A national clinical trial has found that an inexpensive drug, acetazolamide, when combined with a weight loss plan, improves vision for patients with idiopathic intracranial hypertension (IIH) who have mild visual loss.

The trial was funded by the National Eye Institute, part of the National Institutes of Health (NIH), and was conducted at Emory Eye Center and 27 other sites across the country.

The study sought to assist with the management of IIH, also known as pseudomotor cerebri, which causes increased pressure around the brain. IIH predominantly affects women of reproductive age who are also overweight. It is estimated that some 100,000 Americans have IIH, with the number rising along with the proportion of the population that is overweight.

Symptoms include headaches and visual problems, including blind spots, poor side (peripheral) vision, double vision, and temporary episodes of blindness. Approximately five to 10 percent of women with IIH experience disabling vision loss.

"The study provides the necessary evidence that acetazolamide, which neuro-ophthalmologists have used off-label for years, is indeed a beneficial part of our treatment plans for IIH," says neuro-ophthalmologist Beau Bruce, MD, MS, the principal investigator for the trial at Emory Eye Center.

"Our results show that acetazolamide can help preserve and actually restore vision for women with IIH, when combined with a moderate but comprehensive dietary and lifestyle modification plan," says Michael Wall, MD, professor of neurology and ophthalmology at the University of Iowa and the study’s trial director.

IIH’s high pressure around the brain can lead to swelling and damage of the optic nerves that connect the eye to the brain. A weight reduction of five to 10 percent can help improve symptoms. The drug acetazolamide is known to reduce fluid production in the brain, and has often been used as an add-on therapy for IIH. In severe cases, surgical procedures may be used to relieve pressure on the optic nerve.

In the study at six months, participants’ vision on acetazolamide improved by twice as much as those on placebo, and the drug seemed to reduce swelling of the optic nerve as well. The drug-weight loss combination also led to greater improvements in daily function and quality of life compared to weight loss alone.

The trial was funded by the NIH and was coordinated by the Neuro-Ophthalmology Research Disease Investigator Consortium (NORDIC).

The results were published April 22 in the Journal of the American Medical Association, and will be presented on May 2 during the Clinical Trials plenary session of the American Academy of Neurology meeting in Philadelphia. The trial will follow participants for five years to gauge whether they are able to maintain a healthy weight and control their symptoms over the long term.

The trial is funded by cooperative agreements from NEI (EY017281 and EY017387).

Reference:

Wall M et al. for the NORDIC IIH Study Group. Effect of Acetazolamide on Visual Function in Patients with Idiopathic Intracranial Hypertension and Mild Visual Loss: The Idiopathic Intracranial Hypertension Treatment Trial. Journal of the American Medical Association, April 2014. DOI: 10.1001/jama.2014.3312.