Contact lens wear alters the production of certain inflammatory mediators in tears.

Contact lens wear has been associated with an increased risk of corneal infection and/or inflammation. We studied the hypothesis that contact lens wear alters the number of polymorphonuclear leukocytes (PMNs) on the cornea during sleep and the levels of inflammatory mediators in the tear film. Three groups of subjects were analysed: a non-contact lens wearing group (NCLW), non-adapted (neophyte) contact lens wearers (NACLW) who wore lenses during sleep for the first time in this study and adapted contact lens wearers (ACLW) who normally wore lenses on a daily wear schedule. Ocular PMNs were collected by a non-contact irrigation technique and their numbers counted after staining. Tears were collected from each group and analysed using ELISAs for the presence of the PMN chemoattractants IL-8 and LTB(4)and the cytokines IL-1beta, IL-6 and GM-CSF. Corneal irrigation data demonstrated significantly higher numbers of PMNs from NACLW (P<0.05) compared to the other groups. ACLW showed significantly fewer PMNs (P =0.03) compared to NCLW group. The NACLW group had significantly lower concentrations (P<0. 05) of IL-8, LTB(4)and IL-6 in their tears after 8 hr of sleep compared to the other groups. The ACLW group had significantly (P<0. 05) higher levels of IL-8 at most time points compared to the other two groups. The levels of the chemoattractants IL-8 and LTB(4)in tears were inversely related to the numbers of PMNs from the corneal surface and the chemotaxis of PMNs in vitro. During one night sleep in contact lenses the numbers of PMNs and the concentration of certain inflammatory mediators are significantly altered compared to no lens wear. However, this alteration changes from NACLW to ACLW. This may have effects on the ability of the eye to defend itself during contact lens wear. Copyright 2000 Academic Press.