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Published on: March 12, 2016
[Effect of preservatives on the conjunctiva: a comparative study of beta-blocker eye drops with and without
P J Pisella1, E Lala, V Parier
1Service d'Ophtalmologie, CHU de Tours, Hôpital Bretonneau, 2, boulevard Tonnellé, 37044 Tours Cedex 1. pj.pisella@chu-tours.fr
Purpose:
To compare the effect of timolol with or without preservatives on the conjunctival epithelium of glaucoma patients.
Methods:
A retrospective study using impression cytology (IC) was conducted on patients treated with 0.5% timolol with or without 0.01% benzalkonium chloride (BAC). Fifteen eyes from 15 patients treated with timolol, BAC+ and 17 eyes from 17 patients treated with timolol, BAC- were included in two groups comparable for age and duration of treatment lasting at least 1 year. Specimens were analyzed by flow cytometry for inflammatory profile (using antibodies directed against HLA DR and ICAM-1) and mucin detection (anti-M1/MUC5AC antibody).
Results:
IC analyses showed a significant increase in the expression of the two inflammatory markers, HLA DR and ICAM-1 in the timolol, BAC+ group and also a significant decrease in goblet cell density in the same group as compared to the timolol, BAC- group.
Conclusion:
The use of long-term preserved beta-blocker in glaucoma patients is associated with a direct subclinical epithelial toxicity in the conjunctiva, as already demonstrated by previous experimental studies.
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