The diagnosis of glaucoma is uneven across the US, according to a new analysis of Medicare records.

Researchers found that people in New England or the Mid-Atlantic states had about 30 percent higher chance of being diagnosed with glaucoma than people in the Southeast. The findings are published in the journal Ophthalmology.

The difference in the physician’s style of examination is one reason for the Lower diagnosis rates in less-urbanized settings, the other being fewer eye-care visits by patients, Quigley, a professor of ophthalmology at Johns Hopkins University School of Medicine who worked on the study told Reuters Health.

"We're seeing that potentially both physicians and patients in (predominantly rural) areas are not getting the healthcare that would be obtained in a large urban setting," such as the New York-Baltimore-Philadelphia area, said Dr. Harry Quigley.

Glaucoma is a group of conditions that cause damage to the optic nerve, which bridges the eye to the brain. If left untreated, glaucoma can in fact cause blindness.

"For most people, if you treat early, you should have vision for a lifetime," said Dr. Mark Fromer, an ophthalmologist at Lenox Hill Hospital and medical director of the Fromer Eye Centers, both in New York City, and the eye surgeon director for the New York Rangers hockey team.

"It's easy to forget about any asymptomatic disease that you don't notice until it has already made you blind or already caused you a stroke," Quigley told Reuters.

Overall, the glaucoma rates rose from 10.4 percent in 2002 to 11.9 percent in 2008. Women were more prone to have the condition than men and the rates of most forms of the condition rose until age 80 then fell thereafter.

Researchers examined a random sample of Medicare claims submitted by ophthalmologists, optometrists and outpatient surgery centers. They analyzed seven years of data, from 2002 through 2008, across nine large geographic regions and 179 sub regions. From that data, the researchers formed the conclusion that acute glaucoma was seriously under diagnosed.

The incidence of glaucoma is high in New York City which shows that physicians are over diagnosing it.

"Healthcare providers need to be performing gonioscopy on a regular basis," said Sandra Cassard, the study's lead author. Gonioscopy, an eye exam, is necessary to diagnose acute glaucoma.

"This may indicate lack of continuity in care among the very old," Cassard told Reuters Health." Seniors need to be encouraged to visit eye-care professionals," especially those over age 80 who may not be making the recommended yearly office visit, she said.

Both over diagnosis and under diagnosis have got its own complications. Under diagnosis of glaucoma can lead to blindness where as improper workup and lack of infrastructure in the clinic coupled with fear of blindness due to glaucoma end up in over-diagnosis or treatment in many situations.

According to Dr. Shakeel Shareef, an associate professor of ophthalmology at the University of Rochester Medical Center, about 30 percent of his glaucoma referrals turn out not to have the condition.

"But at least the referring doctor did not subject someone to treatment for life on medications" that were unnecessary, Dr. Shakeel told Reuters Health.

However treatment is also important. "If you develop severe pain in your eye, get seen right away at the ER," said Dr. Gregory Harmon, a New York City ophthalmologist who's chairman of the Glaucoma Foundation. "Without treatment, you can have a permanent loss of vision."