Choroidal Inflammation and Choriocapillaris Ischemia in Focal Choroidal Excavation in Comparison to Pachychoroid Neovasculopathy

Abstract

To investigate the choriocapillaris and choroidal characteristics of focal choroidal excavation (FCE) to establish pathomechanisms of the disease.Methods: Thirty eyes with FCE, 26 eyes with pachychoroid neovasculopathy (PNV), and 25 participants without any conditions (control group) were analyzed retrospectively. The thickness of both choriocapillaris equivalent and whole choroid was measured at three different points: under the lesion (excavation or neovascularization), in the normal retina, and in the fovea of fellow eye. Indocyanine green angiographic images were collected to confirm choriocapillaris ischemia and the presence of choroidal inflammation.Results: In both FCE and PNV, choriocapillaris-equivalent attenuation was observed under the lesion compared with other region of the retina (28.1 ± 11.3 mm vs. 69.4 ± 20.0 mm in FCE; 23.5 ± 9.7 mm vs. 62.3 ± 14.7 mm in PNV; both P , 0.001). We also observed focal thinning of the whole choroid under the lesion (149.7 ± 88.7 mm vs. 296.6 ± 83.2 mm; P , 0.001) in FCE but not in PNV. Pachyvessels distribution on optical coherence tomography and numerous dark areas on indocyanine green angiography implied that choroidal inflammation was related to the FCE occurrence.Conclusion: Choriocapillaris ischemia was related to both FCE and PNV. The choroidal thinning under the excavation and adjacent pachyvessels observed in FCE suggested that focal inflammation and scarring may contribute to choriocapillaris ischemia and eventual retinal pigment epithelium retraction with dysfunction in the pathomechanism.

Case Report: Complete tomographic resolution of focal choroidal excavation complicated with choroidal neovascularization after anti-VEGF treatment

“…In fact, choroidal vascular abnormalities have been described in association with FCE and included choroidal venous dilation (pachyvessels) and choroidal filling defects. 15 These findings suggest that local choroidal ischemia may affects the underlying RPE and outer retinal layers, leading in some cases to the development of a CNV. CNV is usually located within the excavation, as seen in our patient, or adjacent to the excavation.…”

Chronic choriocapillaris ischemia in dilated vortex vein region in pachychoroid neovasculopathy

“…Grade 0: no tendency for overlapping between filling delay or CVH area and dilated vortex vein region. previous reports demonstrated choriocapillaris filling defects on ICGA or reduced choriocapillaris flow on OCT angiography (OCTA) in pachychoroid spectrum diseases 19,20 . Miyake and colleagues studied the phenotypic/genetic differences between neovascular AMD and PNV including PCV 21 .…”

Pachychoroid Spectrum Disorders: An Updated Review

“…[ 41 ] On OCT and ICGA, these cases also tend to demonstrate choroidal attenuation directly below the excavation area corresponding to outer choroidal vessel dilation. [ 73 ]…”

“…[ 67 ] Other investigators have suggested the disease can also be acquired, with some proposing that inflammation, fibrosis, CNV, or choriocapillaris atrophy may weaken the junction between the RPE and BM, decreasing the overall architectural support and leading to FCE development. [ 67 , 73 , 78 ]…”