Choroidal morphology under pachydrusen

Abstract

Importance To reveal choroidal morphological profiles under pachydrusen. Background Drusen in pachychoroid disorders show certain differences from conventional drusen and are recently named as “pachydrusen.” This study analysed the specific choroidal morphology under pachydrusen. Design This study is a cross‐sectional case series. Participants Enrolled were 136 eyes with pachydrusen from 134 patients. Methods The presence of pachydrusen in fundus area covered by a 12 × 9 mm2 optical coherence tomography (OCT) image was accessed in eyes with pachychoroid‐related diseases or their fellow eyes using colour fundus photography and swept source OCT. Choroidal morphology under the pachydrusen was analysed using OCT B‐scans and en face images. Main Outcome Measures Choroidal thicknesses and topographical correlation between pachydrusen and pachyvessels. Results A total of 225 pachydrusen in 136 eyes were analysed. The mean number of pachydrusen was 1.65 ± 1.07 per eye. Most pachydrusen were located para‐ or perifoveally (37 subfoveal, 86 parafoveal and 102 perifoveal). The proportion of Haller's layer to total choroidal thickness was higher at the area of the pachydrusen compared to the subfovea (0.881 ± 0.081 vs 0.765 ± 0.111, P < 0.001). In multimodal image analysis, 90.1% of pachydrusen identified using fundus photography and OCT B‐scan were located at the area of a dilated Haller vessel (pachyvessel) seen on en face images. Conclusions and Relevance Choroidal morphology under the pachydrusen showed increased Haller's layer thickness with an attenuated choriocapillaris layer, which is the hallmark of pachychoroid definition. Topographically, their locations correlated with the underlying pachyvessel.

Characteristics of Pachychoroid Diseases and Age-Related Macular Degeneration: Multimodal Imaging and Genetic Backgrounds

“…Roles of pachydrusen in the development of pachychoroid diseases have not been elucidated. Although pachyvessels are demonstrated to locate under pachydrusen both in AMD and CSC [ 196 , 197 ], it has not been concluded whether pachydrusen causes pachyvessels or vice versa. The genetic background of pachydrusen has also not been fully elucidated.…”

Clinical and genetic characteristics of pachydrusen in patients with exudative age-related macular degeneration

“…Pachydrusen is a relatively new entity characterized by isolated or scattered yellow-white deposits, the larger ones exceeding 125 µm in diameter, and having a better-defined outer border. They are seen over the posterior pole of the eye, which has a thickened choroid 12 , and choroidal morphology under pachydrusen showed increased Haller’s layer thickness with attenuation of choriocapillaris 13,14 . SD-OCT revealed that pachydrusen are drusenoid deposits 15,16 .…”

Drusen and pachydrusen: the definition, pathogenesis, and clinical significance

“…The morphology of the choroid was analyzed using en face OCT. The study identified an increased choroidal thickness under the PCD, due to enlarged choroidal vessels in the Haller layer with atrophy of the choroidal capillaries [115]. Kang et al found that soft drusen is closely related to the development of neovascular AMD, but alterations in the RPE are associated with PCV.…”