Tear cytokines and conjunctival microvascular alterations in dry eye patients in responses to anti-inflammation treatment

Abstract

Purpose : To characterize the alterations of tear cytokines and conjunctival microvascular parameters in patients with dry eye (DE) in responses to anti-inflammation treatment.

Methods : Nine patients with DE (3 females and 6 males, aged 37.8 ± 9.8 years, mean ± standard deviation) were recruited and filled out the ocular surface disease index (OSDI). The levels of inflammatory cytokines in tears were measured in these patients. The conjunctival blood flow velocities (BFVs), blood flow rate (BFR) and vessel diameters were measured using Functional Slit-lamp Biomicroscopy (FSLB). Other clinical measurements were also administrated including the noninvasive tear-film break-up times (NI-fBUT and NI-avBUT), the hyperemia index (HI) of the bulbar conjunctiva, OSDI, Schirmer I test (ST) scores and corneal fluorescein staining (CFS) scores. The repeat measurements were performed at 30 and 60 days during anti-inflammation treatment.

Results : The conjunctival BFR, BFVs, vessel diameters and HI; tumour necrosis factor alpha (TNF-α), interleukin (IL)-12 and IL-17α levels; OSDI and CFS scores were significantly lower 60 days after commencement of anti-inflammatory therapy than at baseline (all p _corrected < 0.05). Significant increases in NI-fBUT, ST and NI-avBUT were observed. Moreover, BFVs was positively correlated with the levels of TNF-α (r = 0.52, p < 0.01), IL-12 (r = 0.39, p < 0.05) and IL-17α (r = 0.45, p < 0.05). BFR was significantly correlated with TNF-α levels (r = 0.48, p < 0.05), as was vessel diameter (r = 0.39, p < 0.05).

Conclusions : This study reveals the significant correlation between inflammatory cytokines and conjunctival microvascular alterations in responses to anti-inflammatory treatment in dry eye patients. The results suggest that conjunctival BFV, BFR, HI and vessel diameter may be used as directly imaging markers for evaluating ocular surface inflammatory state and treatment efficacy in DE.

This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.

 

Figure 1: Correlations between microcirculatory parameters and inflammatory cytokines.
All data regarding both inflammatory cytokines and bulbar microvascular and microcirculatory parameters from baseline and 30 and 60 days after commencement of anti-inflammatory treatment were included in the analysis (27 cases in total). Significant correlations were noted between the post-treatment microvascular changes and the levels of inflammatory cytokines (IL-12, IL-17α, and TNF-α).