Retinal Angiomatous Proliferation and Pachychoroid: A Case Report.

Retinal angiomatous proliferation (RAP), also known as type 3 macular neovascularization (MNV), is a distinct and less common subtype of neovascular age-related macular degeneration (nAMD). This condition is typically associated with a thinner subfoveal choroid than in age-matched control eyes. However, the coexistence of RAP and pachychoroid, which is characterized by increased choroidal thickness and choriocapillaris attenuation, is rarely documented in the literature. In this report, we present the case of a 56-year-old male patient diagnosed with RAP in conjunction with pachychoroid. This case highlights the importance of multimodal imaging techniques, including optical coherence tomography (OCT), fluorescein angiography (FA), and optical coherence tomography angiography (OCT-A), to achieve a comprehensive assessment. Additionally, we emphasize the need for a thorough differential diagnosis to accurately identify and manage such overlapping retinal disorders. We hypothesize that choroidal ischemia secondary to compression of choriocapillaris by choroidal pachyvessels led to outer retinal ischemia and upregulation of vascular endothelial growth factor (VEGF), which caused RAP formation starting at the level of retinal superficial and deep capillary plexus and extended to the outer retina. Thus, our hypothesis supports that choriocapillaris atrophy is a common pathology between these two entities and may explain their coexistence.