Page 99 - DUOKOPT BIBLIOBOOK

EFFICACY

Effect of Dorzolamide Timolol Combination

Versus Timolol 0.5% on Ocular Bloodflow in

Patients With Primary Open-angle Glaucoma

ALON HARRIS, MS, PHD, CHRISTIAN P. JONESCU-CUYPERS, MD, PHD,
LARRY KAGEMANN, MS, BME, ELIZABETH ANNE NOWACKI, BA,
HANNA GARZOZI, MD, CRAIG COLE, BS, AND BRUCE MARTIN, PHD

● PURPOSE: Addition of dorzolamide to timolol in pri- ECAUSE ELEVATED INTRAOCULAR PRESSURE RE-
mary open-angle glaucoma shows augmented reduction of mains the primary identified risk factor for the
intraocular pressure. It is unknown as yet if addition of B development and progression of glaucoma, drug
dorzolamide will alter hemodynamics. development for glaucoma has concentrated on the search
● METHODS: Fifteen patients with primary open-angle for novel, effective ocular hypotensive agents that have
glaucoma were placed on a medication-dependent 1-week minimal adverse ocular and systemic side effects. Dorzol-
to 4-week washout that included maintenance on timolol. amide, a potent inhibitor of carbonic anhydrase II and IV
After washout, baseline measurements were taken (timo- in the ciliary processes, has been developed as an ocular
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lol). They were studied after a month on timolol or hypotensive with minimal side effects. 2,3 Well tolerated,
dorzolamide-timolol (Cosopt�; Merck, Inc, Whitehouse especially in comparison with system-wide carbonic anhy-
Station, New Jersey), with the second drug preceded by drase inhibition (for example, with acetazolamide), dorzo-
another month of timolol maintenance and second base- lamide has been shown to augment the intraocular
line measurements. At each visit, visual function, in- pressure–lowering effect of -adrenergic blocking agents,
traocular pressure, and ocular hemodynamics were such as timolol. 2,3
monitored, including indocyanine green and fluorescein Whereas drug treatment for glaucoma focuses primarily
angiography and color Doppler imaging. on intraocular pressure reduction, other aspects of drug
● RESULTS: Cosopt� significantly reduced intraocular action on the eye warrant evaluation as well. Foremost
pressure (14.7 to 13.4 mm Hg, P < .05) and increased among these is the effect of the agent on vascular nutrition
arteriovenous passage time (superior temporal artery) of of the choroid, retina, and optic nerve; there is evidence
fluorescein dye (2.13 to 1.76 seconds, P .01) but had that glaucoma initiation and progression may be enhanced
no effect on visual function. by ischemia. In normal tension glaucoma, dorzolamide
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● CONCLUSIONS: When compared with timolol in pri- accelerates retinal arteriovenous transit without altering
mary open-angle glaucoma, Cosopt� augments ocular retrobulbar flow velocities. However, it is unknown if
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tension reduction and reduces the amount of time re- these same effects will occur when dorzolamide is used in
quired for blood to pass through the superior retinal combination with timolol for enhanced reduction of in-
vasculature. (Am J Ophthalmol 2001;132:490–495. traocular pressure in primary open-angle glaucoma. Ac-
© 2001 by Elsevier Science Inc. All rights reserved.) cordingly, in this study, we evaluated the impact of
dorzolamide addition to timolol treatment in primary
Accepted for publication Jul 13, 2001. open-angle glaucoma, in terms of both visual function and
From the Department of Ophthalmology, Indiana University School of
Medicine (A.H., C.P.J., L.K., E.A.N., H.G., Y.R.), Indianapolis, Indiana; intraocular pressure, and in terms of effects on retrobulbar,
Medical Sciences Program, Indiana University (B.M.), Bloomington, choroidal, and retinal blood flow.
Indiana.
This work was supported in part by Grant EY10801 (AH) from the
National Institutes of Health, Bethesda, Maryland, an unrestricted grant
from Research to Prevent Blindness, New York, New York, and an METHODS
unrestricted grant from Merck, Inc. Study medications were provided by
Merck, Inc. A.H. is a recipient of the William and Mary Greve Award
from Research to Prevent Blindness. FIFTEEN PATIENTS WITH PRIMARY OPEN-ANGLE GLAU-
Reprint requests to Alon Harris, PhD, Letzter Chair of Ophthalmology, coma were studied in a randomized, cross-over, double-
Indiana University School of Medicine, 702, Rotary Circle, Rm 137, masked design that included initial washout of medications
Indianapolis, IN 46202; fax: (317) 279-1007; e-mail: alharris@
indiana.edu other than timolol, maintenance treatment on timolol,
490 © 2001 BY ELSEVIER SCIENCE INC.ALL RIGHTS RESERVED. 0002-9394/01/$20.00
PII S0002-9394(01)01158-8
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