Sustained perimacular vascular and visual response to topical beta blockers in normal human eyes.
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.
Sponsel
William E
WE
South Texas Ocular Imaging Center, University of Texas Health Science Center, San Antonio, TX, USA. Sponsel@uthscsa.edu
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
D000319:Adrenergic beta-Antagonists