Fabry disease is a rare genetic disorder, but one of its hallmark signs is easily visible in the cornea during a routine exam. Doctors of optometry who are able to diagnose this often overlooked disease can help patients receive critical treatment.
Fabry disease, which is estimated to occur in 1 in 40,000 live births, is a lysosomal storage disorder in which the enzyme that normally breaks down a particular fatty substance called globotriaosylceramide is defective. This causes the fat to build up over time in blood vessels, which can lead to kidney damage, heart disease and stroke. Fabry disease symptoms usually show up in childhood as pain and discomfort in the hands and feet. Symptoms include the inability to sweat, spontaneous diarrhea and a dark red rash in the area from their navel to their knees. Patients may go undiagnosed for 15 to 20 years or more.
It is not difficult to discover—if doctors know what to look for. Nearly all patients with Fabry disease have corneal verticillata, a golden-brown “whorling” pattern typically seen in the inferior corneal epithelium during a regular exam.
“The whorling is very thin, half a micron thick, so it has no effect on acuity,” says Albert Morier, M.A., O.D., an associate clinical professor of ophthalmology at Albany Medical College in New York.
Certain medications, such as the anti-malarial chloroquine and heart drug amiodarone, also can cause whorling, so doctors should rule out prescription drug use as a cause. However, patients may be taking amiodarone for heart issues related to undiagnosed Fabry disease. Doctors should refer the patient to a genetic specialist, who will conduct DNA testing to confirm Fabry disease. There is no cure, but patients can benefit from enzyme replacement therapy.
Read the rest of the article on aoa.org. Photo credit: The American Optometric Association.