The cornea is the windshield of the eye. It is subject to numerous diseases but may also be malformed as a result of gene mutations. When it is larger than normal on a congenital basis, it is called megalocornea. The rare condition described here is characterized by enlarged corneas and is often associated with a lens that is loose and excessively mobile resulting in glaucoma in some individuals. The lenses are normally clear and act like a magnifying glass to focus images on the retina.
Infants are born with enlarged corneas in most cases. There may be no indication of other problems until later when the excessively small and spherical lens either dislocates from its normal position causing blurred vision or glaucoma. This can occur in childhood or adult life. The glaucoma is severe and often is manifest as a red, painful eye, with tearing, and blurred vision.
A few patients appear tall and may have a highly arched palate.
This is an autosomal recessive disorder in which a double dose of a single gene mutation is required for the disease to occur. The parents, who are often related to each other, are clinically normal but each carries one copy of the mutation. Together, they have a 25 per cent chance for each of their children to inherit the double mutation and have this disorder.
The diagnosis can only be made by an ophthalmologist after an eye examination. Individuals require lifelong monitoring because of the high risk of glaucoma and the requirement for glasses if and when the lenses dislocate. The sudden onset of a red, painful eye requires an urgent evaluation, and, sometimes, emergency surgery for the glaucoma. Prompt treatment and intervention can preserve vision but if diagnosis and treatment are delayed, blindness may result.