Nathan Kerr1, Michael Coote1, Gok Ratnarajan2, Andrew Scott3, Keith Barton3

Purpose: To evaluate the safety and efficacy of ab interno gel implant insertion for the surgical treat- ment of glaucoma refractory to topical medications. Methods: Data was analyzed from the International Glaucoma Surgery Registry, a worldwide registry with users in over 20 countries that collects high- quality prospective data on the real-world outcomes of glaucoma surgery. Patients with glaucoma refrac- tory to topical medications (n = 148) underwent ab interno gel implant insertion (XEN; Allergan, Dub- lin, Ireland). The main outcome measures were mean intraocular pressure (IOP) change, glaucoma medication use, ocular adverse event incidence, and requirement for further surgery.
Results: The mean standard deviation (SD) baseline IOP was 22.8 8.0 mmHg and the mean number of topical ocular hypotensive medications was 2.8 1.0 (SD). There were no serious intrao- perative events. Mean IOP reduced 29% from base- line at 12 months to 16.1 8.2 mmHg (P < 0.05) and mean medication usage was reduced to 1.0 1.2 medications (P < 0.05). The most common com- plication was a transient IOP < 6 mmHg (n = 11). Needling was required in 27 eyes (18%). Six eyes (4%) required further glaucoma surgery, most com- monly a glaucoma drainage device. Conclusions: Ab interno gel implant insertion has a favourable safety profile and provides an effective approach to controlling IOP in patients with refrac- tory glaucoma. The IGSR has the potential to make a major contribution to our understanding of opti- mal surgical treatments through its world-wide reach and consistency of data collection to enable future treatment comparisons.