IMMEDIATE EFFECTS OF ARTIFICIAL TEARS VISCOSITY AND PH ON OCULAR SIGNS AND SYMPTOMS

Abstract

Purpose: To evaluate the short-term effects of artificial tears (ATs) with different viscosity and pH; Systane^® Hydration preservative (SH) and non-preservative (SHUD), Optive^® preservative (O) and non-preservative (OUD) on patients’ signs and symptoms in normal and dry eye (DE) groups.

Methods: 120 participants (55: DE group, 65: normal group) involved in this prospective, double-masked randomized study.  Rheometer and digital pH-meter were used to evaluate the viscosity and pH of all ATs. Ocular discomfort between pre and post-instillation (after 60 minutes interval) was evaluated using Ora Calibra™ Ocular Discomfort and 4-Symptom Questionnaire (OOD4SQ). Drop comfort immediately assessed after ATs instillation using Ora Calibra™ Drop Comfort Scale (ODCS). Tear break-up time (TBUT) and tear meniscus height (TMH) were measured at baseline, 5, 15 and 60 minutes after instillations. Tear ferning pattern (TFP) were observed and compared at baseline and 60 minutes after instillation.

Results: Viscosity of all ATs were; SHUD: 32.73cP, SH: 26.7cP, OUD: 14.42cP and O: 13.88cP with pH of 7.74 (SHUD), 7.85 (SH), 7.19 (OUD) and 7.24 (O). Highest DCS was found in SH for both DE (2.00±1.042) and normal group (1.84±0.963). Significant reduction (p<0.05) in all parameters of ocular symptoms (OOD4SQ) were found after instillation of OUD in both groups.  TBUT and TMH for both groups increased significantly (p<0.05) from baseline at all time-interval (except TBUT for O in normal group at 5 minutes post-instillation). TFP improved significantly after 60 minutes instillation of all ATs in both groups.

Conclusion: All ATs improved TBUT, TMH and TFP in both groups, regardless their viscosity and pH. OUD showed better ocular symptoms improvement and less subjective sensation compared to other tested ATs.