Evaluation of the National Eye Institute visual function questionnaire in Graves' ophthalmopathy

Abstract

Purpose: To determine the potential suitability of the 25-item National Eye Institute Visual Function Questionnaire (NEI VFQ-25) for measuring health-related quality of life (HRQL) in patients with Graves' ophthalmopathy.

Design: Cross-sectional study.

Participants: Thirty adult patients with mild to severe Graves' ophthalmopathy.

Methods: Participants self-administered the NEI VFQ-25 and completed a semistructured interview to provide feedback about the questionnaire. The percentage of responses at the maximum and minimum value was calculated to assess ceiling and floor effects, respectively, for the 12 subscales of the NEI VFQ-25. The NEI VFQ-25 scores were compared for Graves' ophthalmopathy patients who reported symptomatic diplopia and those who did not report diplopia using univariate and multivariate linear regression models.

Main outcome measures: The NEI VFQ-25 subscale and composite scores.

Results: Health-related quality of life in those with Graves' ophthalmopathy was moderately impaired, with median composite score of 69. The greatest impairment was measured in the Mental Health (median, 50) and the Role Difficulties (median, 50) subscales. Significant ceiling effects were seen in 7 of the 12 subscales. More than two thirds of Graves' ophthalmopathy patients perceived that the NEI VFQ-25 lacked items relevant to their disease. The NEI VFQ-25 scores were lower for those with diplopia symptoms (composite score, 61) compared with those without diplopia (composite score, 90). Comparing these 2 groups, the largest differences were measured in the Driving and Peripheral Vision subscales.

Conclusions: The NEI VFQ-25 includes many items that are applicable to Graves' ophthalmopathy patients. However, it shows significant ceiling effects in more than half of the subscales and it lacks items on issues that are important to Graves' ophthalmopathy patients, such as altered appearance and ocular discomfort. Efforts to develop an HRQL instrument that adds Graves' ophthalmopathy-specific items to relevant aspects of the NEI VFQ-25 are warranted.