Relationship between photoreceptor layer changes before half-dose photodynamic therapy and functional and anatomic outcomes in central serous chorioretinopathy

Objectives To investigate the relationship between photoreceptor layer (PRL) changes before half-dose photodynamic therapy (PDT) and functional and anatomic outcomes in central serous chorioretinopathy (CSC). Methods Baseline PRL changes were classified based on optical coherence tomography: (1) smooth PRL outer border without a foveal PRL defect; (2) smooth PRL outer border with a foveal PRL defect; (3) granulated PRL outer border and (4) scattered dots of PRL. The best-corrected visual acuity (BCVA), difference in the foveal outer nuclear layer (ONL) thickness between the CSC and normal contralateral eyes and ellipsoid zone (EZ) integrity 12 months after half-dose PDT were compared. Results In total, 132 patients were included. Group 4 eyes had rather poor BCVA (20/2000–20/400) with little improvement ( P = 0.088) at 1 year following half-dose PDT. In the other groups, the mean BCVA improved significantly to 20/25 or better (all P < 0.001). Group 1 eyes had the smallest foveal ONL thickness reduction (−5.12 ± 6.89 μm) and intact EZs (33/33), whereas Group 4 eyes had the largest foveal ONL thickness reduction (−70.00 ± 7.87 μm) and disrupted EZs (4/4). Group 2 and Group 3 eyes behaved similarly: they both had notable foveal ONL thickness reductions (−19.21 ± 18.53 and −20.75 ± 17.62 μm, respectively), but usually continuous EZs (18/19 and 69/76, respectively). Conclusions The PRL change category before half-dose PDT was closely related to functional and anatomic outcomes. This information could aid clinicians to better determine the timing of treatment with half-dose PDT in CSC.