title: The effect of wrist rest, caffeine, and oral timolol on the hand steadiness of ophthalmologists.
abstract: Because hand steadiness is an important aspect of microsurgical technique, hand movement, amplified by a hand-held laser pointer, was measured in 14 ophthalmology trainees on four separate mornings when each had ingested (1) 200mg of caffeine, (2) 12.5mg of timolol (2.5mL of timolol 0.5% ophthalmic solution), (3) a combination of caffeine and the beta-adrenergic blocker, or (4) a placebo. Caffeine increased the resting pulse and hand movement. Although the beta-adrenergic blocker and the combination of caffeine and this drug decreased the resting heart rate from that of placebo, they did not significantly change hand steadiness. However, compared with caffeine alone, the beta-adrenergic blocker-caffeine combination significantly decreased hand movement and the pulse. Resting the wrist significantly steadied hand movements. Hand movement was not correlated with the level of ophthalmology training, the trainee's weight, or their daily caffeine consumption.
authors.affiliation: Department of Pediatric Ophthalmology, Indiana University Hospitals, Indianapolis.
authors.forename: R W
authors.initials: RW
authors.lastname: Arnold
authors.forename: D T
authors.initials: DT
authors.lastname: Springer
authors.forename: W K
authors.initials: WK
authors.lastname: Engel
authors.forename: E M
authors.initials: EM
authors.lastname: Helveston
mesh_terms: D000284:Administration, Oral; D002110:Caffeine / Q000494:pharmacology*; D004311:Double-Blind Method; D005260:Female; D006225:Hand / Q000502:physiology*; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007396:Internship and Residency; D008297:Male; D008866:Microsurgery / Q000379:methods*; D009068:Movement / Q000187:drug effects; D009885:Ophthalmology / Q000295:instrumentation*; D010919:Placebos; D011446:Prospective Studies; D013999:Timolol / Q000494:pharmacology*
chemical_list: D010919:Placebos; D002110:Caffeine; D013999:Timolol