Comparison of half-time and half-irradiance photodynamic therapy in nonresolving central serous chorioretinopathy

Purpose: To compare the efficacy of half-time and half-irradiance photodynamic therapy (PDT) in patients with nonresolving central serous chorioretinopathy (CSC) Methods: This retrospective study included 32 patients with nonresolving CSC, of whom 14 were treated with half-time PDT and 18 with half-irradiance PDT. Therapeutic outcomes, including central retinal thickness (CRT), subretinal fluid (SRF) height, subfoveal choroidal thickness (SFCT), thickness of the Haller layer (HL), thickness of the choriocapillaris/Sattler layer (SL), and best-corrected visual acuity (BCVA), were measured at baseline, and at 1 and 3 months after treatment. Results: CRT, SRF, and SFCT decreased significantly at 1 and 3 months after treatment in both groups. Thickness of the HL decreased significantly at 1 and 3 months, whereas thickness of the choriocapillaris/SL did not. BCVA demonstrated a significant improvement at 3 months in both groups. Changes in outcome parameters were not significantly different between the 2 groups. Conclusion: Both half-time and half-irradiance PDT were effective in SRF resolution and visual improvement, reducing choroidal thickness mainly on HL.