Abstract
BACKGROUND/OBJECTIVES: The initial visual acuity (VA) prior to treatment initiation can significantly influence long-term visual outcomes. The current analysis aimed to examine change in VA by baseline vision categories and their effects on time spent within visual change categories in patients with diabetic macular oedema (DMO) who underwent treatment with the intravitreal fluocinolone acetonide (FAc) implant. SUBJECTS/METHODS: This was a post-hoc analysis of the IRISS-Registry Data. Time-in-range (TIR) was calculated based on three VA letter-score-thresholds: ≥70, ≥65, and ≥60 ETDRS letters after treatment initiation. TIR was stratified by baseline VA in three groups: 0-33, 34-68, and 69-100 letters. The primary outcome was the mean TIR for the ≥70 letters threshold (equivalent to 6/12 in Snellen). RESULTS: A total of 671 eyes from 542 patients were included. VA improved significantly in all VA swimlane groups, with 84.8%, 71.7%, and 60.0% of eyes in the 0-33, 34-68, and 69-100 baseline VA categories, respectively, showing maintained or improved VA at 36 months (p = 0.0367). The mean TIR for the ≥70 letter threshold was significantly longer in the 69-100 letters subgroup (892.7 ± 413.4 days) compared to the 34-68 (648.4 ± 366.4 days) and 0-33 (251.3 ± 175.9 days) subgroups (p < 0.0001). No significant differences in TIR were observed based on the duration of DMO or the number of previous anti-angiogenic injections. CONCLUSIONS: Eyes with better initial VA maintained functionally better visual acuity for longer following FAc implant treatment. TIR emerged as a potentially clinically relevant endpoint for evaluating long-term treatment outcomes in DMO, offering a broader perspective than traditional VA measures.