Tear Volume Increase Facilitated by 3% Diquafosol Sodium Ophthalmic Solution in Normal, Healthy Human Eyes and in Dry Eyes of Sjögren’s Syndrome Patients

Abstract

Purpose: : Animal studies have shown that diquafosol sodium (DQS) combined with the P2Y₂ receptor of the conjunctiva facilitates water secretion from the conjunctiva. The purpose of this present study was to investigate the effect of 3% DQS ophthalmic solution eye drops on tear volume increase in normal, healthy human eyes and in the dry eyes of Sjögren’s syndrome patients.

Methods: : This study involved 20 normal healthy adults (N group; 17 males and 3 females, mean age: 38.8 years) without dry eyes and 22 female Sjögren’s Syndrome patients (SS group; mean age: 65.8 years). Each subject received artificial tear solution (ATS) eye drops in one eye and 3% DQS ophthalmic solution eye drops in their fellow eye in a masked fashion. The radius (R, mm) of curvature of the tear meniscus was then measured by meniscometry at 5, 10, 15, 30, and 60 minutes after eye-drop instillation in the N group and at 15 minutes after in the SS group. At those same intervals, subjects were asked to self-evaluate symptoms of irritation, excessive tearing, and discharge using the visual analog scale (VAS).

Results: : In the N group, delta R (ΔR, the increased value from the baseline; mean±SD) at 5, 10, 15, and 30 minutes in the ATS eyes/DQS eyes were -0.008±0.052/0.045±0.058, 0.001±0.062/0.057±0.071, -0.012±0.062/0.037±0.086, and -0.010±0.071/0.030±0.112, respectively, and the DQS eyes showed significantly greater values (p<0.05) from 5 to up to 30 minutes after the instillation than did the ATS eyes. In the SS group, the respective ΔR at 15 minutes in the ATS eyes/DQS eyes were -0.001±0.049/0.052±0.035, and the DQS eyes also showed significantly greater values (p<0.05) than the ATS eyes. Of the 40 N-group eyes, 13 eyes (7 ATS eyes, 6 DQS eyes) showed abnormal tear film breakup time (BUT) (≤ 5 seconds) prior to the instillation, and as of those 13 eyes, the DQS eyes had significantly greater excessive tearing at 15 minutes after instillation than did the ATS eyes (ΔVAS, the increased value from the baseline; mean±SD: ATS eyes: 1.57±4.43; DQS eyes: 8.50±5.09).

Conclusions: : The findings of this study show that 3% DQS ophthalmic solution eye drops can facilitate tear volume increase in normal, healthy human eyes and in the dry eyes of Sjögren’s Syndrome patients.

Keywords: cornea: tears/tear film/dry eye • conjunctiva • receptors: pharmacology/physiology