Michiya Takamatsu

Circadian intraocular pressure management with latanoprost: diurnal and nocturnal intraocular pressure reduction and increased uveoscleral outflow.

Based on their mechanism of action, the most frequently used ocular hypertensive agents, the beta-blockers, cannot be assumed to reduce IOP during sleep. The need for drugs that reduce IOP around-the-clock is underscored, however, by the fact that inadequate nocturnal ocular perfusion pressure is considered to be one of the likely causes of glaucomatous optic neuropathy especially in some cases of normal tension glaucoma. The studies reviewed here demonstrate that latanoprost, a new ocular hypotensive prostaglandin F2 alpha analogue, applied once a day at a concentration of 0.005%, maintains a statistically highly significant IOP reduction around-the-clock. The magnitude of this IOP reduction was found to be essentially identical during the day and at night, both in patients maintained on timolol and in those not receiving other glaucoma medication. Latanoprost-induced IOP reduction was also found to be associated with increased uveoscleral outflow in normotensive volunteers, both during the day and at night. These circadian studies suggest that this new ocular hypotensive agent can be expected to be particularly useful for the medical management of some forms of glaucoma, such as normal tension glaucoma, when the cause of the glaucomatous damage cannot be linked specifically to diurnal IOP abnormalities.

The Effect of Latanoprost on Circadian Intraocular Pressure

The presence of a circadian variation of both intraocular pressure (IOP) and aqueous humor flow has been demonstrated in several studies. It must therefore be considered important to monitor IOP and evaluate the efficacy of ocular hypotensive drugs over the 24 hours of the day. The efficacy of latanoprost on IOP during both day and night has been evaluated and the most important results from four such studies are reviewed. The studies reviewed here clearly demonstrate that topical administration of latanoprost 0.005% once daily provided a steady reduction of the IOP during both day and night. Given as a single dose to healthy volunteers, latanoprost resulted in a sustained effect with a significant IOP reduction over 24 hours, and the reduction was still present, however less pronounced, even after 48 hours. Latanoprost administered once daily for 4 weeks to patients with glaucoma or ocular hypertension was more effective in reducing the IOP over 24 hours than timolol gel solution 0.5% once daily, timolol aqueous solution 0.5% twice daily, or dorzolamide 2% three times daily. Latanoprost applied once daily thus provided a better effect on the IOP together with a stable and sustained IOP reduction during both day and night.

Ultrasound Biomicroscopic Study of Ciliary Body Thickness After Topical Application of Pharmacologic Agents

PURPOSE To examine the changes in ciliary body thickness after topical application of pilocarpine, cyclopentolate hydrochloride, and PhXA41, a prostaglandin F2alpha analog. METHOD We used high-frequency Humphrey UBM840 ultrasound biomicroscope to examine 36 healthy young Japanese subjects. RESULTS The mean ciliary body thickness increased from 0.67 +/- 0.07 mm to 0.073 +/- 0.08 mm (P < .01) after application of 2% pilocarpine; 1% cyclopentolate hydrochloride and 0.005% PhXA41 decreased the mean ciliary body thickness from 0.75 +/- 0.07 mm to 0.69 +/- 0.05 mm (P < .05) and from 0.78 +/- 0.06 mm to 0.75 +/- 0.06 mm (P < .01), respectively. CONCLUSIONS Our ultrasound study clearly indicates that pilocarpine increased comparative thickness of the ciliary body by 8.3%, whereas PhXA41 decreased comparative thickness by 3.3% in a manner similar to cyclopentolate hydrochloride.

Comparison of the prevalence of plateau iris configurations between angle-closure glaucoma and open-angle glaucoma using ultrasound biomicroscopy.

PurposeTo determine the prevalence of plateau iris configurations in acute primary angle-closure (APAC), chronic angle-closure glaucoma (CACG), and open-angle glaucoma (OAG) eyes using ultrasound biomicroscopy. Materials and MethodsThe study included fellow eyes of 27 APAC patients, 26 OAG patients, and 26 CACG patients with no history of APAC. Patients with a history of earlier intraocular surgery or argon laser peripheral iridoplasty were excluded from the study. Eyes that had not undergone laser peripheral iridotomy were excluded from APAC and CACG groups. Radial scans were carried out using ultrasound biomicroscopy in all 4 quadrants. A plateau iris configuration within a quadrant was defined by the presence of an anteriorly positioned ciliary process, a narrow ciliary sulcus, a steeply rising peripheral iris, followed by a downward angulation from the corneoscleral wall and the presence of a flat iris plane. Eyes with plateau iris configurations were defined as those having at least 2 quadrants fulfilling these criteria. ResultsPlateau iris configurations were found in fellow eyes of 10 of 27 patients with (37.0%) APAC, 9 of 26 (34.6%) patients with CACG, and 5 of 26 (19.2%) patients with OAG. No significant difference in the prevalence of plateau iris configurations was observed among the 3 groups (P=0.314, &khgr;2 test). ConclusionsEyes with OAG had a higher rate of plateau iris configurations than expected. Longitudinal studies to evaluate plateau iris height are required to determine its significance in the pathogenesis of angle-closure glaucoma.

Twenty-four-hour ocular hypotensive effects of 0.0015% tafluprost and 0.005% latanoprost in healthy subjects

PurposeTo compare the intraocular pressure (IOP) reduction over 24 h achieved with tafluprost (0.0015%) with that achieved with latanoprost (0.005%).MethodsTwenty-seven healthy volunteers were studied. After a 24-h IOP baseline measurement was taken, one ophthalmic solution was applied to the right eye daily for 7 days. The drug was then withdrawn for 2 weeks. The other agent was then applied to the left eye in the same manner. IOP was measured every 3 h for 24 h on the seventh day of treatment.ResultsThe 24-h IOP after 7 days’ treatment with latanoprost decreased from 11.5 mmHg at baseline to 9.7 mmHg (−1.8 mmHg) and that with tafluprost from 11.8 to 9.8 mmHg (−1.9 mmHg). Tafluprost was statistically more effective after 24 h (P = 0.007; paired t test). The number of subjects with a 24-h mean IOP reduction of <10% was 8/27 (29.6%) with latanoprost versus 4/27 (14.8%) with tafluprost. The incidence of conjunctival hyperemia with latanoprost was 4/27 (14.8%) and that with tafluprost was 8/27 (29.6%).ConclusionThe overall efficacies of the two agents were not different, but tafluprost was associated with a greater reduction in IOP at 24 h after administration. Tafluprost showed a higher rate of conjunctival hyperemia.

Glaucoma in Atomic Bomb Survivors

Radiation has been associated with increases in noncancerous diseases. An effect of low-dose radiation on the prevalence of clinically detected glaucoma has not been previously reported. We therefore investigated the prevalence of glaucoma in A-bomb survivors and its possible association with radiation dose. A total of 1,589 people who participated in the clinical examination program for A-bomb survivors at the Radiation Effects Research Foundation (RERF) between October 2006 and September 2008 and who had reconstructed radiation doses, were recruited into this cross-sectional screening study. The prevalence of glaucoma and its dose-response relationship to A-bomb radiation were measured. Each subject underwent an initial screening consisting of an interview and ophthalmological examination. Questionable cases with any indication of ocular disease, including glaucoma, were referred to local hospitals for more comprehensive evaluation. A diagnosis of glaucoma was made based on specific optic disc appearance, perimetric results and other ocular findings. Of 1,589 eligible people, we detected 284 (17.9%) cases of glaucoma overall, including 36 (2.3%) cases of primary open-angle glaucoma with intraocular pressure levels greater than 21 mmHg, 226 (14.2%) cases of normal-tension glaucoma and 25 (1.6%) cases of primary angle-closure glaucoma. Seven glaucoma risk factors were examined as potential confounders but only two needed to be included in the final model. Binary regression using a generalized estimating equation method, with adjustment for gender, age, city, cataract surgery or diabetes mellitus, revealed an odds ratio at 1 Gy of 1.31 (95% confidence interval 1.11–1.53, P = 0.001) in the case of normal-tension glaucoma, but no association for other types of glaucoma. The prevalence of normal-tension glaucoma may increase with A-bomb radiation dose, but uncertainties associated with nonparticipation (59% participation) suggest caution in the interpretation of these results until they are confirmed by other studies.

Additive effect of bunazosin on intraocular pressure when topically added to treatment with latanoprost in patients with glaucoma

PURPOSE To investigate whether an alpha-1 blocker, bunazosin, has an additive effect on lowering intraocular pressure (IOP) when topically added to latanoprost treatment in patients with glaucoma. METHODS Bunazosin twice a day was added topically to the treatment for 12 patients with glaucoma who had been instilling latanoprost once a day for more than 1 month. IOP was measured and adverse events were checked 2, 4 and 8 weeks after the addition of bunazosin to their treatment. RESULTS One of the 12 patients dropped out in the course of the study. Therefore, 11 patients were included for the analysis of IOP, and 12 for the analysis of adverse events. IOPs were decreased significantly (P=.008, Wilcoxon signed rank test) from 18.2+/-3.4 mm Hg to 16.6+/-3.5 mm Hg 8 weeks after the addition of bunazosin. Adverse events were seen in 5 of the 12 patients. CONCLUSION Bunazosin has an additive effect on lowering IOP when topically added to latanoprost treatment in glaucoma patients.

Topical latanoprost causes posterior movement of lens in a patient with exfoliation syndrome and subluxated lens: a case report

IntroductionTo report the effect of topical latanoprost on the position of a subluxated lens.Case presentationAfter 0.005% latanoprost was administered topically to a patient with ocular hypertension due to a pseudoexfoliation syndrome and a subluxated lens, the position of the lens was examined by slit-lamp biomicroscopy, and the ciliary body thickness by ultrasound biomicroscopy. The lens had moved posteriorly, and the thickness of the ciliary body had decreased after the latanoprost.ConclusionWe suggest that the decrease in the thickness of the ciliary body resulted in an increase in the tension of the zonule of Zinn fibers, thus pulling the subluxated lens posteriorly.

Systemic steroid-pulse therapy in a patient with idiopathic choroidal detachment: a case report.

Aim: To report on the effectiveness of systemic steroid-pulse therapy in treating idiopathic choroidal detachment. Case Presentation:Our patient developed idiopathic choroidal detachment after cataract surgery for pseudoexfoliation glaucoma and glaucoma filtration surgery. Systemic steroid-pulse therapy was performed, and the choroidal detachment resolved completely. Conclusion: We suggest systemic steroid-pulse therapy as a treatment option for idiopathic choroidal detachment with low intraocular pressure.