[Infrared thermographic investigation of the mechanism of action of timolol (author's transl)].

Distribution of local temperature in the anterior segment was investigated after topical administration of Timolol 0.5% utilizing infrared thermography. Eighty patients were included in this study; the untreated eye was used as a control. Within 30 minutes of instillation of Timolol a decrease in local temperature of up to 3 degrees C could be observed in 44% of the cases, whereas in 32% no change and in the remaining 24% a small increase of up to 1 degree C occurred. In ten other patients thermography and applanation tonometry were carried out simultaneously over a period of 4 hours following topical administration of Timolol; in this preliminary series a maximal local temperature decrease occurred after 90 minutes, i.e., prior to the maximal effect on intraocular pressure. It is concluded from these results that topical administration of Timolol reduces the ciliary blood flow.