Purpose: To compare the short-term and long-term efficacy, safety and costs of half-fluence and half-dose photodynamic therapy (PDT) in chronic central serous chorioretinopathy (CSC).
Methods: Multicenter retrospective comparison study 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 retinal thickness (CRT) and resolution of subretinal fluid on optical coherence tomography at 1 month and at the last-follow-up visit (LFU) were assessed. Cost analysis was also performed.
Results: Snellen BCVA improved significantly (p<0.001) both in the half-fluence group from 0.70 (±0.23) to 0.87 (±0.21) and in the half-dose group from 0.76 (±0.16) to 0.87 (±0.16) at the LFU. There was no difference in final BCVA between the 2 groups. At 1 month a complete resolution of subretinal fluid was observed in 19 (61.3%) half-fluence treated eyes and in 25 (86.2%) half-dose treated eyes (p =0.04). At the LFU, a complete resolution of sub-retinal fluid was achieved in 26 (83.9%) half-fluence treated eyes and 29 (100%) half-dose treated eyes (p = 0.0529; OR, 5.20; 95% CI, 1.75-15.42). Nine (25.8%) eyes in the half-fluence group and 5 (17.2%) eyes in the half-dose group had at least one recurrent episode of subretinal fluid (OR, 1.96; 95% CI, 0.57-6.76). Overall there were 15 and 5 recurrences in the half-fluence PDT and half-dose PDT respectively (p=0.06; OR, 4.5; 95% CI, 1.36-14.84). The overall cost of half-fluence PDT was twice the cost of half-dose PDT.
Conclusions: Half-dose PDT induced a more rapidly reabsorption of the fluid, a more lasting effect and a halving of the costs respect to half-fluence PDT