Viscodilation of Schlemm's canal for the reduction of IOP via an ab-interno approach

Purpose: The aim of this study was to compare the 1-year efficacy and safety profile of ab-interno canaloplasty (ABiC) when performed as a stand-alone procedure or as an adjunct to cataract extraction in reducing IOP and glaucoma medication dependence.

Patients and methods: This retrospective, comparative, consecutive case series included patients with uncontrolled primary open-angle glaucoma (POAG) who underwent ABiC as a stand-alone procedure or in conjunction with cataract extraction. Data were collected over a 12-month period. Primary outcome measures were mean lower IOP and mean number of glaucoma medications. Secondary endpoints included surgical and postsurgical complications and secondary interventions.

Results: The study included 75 eyes of 68 patients (mean age: 73.7±9.9 years) with a mean baseline IOP of 20.4±4.7 mmHg on 2.8±0.9 medications, which reduced to 13.3±1.9 mmHg (n=73) on 1.1±1.1 medications at 12 months postoperative (both P<0.0001). At 12 months, 40% of eyes were medication free. In the ABiC/phacoemulsification subgroup (n=34 eyes), the mean IOP and medication use decreased from 19.4±3.7 mmHg on 2.6±1.0 medications preoperatively to 13.0±1.8 mmHg on 0.8±0.2 medications at 12 months (both P<0.001). In the stand-alone ABiC subgroup (n=41), the mean IOP and medication use decreased from 21.2±5.3 mmHg on 3.0±0.7 medications preoperatively to 13.7±1.9 mmHg on 1.3±1.1 medications at 12 months (P=0.001 and <0.001, respectively). No serious adverse events were recorded.

Conclusion: These data demonstrate that ABiC was effective at reducing IOP and medication use in eyes with uncontrolled POAG with or without cataract surgery.