Role of Optical Coherence Tomography in Pachychoroid Spectrum Diseases

The pachychoroid spectrum encompasses a newly defined group of ocular pathologies characterized by increased choroidal thickness, dilatation of the outer choroidal vessels, and attenuation of the inner choroidal layers. Optical Coherence Tomography has become the primary imaging modality for identifying these diseases, as it allows for the precise visualization of the structural changes occurring within the choroid and the retinal pigment epithelium. As the spectrum evolves into Pachychoroid Neovasculopathy, Optical Coherence Tomography reveals pathognomonic features such as flat, irregular pigment epithelial detachments, frequently referred to as the double-layer sign. This finding is instrumental in distinguishing Pachychoroid Neovasculopathy from neovascular age-related macular degeneration. In Polypoidal Choroidal Vasculopathy, Optical Coherence Tomography and its advanced applications remain central to identifying the choroidal circulation disturbances that define the condition. Ultimately, advancements in Optical Coherence Tomography imaging have not only clarified the pathophysiology of the pachychoroid spectrum but have also established the definitive criteria for the differential diagnosis of its various clinical subtypes.