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

Abstract

<jats:p>The emergence of pachychoroid disease is changing the concept of age-related macular degeneration (AMD). The concept of pachychoroid diseases was developed through clinical observation of multimodal images of eyes with AMD and central serous chorioretinopathy; however, recent genetic studies have provided a proof of concept for pachychoroid spectrum disease, which should be differentiated from drusen-driven AMD. The genetic confirmation of pachychoroid concept further provides novel viewpoints to decode previously reported findings, which facilitates an understanding of the true nature of pachychoroid diseases and AMD. The purpose of this review was to elucidate the relationship between pachychoroid diseases and AMD by interpreting previous findings on pachychoroid diseases and AMD from the novel viewpoints of genetic associations. We confirmed that previous genetic studies supported the concept of pachychoroid diseases. From a genetic viewpoint, the presence of thick choroid and the presence of choroidal vascular hyperpermeability were important characteristics of pachychoroid spectrum diseases. Previous studies have also suggested the classification of polypoidal choroidal vasculopathy (PCV) into two subtypes, pachychoroid neovasculopathy and drusen-driven PCV. Genetic viewpoints will be beneficial to rearrange subtypes of drusen-driven AMD and pachychoroid spectrum diseases. Further genetic studies are needed to investigate pachyvessels, pachydrusen and the significance of polypoidal lesions in pachychoroid neovasculopathy and drusen-driven AMD/PCV.</jats:p>

Rate of misdiagnosis and clinical usefulness of the correct diagnosis in exudative neovascular maculopathy secondary to AMD versus pachychoroid disease

“…2) 25 . Noteworthy, although it is well known that the latter disease has an higher prevalence in Asians 26 , our results suggest that also in Caucasians the prevalence of pachychoroid disease complicated by exudative MNV is much higher than that conventionally believed. In addition, at baseline, the two groups significantly differed in terms of demographics and clinical characteristics.…”

Genetic Variants Affecting Anti-VEGF Drug Response in Polypoidal Choroidal Vasculopathy Patients: A Systematic Review and Meta-Analysis

“…The G allele of the SNP 162V (rs8002921) in the CFH gene is a risk allele for drusen, more choroidal neovessels, and nAMD. The A allele is a risk allele for thick choroid, choroidal hyperpermeability, less choroidal neovessels, and PCV [ 41 ]. ARMS2 A69S risk allele frequency was lower in pachychoroidal neovasculopathy but slightly higher in nAMD [ 42 ].…”

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

“…Pachydrusen are found to be associated with thick subfoveal choroid by SS-OCT, further confirming that pachydrusen are a new entity distinct from soft drusen [1]. Subsequently the predictive role of pachydruen in disease progression has been established from nine publications from 2018 to 2020, confirming that pachydrusen are a precursor of PCV [24][25][26][27][28][29][30][31][32] and seven with CSC [27,30,[33][34][35][36]. Pachydrusen are included as member of PCD spectrum because they are associated with common PCD features including reduced choroidal vascular markings in fundus and small pigment epithelium detachments due to the drusenoid RPE changes.…”