No-Dose Photodynamic Therapy Against half-dose Photodynamic Therapy for Treatment of Central Serous Chorioretinopathy

Abstract Objective To describe the effects of no-dose full fluence photodynamic therapy without verteporfin (no-dose PDT) and to compare no-dose PDT with half-dose verteporfin full-fluence photodynamic therapy (HDFF PDT) for managing chronic central serous chorioretinopathy (cCSC). Methods This retrospective study evaluated 11 patients with chronic recurrent CSC treated with no-dose PDT between January 2019 and March 2022. Most of these patients were also treated with half-dose full-fluence PDT (HDFF PDT) a minimum of 3- months before and were considered as control group. We described the changes of best-corrected visual acuity (BCVA), maximum subretinal fluid (mSRF), foveal subretinal fluid (fSRF) and choroidal thickness (CT) 8 ± 2 weeks after no-dose PDT, and we compared BVCA, mSRF, fSRF and CT of no-dose PDT with those of the of same patients previously treated with HDFF PDT. Results Fifteen eyes of 11 patients (10 males, mean age 54 ± 12 years) received no-dose PDT; among these, 10 eyes of 8 patients (7 males, mean age 53 ± 12 years) received also HDFF PDT. Three eyes showed complete resolution of fSRF after no-dose PDT. No significant differences were disclosed between treatment with and without verteporfin comparing BCVA, mSRF, fSRF, and CT at the baseline and 8 ± 2 weeks from the treatment (p > 0.05 in all analyses). Conclusion BVCA and CT significantly improved after no-dose PDT. Short-term functional and anatomical treatment outcomes for cCSC were similar for HDFF PDT and no-dose PDT. We hypothesize that the potential benefits of no-dose PDT may arise thermal elevation triggers and enhances photochemical activities by endogenous fluorophores that activates a biochemical cascade response that rescues / replaces sick, dysfunctional RPE cells. Results of this study suggest the potential value of a prospective clinical trial to evaluate no-dose PDT for managing cCSC, especially when verteporfin is contraindicated or unavailable.