COMPARISON OF PHOTODYNAMIC THERAPY USING HALF-DOSE OF VERTEPORFIN OR HALF-FLUENCE OF LASER LIGHT FOR THE TREATMENT OF CHRONIC CENTRAL SEROUS CHORIORETINOPATHY.

PURPOSE: To compare the efficacy and the detrimental effects of half-drug dose and half-laser light fluence of photodynamic therapy (PDT) for the treatment of chronic central serous chorioretinopathy.

DESIGN: We conducted a prospective randomized, observer-masked comparison study.

METHODS: Forty eyes (40 patients) with chronic central serous chorioretinopathy were enrolled in this study and were equally divided into 2 groups. The first (half-dose) group received only half the standard dose of verteporfin infusion (3 mg/m) and were irradiated by the standard 83 seconds of laser light (50 J/cm) for the PDT treatment; the second (half-fluence) group received the standard dose of verteporfin infusion (6 mg/m) and were irradiated by only 42 seconds of laser light (25 J/cm). Patients were examined at baseline and 1 week, 1 month, 3 months, and 6 months after PDT treatments with best-corrected visual acuity and optical coherence tomography. Fluorescein angiography and indocyanine green angiography (ICGA) were performed at baseline and at 1 month, 3 months, and 6 months after PDT treatment. Primary outcome measures were the changes in the best-corrected visual acuity and in central retinal thickness and subretinal fluid in optical coherence tomography. Secondary outcomes were the changes in the choroidal perfusion in the ICGA, which was measured as the fluorescein ratio of the PDT-treated area to a nontreated reference area in ICGA.

RESULTS: Best-corrected visual acuity was significantly improved at post-PDT 1 month, 3 months, and 6 months (all P < 0.01) in both the half-dose and the half-fluence group. Central retinal thickness was significantly improved at all post-PDT time points in both groups (P < 0.05). All patients in the half-dose group and 19 patients (95%) in the half-fluence group had complete absorption of subretinal fluid at post-PDT 3 months and 6 months. The choroidal perfusion (as reflected by the decrease of the ratio of fluorescence) in ICGA was significantly decreased at all post-PDT follow-up time points in both groups (P < 0.01). However, there were no significant differences in all the measurements between the two groups, including best-corrected visual acuity, central retinal thickness, and hypofluorescence in ICGA at baseline and at each post-PDT follow-up time point.

CONCLUSION: Both half-dose and half-fluence modifications of PDT were similarly effective in improving the visual acuity and subretinal fluid for chronic CSC. Both types of modification of PDT were also similar in causing postlaser choroidal hypoperfusion.