Translation and validation of the 5-Item Dry Eye Questionnaire into Portuguese.

Purpose: Dry eye disease is a multifactorial disease that is very common in clinical ophthalmic practice. The use of validated dry eye questionnaires makes it possible to screen this disease in the general population and assess the prevalence of symptoms and frequency of diagnosis, allowing early and appropriate treatment for this condition. The 5-Item Dry Eye Questionnaire (DEQ-5) is a tool that is used to assess the frequency and intensity of ocular discomfort and dryness and the frequency of tearing, which has already been validated in English and Spanish, but not in Portuguese. The aim of this study is to translate and validate the DEQ-5 to Portuguese.

Methods: The DEQ-5 was used, consisting of five simple and direct questions: two questions for ocular discomfort, two for ocular dryness, and one for tearing. The initial translation of the English version of the questionnaire into Portuguese was conducted by two Portuguese native-speaking translators, followed by an evaluation and compilation of a single version by an interdisciplinary committee of the translated versions. Furthermore, this version was translated back into English by two individuals whose first language was English, followed by the evaluation and comparison with the original version in English by the same interdisciplinary committee. Afterwards, the final version of the questionnaire was administered to 31 volunteers at two different times.

Results: The interobserver reliability of the five questions ranged from 0.584-0.813, and the Pearson correlation from 0.755-0.935, with a p-value of <0.0001. Internal consistency was α=0.887. All questions had moderate to high agreement.

Conclusions: The statistical analysis of the collected data found excellent concordance rates (moderate to high for all analyzed questions), allowing the use of the Portuguese version of DEQ-5 in research as a screening test for dry eye disease and tool used to monitor the symptoms.