MONDAY, Aug. 13 (HealthDay News) -- Even if a glaucoma patient's eye pressure remains low overall, fluctuations in eye pressure may still be associated with a shrinking peripheral field of vision, South Korean researchers say.

Researchers at the Yonsei University College of Medicine in Seoul studied 408 eyes of patients (average age 66.5 years) who'd had triple glaucoma treatment, including surgery. All the patients had low intraocular pressure (IOP) after surgery.

The patients, whose visual field and IOP were checked for a number of years after surgery, were divided into two groups -- those with greater IOP fluctuation and those with less fluctuation.

When the final follow-up examination was conducted 13 years after surgery, patients with greater IOP fluctuation had significantly worse visual field loss.

"Our results suggest that glaucomatous visual field damage cannot be stabilized by only lowering the postoperative IOP but also requires reducing the long-term fluctuation of the post-operative IOP," the researchers concluded.

The study is published in the August issue of the journal Archives of Ophthalmology.

More information

The American Academy of Family Physicians has more about glaucoma.