November 1977
Volume 16, Issue 11
Articles  |   November 1977
Comparison of the effects of timolol and other adrenergic agents on intraocular pressure in the rabbit.
Investigative Ophthalmology & Visual Science November 1977, Vol.16, 987-996. doi:
  • Views
  • PDF
  • Share
  • Tools
    • Alerts
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      P Vareilles, D Silverstone, B Plazonnet, J C Le Douarec, M L Sears, C A Stone; Comparison of the effects of timolol and other adrenergic agents on intraocular pressure in the rabbit.. Invest. Ophthalmol. Vis. Sci. 1977;16(11):987-996.

      Download citation file:

      © ARVO (1962-2015); The Authors (2016-present)

  • Supplements
This content is PDF only. Please click on the PDF icon to access.

The effect of timolol, propranolol, epinephrine, and isoproterenol on intraocular pressure (IOP) (measured by tonometry) were compared after topical administration in conscious rabbits. Epinephrine and isoproterenol decreased IOP in normotensive rabbits, whereas propranolol had no effect. Timolol produced only a slight and inconsistent lowering of IOP in normotensive rabbits. All four agents reduced IOP elevated by an oral water load; the adrenergic agonists were substantially more active than the two beta-adrenergic blocking agents. In alpha-chymotrypsin-induced ocular hypertension, epinephrine, isoproterenol, and timolol were essentially equally effective, whereas propranolol exhibited only weak activity. In this latter model, timolol did not lose its effectiveness after multiple instillations (three/day) over an 8-day period. The concentration of timolol in the acqueous humor after topical application of effective hypotensive doses was relatively high as compared to that found in plasma. In addition, topical doses of timolol required to lower IOP were considerably greater than those needed to reduce or block the ocular hypotensive activity of isoproterenol. The mode of action and therapeutic implications of beta-adrenergic blocking agents in glaucoma are discussed.


This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.