To investigate the intraocular pressure (IOP)-lowering efficacy of bleb-free ab interno trabeculectomy by means of the Kahook Dual Blade (KDB).

This retrospective cohort study enrolled patients with uncontrolled open angle glaucoma (OAG) who underwent standalone KDB ab interno trabeculectomy. Changes in IOP, the number of preoperative and postoperative IOP-lowering medications, as well as intraoperative and postoperative surgical profiles were analyzed. All participants completed a 6-month follow-up. Arithmetic mean, standard deviation (SD) and frequency were calculated, and the Wilcoxon test was used for statistical analysis.

A total of 23 participants (15 males) were included, with a mean age of 69.3±9.6y. The baseline mean IOP was 21.7±5.6 mm Hg, with patients taking an average of 3.1±1.0 topical IOP-lowering medications, and 10 patients received adjuvant systemic acetazolamide preoperatively. At the 3-month follow-up, the mean IOP decreased to 12.7±4.3 mm Hg, with a mean medication score of 2.9±1.8. At the 6-month follow-up, mean IOP was reduced by 40.6% from the baseline level (P<0.01), with a mean medication requirement of 2.8±1.0; one-fifth of all participants discontinued glaucoma medications completely. Only mild postoperative hyphemata occurred in 10 cases, and no other surgery-related adverse complications were observed.

Standalone ab interno trabeculectomy with KDB yields significant IOP reduction and favorable surgical safety in patients with uncontrolled OAG, meanwhile decreasing the requirement of topical IOP-lowering medications. Long-term therapeutic efficacy remains to be further validated. Distinct from previous published studies, this study focuses on a Caucasian population and confirms surgical efficacy of KDB as a single glaucoma procedure.