Effect of Tiotropium on eye findings in the treatment of chronic obstructive pulmonary disease

Background: Chronic obstructive pulmonary disease (COPD) is a persistent, chronic inflammatory disease of the lungs. Tiotropium, used in the treatment of COPD, is a muscarinic receptor antagonist that provides long-acting bronchodilation. Our study aimed to investigate the effects of Tiotropium on anterior chamber parameters.

Methods: The study was conducted as an observational cross-sectional and prospectively between October 2023 and April 2024. Patients were examined in three groups: Group 1 consisted of untreated COPD patients; Group 2 consisted of healthy volunteers similar age and gender, and Group 3 included COPD patients receiving Tiotropium 18 mcg via HandiHaler. Anterior chamber parameters, intraocular pressure values, and photopic-mesopic pupil diameters were measured at the initial visit for Group 1 and Group 2 patients, and at the third month of treatment for Group 3 patients.

Results: Thirty-six patients were included in each group in the study. No significant differences were observed in ocular findings between the patient and control groups. In COPD patients receiving Tiotropium, narrowing of angle parameters, an increase in photopic-mesopic pupil diameters, and intraocular pressure were observed at the third month of treatment.

Conclusion: This study is the first research that investigate the effects of Tiotropium on anterior chamber parameters, pupil diameters, and intraocular pressure in COPD treatment. In conclusion, patients with COPD receiving Tiotropium therapy for three months showed narrowing in angle parameters, an increase in intraocular pressure, and photopic-mesopic pupil diameter; however, no patients developed drug-induced acute angle closure glaucoma.

Trial registration: An independent ethics committee approved the study (Giresun EAH KEAK 2023/180 and 9.10.2023/02) which was performed in accordance with the Declaration of Helsinki, Guidelines for Good Clinical Practice. The study was conducted as prospectively, observational case-control. The Clinical Trial Number obtained for the study is NCT06525051 and was taken on 2024-07-29.