[Translation and validation of ocular surface disease index to Portuguese]

To develop a cross-cultural Ocular Surface Disease Index (OSDI) for the Brazilian population and analyze its validity and effectiveness.

Based on the guidelines of Guillemin et al., four English teachers, an ophthalmologist, a rheumatologist, two ophthalmology residents and a native American who does not speak Portuguese were invited. The procedure followed the steps: translation into Portuguese by two English teachers; transformation of the two translations to a single version; application of this version of the questionnaire to 27 people in the ophthalmology clinic of the Evangelic University Hospital of Curitiba, asking questions and making changes for a better understanding by the patients; retranslation into English by two English teachers who lived in the USA.; assessment for a single version, and reading them by a native USA. citizen who does not speak Portuguese to assess the comprehension of the questionnaire. The validated questionnaire was administered to 22 people in the ophthalmology clinic of the Evangelic University Hospital of Curitiba to evaluate the effectiveness of inter-and intra-interviewer.

The study of intra-observer for each of the questions showed that the questions 1, 2, 3, 4, 7 and 11 have substantial agreement; that the question 8 had almost perfect agreement and questions 5, 6, 9, 10 and 12 have moderate agreement. Studying the inter-observer agreement it was found that there are two questions with almost perfect agreement (2 and 7); substantial agreement with seven questions (questions 1, 2, 4, 5, 6, 8 and 9) and three questions with moderate agreement (10, 11 and 12).

The obtained version of OSDI has good inter and intra-observer agreement and can be used in Portuguese to evaluate the quality of life of people with dry eye.