Treatment Patterns and Visual Outcomes during the Maintenance Phase of Treat-and-Extend Therapy for Age-Related Macular Degeneration

Abstract

Purpose: To present the treatment patterns, disease activity, and visual outcomes of eyes in the maintenance phase of a treat-and-extend regimen for neovascular age-related macular degeneration (nAMD). To compare the maintenance phase behavior of eyes with a shorter induction phase (≤3 injections) with those requiring a longer induction phase (>3 injections).

Design: Database observational study.

Participants: Eyes with nAMD receiving anti-vascular endothelial growth factor (VEGF) treatment using a treat-and-extend protocol. Persistently active eyes were excluded, as were eyes with <12 months follow-up during the maintenance phase.

Methods: Clinical information from a large prospective international voluntary registry of nAMD was analyzed. The maintenance phase was defined as starting at the first clinician-reported grading of lesion inactivity.

Main outcome measures: For analyses by eye: treatment interval at first reactivation; time to first reactivation; and visual acuity change during the study period. For analyses by visit: choroidal neovascular membrane activity graded by the treating physician; time since previous injection; and visual acuity loss since previous injection (>0 letters and ≥15 letters).

Results: The mean change in visual acuity during the maintenance phase was +1.0 letters at 12 months -0.6 letters at 24 months and -1.5 at 36 months. Median treatment interval increased from 35 days at study entry to 63 days at 12 months and was 60 days at 36 months. 38.5% of eyes remained inactive at all observed visits during the maintenance phase (minimum 1 year follow-up, mean 945 days). The most common treatment interval at first reactivation was 8 weeks. Treatment intervals beyond 12 weeks seemed to be associated with increased risk of disease reactivation, with risk of reactivation reaching 37.4% at treatment intervals of ≥20 weeks. Eyes with a longer induction phase had worse visual outcomes in the maintenance phase, and earlier and more-frequent disease reactivation, although they received injections less frequently.

Conclusions: The detailed behavior of eyes in the maintenance phase of treat-and-extend management for nAMD is presented. Visual acuity was well maintained during the study period. The most common interval at which reactivation first occurred was 8 weeks. Longer duration of induction phase was associated with worse visual acuity outcomes and earlier disease reactivation, perhaps because of undertreatment.