Half-Fluence Versus Half-Dose Photodynamic Therapy in Chronic Central Serous Chorioretinopathy

Purpose To compare the efficacy and safety of half-fluence vs half-dose photodynamic therapy (PDT) in chronic central serous chorioretinopathy (CSC). Design Multicenter retrospective comparison study. Methods Retrospective review of 56 patients affected by chronic CSC, including 28 patients (31 eyes) who received half-fluence PDT and 28 patients (29 eyes) who received half-dose PDT. Best-corrected visual acuity (BCVA), central foveal thickness (CFT), and resolution of subretinal fluid on optical coherence tomography at 1 and 12 months were assessed. Results The mean logMAR BCVA improved significantly ( P < .001), both in the half-fluence group (from 0.187 [± 0.187] to 0.083 [± 0.164]) and in the half-dose group (from 0.126 [± 0.091] to 0.068 [± 0.091]), at 12 months, without significant difference between the 2 groups. At 1 month a complete resolution of subretinal fluid was observed in 19 half-fluence-treated eyes (61.3%) and in 25 half-dose-treated eyes (86.2%) ( P = .04). At 12 months, a complete resolution of subretinal fluid was achieved in 26 half-fluence-treated eyes (83.9%) and 29 half-dose-treated eyes (100%) ( P = .0529). Nine eyes (29%) in the half-fluence group and 5 eyes (17.2%) in the half-dose group had at least 1 recurrence of subretinal fluid during the follow-up. Overall there were 15 and 5 recurrences in the half-fluence PDT and half-dose PDT groups, respectively ( P = .07). In no eye of either groups was atrophy of the retinal pigment epithelium observed in the area of treatment. Conclusion Half-dose PDT induced a more rapid reabsorption of the fluid, a more lasting effect, and equal safety with respect to half-fluence PDT.