Long term effect of latanoprost on intraocular pressure in normal tension glaucoma

Comparative analysis of medical treatments for long-term control of normal tension glaucoma: A systematic review and model-based network meta-analysis

BACKGROUND

To evaluate and compare the long-term efficacy of medical treatments for normal tension glaucoma (NTG) in controlling intraocular pressure (IOP), and establish a hierarchical ranking based on their effectiveness. 'Long-term' is defined as a treatment duration of over 12 weeks in randomised controlled trials (RCTs).

METHODS

This systematic review and model-based network meta-analysis (MBNMA) collected data of 795 patients with 997 eyes from RCTs. Patients with NTG were selected based on strict inclusion/exclusion criteria, with randomsation procedures and masking as reported in the individual trials. Eight different medications were compared, including prostaglandin analogues, beta-blockers, brimonidine, unoprostone isopropyl, brovincamine, and palmitoylethanolamide (PEA). Notably, PEA is an oral medication, while other drugs are topical agents.

RESULTS

Primary outcome is the long-term efficacy of IOP control across medications with different follow-up durations. Among the eight medications, PEA demonstrates the highest efficacy (Surface under the cumulative ranking, SUCRA = 7.46%), followed by two prostaglandin analogues: travoprost (SUCRA = 6.86%) and latanoprost (SUCRA = 6.76%), then two beta-blockers: nipradilol (SUCRA = 4.90%) and timolol (SUCRA = 4.89%). Both brimonidine and unoprostone isopropyl have SUCRA scores below 4.0%, indicating modest but limited efficacy. Brovincamine has the lowest SUCRA score (1.32%), reflecting minimal effectiveness.

CONCLUSIONS

This study revealed PEA as a promising agent for long-term IOP control in NTG patients, suggesting potential use as primary or adjunctive therapy. The outcomes call for PEA's consideration in clinical practice and highlight the need for further research into its long-term efficacy and safety for NTG.

The TGFβ Induced MicroRNAome of the Trabecular Meshwork

Primary open-angle glaucoma (POAG) is a progressive optic neuropathy with a complex, multifactorial aetiology. Raised intraocular pressure (IOP) is the most important clinically modifiable risk factor for POAG. All current pharmacological agents target aqueous humour dynamics to lower IOP. Newer therapeutic agents are required as some patients with POAG show a limited therapeutic response or develop ocular and systemic side effects to topical medication. Elevated IOP in POAG results from cellular and molecular changes in the trabecular meshwork driven by increased levels of transforming growth factor β (TGFβ) in the anterior segment of the eye. Understanding how TGFβ affects both the structural and functional changes in the outflow pathway and IOP is required to develop new glaucoma therapies that target the molecular pathology in the trabecular meshwork. In this study, we evaluated the effects of TGF-β1 and -β2 treatment on miRNA expression in cultured human primary trabecular meshwork cells. Our findings are presented in terms of specific miRNAs (miRNA-centric), but given miRNAs work in networks to control cellular pathways and processes, a pathway-centric view of miRNA action is also reported. Evaluating TGFβ-responsive miRNA expression in trabecular meshwork cells will further our understanding of the important pathways and changes involved in the pathogenesis of glaucoma and could lead to the development of miRNAs as new therapeutic modalities in glaucoma.

Therapeutic Potential of Antioxidants and Hybrid TEMPOL Derivatives in Ocular Neurodegenerative Diseases: A Glimpse into the Future

Reactive oxygen species play a significant role in the pathogenesis of various ocular neurodegenerative diseases especially glaucoma, age-related macular degeneration (AMD), and ocular ischemic stroke. Increased oxidative stress and the accumulation of ROS have been implicated in the progression of these diseases. As a result, there has been growing interest in exploring potential therapeutic and prophylactic strategies involving exogenous antioxidants. In recent years, there have been significant advancements in the development of synthetic therapeutic antioxidants for targeting reactive oxygen species (ROS) in neurodegenerative diseases. One area of focus has been the development of hybrid TEMPOL derivatives. In the context of ocular diseases, the application of next-generation hybrid TEMPOL antioxidants may offer new avenues for neuroprotection. By targeting ROS and reducing oxidative stress in the retina and optic nerve, these compounds have the potential to preserve retinal ganglion cells and trabecular meshwork and protect against optic nerve damage, mitigating irreversible blindness associated with these diseases. This review seeks to highlight the potential impact of hybrid TEMPOL antioxidants and their derivatives on ocular neurodegenerative disorders.

Effects of sustained daily latanoprost application on anterior chamber anatomy and physiology in mice

Latanoprost is a common glaucoma medication. Here, we study longitudinal effects of sustained latanoprost treatment on intraocular pressure (IOP) in C57BL/6J mice, as well as two potential side-effects, changes in iris pigmentation and central corneal thickness (CCT). Male C57BL/6J mice were treated daily for 16 weeks with latanoprost. Control mice were treated on the same schedule with the preservative used with latanoprost, benzalkonium chloride (BAK), or handled, without ocular treatments. IOP and CCT were studied at pre-treatment, 2 "early" time points, and 2 "late" time points; slit-lamp analysis performed at a late time point; and expression of corneal and iridial candidate genes analyzed at the end of the experiment. Latanoprost lowered IOP short, but not long-term. Sustained application of BAK consistently resulted in significant corneal thinning, whereas sustained treatment with latanoprost resulted in smaller and less consistent changes. Neither treatment affected iris pigmentation, corneal matrix metalloprotease expression or iridial pigment-related genes expression. In summary, latanoprost initially lowered IOP in C57BL/6J mice, but became less effective with sustained treatment, likely due to physiological adaptation. These results identify a new resource for studying changes in responsiveness associated with long-term treatment with latanoprost and highlight detrimental effects of commonly used preservative BAK.

Change in Central Corneal Thickness After the Discontinuation of Latanoprost in Normal Tension Glaucoma-Change in Central Corneal Thickness After Stop of Latanoprost

PURPOSE

To assess the impact of latanoprost on central corneal thickness (CCT) after ceasing medication in patients with normal tension glaucoma (NTG).

METHODS

A total of 46 eyes from 46 NTG patients, and 44 eyes from 44 individuals with glaucoma suspect (controls), were included in this retrospective study. Newly diagnosed early NTG patients (visual field mean deviation >-6.00) were administered latanoprost 0.005% monotherapy once a day. CCTs were measured by ultrasound pachymetry before treatment, for 5 years during treatment, and for 2 years after ceasing treatment.

RESULTS

Mean CCT was reduced significantly in the NTG group during treatment [544.4 ± 35.8 μm vs. 531.4 ± 32.5 μm (n = 46), P < 0.001]. After ceasing latanoprost treatment, mean CCT increased [531.4 ± 32.5 μm vs. 544.6 ± 37.1 μm (n = 46), P < 0.01] over the course of 2 years. In the control group, however, mean CCT was not significantly different [553.5 ± 27.5 μm vs. 561.8 ± 24.7 μm (n = 44), P = 0.06] at the 7-year follow-up.

CONCLUSIONS

Latanoprost significantly reduced CCT in NTG patients after 5 years of treatment; however, the reduction was reversed 2 years after discontinuation of treatment.

PTGFR and SLCO2A1 Gene Polymorphisms Determine Intraocular Pressure Response to Latanoprost in Han Chinese Patients with Glaucoma

PURPOSE

To determine the relationship between the polymorphisms of the prostaglandin F2α receptor (PTGFR) and solute carrier organic anion transporter family 2A1 (SLCO2A1) genes and response to latanoprost treatment in Han Chinese patients with glaucoma.

MATERIALS AND METHODS

89 patients with POAG or OH received latanoprost treatment and intraocular pressure (IOP) data was collected on day 7 and day 30. The rs12093097, rs35586449, rs3753380, and rs3766355 single-nucleotide polymorphisms (SNPs) in the PTGFR gene and rs2370512, rs34550074, and rs4241366 SNPs in the SLCO2A1 gene were analyzed using direct DNA sequencing or polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).

RESULTS

The IOP in patients with GG allele of rs4241366 was lower than in patients with GC+CC on day 7 (p = 0.007). The IOP in patients with CC allele of rs3766355 was lower than in patients with CA+AA on day 30 (p = 0.024). Multiple regression analysis demonstrated that even after adjusting for baseline IOP, the rs4241366 in SLCO2A1 gene and the rs3766355 in PTGFR gene correlated with response to latanoprost on day 7 (rs4241366, p = 0.014) and day 30 (rs3766355, p = 0.035), respectively, in Han Chinese patients with glaucoma.

CONCLUSIONS

An association was found between single nucleotide polymorphisms of the PTGFR and SLCO2A1 genes and the response to latanoprost in Han Chinese patients with glaucoma. These SNPs may be important determinants of differential response to latanoprost.

Nonresponders to Prostaglandin Analogs Among Normal-Tension Glaucoma Patients

PURPOSE

To investigate patients whose intraocular pressure (IOP) did not decrease after treatment using a prostaglandin analog (nonresponders).

METHODS

This was an open-label, retrospective, case series study from a single institution. We retrospectively investigated the mean IOP reduction rates, and the proportions of nonresponders, among normal tension glaucoma (NTG) patients (209 cases, 209 eyes) treated using 1 of 4 prostaglandin analogs: latanoprost (40 patients), travoprost (64 patients), tafluprost (52 patients), or bimatoprost (53 patients). Absolute IOP was compared with pretreatment values for all 4 groups at the first and second visits after commencement of prostaglandin analog monotherapy. The IOP reduction rate was compared between groups. The proportion of nonresponders, defined as patients with IOP reduction rate <10% at both visits, was calculated in each group.

RESULTS

The average IOP had significantly decreased from the pretreatment value at the first visit after treatment; the average IOP reduction rate ranged from 15.3% to 22.6%. The IOP reduction rate in the bimatoprost group was significantly higher than those in the travoprost and tafluprost groups (P < 0.001). We identified 6 nonresponders (15.0%) in the latanoprost group, 9 (14.1%) in the travoprost group, 4 (7.7%) in the tafluprost group, and none (0.0%) in the bimatoprost group; nonresponse rates were significantly lower in the bimatoprost group than in the other groups (P ≤ 0.05).

CONCLUSION

Among NTG patients treated using prostaglandin analogs, from 0% to 15% were classified as nonresponders, depending on the prostaglandin analog used. The proportion of nonresponders was significantly lower in the bimatoprost group.

Preservative-free tafluprost in the treatment of naive patients with glaucoma and ocular hypertension

PURPOSE

The study reported here investigated the efficacy, tolerability, and safety of the preservative-free prostaglandin analog tafluprost 0.0015% in treatment-naive patients.

PATIENTS AND METHODS

Data were collected in two non-interventional, prospective, multicenter, observational, open-label studies of identical design that were conducted in Germany and the Czech Republic. All subjects received preservative-free tafluprost 0.0015% once daily. Intraocular pressure (IOP) levels were recorded for each eye at untreated baseline and 3 months after initiation of medical treatment. The primary outcome was change in mean IOP from baseline to month 3. In the primary open-angle glaucoma (POAG) and ocular hypertension (OH) patient subgroups, analyses were stratified by the level of baseline IOP: ≥20 to 23 mmHg versus ≥24 mmHg. In addition, responder rates and the achievement of pre-specified IOP levels at month 3 were evaluated. Local tolerance of preservative-free tafluprost was evaluated by the patients at final visit. Overall satisfaction with the medical treatment was evaluated by both patients and physicians. All adverse events were recorded.

RESULTS

A total of 579 treatment-naive patients with POAG (n = 349), OH (n = 105), normal tension glaucoma (n = 71), exfoliative glaucoma (n = 27), or other glaucomas (n = 27) were included in this observational study. Mean IOP level at baseline for all patients was 23.6 ± 4.0 mmHg. Mean IOP at month 3 was 16.8 ± 2.9 mmHg (-28.8% vs baseline). At month 3, significant reductions in mean IOP (P < 0.001) were seen in all patients and all subgroups. Preservative-free tafluprost lowered mean IOP significantly in patients with POAG and OH with IOP levels ≥ 20 to 23 mmHg from 21.9 ± 1.1 mmHg at baseline to 16.5 ± 2.2 mmHg, and in the subgroup with IOP levels ≥ 24 mmHg from 26.2 ± 2.4 mmHg to 17.9 ± 2.4 mmHg. In the subgroups of patients with POAG and OH, an IOP response ≥20%, ≥30%, and ≥40% was achieved by 83.4%, 44.1%, and 12.8%, respectively. Overall, patients with higher baseline IOP values showed a better response than patients with lower baseline IOP levels. Preservative-free tafluprost was well tolerated and safe. After 3 months, 97.9% of all patients remained on therapy.

CONCLUSION

In this real-world observational study, treatment with once-daily preservative-free tafluprost proved efficacious, well tolerated, and safe in treatment-naive patients.

Current primary open-angle glaucoma treatments and future directions

Primary open-angle glaucoma (POAG) is a leading cause of blindness with no known cure. Management of the disease focuses on lowering intraocular pressure (IOP) with current classes of drugs like prostaglandin analogs, beta-blockers, alpha-agonists, and carbonic anhydrase inhibitors. These treatments have not helped all patients. Some patients continue to experience deterioration in the optic nerve even though their IOPs are within the normal range. New views have surfaced about other pathophysiological processes (such as oxidative stress, vascular dysfunction, and retinal cell apoptosis) being involved in POAG progression, and adjunctive treatments with drugs like memantine, bis(7)-tacrine, nimodipine, and mirtogenol are advocated. This review examines the current and proposed treatments for POAG. Some of the proposed drugs (bis(7)-tacrine, nimodipine, vitamin E, and others) have shown good promise, mostly as monotherapy in various clinical trials. It is recommended that both the current and proposed drugs be put through further robust trials in concurrent administration and evaluated.

Effect of travoprost on 24-hour intraocular pressure in normal tension glaucoma

PURPOSE

The effect of travoprost 0.004% on 24-hour intraocular pressure (IOP) was examined in patients with normal tension glaucoma (NTG).

SUBJECTS AND METHODS

This study included 17 patients with newly diagnosed unilateral NTG. IOP was measured at three-hour intervals over 24 hours by Goldman applanation tonometer in patients taking topical travoprost 0.004% and was compared retrospectively with 24-hour IOP data in untreated eyes.

RESULTS

IOP values were significantly reduced at individual time points after treatment (P < 0.01). Mean 24-hour IOP, maximum 24-hour IOP, minimum 24-hour IOP, and 24-hour IOP fluctuations at baseline (mean +/- SD) were 12.9 +/- 2.2 mmHg, 15.4 +/- 2.7 mmHg, 10.5 +/- 2.2 mmHg, and 4.9 +/- 1.2 mmHg, respectively, and were significantly reduced to 10.3 +/- 2.0 mmHg, 12.4 +/- 2.5 mmHg, 8.5 +/- 1.9 mmHg (all P < 0.001), and 3.9 +/- 1.5 mmHg (P < 0.05), respectively, after treatment. The rate of IOP reduction greater than 20% was 58.8% (10 eyes) for maximum 24-hour IOP and 53.0% (nine eyes) for mean 24-hour IOP.

CONCLUSION

Travoprost reduced IOP throughout the 24-hour study period, with over half of the eyes examined showing IOP reduction exceeding 20%.

Predictors of additional intraocular pressure reduction in patients changed to latanoprost/timolol fixed combination

Background

Given the growing number of ocular hypotensive medications available, it is important to be able to predict a positive response to therapy. The purpose of the present study was to identify predictors of an additional 10% intraocular pressure (IOP) reduction after 12 weeks of treatment with latanoprost/timolol fixed combination (FC) in patients requiring a change in their previous ocular hypotensive medication.

Methods

This multicenter, open-label, prospective, phase IIIb study included subjects ≥18 years of age with open-angle glaucoma (OAG) or ocular hypertension (OHT). Eligible subjects had baseline IOP ≥21 mmHg and insufficient response to current beta-blocker monotherapy. The primary efficacy analysis (logistic regression) identified predictors of a positive response after 12 weeks of latanoprost/timolol FC.

Results

The intent-to-treat (ITT) population included 383 subjects treated with ≥1 drop of FC and having ≥1 follow-up IOP assessment. Mean IOP was 22.19 ± 2.16 mmHg at baseline and was reduced by 5.42 ± 2.71 mmHg at study end. In all, 325 (84.9%) subjects had a positive response to latanoprost/timolol FC; the response rate was similar across groups: OAG (n = 208; 82.7%); OHT (n = 161; 87.6%); OAG+OHT (n = 14; 85.7%). Higher baseline IOP (odds ratio: 1.284; 95% confidence interval [CI]: 1.101, 1.497; p = 0.0014) and absence of adverse events (odds ratio: 0.318; 95% CI: 0.161, 0.629; p = 0.0010) were significant predictors of positive response. Age, gender, ethnic origin, diagnosis, family history of OAG/OHT, corneal thickness, and concomitant systemic beta-blocker were not significant predictors of a positive response in the ITT analysis. The FC was well tolerated. The most common adverse events were related to the eye and were consistent with known adverse events associated with latanoprost and timolol.

Conclusions

These results support the use of latanoprost/timolol FC in patients whose IOP is insufficiently controlled on beta-blocker monotherapy. Patients with higher baseline IOP levels and who do not experience adverse events while on therapy are most likely to achieve a positive response to latanoprost/timolol FC.

Trial Registration

Study registration number: NCT00230763

First-line latanoprost therapy in ocular hypertension or open-angle glaucoma patients: a 3-month efficacy analysis stratified by initial intraocular pressure

Background

Prospective, multicenter, randomized, double-masked trials have shown latanoprost instilled once daily to be at least as effective as and generally superior to timolol administered twice daily and to be as effective as other frequently prescribed prostaglandin analogues. This study prospectively assessed the efficacy of latanoprost monotherapy in a large cohort of treatment-naive patients with a broad range of baseline intraocular pressure (IOP) levels treated in actual clinical practice settings.

Methods

This prospective, open-label, multicenter, uncontrolled, phase IV study included treatment-naive ocular hypertension or open-angle glaucoma subjects initiating latanoprost once daily (evening). IOP levels were measured at baseline and after 1 and 3 months. The primary efficacy outcome was mean change in IOP from baseline to month 3. Analyses were stratified by baseline IOP: ≥ 20 and <24 mmHg vs ≥ 24 mmHg.

Results

Efficacy analyses (intent to treat) included 572 subjects: 20 to <24 mmHg group, N = 252; ≥ 24 mmHg group, N = 320. Mean baseline IOP levels were 22.2 ± 0.9 mmHg and 26.7 ± 2.8 mmHg, respectively. At month 3, significant IOP reductions were seen in both groups (p < 0.0001, within-group differences); reductions were smaller in the 20 to <24 mmHg group (-6.3 ± 2.4 vs -9.2 ± 3.7 mmHg, respectively; -28.0 ± 10.6% vs -34.1 ± 11.9%, respectively). An IOP reduction of ≥ 30% from baseline to month 3 was noted in 48.4% and 65.6% of subjects, respectively (p < 0.0001). At month 3, targets IOPs of ≤ 18 mmHg were achieved by ≥ 70% of subjects in both groups. Latanoprost was well tolerated with an adverse event profile similar to that reported in the literature.

Conclusions

This "real world" study found once-daily latanoprost to be effective and safe in treatment-naive ocular hypertension or open-angle glaucoma patients. Patients with baseline IOP levels of 20 to <24 mmHg as well as ≥ 24 mmHg benefitted from initial latanoprost therapy.

Trial Registration

Trial Registration Number: NCT00647101

Effect of Latanoprost on Cultured Porcine Corneal Stromal Cells

PURPOSE

Latanoprost reduces intraocular pressure mainly by enhancing uveoscleral outflow that may be involved in the decreased of extracellular matrixes such as collagens. However, the effect of latanoprost on corneal stromal cells is not well understood. In the current study, we investigated the changes of cultured porcine corneal stromal cells upon exposure to latanoprost.

METHODS

Porcine corneal stromal cells were acquired from primary culture and maintained in fetal bovine serum-containing medium. Cells were estimated on 3H-thymidine, 3H-leucine, 3H-uridine, 3H-proline uptakes and migration. Dead and living cells were estimated with MTT assay. The changes of type 1 collagen and fibronectin proteins were detected by means of immunofluorescent staining and Western blot assay. Intracellular free Ca2+ ([Ca2+]i) mobility was studied by spectrofluorophotometer after loading with fura-2-AM.

RESULTS

Latanoprost has remarkable effects inhibiting cultured corneal stromal cells on 3H-thymidine, 3H-leucine, 3H-uridine, 3H-proline uptakes and cellular migration. The inhibitory effects are in a dose-dependent manner at concentrations ranging from 10(- 5), 10(- 6), 10(- 7) to 10(- 8) M. The 50% inhibitory dosages (ID50) for latanoprost to corneal stromal cells, as measured by 3H-thymidine uptake, 3H-uridine uptake, 3H-leucine uptake, 3H-proline uptakes and cellular migration were 5.01 x 10(- 6) M, 2.81 x 10(- 6) M, 2.09 x 10(- 6) M, 3.89 x 10(- 7) M and 2.2 x 10(- 6) M, respectively. In the presence of latanoprost, the cellular MTT values were also decreased significantly. Immunofluorescent staining displayed that latanoprost changed type 1 collagen distribution in cultured corneal stromal cells. Western blot assay revealed that latanoprost caused cells to decrease in fibronectin protein. In Ca2+-containing buffer, latanoprost induced a significant rise in [Ca2+]i at 10(- 5) and 10(- 6) M.

CONCLUSIONS

These results indicate that latanoprost may induce the morphological and biochemical changes in cultured corneal stromal cells. Long-term use of latanoprost needs to be carefully monitored for change in corneal stroma.

Long-term effects of latanoprost monotherapy on intraocular pressure in Japanese glaucoma patients

PURPOSE

To assess the long-term effects of latanoprost monotherapy on intraocular pressure (IOP) reduction in Japanese patients with glaucoma.

METHODS

Those enrolled were patients with glaucoma who had been treated on an outpatient basis for more than 5 years at the Glaucoma Outpatient Clinic of the University of Yamanashi Hospital, with only latanoprost ophthalmic solution as the first drug of choice. Subjects who underwent treatment with a drug other than latanoprost, laser therapy, or surgery were eliminated from the study, and IOP reduction by latanoprost, the dropout rate and causative reasons, and the types of additional therapy were assessed in a retrospective manner.

RESULTS

Seventy-two patients (age: 68.3+/-13.0 y) were enrolled, including 40 men and 32 women for the checking of 72 eyes. There were 47 eyes with normal tension glaucoma (NTG) and 25 with primary open angle glaucoma (POAG). The mean duration of latanoprost monotherapy was 4.1+/-2.0 years (range: 5 mo to 7 y, median: 4.0 y). IOP reduction rates (cumulative dropout rates) relative to the mean IOP before the start of latanoprost monotherapy (17.8+/-3.4 mm Hg) were 11.5% (8.3%), 15.5% (8.3%), 13.0% (9.7%), 13.4% (13.9%), 13.5% (19.4%), and 10.6% (30.6%) at 6 months, 1 year, 2 years, 3 years, 4 years, and 5 years after the start of monotherapy, respectively. Although latanoprost demonstrated significant IOP reduction in POAG and NTG, eyes with POAG showed significant IOP reduction than those with NTG. Two eyes presented with local adverse events resulting from the discontinuation of use of latanoprost, and 4 eyes required filtering surgery.

CONCLUSIONS

Latanoprost stably reduced IOP over a long term and maintained visual field in approximately 70% of eyes with glaucoma after treatment for 5 years.

Effect of travoprost on intraocular pressure during 12 months of treatment for normal-tension glaucoma

PURPOSE

To evaluate the intraocular pressure (IOP)-lowering effect of travoprost in normal-tension glaucoma (NTG) over a 12-month follow-up.

METHODS

Forty-five eyes of 45 patients with unilateral NTG were treated with travoprost (0.004%) once a day for 12 months. Mean IOP and the IOP reduction from baseline were assessed at 0.5, 1, 3, 6, 9, and 12 months after the initiation of the treatment. Adverse ocular event frequency and the frequency of discontinuation of treatment due to adverse events were evaluated.

RESULTS

Mean IOP during 12 months of travoprost treatment ranged from 11.17 to 11.82 mmHg, and the mean IOP reduction in relation to baseline IOP from -2.71 to -3.71 mmHg (-18.3% to -25.1%). Mean IOP and IOP changes in the travoprost-treated and control groups were significantly different at every follow-up (P < 0.05 in each case). Both the magnitude (r = 0.6992) and percentage (r = 0.5464) of IOP reductions correlated positively with baseline IOP values. Ocular adverse events were usually mild to moderate and resolved without treatment.

CONCLUSIONS

Travoprost was well tolerated and significantly reduced IOP in NTG patients. In addition, initial IOP reductions were maintained throughout follow-up. Travoprost was found to be more effective in patients with greater baseline IOP.

A systematic review of the characteristics of randomised control trials featuring prostaglandins for the treatment of glaucoma

AIM

To classify the comparative quantity and quality of the RCT evidence of pharmacological treatment for glaucoma.

METHOD

A systematic review of MEDLINE, EMBASE Cochrane CENTRAL and relevant conference proceedings was conducted up to March 2007. RCTs recruiting adults with primary open angle glaucoma (POAG) and/or ocular hypertension (OH) receiving any topical medication or placebo were included. RCTs containing a prostaglandin treatment arm were specifically considered.

RESULTS

A total of 510 publications were identified. Of these, 181 studies had a prostaglandin treatment arm. The median study duration was 12 weeks (IQR 4-13) and 78% of included trials had a duration of 3 months or less. The four studies over 1 year in duration all included a latanoprost and timolol treatment arm. There was a lack of data on younger populations (median of the mean ages of included patients was 63.4 years [IQR: 61-66 years]). Caucasians constituted 79.6% of the studied population. Evidence by ethnicity as well as by co-morbidity, was scarce. The primary outcome for 92% of studies was IOP reduction; little was reported on other indicators. Most trials reported adverse events, with hyperaemia most commonly reported.

CONCLUSION

The RCT evidence base for glaucoma treatment is extensive. This systematic review is the first to consider the characteristics of all RCTs containing a prostaglandin arm. The majority of trials are of short duration and focus on IOP as the efficacy outcome. The limitations of this study are that only trials with a prostaglandin treatment arm are included and due to the large number of included trials only top line data were extracted.

First-line treatment for elevated intraocular pressure (IOP) associated with open-angle glaucoma or ocular hypertension: focus on bimatoprost

The goal of treatment for open-angle glaucoma or ocular hypertension is to improve quality of life through reduction of intraocular pressure (IOP) to preserve visual function. Prostaglandins, as a newer class of ocular hypotensive agents, have been shown to be effective in IOP reduction by the primary mechanism of action of increase the uveoscleral outflow. Bimatoprost is a member this class, but different from the other members by having an ethyl amide group rather than an isopropyl ester at the C-1 carbon of the alpha chain. Bimatoprost used once daily has been shown to be more effect in IOP reduction than other classes of topical ocular hypotensive agents including beta-blockers, carbonic anhydrase inhibitors, and alpha agonists. Comparing with other topical prostaglandins, bimatoprost may be slightly more effective in IOP reduction, but the clinical significance is uncertain. The commonly reported adverse events associated with bimatoprost are localized to the eye and include conjunctival hyperemia, changes in the pigmentation of the periocular skin and iris, and eyelash darkening and growth. It is currently approved by the Food and Drug Administration (FDA) and the European Commission (EC) for first-line therapy for the reduction of elevated IOP in patients with open-angle glaucoma or ocular hypertension.

Clinical experience in the treatment of normal tension glaucoma with latanoprost in Germany

AIMS

The aim of this analysis was to evaluate the general ophthalmologist's experience in using latanoprost to treat normal tension glaucoma (NTG) patients.

METHODS

NTG patients included in this study were part of an observational cohort of patients that were changed from previous therapy to latanoprost in Germany.

RESULTS

This study included 200 NTG glaucoma patients who were being treated with latanoprost monotherapy (average duration, 1.2 +/- 1.4 years) and had 6 months of follow-up. At the beginning of the observation period, patients had an average intraocular pressure (IOP) of 15.2 +/- 2.5 mmHg and after 6 months, 15.0 +/- 2.4 mmHg (P = 0.769). Eight (8) patients (4.0%) were discontinued from latanoprost during the observation period, with the most common reason noted as the need for further IOP reduction (n = 7; 3.5%). Twenty-four (24) patients (12.0%) noted at least one ocular adverse event during the observation period, with the most common reason noted as burning/stinging (n = 9; 4.5%) or conjunctival hyperemia (n = 9; 4.5%).

CONCLUSIONS

This study suggests that patients with NTG who are already treated with latanoprost monotherapy should continue to have, over a short-term follow-up, generally stable IOPs, low side-effect incidence, and discontinuations, as well as "very good" to "excellent" physician ratings of patient efficacy, tolerability, and satisfaction.

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.

Effect of Latanoprost on the Diurnal Variations in the Intraocular and Ocular Perfusion Pressure in Normal Tension Glaucoma

PURPOSE

To evaluate the effects of latanoprost on the diurnal variations in the intraocular pressure (IOP) combined with the ocular perfusion pressure (OPP) in patients with normal tension glaucoma (NTG).

PATIENTS AND METHODS

Twenty-two eyes from 22 patients with NTG were used for the study. The diurnal variations in the IOP and blood pressure (BP) were measured every 3 hours without therapy, and then the patients were treated with latanoprost (0.005%) once daily for more than 12 weeks. The diurnal variations in the IOP and BP under medication were again measured every 6 hours. The diurnal variation of IOP for 24 hours, mean diurnal IOP, maximum IOP, minimum IOP, range of variation in IOP, OPP, and BP were compared between the baseline and after treatment by means of a paired t test.

RESULTS

At 3 months after the start of the latanoprost treatment regimen, the IOP showed a statistically significant decrease at every assessed time point over 24 hours (P<0.001). Latanoprost significantly reduced the mean diurnal IOP, maximum IOP, minimum IOP, and mean range of variation in the IOP values from baseline (P<0.001, <0.001, <0.001, and 0.009, respectively). OPP after treatment showed no significant difference at any assessed time points from the baseline (P>0.1). Latanoprost did not significantly alter the mean diurnal OPP (P>0.1), and BP (P>0.5) from the baseline.

CONCLUSIONS

Latanoprost was thus found to significantly reduce IOP over 24 hours, whereas it does not affect OPP and BP in NTG patients. Therefore, it may be a useful medication for NTG.