Improved thickness measurement method for choroidal hyperpermeability in central serous chorioretinopathy

To observe choroidal thickness changes in the choroidal hyperpermeability area (CHA) in patients with central serous chorioretinopathy (CSC) after photodynamic therapy (PDT) using indocyanine green angiography (ICGA) combined with optical coherence tomography (OCT).

This was a cohort study of 17 eyes (17 patients) with CSC. In all patients, the range of CHA was determined by ICGA. The patients were divided into two groups based on CHA covered the fovea (group A) or not (group B). All patients received half-dose verteporfin PDT over CHA in ICGA. Choroidal thickness was measured by OCT before, 1, and 3mo after treatment. The choroidal thickness values of the fovea and CHAs were obtained for each measurement. Secondary outcomes were changes in the best-corrected visual acuity (BCVA) and amount of subretinal fluid (SRF).

The differences in center choroidal thickness at baseline and at 1 and 3mo post-PDT were statistically significant in group A and all patients (both P<0.001). There was no significant difference in group B (P=0.059). The differences of thickness of CHA and BCVA at baseline and 1 and 3mo post-PDT were statistically significant in group A, group B, and all patients (all P<0.01). All patients showed complete SRF absorption at 3mo post-PDT.

Center choroidal thickness does not accurately reflect changes in CHA of patients whose CHA does not covered the fovea center. Using CHA as the observation target can make up for this limitation, expand the scope of application, and reduce bias.