To compare the efficacy of photodynamic therapy (PDT) depending on the degree of hyperfluorescence based on indocyanine green angiography (ICGA) for treating chronic central serous chorioretinopathy (CSC).

Twenty-three eyes of 23 patients with chronic CSC were recruited for the present study. The minimum follow-up period was six months. The total energy of PDT was reduced to 25 J/cm² for 83 seconds. The baseline middle-phase ICGA findings were classified as intense or low hyperfluorescence depending on the degree of hyperpermeability from choriocapillaris. The change in mean best-corrected visual acuity, the resolution of subretinal fluid, recurrence rate, and complication were analyzed in relation to each ICGA finding at baseline.

The baseline ICGA findings showed intense hyperfluorescence in 11 eyes (47.8%) and low hyperfluorescence in 12 eyes (52.2%). The subretinal fluid resolved completely one month after a single application of low-fluence PDT in both groups. The subretinal fluid recurred in one of 12 eyes (8.3%) with low hyperfluorescence and in no eyes (0%) with intense hyperfluorescence. There was no statistically significant difference in the rate of recurrence between the two groups.

Low-fluence PDT appears to be an effective and safe treatment option for long-standing chronic CSC regardless of the degree of hyperfluorescence based on the ICGA.