National Eye Institute Visual Function Questionnaire or Indian Vision Function Questionnaire for Visually Impaired: A Conundrum

Impact of glaucoma on vision-specific quality of life in monocular glaucoma patients using the Indian vision function questionnaire

Purpose

To evaluate the determinants affecting the quality of life in monocular glaucoma patients using the Indian vision function questionnaire.

Methods: In this prospective cross-sectional study,

total of 196 patients were divided into two groups: cases and controls. Indian Vision Function Questionnaire (IND-VFQ) was administered and analyzed. One hundred twenty-nine (58.6%) patients who had lost their vision in one eye due to glaucoma were included as cases and 67 (30.4%) patients who had lost their vision due to other causes were taken as controls.

Results

Median composite score of subscales was 54.62 (29.7-74.7) in group 1 and 45.38 (23.7-76.7) in group 2. The psychosocial impact scale was the most affected scale, the median scores were 33.02 (0 to 60.0) and 19.07 (0 to 53.0) in groups 1 and 2, respectively. Among all dimensions of IND-VFQ, the highest score was for color vision 100.0 (0-100.0) and 100.0 (0-100.0), and the lowest median score was found in mental health and dependency in both the groups. Multiple linear regression analysis demonstrated that visual acuity was associated with a low score (P < 0.001). Female gender was significantly associated with the overall score in the univariate model (P = 0.006).

Conclusion

Monocular glaucoma patients have a poor general and vision-related quality of life. Depression associated with monocularity and the perception of dependency and being a burden on their family members greatly impacted the mental health of the participants.

Vision-related quality of life after surgery for vitreoretinal disorders in a Mexican population: an observational study

Visual-related quality of life in retinal diseases has not been explored in the Mexican population, so the study aims to identify it in patients undergoing surgery due to advanced diabetic retinopathy, rhegmatogenous retinal detachment, and other causes of vitrectomy; the Visual Function Quality-25 questionnaire was applied to 76 patients, pre-and postoperative. It was divided into 10 domains and interpreted according to the National Eye Institute scores, where the highest value was the best visual function. Student's t-test for related samples and Wilcoxon's t-test were used to compare each domain between measurements, and Pearson's R test to correlate the total score of age and quality of life; a p value < 0.05 was considered significant. Diabetic retinopathy patients showed an improvement 1 and 3 months after surgery in all domains; in rhegmatogenous retinal detachment, there was an improvement observed up to 3 months, while a decrease in ocular pain was observed in other causes of vitrectomy. Differences found in all the quality-of-life scores were not statistical, but clinically significant. The study shows that visual-related quality of life domains improves after vitrectomy; the inclusion of this analysis might be considered relevant within the parameters of surgical success of the most prevalent vitreoretinal diseases.

Validation and comparison of the National Eye Institute Visual Functioning Questionnaire-25 (NEI VFQ-25) and the Visual Function Index-14 (VF-14) in patients with cataracts: a multicentre study

PURPOSE

The present study aimed to investigate and compare the psychometric properties of the National Eye Institute Visual Functioning Questionnaire-25 (NEI VFQ-25) and the Visual Function Index-14 (VF-14) in a large sample of patients with cataracts.

METHODS

A total of 1052 patients with bilateral age-related cataracts were recruited in the study. Patients with other comorbidities that severely impacted vision were excluded. Participants completed the two questionnaires in random order. Classical test theory and Rasch analyses were used to assess the psychometric properties of the questionnaires.

RESULTS

Complete data were obtained from 899 patients. The mean overall index score on the NEI VFQ-25 was 76.1 ± 19.0, while that on the VF-14 was 46.5 ± 15.0. Cronbach's α-values for the NEI VFQ-25 and VF-14 were 0.89 and 0.95, respectively. Ceiling effects were observed on nine of the 12 subscales in the NEI VFQ-25. The correlation between total scores on the NEI VFQ-25 and VF-14 was moderate (r = 0.600; p < 0.001), and subscales of the NEI VFQ-25 were weakly or moderately correlated with the similar domains on the VF-14. Rasch analysis revealed ordered category thresholds and sufficient person separation for both instruments, while the two questionnaires had critical deficiencies in unidimensionality, targeting and differential item functioning.

CONCLUSION

Neither the NEI VFQ-25 nor VF-14 is optimal for the assessment of vision-related quality of life in typical Chinese patients with cataracts. The potential deficiencies of the questionnaires should be taken into consideration prior to application of the instruments or interpretation of the results.

The patient health questionnaire-9: validation among patients with glaucoma

Background

Depression and anxiety are two common normal responses to a chronic disease such as glaucoma. This study analysed the measurement properties of the depression screening instrument - Patient Health Questionnaire-9 (PHQ-9) using Rasch analysis to determine if it can be used as a measure.

Methods

In this hospital-based cross-sectional study, the PHQ-9 was administered to primary glaucoma adults attending a glaucoma clinic of a tertiary eye care centre, South India. All patients underwent a comprehensive clinical evaluation. Patient demographics and sub-type of glaucoma were abstracted from the medical record. Rasch analysis was used to investigate the following properties of the PHQ-9: behaviour of the response categories, measurement precision (assessed using person separation reliability, PSR; minimum recommended value 0.80), unidimensionality (assessed using item fit [0.7–1.3] and principal components analysis of residuals), and targeting.

Results

198 patients (mean age ± standard deviation  = 59.83±12.34 years; 67% male) were included. The native PHQ-9 did not fit the Rasch model. The response categories showed disordered thresholds which became ordered after category reorganization. Measurement precision was below acceptable limits (0.62) and targeting was sub-optimal (−1.27 logits). Four items misfit that were deleted iteratively following which a set of five items fit the Rasch model. However measurement precision failed to improve and targeting worsened further (−1.62 logits).

Conclusions

The PHQ-9, in its present form, provides suboptimal assessment of depression in patients with glaucoma in India. Therefore, there is a need to develop a new depression instrument for our glaucoma population. A superior strategy would be to use the item bank for depression but this will also need to be validated in glaucoma patients before deciding its utility.

Quality assessment of ophthalmic questionnaires: review and recommendations

PURPOSE

The aim of this article was to systematically review all the available ophthalmic patient-reported outcome (PRO) instruments (questionnaires) that demonstrated interval measurement properties to identify the instruments with the highest psychometric quality for use in different eye diseases and conditions.

METHODS

An extensive literature review was carried out to identify all existing ophthalmic PRO instruments. Instruments were then excluded if they did not have demonstrable interval measurement properties; the remaining instruments were reviewed. The quality of the following psychometric properties was assessed: content development (initial item development process), performance of the response scale, dimensionality (whether the instrument measures a single construct), measurement precision, validity (convergent, concurrent, discriminant, and known groups), reliability (test-retest), targeting (whether the items are appropriate [e.g., difficulty level] for the population), differential item functioning (whether subgroups of people respond differently to an item), and responsiveness.

RESULTS

The search identified 48 PRO instruments that demonstrated interval measurement properties, and these were relevant to nine applications: glaucoma, dry eye, refractive errors, cataract, amblyopia and strabismus, macular diseases, adult low vision, children low vision, and others. These instruments were evaluated against the psychometric property quality criteria and were rated for quality based on the number of criteria met.

CONCLUSIONS

This review provides a descriptive catalog of ophthalmic PRO instruments to inform researchers and clinicians on the choice of the highest-quality PRO instrument suitable for their purpose.