Low Fluence Photodynamic Therapy in Chronic Central Serous Chorioretinopathy: Blind Randomised Clinical Trial of Efficacy and Safety

Purpose:To evaluate in a blind randomized clinical trial the efficacy and safety profile of photodinamic therapy (PDT) with a low fluence rate for treatment of chronic central serous chorioretinopathy (CSC) compared to an untrated group. Methods:Sixteen eyes with chronic CSC were randomized into 2 groups to receive either PDT with verteporfin (fluence 25 J/cm2, light dose rate: 300 mW/cm2) or no therapy. Inclusion criteria were: Best-corrected visual acuity (BCVA) between 0,2 and 1 logMAR; presence of subretinal fluid and/or serous pigment epithelial detachment on optical coherence tomography (OCT) without regression for 3 or more months, RPE leakage on fluorescein angiography and choroidal vascular hyperpermeability on confocal scanning laser indocyanine green angiography (SLO-ICGA). Exclusion criteria were: any previous treatment for CSC; evidence of other chorioretinal disorders; media opacities; and treatment with systemic steroids. The laser irradiation was applied on the areas of choroidal vascular hyperpermeability as observed on ICGA. Nonconfluent laser spots were used in case of multiple hyperpermeable areas, including the fovea, if involved. Primary outcome measures were: far BCVA (logMAR, using ETDRS charts) and near BCVA (logMAR, using MNRead Acuity Charts), central macular thickness (OCT3, Zeiss-Humphrey); secondary outcome measures were macular sensitivity and stability of fixation determined using microperimetry (Nidek MP1). All outcome measures were evaluated 1, 4, 12 and 24 weeks after treatment. Results:No significant changes in all parameters were seen in control untreated group. A significant improvement of far and near BCVA were seen in comparison with both baseline (ANOVA, p=0,008 and 0,000), and the control group (t-TEST, p=0,010 and p=0,000), with the greater effect on week 24. In all eyes treated with low fluence PDT a complete resolution of subretinal fluid was observed, with a significant reduction of central macular thickness. On week 24, in treated eyes a significant improvement in mean fixation stability was also observed (ANOVA, p=0,011). No recurrence was seen during the follow-up period. No adverse event, like persistent occlusive effect on the choriocapillaris, pigmentary changes in the treatment zone, or choroidal neovascularization occurred in any of the treated patients. Conclusions:Low fluence PDT is effective and safe for treating chronic CSC.