The efficacy of latanoprost is independent of the width of the ciliary body face

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.

Relation between axial length of the eye and hypotensive effect of latanoprost in primary open angle glaucoma

AIMS

To study the effect of axial length on the hypotensive effect of latanoprost in primary open angle glaucoma (POAG) in a prospective, observational study.

METHODS

The authors measured axial length and baseline intraocular pressure (IOP) of 109 eyes with POAG, and then repeated the IOP measurements at 1, 3, and 6 months after starting treatment with latanoprost.

RESULTS

The mean IOP level was significantly lower in eyes with a shorter axial length compared with the eyes with a longer axial length both at 3 and 6 months of treatment (p = 0.03 and p = 0.04, respectively, ANOVA).

CONCLUSION

The hypotensive effect resulting from treatment with latanoprost could be related to ocular axial length.

Effects of 0.005% latanoprost on ocular anterior structures and ciliary body thickness

PURPOSE

To assess the effects of 0.005% latanoprost on the anterior segment geometry and ciliary body thickness using ultrasound biomicroscopy. Intraocular pressure, refraction, visual acuity, and pupil size were also evaluated.

PATIENTS AND METHODS

Thirty patients with untreated ocular hypertension or primary open-angle glaucoma (mean age: 59.3 +/- 9.9 years) were recruited into this prospective, controlled, open trial. Before and after 1 week of 0.005% latanoprost administration, the following parameters were tested: refraction, visual acuity, pupil diameter, intraocular pressure, 5 conventional ultrasonographic A-scan variables, 16 ultrasound biomicroscopy parameters, and the ultrasound biomicroscopy ciliary body thicknesses at a distance of 1500 microns (CBT1), 2000 microns (CBT2), and 2500 microns (CBT3) from the scleral spur.

RESULTS

Latanoprost 0.005% caused a marked intraocular pressure-lowering effect in all patients (from 22.8 +/- 3.1 mm Hg to 14.1 +/- 2.9 mmHg; -38%, P < 0.0001), without any refractive, visual acuity, or pupillary alterations. The A-scan echobiometry variables were unchanged, while ultrasound biomicroscopy confirmed a significant posttreatment increase of CBT2 (from 434 +/- 140 microns to 536 +/- 127 microns; +102 microns, P = 0.01) and CBT3 (from 319 +/- 103 microns to 412 +/- 100 microns; +93 microns, P = 0.003) compared with controls (CBT2: from 493 +/- 165 microns to 473 +/- 135 microns, -20 microns, P = NS; CBT3: from 388 +/- 130 microns to 365 +/- 87 microns, -23 microns, P = NS). None of the changes observed in the other UBM parameters was statistically significant. No significant correlation was detected between ciliary body thickness increase and intraocular pressure-lowering effect.

CONCLUSION

The increase of ciliary body thickness, which was measured in vivo by ultrasound biomicroscopy and associated with the intraocular pressure-lowering effect, indirectly supports the mechanism of uveoscleral outflow enhancement induced by latanoprost. These data are in agreement with the biochemical hypothesis of the passage of the aqueous flow through the extracellular spaces of the ciliary muscle.

Update on prostaglandin analogs

Prostaglandin analogs are a novel class of intraocular-lowering medications used primarily for the treatment of glaucoma. These topical medications reduce intraocular pressure primarily by enhancing uveoscleral outflow. The recent literature has enhanced our understanding of the mechanism of action, efficacy, and safety of these agents and has allowed us to better understand the differences between the three commonly used once-daily medications.