The influence of humidity, temperature, and oral contraceptive in tear

Abstract

The aim of this study is to ascertain whether the quantity and quality of tear and eye subjective comfort are influenced by the temperature, humidity and oral Contraceptives Taking or Non-taking (CTNT). Forty-one students, females, from the University of Minho, Braga, Portugal, aged (mean±1standard deviation) of 21.51±1.85 years, ranging from 20 to 30 years, participated in this study. The McMonnies Questionnaire (MMQ), Break Up Time (BUT) and Phenol Red Test (PRT) were accessed between 14-17 hours in four sets of visits throughout the year: Visit 1, Visit 2, Visit 3 and Visit 4. The PRT and BUT values (mean±1standard deviation) for Visit 1, Visit 2, Visit 3 and Visit 4 were respectively 23.88±6.50mm, 22.29±8.00mm, 23.61±6.75mm, 22.88±7.00mm and 6.02±1.58s, 5.62±1.22s, 5.23±0.88s, 5.53±1. 42s. The MMQ scores for Visit 1, Visit 2, Visit 3 and Visit 4 ranged from 2-13, 2-15, 1-14 and 2-14 with medians of 6, 7, 6 and 6, respectively. The influence of temperature, humidity and CTNT on PRT, BUT and MMQ were evaluated using generalized linear mixed model. For BUT and MMQ statistical significant effects were found regarding temperature and humidity. The temperature and humidity influenced the tear quality and subjective comfort but did not influence the tear quantity. The CTNT did not influence tear quantity, quality or subjective eye comfort.