Trabecular bypass stent with phaco reduces IOP, medication use

Ophthalmology. 2011;118(3):459-467.

A minimally invasive trabecular micro-bypass stent in combination with cataract surgery was shown to be more effective in reducing IOP and lowering medication use than cataract surgery alone, a study found.

"The iStent is believed to re-establish natural trabecular outflow, and it leaves the conjunctiva untouched, and avoids the lifelong risk of complications associated with filtering blebs," the study authors wrote.

The prospective, randomized, open-label, controlled, multicenter study included 240 eyes with mild to moderate open-angle glaucoma and an IOP of no more than 24 mm Hg. All eyes were prescribed one to three medications preoperatively.

Patients were randomized into two groups: those undergoing phacoemulsification with iStent (Glaukos) implantation and those undergoing phaco alone, classified as the control group.

At 1 year postop, 72% of eyes implanted with the iStent and 50% of control eyes achieved an unmedicated IOP of less than or equal to 21 mm Hg. Sixty-six percent of those treated with the stent achieved greater than 20% IOP reduction, compared with 48% of control eyes.

According to the study authors, this was the first large-scale randomized, controlled, multicenter clinical trial comparing cataract surgery with a glaucoma drainage device and cataract surgery alone.

Study limitations included the open-label design, the inclusion criteria, which prevented assessment of patients who did not require cataract surgery or who suffered from more advanced glaucoma, and a lack of fellow eye evaluation.