Lipemia Retinalis in an Infant With a PCSK9 Variant of Familial Hypercholesterolemia: A Case Report.

Lipemia retinalis is a rare ophthalmic condition characterized by a milky-white appearance of the retinal vessels caused by markedly elevated blood triglyceride levels. This condition serves as an important clinical indicator of severe hyperlipidemia, particularly hypertriglyceridemia, and may signify an underlying metabolic disorder. Its ocular manifestations can serve as an early warning sign for clinicians, prompting further evaluation of the patient's lipid profile and potential underlying systemic conditions. We present a rare case of a 36-day-old male infant who was hospitalized for acute diarrhea following the initiation of formula feeding and was noted to have a milky-pink discoloration of the blood during venipuncture. An ophthalmology consultation was obtained, and fundus examination revealed bilateral dilated whitish retinal vessels and slightly palish optic discs. The anterior segments were otherwise normal, with no evidence of cataracts. Laboratory investigations demonstrated markedly elevated cholesterol (920.2 mg/dL) and triglyceride (2,742.2 mg/dL) levels, while systemic examination findings were unremarkable. No abnormalities were identified on echocardiography or abdominal ultrasonography. Genetic testing revealed a heterozygous mutation in the PCSK9 gene, confirming the diagnosis of familial hypercholesterolemia (FH). The infant was transitioned to a specialized formula diet. At one-month follow-up, the ocular signs of lipemia retinalis had completely resolved. Ocular manifestations such as lipemia retinalis may represent an early sign of dyslipidemia and should prompt a comprehensive systemic evaluation to facilitate timely diagnosis and prevent potentially serious complications.