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Preventive effect of lacrimal occlusion on topical timolol-induced bronchoconstriction in asthmatics

Authors


  • This study was not supported by any organization or company. We do not have any commercial or proprietary interest in the product or company mentioned in this article. Our previous pilot study presented in 4th International Glaucoma Symposium (2003 Barcelona, Spain) was carried out in a completely different population (see reference no. 28), and supported in part by Abdi Ibrahim-Allergan, Turkey.

Correspondence: Associate Professor Ibrahim F Hepsen, Inonu University, T Ozal Medical Center, Department of Ophthalmology, 44069 Malatya, Turkey. Email: ifhepsen@inonu.edu.tr

Abstract

Aim: 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.

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