Corneal arcus in Japanese family with type IIa hyperlipoproteinemia.

We examined ophthalmologically five affected members of a family with type IIa hyperlipoproteinemia. All of them had increased levels of cholesterol and low-density lipoprotein. Corneal arcus was found in three of the five members; a 50-year-old man, a 43-year-old woman and a 13-year-old boy. We believe that the corneal arcus begins at around 10 years of age in untreated type IIa hyperlipoproteinemia. Detection of corneal arcus at an early age is important to reduce cardiovascular complication in this disorder.