Abstract
Purpose :
Dry eye (DE) disease affects millions of Americans; contact lens (CL) DE is a leading cause of CL wear dropout. The role of stress-related hormones in the pathogenesis of DE is poorly understood. The purpose of this cross-sectional feasibility study was to test the hypothesis that tear serotonin (5-HT) concentration will be higher in CL DE subjects when compared with CL without DE subjects, and that tear 5-HT will be higher in CL DE subjects with higher levels of perceived stress (PS) when compared with CL DE subjects with lower levels of PS.
Methods :
37 student volunteers were enrolled in one of three groups: 1) no CL, no DE (control); 2) CL, no DE; or 3) CL, DE. Subjects completed Ocular Surface Disease Index (OSDI), perceived stress (PSS) and Generalized self-efficacy (GSE) surveys, non-invasive tear break up time (NITBUT), and corneal fluorescein staining. OSDI score >25 and NITBUT <10sec defined DE. Microcapillary tubes were used to collect tear samples from the inferior cul-de-sac, then stored at -80°C. Samples were diluted, then 5-HT expression quantified with a 5-HT enzyme-linked immunosorbent assay (ELISA) kit (Enzo Life Sciences). Following adjustment for dilution factors, 5-HT concentrations were largely within the range of standards. PSS and GSE scores were calculated per published instructions.
Results :
Dilution factor adjusted values were used in analysis; one outlier was removed from group 1. Mann-Whitney U test was used to evaluate differences between groups. Group 1 mean 5-HT concentration (ng/mL) was 1.13±0.76, not significantly different than group 2 (1.50±0.86), yet group 3 was significantly higher (2.78±2.31, p=0.049). Sensitivity testing was done, eliminating 3 samples below ELISA kit detection limits; 5-HT concentration was significantly higher in group 3 compared with group 2 (p=0.046). PSS scores showed an incremental increase between groups, yet did not reach significance; however, a significant increase in PSS was found for third year compared with second year students (p=0.003). No difference was found between groups for GSE.
Conclusions :
Tear 5-HT was higher for CL wearers with DE than non-CL wearers. Study findings support the presence of DE exacerbates the expression of tear 5-HT in CL patients compared to CL patients that do not have DE, suggesting hormonal influence in CL DE. Classes of students demonstrated little difference in stress coping strategies, yet perceived stress differences were identified.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.