Objective

To develop and test the psychometric properties of a 25-item version of the National Eye Institute Visual Function Questionnaire (NEI VFQ-25).

Design

Prospective observational cohort study of persons with 1 of 5 chronic eye diseases or low vision who were scheduled for nonurgent visits in ophthalmology practices and a reference sample of persons without eye disease.

Setting

Eleven university-based ophthalmology practices and the NEI Clinical Center.

Patients

Eligible participants had to have 1 of the following eye conditions: age-related cataracts, age-related macular degeneration, diabetic retinopathy, primary open-angle glaucoma, cytomegalovirus retinitis, or low vision from any cause. Seven of the 12 sites also enrolled persons in a reference sample. Reference sample participants had no evidence of underlying eye disease but were scheduled for either screening eye examinations or correction of refractive error. All eligible persons had to be 21 years or older, English speaking, and cognitively able to give informed consent and participate in a health status interview.

Measurements and main results

To provide the data needed to create the NEI VFQ-25, all subjects completed an interview that included the 51-item NEI VFQ. Estimates of internal consistency indicate that the subscales of the NEI VFQ-25 are reliable. The validity of the NEI VFQ-25 is supported by high correlations between the short- and long-form versions of the measure, observed between-group differences in scores for persons with different eye diseases of varying severity, and the moderate-to-high correlations between the NEI VFQ-25 subscales that have the most to do with central vision and measured visual acuity.

Conclusions

The reliability and validity of the NEI VFQ-25 are comparable to those of the 51-item NEI VFQ field test version of the survey. This shorter version will be more feasible in settings such as clinical trials where interview length is a critical consideration. In addition, preliminary analyses indicate that the psychometric properties of the NEI VFQ-25 are robust for the eye conditions studied; this suggests that the measure will provide reproducible and valid data when used across multiple conditions of varying severity.

Objective

To identify the content area for a questionnaire designed to measure vision-targeted health-related quality of life and to determine whether problems with vision-related functioning are qualitatively similar across different common eye diseases.

Design

Twenty-six condition-specific focus groups were conducted with 246 patients from 5 geographic regions to identify the content area for a questionnaire for use among persons with diabetic retinopathy, glaucoma, macular degeneration, cytomegalovirus retinitis, and cataract. A standard protocol was used to structure each focus group discussion. Sessions were audiotaped, transcribed, and coded in preparation for a content analysis.

Settings

Five university-based ophthalmology practices and 1 nonprofit eye care foundation.

Participants

Eligible participants had to have 1 of the following eye conditions: age-related cataracts, age-related macular degeneration, diabetic retinopathy, primary open angle glaucoma, cytomegalovirus retinitis, or low vision from any cause. All eligible persons were older than 21 years, spoke English, and had sufficient cognitive function to provide informed consent.

Results

Among the 246 participants, 2623 problems with vision-related functioning were mentioned. The mean number of problems per person ranged from 13.5 for those with diabetic retinopathy to 7.9 for persons with glaucoma. For the sample overall, reading problems were mentioned most frequently, followed by driving, general problems with seeing clearly, and mental health complaints caused by vision. Although the proportion of persons who reported each problem varied by condition, at least some persons with each eye disease reported each problem. The 3 most common descriptors associated with each problem were difficulty or ease of performance (13%), psychological distress associated with performance of the activity (11%), and complete inability to participate in a visual activity (11%).

Conclusion

An item-generation strategy for a new questionnaire using a standardized focus group method identified content areas and aspects of visual disability that are not included in currently available vision-specific instruments that assess the impact of common eye diseases on visual functioning in every-day life. Although participants mentioned problems that were unique to their disease, across conditions the problems mentioned were similar. These findings provide empirical evidence of content validity for a vision-targeted, health-related quality-of-life survey designed for use across conditions.

Objective

To test the reliability and validity of the 51-item Field Test Version of the National Eye Institute Visual Function Questionnaire (NEI-VFQ) across 5 common chronic eye conditions.

Design

Prospective observational cohort study of persons with 1 of 5 chronic eye diseases who were scheduled for nonurgent visits in ophthalmology practices or had low vision from any cause, and a reference sample of persons without eye disease.

Setting

Six university-based ophthalmology practices and the National Eye Institute Clinical Center, Bethesda, Md.

Patients

Eligible participants had to have 1 of the following eye conditions: age-related cataracts, age-related macular degeneration, diabetic retinopathy, primary open-angle glaucoma, cytomegalovirus retinitis, or low vision from any cause. Each of the 7 sites also enrolled persons in a reference sample. Reference sample participants had no evidence of underlying eye disease but were scheduled for either screening eye examinations or correction of refractive error. All eligible persons had to be aged 21 years or older, English speaking, and cognitively able to give informed consent and participate in a health status interview.

Measurements and main results

To provide the data needed to assess the reliability and validity of the 51-item NEI-VFQ, all subjects completed an interview that consisted of the 51-item NEI-VFQ, the Medical Outcomes Study 36-Item Short-Form Health Survey, and at least 1 measure of vision-targeted functional status. Estimates of internal consistency and test-retest reproducibility indicate that the 51-item NEI-VFQ is reliable. Tests of association with other scales and clinical variables support the construct validity of the survey.

Conclusions

In this cross-sectional study, the 51-item NEI-VFQ seems to be reliable and valid and should be a useful tool for group-level comparisons of vision-targeted, health-related quality of life in clinical research. Additionally, the psychometric properties of the NEI-VFQ were not influenced by the type or severity of the underlying eye disease, suggesting that the measure will provide reproducible and valid data when used across multiple eye conditions.