Lipid Keratopathy in Sitosterolemia: A Case Report and Review of The Ophthalmic Manifestations

Purpose: The aim of this study was to describe the case of a 9-year-old girl with inferior arcus in her right cornea and discrete inferior lipid deposition in her left cornea. Methods: Serum cholesterol and lipid levels were measured under general anesthesia for treatment with fine-needle cautery and subconjunctival bevacizumab. Results: Serum cholesterol and low-density lipoprotein were elevated at 12 mmol/L (normal range 3–5 mmol/L) and 10.8 mmol/L (normal range <3 mmol/L), respectively. Genetic testing identified a pathogenic variant in the ATP-binding cassette subfamily G member 5 ( ABCG5 ) gene consistent with sitosterolemia, a rare, autosomal recessive disorder of lipid metabolism. Mutations in the ABC genes result in ineffective transport of plant sterols into the intestinal lumen and their subsequent accumulation in the blood. The girl's cholesterol and lipid profile returned to normal following dietary restriction of plant sterol intake and treatment with ezetimibe 10 mg daily and atorvastatin 10 mg daily. Conclusions: This is the first reported case of a discrete lipid deposit at the cornea in a patient with sitosterolemia. Untreated, patients with sitosterolemia can develop coronary artery disease early in life. Ophthalmologists should be aware of the potential for underlying disorders of lipid metabolism in young patients with corneal arcus and/or lipid keratopathy.