CONICET | Buscador de Institutos y Recursos Humanos

Objective: The purpose of our work was to study and compare the cornea and tear film of people and sheepinhabiting in a region of Argentinean Patagonia (PATG), and in a geographically and climatically different region inthe Argentinean Pampa (CAPT).Methods: Using cross sectional study, corneal examinations were performed in people and Merino sheepinhabiting PATG and CAPT regions, respectively. All people completed a questionnaire related to work activity, diet,and the use of hats or sunglasses during their life. Eyes from all participants were examined with a portable handheldslitlamp biomicroscope (BM) to evaluate corneal appearance, epithelium integrity, and transparency. Later on,in a subgroup of participants we studied eyeblinking frequency (EBF), ocular surface staining (FS), breakup time(BUT), Schirmer Tear Test (STT), corneal structure using confocal laser scanning microscopy (CLSM) and lightmicroscopy (LM), and concentrations of serum ascorbate (sAA).Results: BM studies revealed numerous cases of Climatic Droplets Keratopathy (CDK) only in people inhabitingthe PATG region. CLSM studies confirmed typical punctiform deposits at the Bowman´s layer in CDK patients livingin that region. CLSM images from sheep did not show any abnormalities at the Bowman´s layer but exhibited smallhyper reflective dots at the epithelium only in animals pasturing in the PATG region. FS and EBF mean values weresignificant higher in sheep grazing in the PATG region (p <0.05). No differences were found in surface eye testswhen people from both regions were analyzed. Low sAA levels were found only in CDK people living in PATGregion.Conclusions: CDK is a multi-factorial disease not only associated to harsh climate. We provide data that lowsAA levels can play a role in its genesis in Patagonia patients?... Sheep pasturing in this region with a highprevalence of CDK have high concentration of sAA and did not present any sub epithelial corneal abnormalities.