Background/aims To study the time to retreatment in eyes with neovascular age-related macular degeneration (nAMD) that had been treatment-free for intervals of 3 months, 6 months, 9 months and 12 months during the maintenance phase of ranibizumab therapy within the UK National Health Service.

Methods In this multicentre national nAMD database study, structured data were collected from 14 centres (involving 12 951 eyes receiving 92 976 ranibizumab injections). Patients were treated with three fixed, monthly injections in a loading phase of treatment, followed by a pro re nata retreatment regimen in a maintenance phase. Eyes with a treatment-free interval (TFI) of 3 months, 6 months, 9 months or 12 months in the maintenance phase were identified and the time to retreatment after these TFIs was determined.

Results The time to retreatment for the 20th and 50th centiles was 0.58/2.54 months after a 3-month TFI, 2.07/9.62 months after a 6-month TFI, 3.69/15.84 months after a 9-month TFI and 5.90/22.49 months after a 12-month TFI. Following a TFI of 3 months, 6 months, 9 months and 12 months, 68%, 44%, 31% and 21% of eyes required retreatments after an additional 6 months of follow-up, respectively. Similarly, after 12 months of follow-up, 77%, 56%, 43% and 34% of these eyes required retreatment.

Conclusions This study provides times to retreatment in eyes with nAMD that have been treatment-free for intervals of 3–12 months and demonstrates the likelihood of repeat therapy within the next year, even after a TFI of 12 months. These outcomes can help plan appropriate follow-up intervals for patients who have been treatment-free for intervals of up to 12 months.