Trends of Dry Eye Disease Parameters in a Controlled Environment

Abstract

Purpose : Dry Eye Disease (DED) results from dysfunction of the tear film (TF). We hypothesize the TF reacts to environmental changes and that changes may be measured using advanced technologies that measure the TF. Here we study trends of several objective TF parameters as subjects move from the external environment to a temperature- and humidity- controlled facility (THCF).

Methods : This study was approved by Stony Brook’s Institutional Review Board; participants signed informed consent. Subjects were measured immediately upon moving from the external environment to a THCF (68-72°F), 40-45%) at baseline (0), and at 10, 20, 30, 60, and 120 minutes (min). Measures included Tear osmolality (Tosm), tear meniscus height (TMH), Non-invasive Keratographic Break Up Time (NIKBUT), and Lipid layer thickness (LLT) taken with the Tearlab, Oculus Keratograph 5M, and Lipiview 2 devices.

Subjects were stratified according to baseline Tosm and TMH scores into Low (20th %-tile), High (upper 20th %- tile) and Middle (middle 60%). Outcomes were compared between groups (between-subjects) over time (within-subjects) using linear mixed models. To account for correlation between eyes within each subject, random subject effects were included in the model. All analyses were conducted using SAS, version 9.4.

Results : 28 volunteers participated (60% male, mean age 40.2 years).

Segregating the initial group by High (n = 6), Middle (n = 16) and Low (n = 6) Tosm, significant increases (all p < 0.05) from baseline in Tosm were observed in the Low group at most time points. Conversely, the High group showed significant decreases steadily across all time points (p range: 0.0002 – 0.02) (Figure 1).

Segregating the initial group by TMH (High (n = 6), Middle (n = 16) and Low (n = 6)), increases in LLT emerged in the High group at 20 min (20.6%), that continued across time to a maximum 28% at 120 min (p range: 0.0007 – 0.01). Both Low and Middle groups showed small initial increases which declined after 30 min, reaching significance in the Middle group by 120 min (p = 0.02) (Figure 2).

Conclusions : TF parameters change with time when entering a THCF. Observed changes are more apparent looking at subgroups. The power of this study is limited by the small number of subjects in each subgroup and inherent variability in each of the DED measures. The results suggest a complex response occurs in the TF and ocular surface to environmental changes.

This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.