Reduction in choroidal thickness associated with the progression of pachychoroid spectrum diseases

Pachychoroid spectrum diseases reportedly progress from central serous chorioretinopathy (CSC) to pachychoroid neovasculopathy (PNV) and polypoidal choroidal vasculopathy (PCV). We investigated and compared choroidal thicknesses in the macular and peripheral areas among eyes with CSC, PNV, and PCV, as well as in normal control eyes.

Retrospective case-control study.

We studied 117 consecutive eyes with treatment-naïve pachychoroid spectrum diseases, comprising 52 eyes with CSC, 27 with PNV, and 38 with PCV, along with 106 age-, gender-, and axial length-matched normal control eyes. Widefield choroidal thickness maps generated by widefield optical coherence tomography were quantitatively analyzed. Mean choroidal thickness values in the macular, superotemporal, inferotemporal, superonasal, and inferonasal areas were determined, and then compared among the three pachychoroid spectrum diseases, and also assessed in normal controls.

The mean choroidal thickness reduction with aging was greater in eyes with pachychoroid spectrum diseases than in normal controls across all measured areas. Patient age increased in the order of CSC, PNV, and PCV, whereas there was no significant difference between PNV and PCV (P<0.01, CSC vs. PNV, CSC vs. PCV). Mean choroidal thickness exhibited a progressive decrease from CSC to PNV and PCV across all areas, although there were no significant differences between PNV and PCV (P<0.01, CSC vs. PCV, CSC vs. PNV).

Overall choroidal thickness appears to decrease during the progression of pachychoroid spectrum diseases. This decline might be attributable to reduced choroidal blood flow due to the choriocapillaris attenuation associated with aging and pachychoroid pathophysiology.