Ophthalmic Manifestations in Cerebrotendinous Xanthomatosis (CTX)

Cerebrotendinous xanthomatosis (CTX) is a genetic disorder expressed by the mutations in the sterol 27-hydroxylase gene, resulting in accumulation of cholestanol in the eye, tendons, brain, and other tissues. The eye lens is the most common site for lipid deposits in CTX, resulting in the appearance of cataract early in life. The mechanism at which the plasma elevated cholestanol levels cause lens opacifications and cataract will be discussed later. Early diagnosis and treatment reduce the development of cataract and even prevent its appearance. Retinal and optic nerve involvement is also described in CTX. The process in which the retina and optic nerves are damaged due to the lipid metabolic error is not fully understood. Theories to explain these findings are based on some similar metabolic disorders and eye diseases, while other derive partially from resembling pathologic conditions in posterior segment of the eye and the optic nerve. Further studies and investigations are needed to reach a good insight into these ophthalmic manifestations in CTX and to properly approach their treatment and prevention.