Predictive Factors for Morphological and Functional Improvements in Long-Lasting Central Serous Chorioretinopathy Treated with Photodynamic Therapy

<b>Backgrounds</b>: Photodynamic therapy (PDT) is an established treatment modality in central serous chorioretinopathy (CSCR). The goal of our study was to evaluate the morphological and functional effects of PDT in patients with long-lasting CSCR and determine the related predictive factors for improvement. <b>Methods</b>: This retrospective analysis included consecutive patients with chronic CSCR who consented to PDT. The material comprised 98 eyes of 81 patients (67 males and 14 females) with a disease duration longer than 6 months followed for 6 months post treatment. All patients underwent a basic ophthalmological examination including best corrected visual acuity (BCVA) testing and imaging, spectral-domain optical coherence tomography (SD-OCT), and fluorescein angiography. Patients without macular neovascularization (MNV) were subjected to half-dose PDT (3 mg/m²) with standard fluence (50 J/cm²), guided by indocyanine green angiography. Cases complicated by MNV were subjected to full-dose PDT. <b>Results</b>: A morphological response, defined as complete resolution of subretinal fluid, was achieved in 76.29% of cases, and an improvement in BCVA of at least one logMAR line was obtained in 77.53% of cases. The mean BCVA gain was 1.2 logMAR line. All SD-OCT measurements (central retinal thickness, macular volume, mean subfield thickness, subretinal fluid height, and subfoveal choroidal thickness) showed a significant reduction post PDT. A multivariate analysis proved better morphological outcome associations with a younger age and male gender and better visual gains achieved in patients without intraretinal abnormalities. Univariate testing also showed strong relationships between better baseline BCVA and greater functional and morphological improvements, between shorter disease duration and morphological gains, and between the absence of MNV or intraretinal abnormalities and morphological gains. PDT was highly effective in providing a resolution of pigment epithelial detachment (<i>p</i> = 0.0004). The observed effect was significantly dependent upon the lower baseline central retinal thickness (<i>p</i> = 0.0095). Patients with intraretinal abnormalities or MNV showed moderate improvements post PDT. <b>Conclusions</b>: PDT in long-lasting CSCR cases provides good morphological results but generally minor visual gains. Patients' expectations of significant increases in BCVA after prolonged disease with distinct alterations of the neurosensory retina should be managed.