The effects of apraclonidine on conjunctival oxygen tension
C. L. Serdahl, J. Galustian and R. A. Lewis
Department of Ophthalmology, University of California at Davis, Sacramento.
A prospective, randomized study evaluated the effects of unilateral,
topical 1% apraclonidine hydrochloride on conjunctival oxygen tension in 10
normal volunteers using a conjunctival oxygen monitor. Conjunctival oxygen
tension and intraocular pressure were measured prior to instillation of
apraclonidine, then at 1, 3, and 5 hours. Apraclonidine was found to
significantly decrease conjunctival oxygen tension 76% at 1 hour compared
with baseline values. At 3 hours conjunctival oxygen tension was decreased
to 56% and at 5 hours to 10% of baseline. Intraocular pressure was lowered
maximally at 3 hours to 40% of baseline measurements in the treated eye.
The contralateral eye had a small decrease in conjunctival oxygen tension
and intraocular pressure that was not statistically significant. Lid
retraction and conjunctival blanching were noted to occur maximally between
1 and 3 hours. Further study is needed to determine if the
apraclonidine-induced conjunctival hypoxia noted in this study has clinical
significance for ocular blood flow, particularly in patients with glaucoma.
