Cross-over to photodynamic therapy or micropulse laser after failure of primary treatment of chronic central serous chorioretinopathy

Abstract Purpose To assess whether chronic central serous chorioretinopathy (cCSC) patients without a complete resolution of subretinal fluid (SRF) after either half-dose photodynamic therapy (PDT) or high-density subthreshold micropulse laser (HSML) treatment may benefit from cross-over treatment. Design Multi-center prospective interventional case series. Methods: cCSC patients with persistent SRF at the final visit of the PLACE trial were included. Patients received cross-over treatment with either half-dose PDT or HSML. Results 32 patients received PDT and 10 patients received HSML. At the first evaluation visit (6-8 weeks after treatment), 81% of patients in the PDT group had complete resolution of SRF, while none of the HSML-treated patients had complete resolution of SRF. At final visit (1 year after baseline), 78% (p=0.030) and 67% (p=0.109) of the patients, respectively, had a complete resolution of SRF. The mean retinal sensitivity in the PDT group increased from 21.7dB (standard error (SE):0.9) to 23.4dB (SE:0.8) at evaluation visit 1 (p=0.003), to 24.7dB (SE:0.8) at final visit (p Conclusions Cross-over to half-dose PDT after previous unsuccessful HSML treatment for cCSC may lead to improved anatomical and functional endpoints, while cross-over to HSML after half-dose PDT does not seem to significantly affect these endpoints.