[Quality of life after Lasik: part I. Validation of the French translation of the NEI-RQL-42 scale].

Introduction: The objective of this study was to bring some validation elements to a French adaptation of an American refraction-related quality of life scale, as applied to a population of Lasik patients.

Methods: The NEI-RQL-42 scale was developed in 2003 in the United States. It comprises 42 questions and 13 scores exploring quality of vision, functional symptoms, influence of refraction on daily activities and psychological impact. The authors propose here a French adaptation and elements for its validation (internal consistency, discriminating validity and external validity). These were assessed through an observational cross-sectional study, performed in one center on all patients consecutively treated with Lasik between January and March 2008.

Results: The study sample (307 patients) has the expected characteristics of Lasik-treated patients. The French adaptation of the NEI-RQL-42 has a good internal consistency with Cronbach's coefficients greater or equal to 0.7 for 10 scores out of 12. The discriminating validity of the scale was shown though the reference groups techniques: quality of life is generally lower in severe hyperopes compared with non-severe myopes. The scale's external validity is confirmed by the comparison of its results to those of a satisfaction questionnaire that was simultaneously sent to patients.

Conclusion: The results obtained are favorable arguments for the validity of the proposed French adaptation of the NEI-RQL-42. This is the first scale available in French to assess refraction-related quality of life.