title: The effects of apraclonidine on conjunctival oxygen tension.
abstract: 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.
authors.affiliation: Department of Ophthalmology, University of California at Davis, Sacramento.
authors.forename: C L
authors.initials: CL
authors.lastname: Serdahl
authors.forename: J
authors.initials: J
authors.lastname: Galustian
authors.forename: R A
authors.initials: RA
authors.lastname: Lewis
mesh_terms: D000287:Administration, Topical; D000328:Adult; D003000:Clonidine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology; D003228:Conjunctiva / Q000187:drug effects* / Q000378:metabolism; D005260:Female; D006801:Humans; D007429:Intraocular Pressure / Q000187:drug effects; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000378:metabolism*; D011446:Prospective Studies; D011897:Random Allocation
chemical_list: C016986:apraclonidine; D003000:Clonidine; D010100:Oxygen