OBJECTIVE: To assess QOL as measured by patient-reported outcomes (PRO) within the iStent inject pivotal trial. Design: Randomized controlled trial analysis of secondary outcomes.
METHODS: The Vision Function Questionnaire (VFQ-25) and Ocular Surface Disease Index (OSDI©) questionnaire were administered at baseline, months 1, 6, 12, and 24. PRO responders were defined as patients reaching improvement based on minimally important differences.
RESULTS: 505 patients were randomized (N = 386 iStent inject, N = 119 surgery alone). The iStent inject group exhibited a greater percentage of PRO responders across all follow-up visits over 24 months, averaging 58.0% vs. 45.8%; P < .05 for VFQ-25 composite scores and 56.7% vs. 48.9%; P < .05 for OSDI composite scores. Odds of being a responder in the iStent inject group was 60% (P < .05) higher for the VFQ-25 and 32% (P > .05) higher for the ODSI. Driving (49.0% vs. 28.8%; P < .05), ocular pain (59.3% vs. 47.2%; P < .05) and general vision (71.8% vs. 60.0%; P < .05), were the VFQ-25 subscales responsible for differences between treatment groups. At month 24, 76.5% of VFQ-25 responders and 62.5% of non-responders were medication free regardless of treatment group (P < .05).
CONCLUSION: Exploratory analysis suggests that by reducing medication dependence, implantation with the micro-scale iStent inject device with cataract surgery may improve QOL vs. cataract surgery alone over 24 months with improvements influenced by ocular symptoms and vision related activities.
