Purpose
To correlate clinical manifestations with choroidal morphology in pachychoroid spectrum disorders- central serous chorioretinopathy (CSC), pachychoroid pigment epitheliopathy (PPE) and pachychoroid neovasculopathy (PNV)- using en face swept-source OCT (SS-OCT). PPE is thought to represent a forme fruste of CSC wherein RPE changes overlie foci of choroidal thickening with dilated choroidal vessels, in the absence of subretinal fluid. PNV refers to type 1 neovascularization in the context of PPE. Long wavelength SS-OCT images the choroid at greater depth and with shorter acquisition times than EDI SD-OCT. We present en face SS-OCT images of the spectrum of pachychoroid related disease, including patients with CSC, PPE, PNV, and PCV.
Methods
A retrospective study was conducted in a retinal private practice. Patients with CSC, PPE, PNV, and PCV were identified from charts and multimodal imaging data, including fundus photography, fluorescein and/or indocyanine green angiography and SD-OCT. These patients also underwent SS-OCT with production of choroidal thickness maps and en face segments, from which choroidal vascular morphology could be studied.
Results
47 eyes of 26 patients were included. With multi-modal imaging, 14 eyes were diagnosed with CSC, 11 with PPE, 7 with PNV, and 3 with PCV. SS-OCT choroidal thickness maps confirmed increased choroidal thickness (mean 409µm) specifically under areas of CSC, RPE change (PPE), type 1 NV (PNV), or polyps (PCV). En face SS-OCT segments demonstrated dilated outer choroidal vessels and outward displacement of the choroid-scleral interface in areas of increased choroidal thickness. In eyes with chronic disease and atrophy, loss of inner choroidal volume with inward displacement of deep choroidal vessels was also appreciated.
Conclusions
Although clinical manifestations of the pachychoroid spectrum disorders vary considerably, these entities share certain morphologic findings in the choroid. SS-OCT renders choroidal thickness maps and en face segments with sufficient resolution to delineate the morphology of outer choroidal vessels. In the pachychoroid spectrum, increased choroidal thickness and vessel diameter are observed. En face SS-OCT shows that these changes underlie foci of RPE disruption and may be etiological to clinical manifestations. SS-OCT may be predictive in identifying areas of retina susceptible to developing pachychoroid spectrum sequelae.