SUMMARY
A series of individuais (age range 40 to 89 years), 50% women (100 in Brasília, 100 in São Paulo and 100 in Teresina) was studied from June to August 1993, with the purpose of determining the frequency of dry eye and the influence of environmental factors such as temperature and relative humidity of the air.
Identification and environment factors were collected as well as biomicroscopic evaluation, Schirmer I test, Rose Bengal and the determination of break up time (BUT) performed.
Out of the 200 eyes examined in each city, it has was found 38 eyes in Brasília, 30 in São Paulo and 2 in Teresina with a positive Schirmer I test; 22 eyes in Brasília, 37 in São Paulo and 10 in Teresina presented a positive Rose Bengal; and 136 eyes in Brasília, 60 eyes in São Paulo and 14 in Teresina presented a positive BUT.
The average temperatures were: Brasília 21ºC (range l4ºC to 29ºC), São Paulo 17,5ºC (range 12ºC to 23ºC) and Teresina 30ºC (range 28ºC to 32ºC)
The average relative humidities were: Brasília 49,5% (range 12% to 87%), São Paulo 70,5% (range 43% to 98%) and Teresina 58% (range 46% to 70%).
Dry eye was as the ones with at least 2 positive tests out of the 3 (Schirmer I<5mm, Rose Bengal II or III and BUT<10 Seconds).
According to those parameters 44 dry eyes in Brasília, 42 in São Paulo and 5 in Teresina were found. The results did not show the injluence of the temperature or the relative humidity of the air in the diagnosis of the dry eye syndrome.
Key words:
Dry eye; Environment factors; Shirmer I test; Rose Bengal; Break up time