title: Sustained perimacular vascular and visual response to topical beta blockers in normal human eyes.
abstract: OBJECTIVE
  To assess visual and circulatory responses to treatment with topical beta adrenergic antagonists.
  
  
  METHODS
  Institutional prospective randomized clinical trial in normal adults.
  
  
  METHODS
  Twenty adults (36 (mean) +/- 8 (S.D.) years) underwent repeated baseline perimetry (Humphrey 30-2), contrast sensitivity (Vector Vision), perimacular microcirculatory studies (Oculix blue-field entoptic simulator), intraocular pressure (IOP), heart rate (HR), and blood pressure (BP) testing. Subjects commenced either timolol 0.5% or betaxolol 0.5% twice daily on day 1, were retested on days 3 and 35, discontinued treatment for 21 days, whereupon repeated tests were performed. Treatment responses were compared by paired t-test.
  
  
  RESULTS
  Timolol-treated eyes showed improvement in contrast sensitivity (P=0.03) and pericentral perimetric thresholds (P=0.01), but corresponding increases among betaxolol-treated eyes were significantly higher (P=0.03 and 0.04, respectively, relative to timolol-treated eyes). Leukocyte velocity increased with both drugs, each with post-withdrawal carryover (P< or =0.03). Significant IOP reduction (approximately 2.5 mmHg) occurred in both groups, BP fell 2.8 mmHg among betaxolol-treated subjects (P=0.02), and HR was 2 bpm slower among timolol-treated subjects (P=0.03), but all reverted to baseline values after washout.
  
  
  CONCLUSIONS
  Both treatment groups demonstrated significant changes in visual function and perimacular hemodynamics, sustained after the terminal 3-week washout period.
authors.affiliation: South Texas Ocular Imaging Center, University of Texas Health Science Center, San Antonio, TX, USA. Sponsel@uthscsa.edu
authors.forename: William E
authors.initials: WE
authors.lastname: Sponsel
mesh_terms: D000287:Administration, Topical; D000319:Adrenergic beta-Antagonists / Q000008:administration & dosage*; D000328:Adult; D005123:Eye / Q000098:blood supply / Q000187:drug effects*; D005260:Female; D006801:Humans; D007962:Leukocytes / Q000502:physiology; D008266:Macula Lutea / Q000098:blood supply* / Q000187:drug effects* / Q000502:physiology; D008297:Male; D008875:Middle Aged; D014794:Visual Fields / Q000187:drug effects / Q000502:physiology; D014796:Visual Perception / Q000187:drug effects* / Q000502:physiology
chemical_list: D000319:Adrenergic beta-Antagonists