Source: Lancet  |  Posted 10 years ago

Trabeculectomy for glaucoma increases cataract risk by 78 percent after adjusting for age and diabetes.

Researchers with the Advanced Glaucoma Intervention Study (AGIS), a multicentre trial run across the United States, enrolled 591 patients with open-angle glaucoma that was inadequately controlled using drugs.

A total of 789 eyes were treated with one of two sequences. One group underwent argon laser trabeculoplasty (ALT) followed by trabeculectomy and a second trabeculectomy. A second group was treated with trabeculectomy then ALT followed by the second trabeculectomy.

Patients were followed for 7 to 11 years. However, the analysis reports the risk of cataract formation over five years.

Cataracts formed in approximately half the eyes. In patients who had not undergone the procedure before, trabeculectomy either before or after ALT increased cataract risk by 78 percent. Diabetes increased the risk of developing cataracts by 47 percent, while the risk increased by 7 percent for each year age.

The risk of cataract formation also depended on whether patients developed complications following trabeculectomy. The increased risk was 47 percent in patients without postoperative complications compared to 104 percent in patients with complications.

Marked inflammation and a flat anterior chamber increased the likelihood of developing cataracts -- the relative risks were 3.29 and 1.80 respectively. Moreover, post-trabeculectomy complications increased the risk of nuclear, cortical and posterior subcapsular cataracts.