HMO achieved a high switch rate, with little switching back. There was a small but statistically significant reduction in mean IOP after the switch. An appreciable proportion of patients switched had a clinically significant reduction of IOP.

Development of specific Rho-kinase inhibitors and their clinical application

Hexahydro-1-(isoquinoline-5-sulfonyl)-1H-1,4-diazepine, HA-1077, is a known selective inhibitor of Rho-kinase. Although its IC(50) value against Rho-kinase is more than 10 times lower than those for kinases such as PKA, PKB, PKC, PKG, MLCK, CaMKII and others, the molecule still retains relative potent inhibition activities against these kinases. In order to produce highly specific Rho-kinase inhibitors, several HA-1077 analogs were synthesized and their kinase inhibition properties evaluated. (S)-Hexahydro-1-(4-ethenylisoquinoline-5-sulfonyl)-2-methyl-1H-1,4-diazepine was found to be a potent Rho-kinase inhibitor. The IC50 value against Rho-kinase was 6 nM, while those against other kinases remained at almost the same level as that of HA-1077. Furthermore, we designed HA-1077 analogs on the basis of the complex structure of PKA and HA-1077. Amongst these, (S)-hexahydro-4-glycyl-2-methyl-1-(4-methylisoquinoline-5-sulfonyl)-1H-1,4-diazepine and other glycine derivatives were found to be highly specific Rho-kinase inhibitors. These Rho-kinase specific inhibitors were applied to rabbit ocular hypertensive models and were shown to reduce intraocular pressure. These results demonstrate that the new 5-isoquinolinesulfonylamides are not only potent ROCK selective compounds, but are also useful compounds for clinical applications.

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.

Current and emerging medical therapies for glaucoma

Glaucoma is a multifactorial optic neuropathy in which there is a characteristic acquired loss of retinal ganglion cells, at levels beyond normal age-related baseline loss, and corresponding atrophy of the optic nerve. Although asymptomatic in its earlier stages, the disease is nevertheless one of the leading global causes of irreversible blindness. Although elevated intraocular pressure (IOP) is one of the most important risk factors and lowering of IOP is the only proven treatment so far, the definition of glaucoma has evolved from a disease caused by increased IOP to one characterised by an IOP-sensitive, progressive optic neuropathy. In recent years, safer and better tolerated topical medications have been developed to control IOP more effectively, thereby limiting the need for surgery. New research has also noted the importance of diurnal IOP variation as a critical risk factor for progression of glaucomatous optic neuropathy (GON) and subsequent visual field loss. Moreover, new discoveries have further elucidated the basic pathophysiological and genetic mechanisms underlying the elevated levels of IOP, as well as the cellular mechanisms of GON. As our understanding of these complex pathways continues to improve, development opportunities for new therapeutic modalities will be enhanced.

Emerging drugs for ophthalmic diseases

The ocular system is crucial to survival. It is subject to many of the same diseases found in other organ systems (e.g., diabetes) as well as diseases of ageing (e.g., macular degeneration) and other diseases (e.g., myopia). This review describes ocular diseases which are treatable, or potentially treatable, by pharmacological intervention (e.g., glaucoma, ocular infection, ocular allergy, ocular inflammation, dry eye and retinal pathology). Presented is a background of these diseases, the medical need for therapy, and current and potential new treatments.

Switching to latanoprost monotherapy for 24 weeks in glaucoma patients

PURPOSE

To investigate the intraocular pressure lowering effect in glaucoma patients switched to latanoprost therapy from isopropyl unoprostone given as monotherapy or in combination with a beta-blocker.

METHODS

Patients with primary open angle glaucoma or normal tension glaucoma treated with 0.12% isopropyl unoprostone as monotherapy or in combination with a beta-blocker were eligible for this single-center clinical study. Of the 51 patients (51 eyes) enrolled, 18 were men and 33 were women aged 62.1 +/- 12.3 years (mean +/- SD). Twenty-two patients had primary open angle glaucoma, and 29 patients had normal tension glaucoma. Intraocular pressure was measured twice within 3 months prior to the switch, and the mean value was taken as the baseline. The patients were then switched to latanoprost (0.005%) monotherapy (once-daily administration), and changes in intraocular pressure were monitored. One physician measured intraocular pressure after 4, 8, 16, and 24 weeks of administration in this 24-week study.

RESULTS

The mean intraocular pressures were 16.0 +/- 2.4 mmHg at baseline, 13.7 +/- 2.3 mmHg after 4 weeks, 13.1 +/- 2.1 mmHg after 8 weeks, 13.6 +/- 2.0 mmHg after 16 weeks, and 13.3 +/- 2.4 mmHg after 24 weeks. A significant decrease in intraocular pressure was noted at all time points in both groups (paired t-test, p < 0.0001), and the intraocular pressure lowering effect persisted through week 24 of administration (analysis of variance, p < 0.0001).

CONCLUSIONS

Switching to latanoprost monotherapy elicits further reduction in intraocular pressure in patients with primary open angle glaucoma or normal tension glaucoma.

Effects of travoprost 0.004% ophthalmic solution, six weeks after its laminated packaging had been removed, in primary open-angle glaucoma: A randomized, controlled, investigator-blinded study

BACKGROUND

Primary open-angle glaucoma (POAG) is a chronic and progressive optic nerve and retinal nerve fiber layer neuropathy, with characteristic visual field damage. The intraocular pressure (IOP) is typically higher than the level considered statistically normal. Although there is no known cure, appropriate reduction of IOP with hypotensive drugs (eg, the topical prostaglandin analogue travoprost) delays the progression of POAG. Chemical-stability studies of travoprost performed by the manufacturer suggest that the stability of travoprost is maintained beyond the expiration date, which is 6 weeks after the laminated packaging has been opened.

OBJECTIVE

The goal of this study was to assess the efficacy and tolerability of travoprost 0.004% ophthalmic solution, 6 to 12 weeks after its expiration date, in patients with POAG.

METHODS

This randomized, controlled, investigator-blinded study was conducted at 2 centers in Brazil: the Ophthalmology Department, Federal University of Goiás, Goiânia, and the Ophthalmology Department, Santa Casa de Misericordia Hospital in São José do Rio Preto, Sao Paulo. Patients with POAG (in 1 or both eyes) were randomly assigned to receive travoprost, either from a bottle from which the laminated packaging had been removed and that had been stored at room light and temperature for 6 weeks (ie, after the expiration date; opened group), or from a bottle that had been sealed until first use by the patient (control group). Drug was to be administered, 1 drop in the lower conjunctival sac (in the affected eye[s]), QD between 7 pm and 9 pm, for 6 weeks. IOP was measured at study weeks 0 (baseline), 4, and 6. The 2 treatment groups were compared with regard to hypotensor effect and incidence of adverse events (AEs).

RESULTS

: Thirty-one patients completed the study (55 eyes; 28 right and 27 left eyes; 35 eyes of women, 20 eyes of men). The mean (SD) ages of the opened and control groups were 61.8 (13.5) and 62.8 (14.1) years, respectively. Twenty-four patients were included in both treatment groups (ie, 1 eye per group). The baseline IOP was similar between the 2 treatment groups. There was a significant reduction in IOP in both groups at 4 and 6 weeks (both, P < 0.001 vs baseline). However, no significant differences in IOP were found between the 2 treatment groups at any time during the study. Conjunctive hyperemia and a burning sensation in the eye immediately after application were the only AEs reported; the incidence of these was similar between the 2 treatment groups.

CONCLUSIONS

In this study of patients with POAG, IOPs and AEs were similar in eyes receiving 6 weeks of treatment with travoprost 0.004% ophthalmic solution, either from bottles from which the laminated packaging had been opened and that had been stored at room light and temperature for 6 weeks (ie, after the expiration date), or from bottles that had been sealed until first use by the patient. These results suggest that travoprost remains effective for at least 12 weeks after the laminated packaging has been opened.

Low incidence of iris pigmentation and eyelash changes in 2 randomized clinical trials with unoprostone isopropyl 0.15%

OBJECTIVE

To assess whether iris color and eyelash changes occur with the use of unoprostone for 2 years.

DESIGN

The 2 clinical trials described herein were prospective, randomized, double-masked, active-controlled, parallel group, multicenter studies.

PARTICIPANTS

A total of 1131 patients with primary open-angle glaucoma or ocular hypertension participated in 2 clinical trials and received either unoprostone isopropyl 0.15% (659), timolol maleate 0.5% (331), or betaxolol hydrochloride 0.5% (141), 1 drop per eye twice daily for up to 24 months.

METHODS

Color photographs (1:1 magnification) were taken of the iris and eyelid of each patient at baseline and at regular intervals thereafter through month 24 using a standardized camera system. Photography included 7 views of each eye plus a calibration photograph and a patient identification photograph, for a total of 16 photographs per patient per visit. Two independent (masked) readers subjectively compared baseline iris colors to subsequent visits. Side view photographs of the upper and lower eyelashes were used for the eyelash length analysis, with each having sufficient depth of field and a sufficient number of eyelashes in focus. Similarly, frontal eyelash views were used for the eyelash density analysis.

MAIN OUTCOME MEASURES

Changes from baseline in iris color and eyelash length and density within and between treatment groups.

RESULTS

Seven cases of iris color change (1.06%) were confirmed in patients treated with unoprostone for up to 24 months; no confirmed cases were reported in the timolol or betaxolol groups. In the unoprostone group, cases of iris color change were confirmed at months 12 (1 case), 18 (2 cases), and 24 (4 cases). No clinically relevant differences were observed among treatment groups for changes from baseline in eyelash length or density.

CONCLUSION

Although iris hyperpigmentation and abnormal eyelash changes may occur after treatment with unoprostone, the incidence of these events appears to be low in the 2-year clinical study.

The safety and efficacy of unoprostone 0.15% versus brimonidine 0.2%

PURPOSE

To compare the efficacy and safety of unoprostone versus brimonidine both given twice daily in ocular hypertensive or primary open-angle glaucoma subjects.

METHODS

After a 1-month washout period a baseline diurnal curve was measured every 2 hours from 08:00 hours (trough) to 20:00 hours in subjects with a trough intraocular pressure (IOP) and the pressure 24 mmHg. Qualified subjects were randomized to either brimonidine or unoprostone. After 6 weeks of treatment the period 1 diurnal curve was performed. Subjects were then switched to the opposite treatment for 6 weeks and the period 2 diurnal curve was performed.

RESULTS

A total of 33 subjects were included in this study. In the brimonidine-treated group the trough IOP 20.1 +/- 2.8 mmHg was reduced from baseline up to 8 hours after dosing. In the unoprostone-treated group the trough IOP was 19.5 +/- 3.0 mmHg, which was statistically equal to that of brimonidine (p = 0.21), was reduced from baseline for 12 hours after dosing. Brimonidine decreased the IOP statistically more than unoprostone at 10:00 and 12:00 hours (p < 0.0001 and p = 0.02, respectively), while unoprostone reduced the IOP more than brimonidine at 18:00 and 20:00 hours (p = 0.002 and p = 0.05, respectively). Safety levels were similar between groups, but unoprostone caused more ocular stinging than brimonidine (p = 0.008).

CONCLUSION

This study suggests that twice daily brimonidine demonstrates a statistically greater peak reduction in IOP than unoprostone. However, unoprostone, but not brimonidine, decreased IOP over the complete 12-hour daytime dosing cycle.

Pseudoexfoliation syndrome and pseudoexfoliative glaucoma

BACKGROUND

Pseudoexfoliative glaucoma (PXG) is a common secondary glaucoma that occurs when pigment and abnormal basement membrane material from anterior segment anatomical structures deposit in the trabecular meshwork. This anomaly arises from the predisposing condition, pseudoexfoliation syndrome (PXE). Complications are common, making this one of the most difficult glaucomas to manage.

PURPOSE

The literature is reviewed in order to facilitate understanding of this condition.

Brimonidine 0.2% vs unoprostone 0.15% both added to timolol maleate 0.5% given twice daily to patients with primary open-angle glaucoma or ocular hypertension

PURPOSE

To compare the efficacy and safety of brimonidine 0.2% vs unoprostone 0.15%, both added to timolol maleate 0.5% each given twice daily.

METHODS

In this prospective, multi-centred, double-masked, crossover comparison, patients were randomized to one treatment group for a 6-week treatment period, and then crossed over to the opposite treatment. Measurements were performed at 0800, 1000, 1600, 1800, and 2000 h at baseline and at the end of each treatment period.

RESULTS

In all, 33 patients entered this trial and 29 completed. The baseline trough intraocular pressure (IOP) was 23.3+/-2.4 and the diurnal curve IOP was 22.0+/-1.3 mmHg. For the brimonidine and timolol maleate treatment group, the trough IOP was 21.6+/-3.3 and the diurnal curve IOP was 19.8+/-2.1 mmHg, while the timolol and unoprostone treatment showed a trough IOP of 20.9+/-3.8 and a diurnal curve IOP of 19.3+/-2.4 mmHg. There was no significant difference between treatment groups at any time point for the diurnal curve, or in the reduction from baseline (P>0.05). Both treatments failed to statistically reduce the IOP from baseline at 1800 h. There was no difference between treatment groups regarding ocular and systemic unsolicited adverse events, but patients admitted to more dryness (P=0.02) and burning upon instillation (P<0.0001) with unoprostone by survey.

CONCLUSION

Brimonidine 0.2% or unoprostone 0.15% added to timolol maleate 0.5% provide similar efficacy and safety throughout the daytime diurnal curve.

Pigment dispersion syndrome and pigmentary glaucoma

BACKGROUND

Pigmentary glaucoma is a common secondary glaucoma that results from pigment being liberated from the posterior iris with subsequent buildup in the trabecular mesh-work. Following this, there is a decrease in aqueous outflow and resultant rise in intraocular pressure.

PURPOSE

While this presentation typically occurs in white myopic males, there is a distinct subtype that occurs in patients of African descent. While there are similarities between the races, there are also significant differences in the clinical presentation of pigmentary glaucoma in white patients and patients of African descent. Iris transillumination defects, corneal endothelial pigment accumulation, and a concave iris-common in whites-are typically absent in patients of African descent.

METHOD

The literature is reviewed in order to summarize pigment dispersion syndrome and pigmentary glaucoma.

A randomized, investigator-masked comparison of diurnal responder rates with bimatoprost and latanoprost in the lowering of intraocular pressure

In glaucoma and ocular hypertension, clinically relevant intraocular pressure lowering due to a new medication is frequently defined as at least a 15% or 20% reduction from baseline intraocular pressure. This report compares the percentages of treated patients achieving such reductions in intraocular pressure after 6 months of treatment with bimatoprost or latanoprost. In the previously published study (Noecker et al: A six-month randomized clinical trial comparing the intraocular pressure-lowering efficacy of bimatoprost and latanoprost in patients with ocular hypertension or glaucoma. Am J Ophthalmol 135:55-63, 2003), patients with glaucoma or ocular hypertension were randomly assigned to once-daily treatment with bimatoprost 0.03% (n=133) or latanoprost 0.005% (n=136), after washout of any previous glaucoma medications. The primary outcome measure of that study was mean change from baseline intraocular pressure. The secondary, post hoc analysis presented here compares the diurnal and long-term responder rates observed with bimatoprost and latanoprost patients. Diurnal responders were defined as patients who achieved at least a 15% or 20% reduction from baseline intraocular pressure at each of the three timepoints (8 am, 12 pm, and 4 pm) on a given visit. At week 1 and months 1, 3, and 6, in the bimatoprost group, 70.7-81.2% of patients achieved at least a 15% reduction in IOP at each timepoint, and 57.9-68.4% achieved at least a 20% reduction. Significantly fewer patients receiving latanoprost achieved a 15% or a 20% decrease in IOP at each timepoint: 48.5-61.8% of patients achieved at least a 15% decrease and 36.0-47.1% achieved at least a 20% decrease. (P< or =.007). The data presented here suggest that patients using bimatoprost are more likely than patients using latanoprost to achieve intraocular pressure reductions of at least 15% or 20% from baseline throughout the day.

A comparison of latanoprost, bimatoprost, and travoprost in patients with elevated intraocular pressure: a 12-week, randomized, masked-evaluator multicenter study

PURPOSE

To Internet Advance publication at ajo.com Feb 13, 2003. compare the intraocular pressure (IOP)-lowering effect and safety of latanoprost, bimatoprost, and travoprost in patients with open-angle glaucoma (OAG) or ocular hypertension (OH).

DESIGN

Interventional study.

METHODS

This 12-week, randomized, parallel-group study was conducted at 45 US sites. Previously treated patients with OAG or OH and an IOP > or =23 mm Hg in one or both eyes after washout received either latanoprost 0.005%, bimatoprost 0.03%, or travoprost 0.004% once daily in the evening. At baseline and after 6 and 12 weeks of therapy, masked evaluators measured IOP in triplicate at 8:00 AM, 12 noon, 4:00 PM, and 8:00 PM, and masked investigators graded conjunctival hyperemia before the 8:00 AM IOP measurement. The primary efficacy outcome measure was change between baseline and Week 12 in the 8:00 AM IOP (time of peak drug effect).

RESULTS

In all, 410 of 411 randomized patients were included in intent-to-treat analyses (latanoprost, 136; bimatoprost, 136; travoprost, 138). Baseline mean 8:00 AM IOP levels were similar (P =.772); by week 12, reductions were observed in all 3 groups (P <.001 for each). Adjusted (ANCOVA) reductions in mean IOP at 8:00 AM were similar (P =.128) as were those at 12 noon, 4:00 PM, and 8:00 PM. Fewer latanoprost-treated patients reported ocular adverse events (P <.001, latanoprost vs bimatoprost), fewer reported hyperemia (P =.001, latanoprost vs bimatoprost), and average hyperemia scores were lower at week 12 (P =.001, latanoprost vs bimatoprost).

CONCLUSIONS

Latanoprost, bimatoprost, and travoprost were comparable in their ability to reduce IOP in OAG and OH patients. Latanoprost exhibited greater ocular tolerability.

Safety of unoprostone isopropyl 0.15% ophthalmic solution in patients with mild to moderate asthma

PURPOSE

To assess the safety of unoprostone isopropyl 0.15% ophthalmic solution (UIOS) in patients with mild to moderate asthma.

METHODS

Randomized, double-masked, two-period crossover, placebo-controlled study comparing unoprostone 0.15% with vehicle-placebo. Pulmonary function tests conducted at baseline and during the 4-hour postdose observation period included forced expiratory volume in 1 s, forced vital capacity, peak expiratory flow rate, and bronchodilator response after 200 microg inhaled salbutamol.

RESULTS

There were no significant changes in pulmonary function up to 4 h postdose after treatment with 1 drop unoprostone 0.15% in each eye.

CONCLUSION

Unoprostone 0.15% was safe for use in patients with mild to moderate asthma, without affecting the response to bronchodilator therapy.

Timolol 0.5%/dorzolamide 2% fixed combination vs timolol maleate 0.5% and unoprostone 0.15% given twice daily to patients with primary open-angle glaucoma or ocular hypertension

OBJECTIVE

To compare the efficacy and safety of timolol 0.5%/dorzolamide 2% fixed combination vs timolol maleate 0.5% and unoprostone 0.15% given twice daily.

DESIGN

Prospective multicenter, randomized, double-masked, crossover comparison study.

METHODS

Primary open-angle glaucoma or ocular hypertension patients were randomly assigned to one of the treatment groups for a 6-week treatment period and then crossed over to the opposite treatment. Diurnal curve testing was performed at 8:00 AM, 10:00 AM, 4:00 PM, 6:00 PM, and 8:00 PM at baseline and the end of each treatment period. The run-in medicine was timolol twice daily for 28 days.

RESULTS

Thirty-two patients completed this trial. The baseline trough pressure was 24.3 +/- 3.0 mm Hg, and the diurnal curve was 23.4 +/- 3.2 mm Hg. For the fixed combination the treatment trough pressure was 20.8 +/- 4.1 mm Hg and the diurnal curve was 19.6 +/- 3.6 mm Hg, whereas timolol and unoprostone concomitant therapy showed a treatment trough pressure of 20.1 +/- 4.5 mm Hg and a diurnal pressure of 19.8 +/- 4.1 mm Hg. There was no significant difference between treatment groups at any time point, for the diurnal curve, or in the extended reduction from baseline. There was no difference between treatment groups regarding ocular and systemic unsolicited or solicited adverse events. Burning, stinging, and conjunctival hyperemia were the adverse events most noted. There were no serious adverse events during this trial.

CONCLUSIONS

This study suggests that both timolol/dorzolamide 2% fixed combination and concomitant timolol maleate 0.5% and unoprostone 0.15% therapy provide similar efficacy and safety throughout the daytime diurnal curve.

A six-month randomized clinical trial comparing the intraocular pressure-lowering efficacy of bimatoprost and latanoprost in patients with ocular hypertension or glaucoma

PURPOSE

To compare the intraocular pressure (IOP)-lowering efficacy and safety of topical bimatoprost 0.03% with latanoprost 0.005%.

DESIGN

Multicenter, randomized, investigator-masked clinical trial.

METHODS

After washout of glaucoma medications, ocular hypertension or glaucoma patients were randomly assigned to once-daily bimatoprost 0.03% (n = 133) or latanoprost 0.005% (n = 136) for 6 months. The primary outcome measure was mean change from baseline IOP (8 AM, 12 PM, 4 PM). Secondary measures included mean IOP, ophthalmologic examination, adverse events, and the percentage of patients reaching specific target IOPs.

RESULTS

Mean change from baseline IOP was significantly greater for bimatoprost patients than for latanoprost patients at all measurements on each study visit; 1.5 mm Hg greater at 8 AM (P <.001), 2.2 mm Hg greater at 12 PM (P <.001), and 1.2 mm Hg greater at 4 PM (P =.004) at month 6. At the end of the study, the percentage of patients achieving a > or = 20% IOP decrease was 69% to 82% with bimatoprost and 50% to 62% with latanoprost (P < or = .003). In addition, the distribution of patients achieving target pressures in each range (< or = 13 to < or = 15 mm Hg, >15 to < or = 18 mm Hg, and > 18 mm Hg) showed that bimatoprost produced lower target pressures compared with latanoprost at all times measured (P < or = .026). Few patients were discontinued for adverse events (6 on bimatoprost; 5 on latanoprost). On ophthalmologic examination, conjunctival hyperemia (P <.001) and eyelash growth (P =.064) were more common in bimatoprost patients.

CONCLUSIONS

Bimatoprost is more effective than latanoprost in lowering IOP. Both drugs were well tolerated, with few discontinuations for adverse events.

Randomized clinical trial of latanoprost and unoprostone in patients with elevated intraocular pressure

PURPOSE

To compare the intraocular pressure (IOP)-lowering effect and safety of latanoprost 0.005% once daily with that of unoprostone 0.15% twice daily for patients with primary open-angle glaucoma or ocular hypertension.

DESIGN

Randomized clinical trial.

METHODS

In a prospective, 8-week, investigator-masked, parallel-group study conducted at numerous centers in the United States, 165 previously treated patients with IOP >or= 25 mm Hg in one or both eyes after washout were randomly assigned to receive either latanoprost 0.005% once daily in the evening or unoprostone 0.15% twice daily. Observations procedures were Goldmann applanation tonometry, best-corrected visual acuity, slit lamp biomicroscopy, and ophthalmoscopy. The main outcome measure was change in the mean of the IOPs measured at 8:00 AM, 12 noon, and 4:00 PM between baseline (before treatment) and after 8 weeks of treatment.

RESULTS

The change in the mean +/- SD of the IOPs measured at 8:00 AM, 12 noon, and 4:00 PM was -7.2 +/- 3.2 mm Hg (28%) for latanoprost (25.3 +/- 2.8 mm Hg at baseline to 18.2 +/- 2.8 mm Hg at 8 weeks) and -3.9 +/- 2.6 mm Hg (15%) for unoprostone (25.5 +/- 3.3 mm Hg at baseline to 21.6 +/- 4.0 mm Hg; P <or=.001. No serious adverse event related to either medication was reported.

CONCLUSIONS

Over an 8-week period, latanoprost 0.005% once daily lowered IOP more than unoprostone 0.15% twice daily in patients with elevated IOP. Both agents were safe and well tolerated.

Safety of unoprostone isopropyl as mono- or adjunctive therapy in patients with primary open-angle glaucoma or ocular hypertension

This review summarises the safety of unoprostone isopropyl (both at the 0.12 and 0.15% concentrations) instilled twice daily in patients with primary open-angle glaucoma (POAG) or ocular hypertension (OH). For unoprostone 0.15%, combined data from two 12-month comparative monotherapy studies are reported, as well as data from three adjunctive therapy studies and two special population studies. With unoprostone monotherapy, most adverse events were mild or moderate and transient in nature. Less than 7% of unoprostone-treated patients discontinued therapy due to an adverse event. The most common adverse events associated with unoprostone were burning/stinging, burning/stinging directly upon drug instillation, ocular itching, and conjunctival hyperaemia. Unoprostone had no clinically notable effects on vital signs, laboratory profiles, or comprehensive ophthalmic examinations. One of 659 unoprostone 0.15%-treated patients had a change in iris colour after 12 months of monotherapy. Except for a higher incidence of burning/stinging and burning/stinging upon instillation, unoprostone was comparable to timolol 0.5% twice daily and betaxolol 0.5% twice daily. No safety concerns were raised with use of unoprostone as adjunctive therapy. Unoprostone had no significant effect on exercise-induced heart rate in healthy subjects or on pulmonary function in patients with mild-to-moderate asthma. The safety profile of unoprostone 0.15% was consistent with published information on the 0.12% formulation. In conclusion, unoprostone has an excellent safety profile in patients with POAG or OH.

Travoprost--a new prostaglandin analogue for the treatment of glaucoma

Travoprost, a highly selective and potent analogue of the prostaglandin PGF(2)(alpha), has recently been approved and marketed as a topical ocular hypotensive agent for the treatment of ocular hypertension and glaucoma. Following absorption into the eye, the free acid form of travoprost interacts with the endogenous FP prostanoid receptor to enhance aqueous humor outflow and lower intraocular pressure (IOP). Travoprost is distinguished from other marketed prostaglandin analogues in that it is a full agonist at the prostaglandin receptor. It is also highly selective with little or no affinity for other prostanoid or non-prostanoid receptors in the eye. Travoprost provides robust lowering of IOP with little diurnal fluctuation and results in low target pressures in a large percentage of patients. In controlled clinical trials, travoprost 0.004% o.d. used as monotherapy produced greater IOP reduction than timolol 0.5% b.i.d. and equal or greater reduction than latanoprost 0.005%o.d. Travoprost 0.004% was also shown to be an effective adjunctive agent offering an additional 5 - 7 mmHg IOP reduction in patients inadequately controlled on timolol 0.5%. Subgroup analysis of a large Phase III trial revealed travoprost 0.004% to be significantly more effective at lowering IOP in African American patients by almost 2 mmHg compared to non-African Americans. Moreover, a higher percentage of African American patients responded to travoprost 0.004% and reached lower target pressures than with either latanoprost 0.005% or timolol 0.5%. Travoprost is a very stable compound, maintaining its efficacy following exposure to extremely low and high temperatures, repeated freezing and thawing and exposure to light. Throughout all clinical trials, travoprost was found to be safe and well-tolerated with very few (< 5%) discontinuations due to adverse events. Travoprost 0.004% represents a clinically significant advance for the treatment of glaucoma and ocular hypertension, offering superior IOP reduction and diurnal control, especially among African American patients, in a safe, well-tolerated, stable formulation.

Comparison of the cardiovascular effects of unoprostone 0.15%, timolol 0.5% and placebo in healthy adults during exercise using a treadmill test

PURPOSE

To compare the cardiovascular effects of unoprostone 0.15%, timolol 0.5% and placebo in healthy adults during exercise using a treadmill test.

METHODS

Thirty subjects aged 18-37 years (mean age = 24.1 years) were randomized to one of six treatment sequences in a three-treatment, three-period crossover study (William's design). Study medication was instilled b.i.d. for 5 days before visits 2, 3, and 4. Between treatments, study medication was washed out for 9-10 days. Each subject underwent a submaximal treadmill test at visits 2 through 4, 15 min after dosing.

RESULTS

After 15 min of exercise, average heart rates were 143.1 +/- 21.2, 134.5 +/- 20.0 and 145.4 +/- 20.8 bpm for the unoprostone, timolol and placebo treatments, respectively. At no timepoint was there a statistically significant difference between the unoprostone and placebo treatments (p > 0.05). Beginning with the second minute of exercise, timolol produced a greater decrease in heart rate at all timepoints from placebo than unoprostone (p < 0.05). No consistent differences in systolic or diastolic blood pressure were observed between drug treatments (p > 0.05).

CONCLUSIONS

Unlike timolol, unoprostone 0.15% does not reduce exercise-induced heart rate, indicating a lack of clinical effect on systemic beta-adrenergic receptors in young and healthy subjects.

Prostaglandin analog treatment of glaucoma and ocular hypertension

OBJECTIVE

To review available data related to the use of prostaglandin analogs (bimatoprost, latanoprost, travoprost, unoprostone) in the management of ocular hypertension and open-angle glaucoma.

DATA SOURCES

Primary and review articles were identified from a MEDLINE search (1966-May 2001) and requested information from product manufacturers.

STUDY SELECTION AND DATA EXTRACTION

All available information, including that published in articles and abstracts, which was deemed relevant was included in this review. Limited data have been published to date.

DATA SYNTHESIS

The prostaglandin analogs appear to be effective, well-tolerated agents for the reduction of intraocular pressure (IOP) in patients with primary open-angle glaucoma and ocular hypertension. This drug class offers an alternative for patients who do not achieve control with another topical antiglaucoma agent or for those with a contraindication to first-line therapy with beta-adrenergic antagonists. Based on preliminary clinical data, bimatoprost, latanoprost, and travoprost appear to be at least as effective as timolol, while the effectiveness of unoprostone is similar or slightly less. Prostaglandin analogs may be used in conjunction with other antiglaucoma medications, although further studies must establish the optimal combination. Whether clinical experience will yield outcomes in favor of one of the prostaglandin analogs remains to be determined. Patients should be educated on adverse events associated with prostaglandin analogs, particularly the potential for changes in the pigmentation of the iris and eyelashes.

CONCLUSIONS

Bimatoprost, latanoprost, and travoprost appear to be equivalent to the current standard of therapy in the topical treatment of elevated IOP. Further clinical data published in article versus abstract format is required to better assess potential differences among these 3 agents.