Cerulean cataracts, also known as blue dot cataracts, are developmental cataracts characterized by blue and white opacifications scattered in the nucleus and cortex of the lens. Patients with cerulean cataracts are usually asymptomatic until 18-24 months of age and often do not need them removed before adulthood. Treatment is with surgical cataract removal and artificial lens placement.
Cerulean cataracts are inherited as an autosomal dominant trait. At least four loci for the cerulean cataract phenotype have been mapped – congenital cataract-1 (CCA1;17q24), CCA2 (22q11.2-q12.2), CCA3 (2q33-q35), and CC4 (16q22-q23). Multiple causative mutations have been identified, including mutations in the beta-B2-crystallin gene (CRYBB2), gamma-D-crystallin gene (CRYGD), V-MAF avian musculoaponeurotic fibrosarcoma oncogene homolog gene (MAF), and the major intrinsic protein of lens fiber gene (MIP).
Patients with cerulean cataracts usually have preserved visual acuity and rarely need cataract extraction before adult age. Because many newborns are asymptomatic until 18-24 months of age, cerulean cataracts are considered to be a form of developmental cataract rather than a true congenital cataract. Progression of cerulean cataracts is slow and may not become significant until the third or fourth decade of life, when patients begin to notice a gradual decrease in vision in both eyes. However, children who develop signs of visually significant cataracts such as nystagmus and amblyopia may require cataract surgery earlier.
Cerulean cataracts usually present as bilateral, blue-white opacities that begin to form in the fetal nucleus after birth. Patients can be diagnosed via slit lamp examination at ages as early as 18 months, which would reveal tiny blue and/or white opacities in the superficial layer of the lens nucleus.
The differential diagnosis for cerulean cataracts includes other congenital, developmental and traumatic cataracts. These can be distinguished by physical examination, family history, and laboratory tests.
Serial evaluations and surgery
There are no known treatments to prevent the formation and progression of cerulean cataracts. Serial eye evaluations and eventual cataract surgery are the standard of care.
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