To the Editor:

We read with interest the study by Chandra et al. [1] on the 10-year outcome in patients receiving anti-vascular endothelial growth factor therapy (anti-VEGF) for neovascular age-related macular degeneration. Of the 611 patients initiated on anti-VEGF therapy, 149 completed the full follow-up, 244 were excluded and 218 patients deceased. The visual acuity (VA) data on deceased patients is not included in the final analysis and a retention rate of 37.9% is reported. Of the two similar retrospective studies published previously on this topic [2, 3], the study by Gillies et al. [3] has provided data on patients failing to complete the full ten-years of follow-up. The overall retention rate in that study, including the deceased patients, was 21% and 79% of patients dropped-out at various time-intervals (61.4% amongst the Australian & New Zealand patients and 86.9% in the Swiss patients). Including the deceased patients, the overall retention in the current study, drops to 24.3% (149 of 611 patients).

In the current study, the authors have excluded the VA data of the deceased patients, when reporting the data on patients dropping-out at various time-intervals (Table 3). None of their patients dropped out within the first year of follow-up and worse visual outcome was reported only from 3rd year onwards. By not including VA of deceased patients, it is possible that patients with worse visual outcome have been left out. Rather than excluding the details of deceased patients, VA outcome at the last reported follow-up should have been included.

Treatment failure either due to macular atrophy or scar, rendering any further treatment futile was seen in nearly 20% of eyes in the study by Gilles et al. [3] and 11% stopped treatment within the first year. The current study reports that 76.5% of eyes maintained VA, defined as less than 15 letters loss from baseline, however the number of patients in whom treatment was stopped due to permanent structural damage to macula is not mentioned. Retrospective studies including this study have the bias of including patients who continue to gain vision or perceive benefit from treatment and remain under follow-up.