COMPARATIVE STUDY OF PRESERVATIVE-FREE AND PRESERVED LUBRICANTS ON TEAR FILM INTEGRITY AND SLEEP QUALITY IN PATIENTS WITH DRY EYES

Abstract

Background: Dry eye disease (DED) is a complex disorder of the ocular surface, which is associated with disruption of tear-film homeostasis, visual disturbance, discomfort and damage to the ocular surface. Artificial tears are frequently first line symptomatic treatment. But repeated use of preserved formulations can lead to exposure of the ocular surface to preservatives, while preservative-free formulations do not expose the surface to the preservatives of the formulation. It is not completely clear how these formulations compare to each other clinically.

Objective: To evaluate the tear-film integrity (tear-film stability and corneal staining) of preservative-free artificial tears compared to preserved lubricants, tear production, dry eye symptoms and subjective sleep quality in dry eye patients.

Methods: 60 patients suffering from dry eye were included in a randomized controlled study. The participants were randomly divided into two groups. Preserved lubricants were given for 8 weeks to Group B, and preservative-free artificial tears were given to Group A. The following outcome measures were evaluated: Tear Break-Up Time (TBUT), Schirmer I Test, Ocular Surface Disease Index (OSDI), Pittsburgh Sleep Quality Index (PSQI), and fluorescein corneal staining. Data analysed using SPSS. Shapiro–Wilk test was used to assess normality. Continuous variables were compared using paired-samples or independent-samples t-test; categorical variables were compared using Chi-square test. A two-tailed p value of < 0.05 was considered statistically significant.

Results: The five outcomes reported were improved in both groups after eight weeks (reported within-group p < 0.001). In Group A (preservative-free), TBUT increased from 6.82 ± 1.21 to 10.94 ± 1.36 seconds and Schirmer I from 7.43 ± 1.84 to 11.87 ± 2.06 mm; OSDI decreased from 31.46 ± 6.72 to 16.28 ± 5.14, PSQI from 9.13 ± 2.18 to 5.02 ± 1.64, and fluorescein staining from 2.17 ± 0.69 to 0.83 ± 0.54. In Group B (preserved), corresponding changes were 6.71 ± 1.18 to 8.72 ± 1.29 seconds for TBUT, 7.31 ± 1.79 to 9.46 ± 1.91 mm for Schirmer I, 30.98 ± 6.51 to 21.37 ± 5.62 for OSDI, 9.07 ± 2.11 to 6.87 ± 1.83 for PSQI, and 2.13 ± 0.72 to 1.32 ± 0.61 for corneal staining. The comparisons after the treatment were reported to favor Group A (p < 0.001).

Conclusion: Ocular and subjective sleep outcomes significantly improved in both treatment groups after 8 weeks. Preservative-free artificial tears were reported as the superior tear-film stability, corneal staining, sleep quality, and tear production, and as the superior assess of dry eye symptom burden. These results are related to subjective sleep quality, not sleep disorders.