Abstract
Abstract: :
Purpose: There is a growing awareness that some individuals exhibit heightened eye sensitivity and are, therefore, more susceptible to present adverse reactions to externally–applied products. For this reason, there is a need to use reliable diagnostic tools for specific selection of such panelists participating in tests to assess eye tolerance. The aim of this study was to identify such specific endpoints when investigating ocular surfaces of the "sensitive eyes" and contact lens wearers individuals. Methods: 30 self–assessed and ophtalmologically–assessed "sensitive eyes" subjects, aged from 20 to 67 and 30 contact lens wearers, aged from 19 to 60, were included. Detailed questionnaires were filled out by the volunteers for self–assessment of sensitivity of the eyes. The ophthalmologic examination included a more complete subjective assessment, biomicroscopy with examination of the lid margin and the meibomian glands, measurement of lid margin lipidic secretion by using meibometer, phenol red thread test, tear break–up–time, preocular tear film lipid layer examination and corneal and interpalpebral conjunctival staining (sodium fluorescein and lissamine green). Statistical analysis was carried out using the Wilcoxon test to compare both groups. Results: Subjective signs were most severe in the "sensitive eyes" group, where dryness, discomfort caused by cosmetics, pollution or windy, smoky or low temperature conditions, were reported. Clinically, a seborrheic hypersecretion associated with a bulbar conjunctival hyperhemia were higher in the "sensitive eyes" compared to the contact lens wearers, respectively (p<2,98 10–5 and p= 9,82 10–5). The same number of meibomian glands was found in both groups but lipidic secretion on lid margin was significantly increased in the "sensitive eyes" individuals (p=2 10–3). Fluorescein tear BUT was significantly lower in the "sensitive eyes" group than in contact lens wearers (p=1,88 10–5), whereas there was no significant difference in the lipid layer morphology of the preocular tear film. The mean wet length of the thread was significantly lower in the "sensitive eyes" group (p=2 10–3). No differences in corneal and conjunctival stainings were observed between the groups. Conclusions: Subjective assessments and objective diagnostic tests are relevant for differentiating "sensitive eye" individuals from contact lens wearers, and are, therefore, useful for the selection of volunteers in ophthalmological studies.
Keywords: clinical research methodology • contact lens • conjunctiva