Effect of non-steroidal anti-inflammatory ophthalmic solution on intraocular pressure reduction by latanoprost

The Roles Played by FP/EP3 Receptors During Pressure-lowering in Mouse Eyes Mediated by a Dual FP/EP3 Receptor Agonist

Purpose

We investigated the intraocular pressure (IOP)-lowering effect of topical sepetaprost (SPT), a dual agonist of the FP and EP3 receptors. We explored whether certain receptors mediated the hypotensive effect of SPT and outflow facility changes in C57BL/6 mice (wild-type [WT]) and FP and EP3 receptor-deficient mice (FPKO and EP3KO mice, respectively).

Methods

IOP was measured using a microneedle. Outflow facility was measured using a two-level, constant-pressure perfusion method.

Results

SPT significantly reduced IOP for 8 hours after administration to WT mice. The 2-hour IOP reductions afforded by latanoprost were 15.3 ± 2.5, 1.8 ± 2.0, and 12.3 ± 2.4% in WT, FPKO, and EP3KO mice, respectively; the SPT figures were 13.6 ± 2.1, 5.9 ± 2.7, and 6.6 ± 2.6%, respectively. Latanoprost-mediated IOP reduction was significantly decreased in FPKO mice, and SPT-mediated IOP reduction was reduced in both FPKO and EP3KO mice. At 6 hours after administration, latanoprost did not significantly reduce the IOP in any tested mouse strain. SPT-mediated IOP reduction was reduced in both FPKO and EP3KO mice. IOP reduction at 6 hours was significantly higher after simultaneous administration of selective FP and EP3 receptor agonists, but IOP did not fall on administration of (only) a selective EP3 receptor agonist. SPT significantly increased outflow facility in WT mice, but less so in FPKO and EP3KO mice.

Conclusions

The IOP-lowering effect of SPT lasted longer than that of latanoprost. Our data imply that this may be attributable to augmented outflow facility mediated by the FP and EP3 receptors.

The influence of topical non-steroidal anti-inflammatory drugs on the intraocular pressure lowering effect of topical prostaglandin analogues-A systemic review and meta-analysis

PURPOSE

This study aimed to review previous articles and evaluate the influence of topical non-steroidal anti-inflammatory drugs (NSAIDs) on intraocular pressure (IOP) in glaucoma patients who were treated with prostaglandin analogues (PGs).

METHOD

The presenting study was designed as a meta-analysis of previous research. Databases include PubMed, Web of science, Cochrane library, and Embase were searched with keywords of "intraocular pressure, prostaglandin analogues, NSAIDs, latanoprost, travoprost, bimatoprost, tafluprost, unoprostone, latanoprostene bunod, ketorolac, diclofenac, nepafenac, bromfenac, flurbiprofen". Inclusion criteria were: 1. Study population were glaucoma patients; 2. Comparison between PGs monotherapy and PGs in combination with topical NSAIDs; 3. Changes of IOP as final outcomes. Studies with non-randomized design, treatments combining other anti-glaucomatous drugs, or unavailable absolute IOP were excluded from the analysis. Estimated difference in IOP were calculated using STATA 14.0.

RESULT

Seven studies were retrieved for this meta-analysis. Since there is a significant heterogeneity (I2 = 94%) in these studies, random-effect model was used to calculate pooled standardized mean differences (SMD). Our results showed a significantly favorable IOP lowering effect in glaucoma patients treated with combination of topical NSAIDs and PGEs (SMD: 1.3 and -0.03, 95% CI: 0.29 to 2.38 and -0.32 to 0.26, Z = 2.50 and 0.23, p = 0.013 and 0.820, respectively).

CONCLUSION

Results of our meta-analysis suggested that topical NSAIDs may enhance the IOP lowering effect of topical PGs in glaucoma patients.

Effect of topical administration of 0.1% diclofenac sodium ophthalmic solution at four frequencies on intraocular pressure in healthy Beagles

OBJECTIVE

To evaluate effects of topical ophthalmic administration of diclofenac on intraocular pressure (IOP) when applied at 4 frequencies to eyes of Beagles.

ANIMALS

8 ophthalmologically normal Beagles.

PROCEDURES

The study involved four 5-day experimental periods each separated by a 16-day washout period. During each period, 1 drop of 0.1% diclofenac sodium ophthalmic solution was administered to the right eye at 4 treatment frequencies (1, 2, 3, or 4 times/d); 1 drop of eyewash was administered to the left eye as a control treatment. A complete ophthalmic examination was performed on days 0 (day before first treatment) and 5 of each experimental period. Gonioscopy was performed on day 0 of the first period. The IOPs were measured at 7 am and 7 pm on days 1 through 5.

RESULTS

No abnormalities were detected during neuro-ophthalmic and ophthalmic examinations on day 0 of each experimental period. No adverse reactions to administration of diclofenac or eyewash were observed at any time point. No abnormalities were detected during ophthalmic examinations performed on day 5, and IOPs remained < 25 mm Hg in all 4 periods. No significant differences were identified between the treated and control eyes or among the 4 treatment frequencies.

CONCLUSIONS AND CLINICAL RELEVANCE

Topical ophthalmic administration of diclofenac up to 4 times/d in dogs with no ophthalmic abnormalities did not significantly increase the IOP. Additional research is needed to evaluate the effect of topical ophthalmic administration of diclofenac on IOP in dogs with anterior uveitis.

How many aqueous humor outflow pathways are there?

The aqueous humor (AH) outflow pathways definition is still matter of intense debate. To date, the differentiation between conventional (trabecular meshwork) and unconventional (uveoscleral) pathways is widely accepted, distinguishing the different impact of the intraocular pressure on the AH outflow rate. Although the conventional route is recognized to host the main sites for intraocular pressure regulation, the unconventional pathway, with its great potential for AH resorption, seems to act as a sort of relief valve, especially when the trabecular resistance rises. Recent evidence demonstrates the presence of lymphatic channels in the eye and proposes that they may participate in the overall AH drainage and intraocular pressure regulation, in a presumably adaptive fashion. For this reason, the uveolymphatic route is increasingly thought to play an important role in the ocular hydrodynamic system physiology. As a result of the unconventional pathway characteristics, hydrodynamic disorders do not develop until the adaptive routes cannot successfully counterbalance the increased AH outflow resistance. When their adaptive mechanisms fail, glaucoma occurs. Our review deals with the standard and newly discovered AH outflow routes, with particular attention to the importance they may have in opening new therapeutic strategies in the treatment of ocular hypertension and glaucoma.

Effect of a Topical Combination of Latanoprost and Pranoprofen on Intraocular Pressure and the Ocular Surface in Open-Angle Glaucoma Patients

Objective

A prospective study was performed to observe the effects of nonsteroidal anti-inflammatory drug (NSAID) eyedrops on intraocular pressure (IOP) and the ocular surface in primary open-angle glaucoma (POAG) patients treated with 0.005% latanoprost eyedrops.

Methods

Forty-eight subjects were randomized into two study groups (NSAID and control). Latanoprost was continued for 10 weeks in all subjects. At the end of week 4, pranoprofen was added in the NSAID group, and treatment lasted for 4 weeks, whereas patients in the control group were treated with latanoprost alone. IOP was measured in both groups every 2 weeks, and the changes in the ocular surface in the NSAID group were evaluated once a month.

Results

Pranoprofen addition resulted in a decrease in IOP in the NSAID group compared to the control group (p < 0.01). After pranoprofen was discontinued, IOP significantly increased in the NSAID group (p < 0.01), remaining approximately at the same IOP as when they were being treated with latanoprost alone. During the same examination, no significant variations in IOP were found in the control group. Patients who were treated with latanoprost alone showed gradual improvements in ocular surface symptom scores and conjunctival hyperemia scores during the first four weeks of treatment (p < 0.01). When pranoprofen eyedrops were added, ocular surface symptom scores decreased (p < 0.01), but conjunctival hyperemia scores did not change significantly.

Conclusions

For POAG patients treated with latanoprost, the combination of pranoprofen can not only significantly enhance the latanoprost-induced IOP-lowering effect but also relieve the uncomfortable ocular symptoms caused by latanoprost.

Contribution of prostanoid FP receptor and prostaglandins in transient inflammatory ocular hypertension

We explored the involvement of FP receptor and endogenous prostaglandins (PGs) in transient ocular hypertension (OH) induced by PGE2 or PGF2α in mouse eyes. PGE2 and PGF2α were topically applied to induce transient OH in Wild-type (WT) and FP-, EP1-, EP2-, and EP3-deficient (knockout [KO]) mice. To suppress endogenous PG production, the non-steroidal anti-inflammatory drug nepafenac was applied topically before treatment. PGE2 and PGF2α induced significant OH in the WT, FPKO, and EP1–3KO mice compared to the control 30 min after instillation, and the increase in IOP at 30 or 60 min after instillation in FPKO mice was significantly higher than that in the WT mice. The effects of PGF2α on the increase in IOP were significantly weaker than those of PGE2, especially in EP1KO and EP3KO mice. Transient OH induced by PGE2 and PGF2α was significantly attenuated by nepafenac treatment in FPKO mice. Transient OH was induced by PGE2 and PGF2α in WT, FPKO, and EP1–3KO mice, which was enhanced in FPKO mice. This OH was significantly diminished by nepafenac treatment in FPKO mice, suggesting that FP receptor may have an important naïve physiological role in the eye, and could regulate IOP elevation during PG-associated ocular inflammation.

Pathogenesis of Uveitic Glaucoma

Uveitic glaucoma consists one of the most serious complications of intraocular inflammation and, despite its rarity, is considered as one of the leading causes of preventable loss of vision worldwide. It has been associated with a wide spectrum of inflammatory diseases, but its pathogenesis is still not fully comprehended. It appears that the type of inflammation, the steroid-response and the anatomical alterations of the anterior chamber play a pivotal role. To our knowledge, the mechanisms may be both acute and chronic. The main targets of the treatment are to control the inflammation and reduce the intraocular pressure (IOP). The management of glaucoma associated with uveitis remains an extremely challenging condition for ophthalmologists. The successful treatment of uveitic glaucoma is inextricably correlated with prompt and immediate therapeutic decisions. Very often a solid collaboration between clinicians from different specialties may be required for treating the underlying disease.

Further understanding of its pathogenesis can indicate therapeutic targets and may lead to the development of new and more efficient therapeutic approaches. New glaucoma surgical modalities may ameliorate the prognosis after surgical intervention, but this calls for further evaluation. This study aims to highlight the complexity of uveitic glaucoma analyzing the main pathogenetic mechanisms and the correlations with the inflammatory response.

Time Course of Prostaglandin Analog-related Conjunctival Hyperemia and the Effect of a Nonsteroidal Anti-inflammatory Ophthalmic Solution

PURPOSE

It is reported that nonsteroidal anti-inflammatory drug (NSAID) ophthalmic solution affected the therapeutic efficacy of prostaglandin (PG) analog by inhibiting endogenous PG production. However, whether NSAID ophthalmic solution interferes with its conjunctival hyperemia is unknown. We investigated the effect of NSAID ophthalmic solution on its hyperemia.

MATERIALS AND METHODS

This was a prospective, randomized, double-blind, placebo-controlled 1-month trial. Benzalkonium chloride-free travoprost 0.004% was used as a PG analog and administered once daily (08:00) in both eyes. Bromfenac sodium hydrate was assigned randomly to 1 eye twice daily (08:00 and 20:00) (the NSAID side), whereas flavin adenine dinucleotide sodium was applied to the fellow eye of each patient twice daily (08:00 and 20:00) (the control side). Conjunctival photographs of both eyes were taken 3 times (08:00, 14:00, 20:00) on days 1, 2, 7, and 28, and hyperemia was scored from 0 to 5 (H-score). We compared H-scores on the NSAID and control sides.

RESULTS

Twenty-eight Japanese normal subjects completed the study. The H-score on the NSAID side was significantly lower than that on the control side on day 1 at 14:00 (P=0.016, paired t test) and day 2 at 14:00 (P=0.016). But there were no differences at 20:00 on each day and after that time.

CONCLUSIONS

The use of NSAID ophthalmic solution had almost no impact on PG analog-related conjunctival hyperemia. This partly suggests that the action mechanism of endogenous PG after administrating PG analog might be no correlation with conjunctival hyperemia.

Effect of Travoprost and Nonsteroidal Anti-Inflammatory Drug on Diurnal Intraocular Pressure in Normal Subjects with Low-Teen Baseline Intraocular Pressure

PURPOSE

The main purpose was to determine whether a nonsteroidal anti-inflammatory drug (NSAID) ophthalmic solution would affect the intraocular pressure (IOP)-lowering effect of a benzalkonium chloride (BAK)-free prostaglandin analog, travoprost. The secondary purpose was to confirm the IOP-lowering effect of BAK-free travoprost on the diurnal IOP.

METHODS

This was a prospective, randomized, double-blind, placebo-controlled 1-month trial. After baseline diurnal IOP was confirmed, travoprost was administered once daily to both eyes. Bromfenac sodium hydrate was then randomly assigned to one eye, while flavin adenine dinucleotide sodium was applied to the other eye as a control. Both solutions were administered twice daily. IOP was measured three times daily (8:00, 14:00, and 20:00). The IOP of both groups was compared using Student's t-test. The effect of NSAID on IOP was investigated by repeated measures analysis of variance (ANOVA).

RESULTS

Twenty-eight normal Japanese subjects (mean age, 36.6 years) completed the study. After the start of travoprost, remarkable IOP lowering was gained and it settled to 10-11 mmHg. The diurnal IOPs of the NSAID group showed similar tendencies to that of the control group (P = 0.69-1.0). In a 1-month period, the range of IOP reductions compared with the baseline IOP of both groups showed no significant difference (P = 0.76-0.92). NSAID did not have an influence on IOP (F-value = 0.0036, P = 0.95).

CONCLUSIONS

Although BAK-free travoprost showed a powerful IOP-lowering effect in diurnal and 1-month readings, even in eyes with an IOP of <13 mmHg, the NSAID ophthalmic solution did not affect its IOP-lowering effect.

Effect of topical 0.03% flurbiprofen and 0.005% latanoprost, alone and in combination, on normal canine eyes

OBJECTIVE

Evaluate the influence of topically applied flurbiprofen 0.03% and latanoprost 0.005%, alone or in combination, in normal canines.

ANIMALS STUDIED

  10 Normal Beagles.

PROCEDURES

Intraocular pressure (IOP), pupil size, aqueous flare, conjunctival hyperemia, and blepharospasm were evaluated bilaterally five times daily (8 am, 11 am, 2 pm, 5 pm, and 8 pm). The study consisted of a training and acclimation period, followed by 3, 1-week experiment periods. A 2-week washout period occurred between each experiment period. During period 1, all dogs received flurbiprofen (three doses 6-h apart) in the treated eye, whereas in period 2, all dogs received latanoprost (one dose 24-h apart). During period 3, both latanoprost (one dose 24-h apart) and flurbiprofen (three doses 6-h apart) were administered in the treated eye.

RESULTS

Flurbiprofen resulted in a mean IOP elevation of 1.1 mmHg (8.65%) in the treated eye, as compared with the control eye. No effect on pupil size, conjunctival hyperemia, or aqueous flare was noted. Latanoprost resulted in a mean IOP reduction of 3.4 mmHg (30.19%). Combined latanoprost and flurbiprofen resulted in a mean IOP reduction of 2.7 mmHg (24.56%). Miosis was noted in the treated eyes during both latanoprost periods, with maximal pupil constriction 3-h post-dose. This was followed by relative mydriasis 24-h post-dose, persisting 48 h after the last dose. The degree of conjunctival hyperemia varied between individuals. Neither blepharospasm nor aqueous flare was noted at any time point.

CONCLUSION

Concurrent administration of latanoprost and flurbiprofen resulted in a 20.41% reduction in the ocular hypotensive effect relative to latanoprost therapy alone.

Predicting intraocular pressure change before initiating therapy: timolol versus latanoprost

PURPOSE

To study intraocular pressure (IOP) reductions with timolol and latanoprost reached in clinical practice, taking into account data that are routinely collected by the ophthalmologist; to predict IOP reduction from these variables.

METHODS

A cohort of patients with primary open-angle glaucoma (suspect) or ocular hypertension was recruited from nine Dutch centres. Mean absolute and relative IOP reduction was calculated in order to compare timolol to latanoprost. IOP reduction was calculated by comparing patients with certain characteristics to those who had none.

RESULTS

One hundred and fifty-six persons started on timolol and 76 started on latanoprost monotherapy. Mean [95% confidence interval (CI)] absolute reduction was 7.2 mmHg (7.9; 6.5) for timolol and 6.9 mmHg (8.0; 5.8) for latanoprost. Mean relative reduction (95% CI) was 27.2% (29.3; 25.1) for timolol and 26.6% (30.2; 22.9) for latanoprost. No significant difference in IOP reduction between timolol and latanoprost was found when adjusting for data that are routinely collected by the ophthalmologist. At the time of starting treatment, none of these items normally used for the management of glaucoma, except IOP at baseline, could predict change in IOP.

CONCLUSION

In clinical practice, timolol and latanoprost achieve similar IOP reductions that are comparable to those achieved in randomized trials. No clinically relevant information for glaucoma management can be used to predict IOP reduction accurately.

The IOP-lowering effects and mechanism of action of tafluprost in prostanoid receptor-deficient mice

AIM

To clarify the intraocular pressure (IOP)-lowering profile of tafluprost, a newly synthesised prostaglandin F(2alpha) analogue, in mice.

METHODS

C57BL/6J, and EP1, EP2, EP3 and postaglandin F (FP) receptor-deficient wild-type (WT), EP1KO, EP2KO, EP3KO and FPKO, respectively mice were bred and acclimatised under a 12-h (6:00-18:00) light-dark cycle. To evaluate effects of tafluprost (0.002%) on IOP at night, a single 3 microl drop of tafluprost solution was applied topically at 18:00 once into one eye in each mouse. IOP was measured 3 h after the application with a microneedle method. To clarify whether endogenous prostaglandin is concerned with the tafluprost-induced IOP reduction, we applied 0.1% diclofenac Na, a cyclo-oxygenase inhibitor or PBS 30 min before the application of tafluprost in WT and EP3KO mice and measured IOP 3 h after the tafluprost application. We also determined whether animals responded predictably to 0.1% bunazosin HCl, a drug known to increase uveoscleral outflow.

RESULTS

3 h after the application of 0.0015% tafluprost, mean (SEM) IOP reductions were 25.8 (2.1)% 26.3 (0.8)% 24.2 (1.4)% 16.5 (1.7)% and -0.9 (1.5)% in WT, EP1KO, EP2KO, EP3KO and FPKO mice, respectively. IOP reductions in EP3KO and FPKO mice were significantly smaller than in WT mice. Pretreatment with diclofenac Na significantly attenuated the IOP lowering effect of tafluprost in WT mice but not in EP3KO mice. Bunazosin HCl lowered IOP significantly in all genotypes by the same amount.

CONCLUSION

We conclude that tafluprost lowers IOP through the prostanoid FP receptor. A part of ocular hypotensive effect of tafluprost is attributed to FP receptor-mediated prostaglandin production acting through the prostanoid EP3 receptor.

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 non-steroidal anti-inflammatory ophthalmic solution on intraocular pressure reduction by latanoprost in patients with primary open angle glaucoma or ocular hypertension

AIM

To investigate the effects of a non-steroidal anti-inflammatory drug (NSAID) ophthalmic solution on latanoprost induced intraocular pressure (IOP) reduction in glaucoma patients.

METHODS

Examination was conducted on 16 eyes of 16 glaucoma patients who had been given only latanoprost for at least 6 weeks. The NSAID ophthalmic solution, sodium 2-amino-3-(4-bromobenzoyl) phenylacetate sesquihydrate, was additionally given for 12 weeks into one eye (NSAID group), while sodium hyaluronic acid ophthalmic solution was administered into the other eye (control group) in a double masked fashion. The IOP measurement was performed before the start of additional administration of ophthalmic solutions, 2, 4, 6, 8, 10, and 12 weeks after the start of additional administration, and 2, 4, and 6 weeks after discontinuing additional administration.

RESULTS

No significant difference was observed in the IOPs before additional administration of ophthalmic solution between the NSAID group and the control group. Following the additional administration of ophthalmic solution, IOP in the NSAID group was consistently higher than that in the control group, and a maximum difference in IOP between the two groups was 1.08 (SD 1.75) mm Hg (p = 0.03). This trend was observed even after additional administration was discontinued.

CONCLUSION

NSAID ophthalmic solution may partly affect IOP reduction by latanoprost.

Nimesulide oral administration increases the intraocular pressure-lowering effect of latanoprost in patients with primary open-angle glaucoma

PURPOSE

To verify the short-term influence of an orally administered nonsteroidal anti-inflammatory drug on the intraocular pressure (IOP) of primary open-angle glaucoma patients in therapy with a topical prostaglandin analog.

DESIGN

Randomized cross-over double-blind study.

METHODS

Sixteen adults with primary open-angle glaucoma, receiving 0.005% latanoprost eyedrops once daily, were treated with a single dose of either 100 mg nimesulide or placebo. IOP was recorded at baseline and at 1, 2, 4, 8, 12, and 24 hours.

RESULTS

After nimesulide administration, there was a decrease in IOP (with a fall at the second hour, P<.01) that remained significant 8 hours later (P<.05). At 12 and 24 hours, there were unremarkable IOP differences between the two regimens.

CONCLUSIONS

In patients with primary open-angle glaucoma, single-dose nimesulide significantly enhances the latanoprost-induced IOP-lowering effects during the short plasma half-life of this non-steroidal anti-inflammatory drug.

Prostaglandin E2 induces cyclooxygenase-2 expression in human non-pigmented ciliary epithelial cells through activation of p38 and p42/44 mitogen-activated protein kinases

Prostaglandins (PGs) have been implicated in lowering intraocular pressure (IOP). A possible role of cyclooxygenase-2 (COX-2) in this process was emphasized by findings showing impaired COX-2 expression in the non-pigmented ciliary epithelium (NPE) of patients with primary open-angle glaucoma. The present study investigates the effect of the major COX-2 product, PGE(2), on the expression of its synthesizing enzyme in human NPE cells (ODM-2). PGE(2) led to an increase of COX-2 mRNA and protein expression, whereas the expression of COX-1 remained unchanged. Upregulation of COX-2 expression by PGE(2) was accompanied by time-dependent phosphorylations of p38 mitogen-activated protein kinase (MAPK) and p42/44 MAPK, and was abrogated by inhibitors of both pathways. Moreover, PGE(2)-induced COX-2 expression was suppressed by the intracellular calcium chelator, BAPTA/AM, and the protein kinase C inhibitor bisindolylmaleimide II, whereas the protein kinase A inhibitor H-89 was inactive in this respect. Induction of COX-2 expression was also elicited by butaprost (EP(2) receptor agonist) and 11-deoxy PGE(1) (EP(2)/EP(4) receptor agonist), but not by EP(1)/EP(3) receptor agonists (17-phenyl-omega-trinor PGE(2), sulprostone). Consistent with these findings, the EP(1)/EP(2) receptor antagonist, AH-6809, and the selective EP(4) receptor antagonist, ONO-AE3-208, significantly reduced PGE(2)-induced COX-2 expression. Collectively, our results demonstrate that PGE(2) at physiologically relevant concentrations induces COX-2 expression in human NPE cells via activation of EP(2)- and EP(4) receptors and phosphorylation of p38 and p42/44 MAPKs. Positive feedback regulation of COX-2 may contribute to the production of outflow-facilitating PGs and consequently to regulation of IOP.

The influence of diclofenac ophthalmic solution on the intraocular pressure-lowering effect of topical 0.5% timolol and 0.005% latanoprost in primary open-angle glaucoma patients

The aim of this randomized, prospective, masked clinical study has been to verify the influence of a non-steroidal anti-inflammatory drug ophthalmic solution on intraocular pressure reduction induced by 0.5% timolol and 0.005% latanoprost eyedrops in patients affected by primary open-angle glaucoma. Thirty-two glaucomatous patients, compensated with 0.5% timolol, were randomized into two study groups (A and B). Timolol was continued for the first 2 weeks in all subjects. On the 15th day, in both groups timolol was replaced by latanoprost, and this regimen lasted up to the end of the follow-up (8 weeks). At the beginning of the 2nd week of the study, group A additionally started a 5-week therapy with topical 0.1% diclofenac; during the same period, group B received placebo eyedrops with identical modalities. Intraocular pressure was recorded at 7-day intervals during the first 7 weeks and at the 10th week. Non-steroidal anti-inflammatory drug and placebo did not modify the effect of timolol on intraocular pressure. In both groups, latanoprost induced a significant decrease in intraocular pressure. Diclofenac-treated patients exhibited a marked fall in intraocular pressure (p<0.01), whereas in placebo-treated patients, this diminution was less noticeable (p<0.05). After diclofenac withdrawal, in group A intraocular pressure significantly increased (p<0.01), remaining approximately at the same level up to the end of the study. In group B, at the same checks no significant variations in intraocular pressure occurred. In primary open-angle glaucoma patients, diclofenac significantly enhances the hypotensive effect of latanoprost, without influence on timolol efficacy. Because non-steroidal anti-inflammatory drugs are widely employed in medical practice, supplementary ophthalmologic checks should be scheduled during the co-administration of these compounds and prostaglandin analogues.

Latanoprost induces matrix metalloproteinase‐1 expression in human nonpigmented ciliary epithelial cells through a cyclooxygenase‐2‐dependent mechanism

Prostaglandins (PGs) have been implicated in the regulation of intraocular pressure (IOP) by facilitating the remodeling of tissues involved in aqueous humor outflow. A contribution of cyclooxygenase-2 (COX-2)-dependent PGs to this process was emphasized by a recent study showing an impaired COX-2 expression in the nonpigmented ciliary epithelium (NPE) of patients with primary open-angle glaucoma. With the use of human NPE cells (ODM-2), the present study therefore investigated the effect of the antiglaucomatous drug latanoprost (PGF2alpha analog) on the expression of COX-2 and its association with the induction of matrix metalloproteinases (MMPs). In NPE cells, latanoprost led to a concentration- and time-dependent increase of COX-2 mRNA levels. Up-regulation of COX-2 expression was accompanied by phosphorylations of p38 mitogen-activated protein kinase (MAPK) and p42/44 MAPK and was abrogated by specific inhibitors of both pathways. PGE2 formation by latanoprost was abolished by the selective COX-2 inhibitor NS-398 and by the F-prostaglandin receptor antagonist AL-8810. Moreover, latanoprost led to a delayed up-regulation of MMP-1 mRNA, whereas the expression of MMP-2, MMP-9, TIMP-1, and TIMP-2 remained unchanged. Latanoprost-induced MMP-1 mRNA and protein expression was abolished by NS-398 and by COX-2-silencing small-interfering RNA. In line with this finding, MMP-1 expression was also induced by PGE2, a major COX-2 product. As a whole, our results show that MMP-1 expression by latanoprost requires prior up-regulation of COX-2. Induction of COX-2- and subsequent MMP-1 expression in the NPE may represent a potential mechanism underlying the IOP-lowering and antiglaucomatous action of latanoprost.