Abstract
Purpose: :
Tear cytokine levels have been proposed as markers of inflammation in dry eye disease (DED) and some correlations with clinical parameters have been described, mainly in aqueous-deficient DED and in severe meibomian gland disease (MGD). We have analyzed a wide panel of cytokines/chemokines in tears from evaporative-type DED due to MGD, with moderate-to-severe symptoms but with mild-to-moderate signs at the ocular surface. The hypothesis is that cytokines in DED patient's tears will correlate with the underlying inflammation better than vital staining.
Methods: :
A total of 21 mild-to-moderate newly diagnosed and never treated MGD patients, all with a Schirmer test with anesthesia >5 mm and a maximum fluorescein corneal staining of 1.5 (range, 0-5) were recruited. Nine healthy subjects were used as controls. Unstimulated tears (4 µl) were collected from each eye and not pooled. Levels of IL-1β, IL-5, IL-6, IL-8, IL-10,IL-13, IL-17, IP-10, TNF, VEGF, IFNγ, IL-1RA, Fractalkine, GM-CSF, and EGF were measured by multiplex bead analysis (Linco, Millipore).
Results: :
EGF, Fractalkine, IL-1RA, IP-10, and VEGF tear levels were significantly increased compared to control levels. Fracktaline, IL-6, IL-8, IP-10, and VEGF levels inversely correlated with Schirmer test and Lysozime levels but only OD IL-8 levels correlated significantly with Schirmer test. Although no significant, EGF levels positively correlated with Schirmer and tear lysozime levels and negatively with fluorescein and Rose Bengal staining.
Keywords: cornea: tears/tear film/dry eye • cytokines/chemokines • inflammation