Presentation (CTI)

OBJECTIVES: Gene therapies for inherited retinal diseases (IRDs) hold promise for preserving or restoring sight, but traditional clinical measures may not fully capture their benefits. Patient-reported outcome measures (PROMs), especially those tailored to IRDs, offer insights into the patient-perceived effects of treatment and can complement clinical endpoints. However, conventional health technology assessments (HTAs) often depend on generic measures such as the EQ-5D-5L, which lack content validity and sensitivity in vision-related and Quality of Life (QoL) domains. This limitation can lead to underestimation of treatment value in patients with progressive vision loss. IRD-specific PROMs have emerged ranging from symptom-based tools (e.g. MRDQ) to more comprehensive instruments (e.g. IRD Item Bank, ViSIO-PRO). Although these provide more relevant assessments they are not preference-based and thus are not directly usable in a cost-utility HTA framework. To bridge this gap, vision-specific bolt-ons to the EQ-5D-5L can be explored.
METHODS: To inform future research in patient-centered instrument development, we conducted a scoping review to examine the use of EQ-5D-5L vision bolt-ons in IRDs.
RESULTS: Among 63 records, none directly studied the EQ-5D-5L + vision bolt-on in IRDs. However, four studies demonstrated its value in ways relevant to PROM development: (1) Content validity—bolt-ons capture dimensions important to patients but absent from generic measures; (2) Construct validity— bolt-ons enable correlation with IRD-specific domains, supporting divergent validity; (3) Responsiveness— bolt-ons increase sensitivity to meaningful change; and (4) Utility mapping— bolt-ons create a pathway to translate IRD PROM responses into utility values.
CONCLUSIONS: Although mapping algorithms for comprehensive IRD-specific PROMs remain under development, the Rasch-based design and conceptual coverage of health-related QoL domains suggest future integration is feasible. Joint administration with the EQ-5D-5L + vision bolt-on may support more patient-centered, preference-based economic evaluations of gene therapies in IRDs.