Comment on: "Three-year follow-up of ranibizumab treatment of wet age-related macular degeneration: influence of baseline visual acuity and injection frequency on visual outcomes".

Dear editor

I read the current article titled “Three-year follow-up of ranibizumab treatment of wet age-related macular degeneration: influence of baseline visual acuity and injection frequency on visual outcomes” by Razi et al,1 with great interest. Authors present outcomes of ranibizumab treatment of wet age related macular degeneration. I congratulate authors for this well organized study.

Major disadvantage of treatment with anti-VEGF drugs is the recurrence of wet age related macular degeneration. Monthly or bimonthly injection is needed in lots of patients. Changes in visual acuity (VA) at 1, 2 and 3 year were evaluated in this study. Considering recurrence, time between last injection and VA measurement is important. Pro re nata (PRN) treatment regimen was applied to patients in this study. This means that some patients could be treated 1 month before measurement at 1, 2 or 3 years and some patients could be treated more than 1 month before the measurement. Elongation of time interval may increase risk of recurrence and cause a lower measurement of VA. Thus, it would be better to include VA measurements that are taken 1 month after closest treatments to each year. VA was found to be positively correlated with injection frequency. Increase of injection frequency also increases possibility of last treatments of each year to be closer to the measurement.