Incidence of recurrence and development of polypoidal lesions following half-dose and two-thirds dose photodynamic therapy for pachychoroid neovasculopathy

The purpose of this study was to determine the recurrence rate, factors, incidence of polypoidal lesions, and risk factors for developing polypoidal lesions after a reduced dose photodynamic therapy (PDT) for pachychoroid neovasculopathy (PNV) without polypoidal lesions. This study is an observational case-control study. The study included 105 patients (77 men, 28 women; mean age, 61.6 years) with PNV in 105 eyes treated with reduced PDT. Twenty-eight eyes were treated with half-dose PDT and 77 eyes with two-thirds dose PDT, with an average follow-up of 588 days. Logistic regression analysis was used to examine factors of recurrence and polypoidal lesions. Recurrence was observed in six patients (21%) receiving half-dose PDT and 24 patients (31%) receiving two-thirds dose PDT. Polypoidal lesions developed in seven patients (7%). Recurrence factors were duration of follow-up (P < 0.0001), macular neovascularization (MNV) thickness before PDT (P = 0.010), and age (P = 0.002). MNV area before PDT was an independent risk factor for the development of polypoidal lesions (P = 0.001). Long-term follow-up after reduced PDT for PNV is necessary because recurrence factors include follow-up duration, age, and MNV thickness. A risk factor for polypoidal lesions after PNV treatment was the MNV area before PDT.