Comparison of the efficacy and safety between subthreshold micropulse laser, standard-fluence and low-fluence photodynamic therapy for chronic central serous chorioretinopathy

Abstract

To compare the efficacy and safety of subthreshold micropulse laser treatment (SML), standard-fluence photodynamic therapy (PDT) and low-fluence PDT in patients with chronic central serous chorioretinopathy (cCSC). This retrospective study included 52 eyes of 46 patients with chronic CSC who were treated with 577nm SML (n=23), standard-fluence PDT (verteporfin 6mg/m2 and light energy 50J/cm2) (n=13), or low-fluence PDT (verteporfin 6mg/m2 and light energy 25J/cm2) (n=16). The mean changes in best-corrected visual acuity (BCVA) and optical coherence tomography (OCT) parameters, including central retinal thickness (CRT), subretinal fluid (SRF) height, and ellipsoid zone (EZ) disruption, over the follow-up period were evaluated. The mean follow-up period was 8.42±3.34 months. In the SML group, the SRF resolution time was longer than the other groups. At 1 month, the SML group's mean CRT was higher than the other groups. The BCVA improvement was statistically significant in all groups (P<0.05), but in the SML group, it was slower than the other groups. Three eyes in the low-fluence and one eye in the standard-fluence PDT group received a second PDT treatment. The mean number of SML treatments was 2.48±1.08. If the EZ was intact, the rate of complete resolution of SRF was higher than if the EZ was disrupted or lost. SML, standard-fluence PDT, and low-fluence PDT can all improve visual acuity in cCSC. Standard-fluence and low-fluence PDT induced a more rapid reabsorption of the fluid, improvement of BCVA, and equal safety compared with SML. More treatment sessions of SML were required than with the other treatment modalities.