Abstract
Abstract: :
Purpose: Keratoconus (KC) is a corneal ectasia of unknown etiology. Its relation to allergy and eye squeezing is not yet clear. The cornea is part of the ocular surface, which contains specific and non-specific immene compounds. The purpose of this study is to determine the presence of inflammatory markers in tears of patients with clinical diagnosed KC. Methods: 28 KC patients and 20 normal subjects where included in the study (one eye per subject), both groups without active inflammation nor previous contact lens use (at least for one year). Tear samples were obtained by capillarity (>10 µl) and IL-6, TNF-α, ICAM-1, VCAM-2 (Quantiqkine), MMP-9 (Biotrack) and nitric oxid (Colorimetric assay kit) were quantified. Clinical data included: history of allergy and/or eye squeezing, biomicroscopy and corneal topography. Results: There were strongly significative (P<0.0001) increased levels of IL-6, TNF-α and MMP-9 in the KC group. Levels also directly correlated to the degree of KC (mild/moderate vs advanced/severe). Conclusions: Overexpression of inflammatory mediators (ICAM-1, TNF-α and MMP-9) in tears of patients with clinical KC strongly suggest an immune mechanism role in the pathogenesis of this degenerative corneal ectasia. Stimuli for the presence of those markers and how they interact with the corneal stroma remain to be explained.
Keywords: keratoconus • cornea: tears/tear film/dry eye • clinical (human) or epidemiologic studies: nat