Long-term outcomes of phacoemulsification with iStent inject® implantation in narrow angle glaucoma

Abstract

To assess the outcomes of phacoemulsification with iStent inject implantation (phaco-iStent) in patients with narrow angle glaucoma (NAG) at a single tertiary eye centre. Retrospective clinical cohort study. Patients undergoing phaco-iStent for NAG between March 2018 and October 2020 under the glaucoma team at a tertiary referral hospital were included. Data was analysed from a surgical outcome database. Primary outcomes included postoperative change in the mean intraocular pressure (IOP) and medications. Success was defined at two IOP cut-off points:≤21mmHg and≤15mmHg with (qualified) or without (complete) drops. Failure was repeat glaucoma surgery or loss of light perception (LP). Fifty-seven eyes with a mean follow-up of 32months (range 12months to 36months) were included. Mean IOP changed from 19.7±4.2mmHg (range 12-28) to 14.0, 14.9 and 14.6 at 12, 24 and 36months. Drops reduced from 2.2±0.7 to 0.92±1.24 at the last follow-up. Complete success for an IOP≤21mmHg was 49%, 39%, 37% and qualified success was 96%, 92% and 95% at 12, 24 and 36months. An IOP≤15mmHg (qualified) was achieved in 74%, 58%, 54% at 6, 12, 24 and 36months. Three patients (5%) required further glaucoma surgery, one patient underwent selective laser trabeculoplasty and one patient requiring peri-ocular steroid treatment due to persistent cystoid macular oedema. There were no other long-term complications. Phacoemulsification with iStent inject is a safe and effective surgical option in the management of narrow angle glaucoma.