Preventive effect of lacrimal occlusion on topical timolol-induced bronchoconstriction in asthmatics.
OBJECTIVE
To evaluate the potential preventive role of lacrimal occlusion on the topical timolol-induced bronchoconstriction in asthmatics.


METHODS
This was a prospective and single-masked study. Fourteen volunteer subjects with asthma were included. Collagen plugs were inserted into both canaliculi on one side to inhibit lacrimal drainage. The effect of lacrimal occlusion on lung function tests was measured before and 60 min after the instillation of a timolol drop in unplugged and plugged eyes. The spirometric measurements include forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), FEV1/FVC, and mid expiratory flow-rate (FEF25-75).


RESULTS
The timolol (0.5%) drop administration into the eye caused a significant decrease in pulmonary functions in patients with asthma in whom the lacrimal punctae had not been occluded by collagen plug. P values were 0.008 for FVC and 0.001 for FEV1 and FEF25-75. The occlusion of the lacrimal duct by intracanalicular plugs significantly reduced this decrease in pulmonary function. P values were 0.6 for FVC, 0.8 for FEV1, and 0.5 for FEF25-75. The lacrimal occlusion did not affect heart rate and blood pressures. Three subjects complained of epiphora.


CONCLUSIONS
Lacrimal occlusion with intracanalicular collagen plugs may almost completely prevent the bronchoconstriction caused by topical timolol in asthmatics by inhibiting or decreasing systemic absorption of the medication.
Hepsen
Ibrahim F
IF
Department of Ophthalmology, Turgut Ozal Medical Center, Inonu Univeristy, Malayta, Turkey. ifhepsen@inonu.edu.tr
Yildirim
Zeki
Z
Yilmaz
Harun
H
Kotuk
Mahir
M
D000287:Administration, Topical; D000319:Adrenergic beta-Antagonists / Q000008:administration & dosage*; D000328:Adult; D000368:Aged; D001249:Asthma / Q000503:physiopathology / Q000517:prevention & control*; D001794:Blood Pressure / Q000502:physiology; D016084:Bronchoconstriction / Q000187:drug effects* / Q000502:physiology; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology; D007767:Lacrimal Duct Obstruction / Q000503:physiopathology*; D008168:Lung / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D019736:Prostheses and Implants; D019919:Prosthesis Implantation; D012129:Respiratory Function Tests; D016037:Single-Blind Method; D013999:Timolol / Q000008:administration & dosage*
D000319:Adrenergic beta-Antagonists; D013999:Timolol