Long-term effectiveness of the trabecular micro-bypass (iStent): 3-year real world data in glaucoma and ocular hypertension

Purpose This study evaluates the effectiveness and safety profile of the iStent inject® combined with cataract surgery, with 3 years of follow-up in a large patient cohort (n = 464) of various glaucoma phenotypes and disease severity. Methods This retrospective, single-arm, multi-surgeon study included eyes undergoing iStent inject® with cataract surgery. Inclusion criteria was symptomatic cataract in addition to uncontrolled intraocular pressure (IOP) on ≥ 2 IOP lowering agents or contraindication and/or intolerance to IOP lowering medication. IOP, medications, safety profile and cumulative success rates were assessed. Results The mean IOP was 14.8 ± 4.5 mmHg at 3 years, compared to 18.3 ± 5.8 mmHg preoperatively, an IOP reduction of 19.1% ( P < 0.001). The mean number of IOP lowering medications was 1.84 ± 1.40 at 3 years, compared to 2.49 ± 1.12 medications preoperatively. At 3 years 24% of eyes were medication free compared to 3% of eyes preoperatively ( P < 0.001). At 3 years the cumulative probability of eyes achieving complete success; an IOP reduction of ≥ 20% and IOP 6–21 mmHg without medication was 37% and the cumulative probability of achieving this with medication (qualified success) was 67%. No cases of endophthalmitis, hypotony or other sight threatening complications were recorded. 5% of eyes required further glaucoma procedures. Conclusions This large, real-world cohort demonstrates a significant and sustained IOP reduction with an improvement in medication burden 3 years after iStent inject® and phacoemulsification. An excellent safety profile was displayed with a low rate of further glaucoma surgery required.