Longitudinal Changes in Scleral Thickness after Half-dose Photodynamic Therapy in Central Serous Chorioretinopathy

To evaluate longitudinal changes in scleral thickness after half-dose photodynamic therapy (PDT) in eyes with central serous chorioretinopathy (CSC) in parallel with widefield assessment of choroidal thickness.

This retrospective observational study included 41 eyes of 41 patients with unilateral CSC who underwent half-dose PDT for persistent subretinal fluid and completed 12 months of follow-up. Scleral thickness was measured in 4 quadrants using anterior-segment optical coherence tomography (OCT) at baseline and at 3 and 12 months after PDT. Widefield choroidal thickness was assessed using widefield swept-source OCT with an 18-mm grid divided into 9 sectors. Untreated fellow eyes served as a reference group.

In treated eyes, widefield choroidal thickness decreased significantly at 3 months after PDT across all 9 predefined sectors (all P < 0.05) and remained reduced at 12 months, with no significant differences between 3 and 12 months. In untreated fellow eyes, no consistent longitudinal changes in choroidal thickness were observed; however, a statistically significant reduction was noted only in the outer superonasal sector at 3 months (P = 0.015). In contrast, scleral thickness showed no significant changes at any time point in either treated or fellow eyes (all P > 0.05).

Despite widespread and sustained choroidal thinning after half-dose PDT, scleral thickness remained unchanged for at least 12 months in eyes with CSC. These findings suggest that scleral thickening in CSC is unlikely to represent a readily reversible response to treatment-associated choroidal changes and may instead reflect a relatively stable anatomical feature.