Rf. Wang et al., Effect of latanoprost or 8-iso prostaglandin E-2 alone and in combination on intraocular pressure in glaucomatous monkey eyes, ARCH OPHTH, 118(1), 2000, pp. 74-77
Objective: To, evaluate the possible additivity of the effects: of latanopr
ost and 8-iso prostaglandin E-2 (8-iso PGE(2)) on intraocular pressure (IOP
) in monkey eyes with laser-included glaucoma.
Methods: The IOP was measured hourly for 6 hours beginning at 9:30 AM on da
y 1 (baseline day), days 6 and 7 (single-agent therapy), and days 13 and 14
(combination therapy with both agents). Following 1 day of baseline measur
ement. 4 monkeys with unilateral glaucoma received monotherapy twice daily
with either 1 drop of 0.005% latanoprost. or 0.1% 8-iso PGE(2), 25 mu L at
9:30 AM and 3:30 PM from days 2 through 7. From days 8 through 14, both age
nts were applied twice daily 5 minutes apart.
Results: The maximum reduction of IOP (mean +/- SEM) was 8.8 +/- 1.9 mm Hg
(26%) (P<.05) with latanoprost alone and 6.5 +/- 1.0 mm Hg (21%) (P<.01) wi
th 8-iso PGE(2) alone, 2 hours after the morning dosing on day 7. A further
reduction of IOP of 4.0 +/- 0.6 mm Hg was produced when 8-iso PGE(2) was a
dded to latanoprost and of 3.0 +/- 0.7 mm Hg was produced when latanoprost
was added to 8-iso PGE(2) on day 13 before the morning dosing. Combination
therapy with both agents caused maximum IOP reductions from baseline of 11.
3 +/- 3.0 mm Hg (33%) (P<.05) (latanoprost with S-iso PGE(2) added) and of
9.8 +/- 1.3 mm Hg (31%) (P<.01) (8-iso PGE(2) with latanoprost added) on da
y 14.
Conclusion: Latanoprost and 8-iso PGE(2) have an additive effect on IOP in
glaucomatous monkey eyes.
Clinical Relevance: At least 50% of patients are treated with more than 1 o
cular hypotensive medication. Thus, the determination of the additive effec
ts on IOP of glaucoma medications will help to define optimum treatment reg
imens.