Abstract
Purpose :
Interest in tear cytokines is driven by hope for a biomarker which aligns pathophysiology with the signs and symptoms of dry eye disease (DED). Prior work showed cross-sectional association between cytokine ratios (CRs) of pro- to anti-inflammatory cytokines with some DED signs. This secondary analysis describes longitudinal change in these CRs and associations with changes in DED signs and symptoms.
Methods :
Secondary analysis of fifty-four subjects [mean age 57.3 (SD 13.2), 46/54 (85.2%) female; 37/54 (68.5%) white] whom had sufficient tear volumes (≥ 4 uL pooled from two eyes) at months 0, 6, and 12 for cytokine measurement. Pro-inflammatory (IL-1b, IL-6, IL-8, IL-17A, IFN-g, and TNF-a) to anti-inflammatory (IL-6, IL-10) cytokine ratios (CR) were calculated. DED signs (corneal and conjunctival staining scores, tear break-up time, Schirmer test, Meibomian gland plugging, tear osmolarity, composite sign severity score) and symptoms [Ocular Surface Disease Index (OSDI)] were also measured. Spearman correlation coefficients (rho) between changes in CR and changes in DED signs and symptoms over time were calculated.
Results :
DED signs that improved over time (p <0.001) included conjunctival staining score [2.8 (SD 1.3) at month 0, 1.9 (SD 1.4) at month 6, 1.9 (SD 1.3) at month 12], corneal staining score [4.4 (SD 2.3) at month 0, 3.7 (SD 2.1) at month 6, 3.8 (SD 2.4) at month 12], and tear break-up time [2.7 (SD 1.2) at month 0, 3.7 (SD 2.1) at month 6, 3.8 (SD 2.4) at month 12]. With IL-10 as the anti-inflammatory cytokine, changes in corneal and conjunctival staining and composite severity score significantly correlated with changes in pro- to anti-inflammatory CRs from month 0 to 6 (Table 1) but not between month 0 and 12 (|rho|: 0.01 to 0.24, all p>0.08). DED symptoms decreased between month 0 and 6 (p <= 0.001) and month 0 and 12 (p <0.001) for all OSDI measures; these changes did not correlate with changes in CRs (|rho|: 0.00 to 0.29, all p>0.04).
Conclusions :
From month 0 to 6, improvement in some DED signs correlated weakly with decreases in pro- to anti-inflammatory CRs, in alignment with the understanding of DED as inflammatory. DED symptoms, which also improved over time, did not correlate with change in CRs. Greater standardization of tear sampling and further analysis with additional DED samples is needed to determine CR usefulness.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.