Visual functioning and generic health in Stargardt disease (STGD1): a cross-sectional study

Abstract

Purpose : To investigate the impact of Stargardt disease (STGD1) on daily life functioning in terms of vision-related and generic health-related quality of life.

Methods : In this cross-sectional study, 100 STGD1 patients completed two questionnaires. Vision-related quality of life (VR-QoL) was represented by the long form visual functioning scale (LFVFS39), derived from the National Eye Institute Visual Function Questionnaire-39 (NEI VFQ-39). RAND-36 was administered for generic health assessment. Visual acuity (VA), age of onset, and genotype were obtained from medical files.

Results : At the time of questionnaire, the median age was 45 years (range 16-86), and the median disease duration was 20 years (range 2-57). A notable variability in LFVFS39 scores was observed. VR-QoL was significantly worse in patients with blindness (≤0.05 decimals) compared to patients with moderate visual impairment (0.1-0.3 decimals). No significant gender-based differences were found. STGD1 patients scored equally or higher on certain RAND subscales compared to the norm group, and these subscales showed no correlation with LFVFS39. Multiple linear regression analysis demonstrated that visual acuity of the worse eye and the disease duration together explained 40.7% of the variance of LFVFS39 (p<0.001), with the best eye not significantly contributing to the model. Mediation analysis revealed partial mediation of disease duration by visual acuity.

Conclusions : Visual impairment profoundly affects the VR-QoL in STGD1 patients, however it does not influence overall health perception. When selecting patient reported outcome measures for future clinical trials in STGD1, VR-QoL questionnaires are more useful than generic health questionnaires. Yet, VR-QoL questionnaires exhibiting notable inter-individual variability. This variability is influenced not only by disease-specific features but also by various environmental and personal factors. Importantly, the presence of a better-seeing eye does not mitigate the negative impact on VR-QoL caused by the worse eye. Therefore, treatment of the worse eye should not be overlooked. Moreover, even patients with advanced visual loss can still benefit from treatment that halts further disease progression.

This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.