DEC 02, 2013
This retrospective review of ab interno trabeculotomy for open-angle glaucoma shows a lower success rate than previously reported.
They reviewed the charts of patients undergoing ab interno trabeculotomy at the Mayo Clinic between 2006 and 2010 with three months' follow-up or longer. Of 246 patients, 88 had trabeculotomy only, while 158 underwent combined cataract extraction and trabeculotomy.
Applying more stringent criteria of IOP ≤18 mm Hg and a 20 percent pressure reduction, the success rate dropped to 22 percent at two years. Using less stringent criteria (postop IOP of ≤ 21 mmHg or ≥ 20 percent reduction), the success rate was 62 percent.
They note that these success rates are lower than those reported in the four initial ab interno trabeculotomy case series that have been published. A possible explanation for this might be that this was a single-center series with a high patient-retention rate, therefore providing the opportunity to record accurately and for longer follow-up periods the trends in IOP and the number of medications.
Multivariate risk factors for failure included the diagnosis of primary open-angle glaucoma (POAG) (whereas pseudoexfoliation was protective) and prior argon laser trabeculoplasty.
They write that prior studies have reported an excellent safety profile for ab interno trabeculotomy, and the complication rates in this study were similar to those in the published data. However, it is important to recognize that long-term complications, such as symptomatic delayed-onset hyphema, can occur with this procedure.
They conclude that this technique is appropriate for patients requiring a target IOP of 21 mm Hg or above.