Abstract
Abstract: :
Purpose:Artificial tears are routinely recommended for patients with dry eye syndrome. The goal of this pilot study is to evaluate the effect of artificial tear therapy on aqueous tear production in healthy volunteers. Methods: Fifteen healthy individuals (11 female, 4 male; mean age 30.2, range 24–45), without signs or symptoms of dry eye syndrome, participated in the study. Volunteers were instructed to use artificial tears in both eyes, three times per day. The Schirmer test, without anesthesia, was performed at baseline and at the end of weeks 1, 2, and 4. The artificial tears were discontinued after four weeks of therapy. Results:Mean tear production, as measured by the Schirmer test, without anesthesia, was 14.6 mm (SEM ± 1.96 mm) at baseline, 15.9 mm (SEM ± 2.62 mm) at week 1, 12.2 mm (SEM ± 1.58 mm) at week 2, and 10.9 mm (SEM ± 2.08) at week 4. Therefore, the mean decline in tear production from baseline to week 4 was 3.7 mm (p = 0.037, Student's t–test). Conclusions: This study suggests that artificial tear therapy may decrease tear production in normal subjects. This may result from a physiological feedback mechanism or from preservative toxicity. If the results of our pilot study generalize to patients with dry eye syndrome, physicians and their patients may need to apply caution regarding overzealous use of artificial tears as a therapeutic measure.
Keywords: cornea: tears/tear film/dry eye • cornea: clinical science