BACKGROUND: Amyloidosis refers to a heterogeneous group of diseases characterized by extracellular deposits of amyloid. Transthyretin is one of the precursor proteins in hereditary forms, where amyloid mainly accumulates in peripheral nerves, the heart and the eye. One of the ocular manifestations is floaters and a progressive decrease in visual acuity, due to its accumulation in the vitreous humour. CLINICAL CASE: A 70-year-old man consulted due to a bilateral decrease in visual acuity. Dense vitreous opacities were observed during the ocular fundus exam, so a therapeutic pars plana vitrectomy was performed. The samples were sent for pathology analysis with a suspicion of ocular amyloidosis. The histopathological examination revealed amorphous cellular material showing apple-green birefringence with Congo red staining. Immunohistochemical staining and genetic testing identified a variant associated with familial amyloidotic polyneuropathy. Subsequently, a comprehensive systemic evaluation was performed, including an echocardiogram and magnetic resonance imaging, which revealed mild septal hypertrophy and diastolic dysfunction. CONCLUSIONS: We present a case of cardiac involvement caused by hereditary amyloidosis, diagnosed through vitreous biopsy. This case highlights the importance of ophthalmological clinical suspicion and its role in facilitating a systemic evaluation leading to the right diagnosis and the early initiation of the appropriate therapy.