The effects of apraclonidine on conjunctival oxygen tension

Arch Ophthalmol. 1989 Dec;107(12):1777-9. doi: 10.1001/archopht.1989.01070020859027.


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.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Topical
  • Adult
  • Clonidine / administration & dosage
  • Clonidine / analogs & derivatives*
  • Clonidine / pharmacology
  • Conjunctiva / drug effects*
  • Conjunctiva / metabolism
  • Female
  • Humans
  • Intraocular Pressure / drug effects
  • Male
  • Middle Aged
  • Oxygen / metabolism*
  • Prospective Studies
  • Random Allocation


  • apraclonidine
  • Clonidine
  • Oxygen