Surgery lowers IOP more than medication, review of glaucoma studies finds

In general, surgery lowers IOP more than medication in patients with mild open-angle glaucoma, a literature review found.

J. Burr and colleagues in London conducted a review of published literature to compare the relative effects of surgical intervention and medical treatment in patients with open-angle glaucoma (OAG). Four trials involving 888 patients with previously untreated OAG were included. In three of the trials, the primary medical treatment was pilocarpine, and in one trial a beta-blocker. In three trials, the primary surgical treatment was trabeculectomy, and in one trial the Scheie procedure.

Reduction of vision, a higher risk of developing cataract and more patient discomfort was more likely after trabeculectomy than with medical treatment.

“There is some evidence, from three trials, for people with moderately advanced glaucoma that medication is associated with more progressive visual field loss and 6 to 8 mm Hg less IOP lowering than surgery,” the study authors said in the review published in The Cochrane Library.

There was a trend towards an increased risk of failed IOP control over time when patients were treated with pilocarpine compared to those treated surgically. Over the long-term, risk of failure was significantly greater with medication than trabeculectomy.

The authors noted that evidence was lacking in a number of areas. The published literature gave no evidence regarding the effectiveness of contemporary medications compared to surgery in severe OAG and in black patients.