Risk factors of persistent subretinal fluid after half-dose photodynamic therapy for treatment-naïve central serous chorioretinopathy

To investigate the prognostic factors on spectral domain optical coherence tomography (SD-OCT) associated with incomplete subretinal fluid (SRF) absorption in treated-naïve eyes with central serous chorioretinopathy (CSC) after the half-dose verteporfin photodynamic therapy (vPDT).Patients with CSC who underwent half-dose vPDT with a follow-up period of more than 3 months were included in this retrospective study. Logistic regression was performed to determine the risk factors associated with the SRF persistence at 3 months after the treatment.A total of 143 patients with 150 eyes were enrolled in this study (102 male and 41 female patients). The rate of complete SRF resolution was 82.7% at 3 months for all cases. The duration of symptoms 6 months (odds ratio [OR] = 3.135, 95% confidence interval [95% CI] (1.147-8.573), p = 0.026), larger SRF area with base diameter 3 mm (odds ratio (OR) = 4.051, 95% CI: 1.336-12.284, p = 0.013), and larger flat irregular pigment epithelium detachment (FI-PED) area with base diameter 1 mm (OR = 3.311, 95% CI: 1.249-8.780, p = 0.016) on OCT B-scans were risk factors for incomplete SRF absorption after half-dose vPDT, while outer nuclear layer (ONL) thickness was not significantly associated with the anatomical outcome (OR = 1.015, 95% CI: 0.995-1.036, p = 0.145).The duration of symptoms, baseline SRF, and FI-PED base diameter on SD-OCT were important predictors for the anatomical outcome at 3 months after half-dose vPDT. Further studies are needed to establish a better therapeutic strategy for patients with poor response to half-dose vPDT.