Long-term titrated IOP control with one, two, or three trabecular micro-bypass stents in open-angle glaucoma subjects on topical hypotensive medication: 42-month outcomes

Abstract

Purpose

Evaluate long-term outcomes after one, two, or three trabecular micro-bypass stents implanted in a standalone procedure in eyes with open-angle glaucoma taking ocular hypotensive medication.

Patients and methods

Prospective randomized ongoing study of 119 subjects (109 with 42-month follow-up) with open-angle glaucoma, preoperative intraocular pressure (IOP) 18–30 mmHg on one to three glaucoma medications, and unmedicated (post-washout) IOP 22–38 mmHg. Subjects were randomized to receive one (n=38), two (n=41), or three (n=40) iStent trabecular micro-bypass stents in a standalone procedure. Postoperatively, IOP was measured with medication and annually following washout. Data included IOP, medications, gonioscopy, pachymetry, visual field, visual acuity, adverse events, and slit-lamp and fundus examinations.

Results

Preoperative mean medicated IOP was 19.8±1.3 mmHg on 1.71 medications in one-stent eyes, 20.1±1.6 mmHg on 1.76 medications in two-stent eyes, and 20.4±1.8 mmHg on 1.53 medications in three-stent eyes. Post-washout IOP prior to stent implantation was 25.0±1.2, 25.0±1.7, and 25.1±1.9 mmHg in the three groups, respectively. Postoperatively, Month 42 medicated IOP was 15.0±2.8, 15.7±1.0 and 14.8±1.3 mmHg in the three groups, and post-washout IOP (Months 36–37) was 17.4±0.9, 15.8±1.1 and 14.2±1.5 mmHg, respectively. IOP reduction ≥20% without medication was achieved in 89%, 90%, and 92% of one-, two-, and three-stent eyes, respectively, at Month 12; and in 61%, 91%, and 91% of eyes, respectively, at Month 42. The need for additional medication remained consistent at Months 12 and 42 in multi-stent eyes (four two-stent eyes and three three-stent eyes at both time points), whereas it increased in single-stent eyes (four eyes at Month 12 versus 18 eyes at Month 42). Safety parameters were favorable in all groups.

Conclusion

The standalone implantation of either single or multiple iStent^® device(s) produced safe, clinically meaningful IOP and medication reductions through 42 months postoperatively, with incrementally greater and more sustained reductions in multi-stent eyes.

Keywords:

• microinvasive glaucoma surgery/MIGS
• iStent
• surgery
• standalone
• multiple

Acknowledgments

The sponsor, Glaukos Corporation, San Clemente, CA, USA, provided study devices, sponsorship for performing this study, data collection, data management, data analysis, and editorial assistance in the preparation of this manuscript.

Disclosure

LJK is a shareholder in Aerie Pharm., Glaukos, and Mati Ther, he received grant support from Allergan, Aerie Pharm., Mati Therapeutics, Diopsys, Heidelberg Eng., Alcon, and Zeiss; speaker honoraria from Alcon, Allergan, Bausch & Lomb, Aerie Pharm., and Glaukos; and a medical monitor consulting fee from Glaukos; he is a consultant to Allergan, Alcon, Glaukos (Chief Medical Officer), Aerie Pharm., Inotek, Mati Ther., Diopsys, and DSM Biomed. CE is a consultant to Alcon, Zeiss, OmniVision, and Visufarma, and received speaker honoraria from Alcon, Allergan, Bausch & Lomb, Novartis, Thea, Santen, Visufarma, Glaukos, and Zeiss. ACG received financial support from Glaukos for his work as an investigator in this study. AMF received financial support from Glaukos for his work as an investigator in this study. LV received financial support from Glaukos for her work as an investigator in this study. DMH and JEG are employees of Glaukos. The authors report no other conflicts of interest in this work.