Comparison of 24-hour intraocular pressure reduction with two dosing regimens of latanoprost and timolol maleate in patients with primary open-angle glaucoma
Agp. Konstas et al., Comparison of 24-hour intraocular pressure reduction with two dosing regimens of latanoprost and timolol maleate in patients with primary open-angle glaucoma, AM J OPHTH, 128(1), 1999, pp. 15-20
PURPOSE: To compare the 24-hour diurnal ocular hypotensive efficacy of two
dosing regimens of latanoprost, once daily (8 AM or 10 PM), vs timolol male
ate, twice daily.
METHODS: We measured six diurnal intraocular pressure curves (6 AM, 10 AM,
2 PM, 6 PM, 10 PM, and 2 AM) in one randomly selected eye of 34 Greek patie
nts newly diagnosed with primary open-angle glaucoma. The first diurnal cur
ve was an untreated baseline. Patients began taking timolol 0.5%, twice dai
ly, for 2 months. Patients were randomly assigned to latanoprost 0.005% giv
en at 8 AM or 10 PM for 1 month and then changed to the other dosing regime
n for 1 month. A diurnal curve was performed after each dosing period.
RESULTS: The baseline diurnal pressure for all 34 subjects was 23.1 +/- 3.7
mm Hg. The average intraocular pressures at 6 AM for patients who were giv
en latanoprost in the evening (17.9 +/- 2.9 mm Hg) was statistically lower
than that in patients given timolol solution (20.1 +/- 2.5 mm Hg, P = .003)
; however, patients who were given timolol demonstrated a similar diurnal i
ntraocular pressure (19.1 +/- 2.8 mm Hg) to both morning (18.8 +/- 3.7 mm H
g) and evening doses (18.8 +/- 3.6 mm Hg) of latanoprost (P = .329). When t
he two latanoprost dosages were compared directly, evening administration p
rovided a statistically lower intraocular pressure at 10 AM (P = .0001) and
morning administration at 10 PM (P = .0001). This study had an 80% power t
o exclude a 1.2-mm Hg difference between groups.
CONCLUSIONS: This study indicates that in a small population, both latanopr
ost and timolol are effective in lowering intraocular pressure throughout a
24-hour period; however, latanoprost is most effective in the 12-hour to 2
4-hour period after administration. (Am J Ophthalmol 1999;128:15-20. (C) 19
99 by Elsevier Science Inc. All rights reserved.)