Intraocular pressure–reducing effects and safety of latanoprost versus timolol in patients with chronic angle-closure glaucoma

Meta-analysis of randomized controlled trials comparing latanoprost with other glaucoma medications in chronic angle-closure glaucoma

PURPOSE

To evaluate the efficacy and safety of latanoprost compared with other glaucoma medications in the treatment of chronic angle-closure glaucoma (CACG) and to provide the basis for clinical medication.

METHODS

Major literature databases were searched for randomized controlled trials (RCT) involving latanoprost among patients with CACG. Primary outcome measures were absolute changes in intraocular pressure (IOP) and incidence of ocular adverse events. Statistical analyses included the calculation of standardized mean difference (SMD) and relative risk (RR). The statistical analysis was performed using STATA version 12.0 software.

RESULTS

Ten RCT involving 1096 patients were included in this meta-analysis. Analysis showed that latanoprost was not significantly different from other glaucoma medications in reducing IOP (SMD = 0.29, 95% confidence interval [CI] -0.02 to 0.59, p=0.069). Further subgroup analysis revealed that latanoprost was superior compared with timolol (SMD = 0.64, 95% CI 0.46 to 0.82, p<0.001) and marginally inferior to travoprost and bimatoprost (SMD = -0.19, 95% CI -0.35 to -0.02, p = 0.026). As for conjunctival hyperemia, latanoprost caused a higher proportion than timolol (RR = 2.36, 95% CI 1.27 to 4.37, p = 0.007). However, latanoprost was associated with lower incidence of conjunctival hyperemia (RR = 0.42, 95% CI 0.30 to 0.59, p<0.001), and with fewer occurrence of other ocular side effects (excluding conjunctival hyperemia) than travoprost and bimatoprost (RR = 0.61, 95% CI 0.48 to 0.78, p<0.001).

CONCLUSIONS

Travoprost and bimatoprost are superior in IOP control than latanoprost, but latanoprost is better tolerated in patients with CACG.

Efficacy and tolerability of latanoprost compared with timolol in the treatment of patients with chronic angle-closure glaucoma

OBJECTIVE

To evaluate the efficacy and tolerability of latanoprost compared with timolol in the treatment of patients with chronic angle-closure glaucoma (CACG).

METHODS

Pertinent publications were identified through systematic searches of PubMed, EMBASE, the Cochrane Controlled Trials Register and the Chinese Biomedicine Database. Randomized controlled trials comparing latanoprost with timolol in patients with chronic angle-closure glaucoma (CACG) who had inadequate intraocular pressure (IOP) control after peripheral iridotomy (PI) were selected. The main efficacy measures were the weighted mean difference (WMD) in the reduction from baseline to end of treatment in IOP at peak, trough, and diurnal curve. The main tolerability measures were the odds ratio (OR) for the individual adverse events. The pooled estimates and 95% confidence intervals (CIs) were carried out in RevMan version 5.2 software.

RESULTS

Five published randomized controlled trials involving 528 patients were included in the present meta-analysis. The IOP reduction (IOPR) was significantly greater in the latanoprost group than in the timolol group at diurnal curve (WMD: 2.22 mmHg [95% CI, 1.65 to 2.79], P < 0.00001), peak (WMD: 2.44 mmHg [0.85 to 4.03], P = 0.003) and trough (WMD: 2.67 mmHg [1.93 to 3.41], P < 0.00001). Timolol caused conjunctival hyperemia in less patients than latanoprost (pooled OR: 2.74 [95% CI, 1.33 to 5.61], P = 0.006).

CONCLUSIONS

Latanoprost provides greater IOP-lowering efficacy than timolol in the treatment of patients with CACG. Latanoprost caused conjunctival hyperemia in more patients than timolol. Further clinical trials are needed because of short duration of included studies.

Meta-analysis of randomized controlled trials comparing latanoprost with timolol in the treatment of Asian populations with chronic angle-closure glaucoma

BACKGROUND

To evaluate the efficacy and safety of latanoprost compared with timolol in the treatment of Asian patients with chronic angle-closure glaucoma (CACG).

METHODS

Relevant trials were identified through systematic searches of Medline, EMBASE, PubMed, Cochrane Library, Google Scholar and several Chinese databases. The main outcome measures included absolute and relative reduction of intraocular pressure (IOP) at mean, peak and trough from baseline, ocular adverse effects and systemic adverse events.

RESULTS

Seven randomized controlled trials with 685 patients were included. In comparison with timolol, latanoprost reduced absolute IOP in CACG patients by more than 2.3 mmHg (95%CI, 1.8∼2.9, P<0.01), 2.4 mmHg (95%CI, 1.9∼2.9, P<0.01) and 2.5 mmHg (95%CI, 1.6∼3.3, P<0.01) at mean, peak and trough, respectively. As for relative IOP, there is 9.0% (95%CI, 6.6∼11.4, P<0.01), 9.7% (95%CI, 7.6∼11.8, P<0.01), and 10.8% (95%CI, 7.4∼14.3, P<0.01) greater reduction among latanoprost users than among timolol users. The differences were statistically significant at all time points (1, 2, 4, 8, 12, and 24 weeks). More ocular adverse effects (OR = 1.49, 95% CI, 1.05∼2.10, P = 0.02) and less systemic adverse events (OR = 0.46, 95% CI, 0.25∼0.84, P = 0.01) were observed in latanoprost group in comparison with timolol group.

CONCLUSION

Compared with timolol, latanoprost was significantly more effective in lowering IOP of Asian patients with CACG, with higher risk of ocular adverse effects but lower risk of systemic adverse events, and might be a good substitute for CACG patients.

Topical prostaglandin analogues and conjunctival inflammation in uveitic glaucoma

Purpose:

A pilot study to determine whether topical prostaglandin analogues alter the expression of conjunctival inflammatory markers in patients with uveitic glaucoma.

Methods:

Prospective, single-masked case series of 20 patients with uveitis and secondary raised intraocular pressure. Participants were divided into four groups of five patients dependent on their use of topical medication: (1) prostaglandin analogues only, (2) corticosteroids only, (3) both prostaglandin analogues and corticosteroids, (4) no topical medication. Conjunctival cells were harvested by impression cytology and were examined for inflammatory markers (CD3, CD54, HLA-DR, CCR4, CCR5) by flow cytometry. A tear fluid sample was also examined for inflammatory cytokines (IL-12p70, IL-2, IL-10, IL-8, IL-6, IL-4, IL-5, IFN-gamma, IL-1beta, IFN-alpha, IFN-beta) by multiplex bead arrays.

Results:

All groups demonstrated increased markers of conjunctival inflammation. There was no significant difference in levels of any inflammatory markers between the four groups, suggesting that the use of topical prostaglandin analogues does not increase conjunctival levels of inflammation beyond those already seen in uveitis.

Conclusions:

The use of topical prostaglandins does not appear to induce conjunctival inflammation over that which is already present in patients with uveitic glaucoma. This supports the use of topical prostaglandin analogues in patients with uveitic glaucoma, indicating that their use is unlikely to adversely affect subsequent glaucoma filtration surgery through the induction of chronic conjunctival inflammation.

Cytotoxicity of prostaglandin analog eye drops preserved with benzalkonium chloride in multiple corneoconjunctival cell lines

Purpose:

This study evaluated the cytotoxicity of five prostaglandin analog ophthalmic solutions on four ocular surface cell lines, ie, Chang (human conjunctiva), SIRC (rabbit cornea), RC-1 (rabbit cornea), and BCE C/D-1b (bovine cornea).

Methods:

Cell viability was measured by neutral red and MTT assays in cells treated for 10, 30, or 60 minutes with various doses of prostaglandins (undiluted, and 2- and 10-fold dilutions). The number of cell lines with viability ≥50% in the presence of selected dilution of the drug (CVS₅₀) was used for comparison. In addition, 24 cell viability comparisons (four cell lines, two assays, and three exposure times) were made between latanoprost (Xalatan^®) and each other solution at each dose. A comparison between the newly introduced tafluprost (Tapros^®) with 0.01% benzalkonium chloride was also made.

Results:

The order of cell viability determined by CVS₅₀ was Travatan Z^® (travoprost with the SofZia system) > Tapros ≥ Travatan^® (travoprost) = Xalatan > Rescula^® (unoproston). This was consistent with the results of direct comparisons between Xalatan and the other drugs. There was no clear difference in cell viability between Tapros and benzalkonium chloride.

Conclusions:

Use of two assays, multiple cell lines, and various dilutions and exposure times provided a unique evaluation of cytotoxicity among ophthalmic solutions. CVS₅₀ was useful for comparison of the cell viability of the solutions.

In vivo comparative study of ocular vasodilation, a relative indicator of hyperemia, in guinea pigs following treatment with bimatoprost ophthalmic solutions 0.01% and 0.03%

Objective:

The objective of this in vivo study was to compare the incidence of vasodilation in guinea pigs following topical administration of bimatoprost ophthalmic solutions 0.01% and 0.03%.

Methods:

The study comprised 20 guinea pigs assigned to 2 treatment groups (10 per treatment group) to receive either bimatoprost 0.01% or bimatoprost 0.03%. Animals were hand-held under 2.75 × magnification to score ocular vasodilation (a measure of hyperemia), using a scoring system developed at Alcon Research, Ltd. Following baseline ocular scoring, each animal received a 30 μL dose to the left eye of either bimatoprost 0.01% (3 μg) or bimatoprost 0.03% (9 μg). Vasodilation was again scored at 1, 2, 3, 4, 5 and 6 hours after dosing. Incidence of vasodilation was calculated as the percent of total eyes in each 2-hour time interval with scores ≥2.

Results:

The incidence of vasodilation was higher in the bimatoprost 0.01% treatment group (range, 45.0% to 60.0%) than the bimatoprost 0.03% treatment group (range, 30.0% to 52.2%) at all post-dosing time points.

Conclusion:

The 2 bimatoprost formulations elicited ocular vasodilation of long duration (>6 hours) in the guinea pig model, with the bimatoprost 0.01% treatment group showing a higher incidence of ocular vasodilation than the bimatoprost 0.03% treatment group. Further clinical studies would be needed to determine whether the higher incidence of vasodilation may also be attributed to the increased BAK concentration in the bimatoprost 0.01% formulation.

A meta-analysis of topical prostaglandin analogs in the treatment of chronic angle-closure glaucoma

OBJECTIVE

To evaluate the intraocular pressure (IOP)-lowering efficacy of prostaglandin analogs topical medications in patients with chronic angle-closure glaucoma (CACG).

METHODS

Pertinent publications were identified through systematic searches of PubMed, EMBASE, KoreaMed, Chinese Biomedicine Database, and the Cochrane-Controlled Trials Register. Randomized clinical trials involving CACG patients treated with latanoprost, bimatoprost, or travoprost monotherapy were selected. Methodologic quality was assessed by a Delphi list with additions and scored out of a maximum of 18. The outcome measures were absolute and relative reduction in IOP from baseline, for diurnal curve, peak, and trough. The pooled effects were calculated using 2-step DerSimonian and Laird estimate method of the random effects model.

RESULTS

Nine randomized clinical trials enrolling a total of 1,090 patients were included in the meta-analysis. Quality scores of included studies were generally high, a mean of 14.9 (range, 12-18). The difference in absolute IOP reduction between prostaglandin analogs and timolol varied from 0.4 to 1.6 mm Hg at diurnal curve, 0.9 to 2.3 mm Hg at peak, and 1.3 to 2.4 mm Hg at trough. Relative IOP reduction were diurnal curve, 31% (95% confidence interval, 27% to 34%), peak, 34% (31% to 37%), and trough 31% (28% to 35%) for latanoprost; diurnal curve, 26% (21% to 30%), peak, 28% (24% to 32%), and trough 27% (23% to 30%) for bimatoprost; diurnal curve, 28% (20% to 36%), peak, 32% (31% to 34%), and trough 31% (29% to 33%) for travoprost; and diurnal curve, 23% (19% to 27%), peak, 24% (20% to 29%), and trough 21% (19% to 24%) for timolol.

CONCLUSIONS

Latanoprost, travoprost, and bimatoprost provide significant IOP-lowering efficacy in eyes with CACG; and the 3 prostaglandin analogs are associated with at least as effective as timolol.

Do antiglaucomatous prostaglandins induce melanogenesis in human conjunctiva?: an impression cytology pilot study

PURPOSE

To determine the effect of antiglaucomatous prostaglandin analogs on conjunctival melanogenesis.

METHODS

For this pilot study, 30 glaucomatous patients treated with prostaglandin drops (alone and in association to beta-blockers) and 30 control subjects (15 healthy volunteers and 15 patients treated with beta-blockers) were included in this transversal, single masked, case-control, observational study. Skin complexion, eye color, conjunctival pigmentation, lacrimal tests, and corneal fluorescein staining were evaluated. Immunoreactivity for Tyrosinase was assayed on conjunctival imprints.

RESULTS

Twenty percent of patients treated with prostaglandins and 10% of the control subjects clinically manifested conjunctival pigmentation (P=0.279). Only 4% (8/198) of the conjunctival specimens were positive to Tyrosinase immunostaining, with no statistically significant difference among the groups (P=0.449). In all cases, the proportion of positive cells was below 4%. When compared with subjects having negative specimens, those with positive immunostains did not show any statistically significant difference in skin complexion, eye color or exposure to irritants, and ultraviolet (P>0.05).

CONCLUSIONS

According to our preliminary results, prostaglandin antiglaucomatous analogs do not significantly enhance pigmentation in the superficial layers of the conjunctiva. The existence of the Tyrosinase enzyme in the superficial layers of the conjunctiva suggests that basal melanocytes may transfer their melanogenic apparatus to superficial epithelial cells.

Optic nerve head morphologic characteristics in chronic angle-closure glaucoma and normal-tension glaucoma

PURPOSE

To determine whether the morphometric features of the optic disk in eyes with chronic angle-closure glaucoma (CACG) are different from those with normal-tension glaucoma (NTG).

PATIENTS AND METHODS

This is a retrospective, case-matched study. Patients with CACG or NTG in an early or moderate stage were recruited. On the basis of age, sex, and visual field mean defect, patients with CACG were matched to those with NTG on a case-by-case basis. Heidelberg retina tomography was used to evaluate the optic disk, and parameters were compared between the 2 groups.

RESULTS

Sixty-three patients were recruited for the study. Twenty cases (eyes) with CACG were matched to 20 cases (eyes) with NTG. The total, temporal/inferior, nasal/superior, and nasal/inferior rim area of the optic disk were significantly larger (P<0.05) in the CACG group. In patients with CACG rather than NTG, the cup volume in total and in each sector (except temporal) was significantly smaller (P=0.007 to 0.041). In patients with CACG rather than NTG, the mean cup depth and cup shape measure of the optic disk in total and in each sector (except temporal and temporal/inferior) were smaller (P=0.002 to 0.054).

CONCLUSIONS

The morphometric features of the optic disk in eyes with CACG are different from those with NTG.

Mean target intraocular pressure and progression rates in chronic angle-closure glaucoma

PURPOSE

The aim of this study was to evaluate risk factors for progression in chronic angle-closure glaucoma (CACG) patients.

METHODS

A retrospective cohort of patient records in East Asia were evaluated for risk factors associated with progressive optic-disc and visual-field loss. There were 101 CACG patients with 5 years of follow-up.

RESULTS

Seventy-one percent (71%) of patients with intraocular pressures (IOP) of >22 mmHg progressed, whereas 26% of patients with IOPs of 13-21 mmHg progressed, and 0% of patients with IOPs of <12 mmHg progressed. The mean IOP was 16.6 +/- 3.4 mmHg in the stable group and 18.8 +/- 3.5 mmHg in the progressed group (P = 0.007). The highest average peak IOP was 23.2 +/- 6.3 mmHg in the stable group and 26.5 +/- 6.5 mmHg in the progressed group (P = 0.03). Generally, patients whose standard deviation of IOP was <2 mmHg (12% progressed) were more often stable, compared to those who were >3 mmHg (33% progressed). A multivariate regression analysis was positive for mean IOP as a clinically important risk factor for progression.

CONCLUSIONS

IOP reduction in CACG patients may help prevent progressive visual-field and optic-disc damage.

Angle-closure: risk factors, diagnosis and treatment

INTRODUCTION

Primary angle-closure glaucoma (PACG) is the leading cause of blindness in East Asia. The disease can be classified into primary angle-closure suspect, primary angle closure (PAC), and PACG. Pupil-block, anterior nonpupil-block (plateau iris and peripheral iris crowding), lens related and retrolenticular mechanisms have been suggested as the four main mechanisms of angle closure.

RISK FACTORS

The risk factors for PAC are female gender, increasing age, Inuit or East Asian ethnicity, shallow anterior chamber, shorter axial length, and genetic factors.

DIAGNOSIS

The diagnosis of acute PAC is mainly clinical. Diagnosis can be made with careful slit lamp examination, including intraocular pressure (IOP) measurement and gonioscopy. The diagnosis of chronic PAC and chronic PACG also require a careful history to assess risk factors, slit lamp examination including IOP and gonioscopy. Further investigations may also be required including visual fields, ultrasound biomicroscopy, and other imaging methods.

MANAGEMENT

In acute PAC, rapid control of the IOP needs to be achieved to limit optic-nerve damage. This can be carried out medically, and/or by laser iridoplasty. Both the affected and fellow eye should undergo laser peripheral iridotomy (PI). The aim of treating chronic PAC is to eliminate the underlying pathophysiological mechanism and to reduce IOP. This can be done by carrying out laser PI, iridoplasty, medical therapy, or surgery (trabeculectomy, lens extraction, combined lens extraction with trabeculectomy and goniosynechialysis).

CONCLUSION

Angle-closure glaucoma is usually an aggressive, visually destructive disease. By assessing the risk factors and diagnosing the mechanism involved in a patient's condition, the management of that patient can be tailored appropriately.

Comparison of the Effects of Latanoprost and Travoprost on Intraocular Pressure in Chronic Angle-Closure Glaucoma

PURPOSE

The aim of this study was to compare the intraocular pressure (IOP)-lowering effect of latanoprost and travoprost as primary therapy in patients with chronic angle-closure glaucoma (CACG) after peripheral iridotomy.

METHODS

Seventy-three (73) CACG patients with IOP>19 mmHg after peripheral iridotomy and without previous antiglaucoma medication were consecutively recruited. CACG was defined as the presence of chronically elevated IOP, glaucomatous optic neuropathy, and a corresponding visual field defect in eyes with occludable angle and peripheral anterior synechiae on gonioscopy. Patients were randomly assigned to 2 groups, based on daily treatment with either latanoprost 0.005% or travoprost 0.004% in the evening for 12 weeks. The IOP was measured at 9 AM and 4 PM at baseline and at 4, 8, and 12 weeks. Between-group differences in mean diurnal IOP and IOP reduction were analyzed.

RESULTS

After 12 weeks of treatment, mean IOP for both the latanoprost and travoprost groups was significantly reduced, when compared to the baseline IOP (from 21.3+/-1.8 mmHg to 16.0+/-2.3 mmHg and 21.7+/-1.7 to 16.7+/-2.2 mmHg; P<0.001 for both). There was no significant difference in IOP reduction between the 2 treatment groups (P=0.19). At 4 and 8 weeks, the IOP changes from the baseline were statistically significant at all time points for both drugs (all P<0.001).

CONCLUSIONS

Both latanoprost and travoprost significantly reduced IOP in our sample of CACG patients after peripheral iridotomy.

Prise en charge de l’hypertonie oculaire et du glaucome chronique à angle ouvert par les ophtalmologistes français : rôle de la pression intra-oculaire cible

PURPOSE

A low level of intraocular pressure (IOP) can reduce or even stop the progression of glaucoma. It is essential to limit conversion from ocular hypertension (OHT) to glaucoma. The IOP value that protects the visual field and the optic nerve is called target IOP. This study analyzes how French ophthalmologists determine the target IOP level.

MATERIAL AND METHODS

The main objective of this prospective, multicenter national survey was to analyze the management of OHT or glaucoma patients and to evaluate the importance of target IOP in the therapeutic strategy.

RESULTS

A total of 972 ophthalmologists included 11.177 patients from May 2002 to March 2004. In 68.7% of cases, the practitioner determined the target IOP level using the following methods: a target of 15 mmHg or 17 mmHg or a reduction of the IOP level in percentage (EGS guidelines). This mean target IOP ranged from 14.3 to 17.3 mmHg.

DISCUSSION

The estimation of target IOP is used by the majority of French ophthalmologists.

CONCLUSION

This study shows that the determination of target IOP is becoming increasingly important in the therapeutic decision and follow-up in the routine practice of French ophthalmologists.

Comparison of Latanoprost Monotherapy and Combined Therapy of 0.5% Timolol and 1% Dorzolamide in Chronic Primary Angle-Closure Glaucoma (CACG) in Japanese Patients

To compare the efficacy, adverse effects, and patient compliance of latanoprost monotherapy with unfixed combination therapy with 0.5% timolol maleate and 1% dorzolamide in the treatment of chronic primary angle-closure glaucoma (CACG), 36 Japanese patients with CACG following laser iridotomy (LPI) were treated for 12 weeks with instillation of latanoprost alone or with unfixed combination therapy of 0.5% timolol maleate and 1% dorzolamide hydrochloride. After 12 weeks of treatment, latanoprost reduced intraocular pressure (IOP) from 22.2 +/- 2.0 mmHg to 14.8 +/- 1.9 mmHg (33% reduction); timolol maleate and dorzolamide hydrochloride also reduced IOP from 22.5 +/- 2.2 mmHg to 17.1 +/- 2.7 mmHg (24% reduction). Latanoprost monotherapy significantly lowered IOP compared with unfixed combination therapy of 0.5% timolol maleate and 1% dorzolamide hydrochloride. Furthermore, a systemic adverse effect of bradycardia was not observed in the latanoprost monotherapy group. Concerning compliance, no significant difference was observed between the two groups. Thus, latanoprost monotherapy is more effective than unfixed combination therapy with 0.5% timolol maleate and 1% dorzolamide in the treatment of CACG following relief of pupillary block in Japanese patients.

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

OBJECTIVE

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

DESIGN

Prospective observational case series.

PARTICIPANTS

One hundred thirty-seven Asian subjects with CACG.

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

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