Purpose
To investigate the effects of diquafosol sodium eye drops (DQS), a purinergic P2Y2 receptor agonist, on tear film stability in patients with unstable tear film.
Methods
Two prospective studies were conducted. One was an exploratory non-randomized trial on 39 eyes with dry eye symptoms and short tear film break-up time (BUT), but without epithelial damage. Schirmer’s test value was not considered as an inclusion or exclusion criterion. Changes in questionnaire and Visual Analog Scale (VAS) scores for symptoms, BUT, Schirmer’s value, and fluorescein staining scores of the cornea and conjunctiva were studied for 3 months. The other was a randomized clinical trial (RCT) of DQS and artificial tears in 17 eyes with short BUT. Eyes with decreased Schirmer’s values (<5mm) were excluded. Changes in symptoms, BUT, fluorescein staining score, and tear film stability using continuous corneal topographic analysis were studied for 4 weeks.
Results
In the exploratory study, significant improvements in VAS scores and BUT were noted at both 1 months (P = 0.053 and 0.0005, respectively) and 3 months (P = 0.022 and <0.0001, respectively). Schirmer’s values were not significantly increased at 1 or 3 months. Significant improvements in symptoms and BUT were more noted in eyes without decreased Schirmer’s values than in eyes with decreased Schirmer’s values. In the RCT, significant improvements in subjective symptoms were noted in the DQS groups (P = 0.0039), but not in the artificial tear group, at 2 weeks. BUT was significantly prolonged in the DQS group at 4 weeks (P = 0.029), but not in the artificial tear group. No significant changes were noted in fluorescein scores or tear film stability.
Conclusions
DQS improved subjective symptoms and prolonged BUT in eyes with unstable tear film not associated with low tear secretion and ocular surface epithelial damage. Because many patients who have unstable tear film are refractory to conventional treatments, DQS may offer benefits in the treatment of dry eyes.
Keywords: 486 cornea: tears/tear film/dry eye