Controlling the pressure within the eyeball could help reduce the incidence of glaucoma, a disease affecting vision amongst the elderly, a new study has suggested.

Canadian researchers conducted a study involving 216 patients with open-angle glaucoma to determine how a reduction in intraocular pressure can control more rapid visual field change.

All the participants were given standard treatment for controlling intraocular pressure with a targeted reduction of 30 percent or more and were followed up with re-examination every four months. The patients were treated to achieve an additional 20 percent or more reduction in intraocular pressure for those who reported constant progression of glaucoma.

On analyzing the results, it was found that being older and having abnormal levels of anticardiolipin antibody were associated with a more rapid rate of visual change. Anticardiolipin is an antibody directed against a certain protein in the body.

But the investigators also found that reducing intraocular pressure appeared to slow down the rate at which some of these patients experienced declines in visual field.

While the degree of this rate of decline may not have been clinically significant for some patients, the difference could be significant over 20 years, according to Balwantray C. Chauhan, of Dalhousie University, Halifax, Nova Scotia, Canada, and colleagues in the Canadian Glaucoma Study Group.

"In younger patients with more advanced damage, this difference is likely to be important," Chauhan and colleagues wrote in the study released online prior to its publication in the October issue of the Archives of Ophthalmology.

Glaucoma is a complicated disease in which damage to the optic nerve results in vision loss. There are several forms of glaucoma; the two most common forms are primary open-angle glaucoma (POAG) and angle- closure glaucoma (ACG). There are typically no early warning signs or symptoms of open-angle glaucoma. It develops slowly and sometimes without noticeable sight loss for many years.