Choroidal Thickness After Extrafoveal PDT with Verteporfin in CSC
Danish investigators sought to evaluate the effect of verteporfin photodynamic treatment (PDT) on choroidal thickness in patients with central serous chorioretinopathy (CSC).
They measured choroidal thickness with enhanced depth imaging–optical coherence tomography (EDI–OCT) before and after verteporfin PDT (full-dose verteporfin, half-light dose) in 16 eyes in 16 patients with serous detachment of the fovea secondary to extrafoveal angiographic fluorescein leakage. They confined treatment to the area of leakage, and assessed choroidal thickness before and after treatment over a larger area of the fundus using OCT.
The study investigators reported complete resolution of the serous detachment in all 16 eyes within one month of extrafoveal PDT, while choroidal thickness in the area where PDT was applied decreased from 407 µm [mean; 95% confidence interval (CI95) 356–458 µm] to 349 µm (mean; CI95 300–399 µm; p<0.0001), and subfoveal choroidal thickness was reduced from 421 µm (mean; CI95 352–489 µm) to 346 pm (mean; CI95 278–414 µm; p=0.0001). Initially, subfoveal choroidal thickness was significantly increased in the treated eye compared with the healthy fellow eye (mean 324 µm; CI95 273–376 µm; p=0.0003), but after treatment, the difference was not significant.
PDT of active CSC was followed by choroidal thickness reduction, not only locally, but also at considerable distance from the treated area. Thus, the process that causes choroidal thickening in CSC appears to spread laterally within the choroid.