Long-term chorioretinal changes after photodynamic therapy for chronic central serous chorioretinopathy

To evaluate morphological and functional chorioretinal changes 5 years after standard photodynamic therapy (PDT) for chronic central serous chorioretinopathy (CSC).

A retrospective, nonrandomized study, including patients with chronic CSC treated with standard PDT and followed for at least 60 months. All patients underwent a complete ophthalmological examination, and the location and number of treatments were registered. Five or more years after treatment, subfoveal and non-subfoveal treated areas were evaluated with Spectralis optical coherence tomography and microperimetry.

Seventeen eyes of 15 patients were included, with mean age of 48.3 ± 8.4 years and a mean follow-up of 80.6 ± 12.4 months (range from 62 to 104 months). All eyes had neurosensory detachment (NSD) at baseline. Treatment was performed under the fovea in 58.8 % and in a non-foveal area in 41.2 % of the eyes. At the final visit all eyes had resolution of the NSD, with a statistical significant reduction in central macular thickness (p = 0.005) and preserved neuroretinal thickness (p = 0.839). There was a statistical difference between initial and final BCVA (p < 0.001) and a mean gain of 8.4 ± 7.8 letters. Subfoveal morphological changes in external limiting membrane (ELM) and in photoreceptor inner and outer segment junction (IS/OS) were correlated with final BCVA (p = 0.015 and p = 0.014 respectively), but not with the variation of BCVA. There was a statistical correlation between morphological changes in IS/OS line and retinal sensitivity in the central 12° and 2° (p = 0.003 and p = 0.002 respectively). The morphological changes in the subfoveal layers were not dependent on treatment location (p = 0.154, p = 0.644, and p = 1.0 for ELM, IS/OS line, and retinal pigment epithelium respectively). Subfoveal final mean choroidal thickness was 295.1 ± 68.7 μm, and showed no statistical difference from the normal population (p = 0.633).

Morphological and functional chorioretinal changes, observed 5 or more years after standard PDT for chronic CSC, were not correlated with the location of treatment, neither with the progression of visual acuity or with the location of treatment, and are more likely to be related to the disease itself than with the treatment provided.