rss
Br J Ophthalmol 1990;74:409-412 doi:10.1136/bjo.74.7.409
  • Research Article

Effects of topical timolol (0.5%) and betaxolol (0.5%) on corneal sensitivity.

  1. S S Weissman and
  2. P A Asbell
  1. Department of Ophthalmology, Mount Sinai School of Medicine, New York, NY.

      Abstract

      There are conflicting reports on the propensity of topical beta blockers to produce corneal anaesthesia. We measured corneal sensitivity thresholds quantitatively for 10 minutes following the administration of one drop of topical timolol maleate (0.5%), betaxolol hydrochloride (0.5%), or saline in 30 eyes of 18 normal subjects in a randomised, double-masked study. Most subjects had insignificant changes in corneal sensitivity thresholds. We identified, however, a subgroup of four subjects (five eyes) that had a marked and prolonged increase of corneal sensitivity threshold (corneal anaesthesia) after timolol (three eyes) and betaxolol (two eyes). The group mean age of these 'responders' (49.0 years) was significantly greater (p less than 0.005) than that of the non-responders (35.0). We recommend periodic measurements of corneal sensitivity in older patients receiving topical timolol or betaxolol, especially when given in higher concentrations, to identify responders, who may be at risk of developing keratitis.

      Register for free content

      The full back archive is now available for all BMJ Journals. Institutional subscribers may access the entire archive as part of their subscription. Personal subscribers will also have access to all content when logged in. Non-subscribers who register have free access to all articles published before 2006 right back to volume 1 issue 1. Register here to access the free archive of all BMJ Journals.

      Don't forget to sign up for content alerts so you keep up to date with all the articles as they are published.