Serous Maculopathy Due to Aspecific Choroidopathy (SMACH): A Case Report with Differential Diagnosis Based on Multimodal Imaging Analysis

Background Serous Maculopathy Due to Aspecific Choroidopathy (SMACH) is a rare chorioretinal disease characterized by polymorphic, non-pigmented choroidal lesions, with or without subretinal fluid (SRF). Its clinical manifestations overlap with common conditions such as central serous chorioretinopathy (CSC) and age-related macular degeneration (AMD), leading to a high risk of misdiagnosis, particularly in elderly patients. Multimodal imaging, including optical coherence tomography (OCT), OCT angiography (OCTA), fluorescein fundus angiography (FFA), and indocyanine green angiography (ICGA), is critical for accurate diagnosis. Case Presentation A 76-year-old Asian female presented with a 6-month history of blurred vision in her left eye. Ophthalmic examination revealed multiple yellowish-white subretinal lesions with mild elevation in the posterior pole of the left eye. OCT and OCTA demonstrated hyperreflective fibrinous exudates between the retinal pigment epithelium (RPE) and Bruch's membrane, choroidal thickening, and outer retinal damage. Fluorescein fundus angiography (FFA) and indocyanine green angiography (ICGA) provided complementary findings consistent with choroidal dysfunction and blood-retinal barrier disruption. Systemic evaluations, including laboratory tests for rheumatological immune indicators, tuberculin test, syphilis serology, and imaging examinations, excluded other systemic diseases. Based on these multimodal imaging findings and exclusion of alternative diagnoses, the patient was diagnosed with SMACH. Conclusions This case report describes a typical presentation of SMACH in an elderly patient, emphasizing that multimodal imaging, as demonstrated in this case, can help identify characteristic features of SMACH (choroidal thickening, hyperreflective exudates), though its diagnostic reliability in larger populations requires further validation.The exclusion of systemic diseases and differentiation from similar chorioretinal disorders (e.g., CSC, AMD) are crucial for accurate diagnosis.This case adds to the existing limited data on SMACH in elderly populations and further supports the role of multimodal imaging in improving diagnostic accuracy to reduce misdiagnosis. This case report describes a 76-year-old Asian female who presented with blurred vision in her left eye for six months. Ophthalmic examinations revealed multiple yellowish-white subretinal lesions with mild elevation in the posterior pole of the left eye. Optical coherence tomography (OCT) and OCT angiography (OCTA) indicated hyperreflective fibrinous exudates between the retinal pigment epithelium (RPE) and Bruch's membrane, choroidal thickening, and outer retinal damage. Combined with findings from fluorescein fundus angiography (FFA), indocyanine green angiography (ICGA), and exclusion of systemic diseases, the patient was diagnosed with Serous Maculopathy Due to Aspecific Choroidopathy (SMACH).