Br J Ophthalmol 1998;82:758-762 ( July )
Topical carbonic anhydrase inhibition increases ocular pulse
amplitude in high tension primary open angle glaucoma
Karl-Georg Schmidt,a
Andrea von Rückmann,a
Lutz E Pillunatb
a Department of
Ophthalmology, Justus Liebig University, Giessen, Germany, b Department of
Ophthalmology, University of Hamburg, Hamburg, Germany
Correspondence to: Dr med K-G Schmidt, Universitäts-Augenklinik,
Friedrichstrasse 18, D-35385 Giessen, Germany.
; Accepted for publication 29 January 1998
BACKGROUND
Ocular
pulse amplitude (OPA) is reduced in normal tension primary open angle
glaucoma (NTP) patients when compared with healthy age matched controls
(CTL) while increased OPA appears to protect ocular hypertensive
patients from visual field loss. If NTP is accompanied by vasospasm, as
in roughly half of the primary open angle glaucoma (POAG) population
(independent of intraocular pressure, IOP), calcium channel blockers
increase OPA and thus stabilise visual fields in these patients.
Current glaucoma drugs reduce IOP but do not activate (compromised)
ocular perfusion.
METHODSThe influence
of dorzolamide, a topical carbonic anhydrase inhibitor in standard
dosage (three times daily, one eye) on OPA, IOP, blood pressure, and
heart rate was investigated in a randomised, prospective, masked
clinical trial assessing the acute effects of dorzolamide
v placebo before and 2 days after
application in 33 cataract patients with (n = 14) and without (n = 19)
high tension POAG (HTP) who provided informed consent.
RESULTSFollowing
application of dorzolamide (D) IOP (mm Hg, mean (SEM)) in
HTPD (20.2 (0.5)/16.3 (0.5)) and in CTLD (16.0 (0.5)/12.3 (0.5)) was highly significantly (p <0.001) reduced and was
significantly (p<0.03) reduced in vehicle (V) treated eyes
(HTPV: 20.3 (0.4)/19.0 (0.4)) and CTLV: 15.8 (0.4)/14.9 (0.3)) when compared with respective baseline measurements.
OPA (mm Hg) in HTPD (2.1 (0.1)/2.5 (0.1)) and
CTLD (2.2 (0.1)/2.6 (0.2)) eyes was significantly (p<0.05) increased and unaffected in vehicle treated eyes when compared with
respective baseline measurements. Systemic perfusion variables were
also unchanged.
CONCLUSIONDorzolamide
increased OPA in HTP and CTL. Drugs stimulating OPA may improve
prognosis of POAGs.
Keywords:
ocular pulse amplitude;
primary
open angle glaucoma;
dorzolamide
© 1998 by British Journal of Ophthalmology
