Weissman S S, Asbell P A
Department of Ophthalmology, Mount Sinai School of Medicine, New York, NY.
Br J Ophthalmol. 1990 Jul;74(7):409-12. doi: 10.1136/bjo.74.7.409.
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.
关于局部用β受体阻滞剂产生角膜麻醉的倾向，存在相互矛盾的报道。在一项随机、双盲研究中，我们对18名正常受试者的30只眼睛滴入一滴局部用马来酸噻吗洛尔（0.5%）、盐酸倍他洛尔（0.5%）或生理盐水后，定量测量了10分钟内的角膜敏感性阈值。大多数受试者的角膜敏感性阈值变化不明显。然而，我们确定了一个由四名受试者（五只眼睛）组成的亚组，他们在使用噻吗洛尔（三只眼睛）和倍他洛尔（两只眼睛）后，角膜敏感性阈值出现了显著且持续的升高（角膜麻醉）。这些“反应者”的平均年龄（49.0岁）显著高于无反应者（35.0岁）（p<0.005）。我们建议对接受局部用噻吗洛尔或倍他洛尔治疗的老年患者定期测量角膜敏感性，尤其是在使用较高浓度药物时，以识别可能有发生角膜炎风险的反应者。
