Unilateral Situs Inversus of the Optic Disc in a Patient With Retinal Arteriolar Tortuosity

Familial retinal arteriolar tortuosity (fRAT) is a rare autosomal dominant disorder that is characterized by tortuosity of the second- and third-order arterioles around the posterior pole of retina. Most cases with fRAT lack associated systemic vascular abnormality. Situs inversus, a congenital anomaly, features emergence of retinal vessels from the optic nerve head in a nasal direction, usually occurs bilaterally. In this case report, the authors describe a unique case of fRAT with unilateral situs inversus.