MONDAY, March 10 (HealthDay News) -- Black Americans are more likely than other racial groups to lose their vision due to idiopathic intracranial hypertension, or increased pressure in the brain, according to a new study.

Researchers at Emory University School of Medicine in Atlanta reviewed the medical records of all 450 intracranial hypertension patients treated at Emory over a 17-year period. Of those patients, there were 246 whites, 197 blacks, five Hispanics, and two Asians.

The black patients were 3.5 times more likely to have severe vision loss in at least one eye, and almost five times more likely to become legally blind, than the other patients.

"The racial difference does not appear to be based on differences in diagnosis, treatment or access to care," study author Dr. Beau Bruce said in a prepared statement. "The disease affects black people more aggressively. Doctors may need to monitor their black patients more closely and take steps to prevent vision loss earlier than with other patients."

The black patients in this study did have other risk factors -- higher body mass index, high frequency of low blood iron, and higher pressures around the brain -- that could partially account for their increased risk of vision loss, Bruce said.

The study is published in the March 11 issue of the journal Neurology.

It's not known what actually causes intracranial hypertension, which is most common in young, obese women. Symptoms include headache, ringing in the ears, and vision problems such as blurriness and double vision.

More information

The MedlinePlus Medical Encyclopedia has more about idiopathic intracranial hypertension.