Results of Switching from Pro Re Nata to Treat-and-Extend Regimen in Treatment of Patients with Type 3 Neovascularization.

Purpose : To investigate outcomes associated with switching from pro re nata (PRN) to treat-and-extend (TAE) anti-vascular endothelial growth factor (VEGF) regimen in patients with type 3 neovascularization. Methods : This retrospective study included 17 eyes diagnosed with type 3 neovascularization. All eyes underwent monthly anti-VEGF injections as the initial treatment for 3 months, followed by PRN-based retreatment. During the course of treatment, the strategy was changed to that of a TAE regimen. Best-corrected visual acuity (BCVA) measurements were compared across the three time points: After the loading injection, after the PRN phase, and after the TAE phase. Results : After the loading injection, the eyes were treated for 16.2 ± 5.5 months using the PRN regimen with 5.1 ± 1.5 anti-VEGF injections. After switching to the TAE regimen, 7.5 ± 3.0 injections were administered over 20.5 ± 8.2 months. The mean logarithm of the minimum angle of resolution BCVA was 0.44 ± 0.30 (Snellen equivalents = 20/55) after three loading injections, 0.58 ± 0.32 (20/76) after the PRN phase, and 0.62 ± 0.33 (20/83) after the TAE phase. The BCVA after the PRN phase was significantly deteriorated as compared to that after the three loading injections ( P = .015), whereas the BCVA values were not different after the TAE and PRN phases ( P = .342). Conclusions : In type 3 neovascularization, visual acuity was maintained for an average of 20.5 months after switching from the PRN regimen to the TAE regimen. Further studies with larger study populations and controlled study designs are required to confirm our findings.