Efficacy of two trabecular micro-bypass stents combined with topical travoprost in open-angle glaucoma not controlled on two preoperative medications: 3-year follow-up

Abstract

Purpose: To evaluate the long-term intraocular pressure (IOP)-lowering effect and safety parameters following treatment with two trabecular micro-bypass stents and topical prostaglandin in phakic eyes with open-angle glaucoma (OAG) not controlled on two preoperative medications.

Methods: This prospective, single-arm, unmasked study enrolled 39 qualified phakic eyes with OAG not controlled on 2 medications, preoperative medicated IOP of 18-30 mmHg, and IOP following medication washout of 22-38 mmHg. Two trabecular micro-bypass stents were implanted as a standalone procedure, and travoprost was started on postoperative day 1. Evaluations included IOP, best-corrected visual acuity, medication use, fundus and slit-lamp examinations, visual field, cup:disc ratio, central corneal thickness, and ocular complications. Data through 18 months were summarized previously. Thirty-seven of the original 39 subjects have been followed for 3 years postoperatively; follow-up is continuing for 5 years.

Results: At 3 years postoperative, 97% of eyes had achieved an IOP reduction of ≥20% from baseline with a reduction of 1 medication. Eighty-six percent of eyes had IOP of ≤18 mmHg with a reduction of 1 medication. Mean medicated IOP decreased to 14.0±2.6 mmHg on 1 medication versus 22.4±2.3 mmHg on 2 medications preoperatively. The mean unmedicated IOP decreased to 17.7±1.7 mmHg at 37 months from 25.3±1.9 mmHg preoperatively. Long-term postoperative adverse events included cataract surgery in 3 eyes due to cataract progression, and trabeculectomy in 1 eye due to uncontrolled IOP of 23 mmHg. No intraoperative or device-related adverse events occurred.

Conclusion: Significant and sustained reduction in IOP and medications with a favorable safety profile was shown through 3 years after implantation of 2 trabecular micro-bypass stents combined with postoperative travoprost in phakic OAG eyes uncontrolled on 2 preoperative medications. These findings demonstrate the long-term performance and safety of trabecular bypass stents in combination with topical prostaglandin for OAG patients.

Keywords: IOP; MIGS; glaucoma; medication; trabecular micro-bypass.

Conflict of interest statement

Disclosure Drs Donnenfeld, Solomon, Chang, Samuelson, Ahmed, and Katz received nonfinancial support for their work as investigators in this study. Drs Voskanyan, Chang, and Samuelson received financial support from Glaukos for their work as investigators in this study. Dr Katz received financial support from Glaukos for his work as a medical monitor for this study. Drs Donnenfeld, Solomon, Samuelson, Ahmed, and Katz received nonstudy financial support from Glaukos. All authors except Dr Chang are consultants of Glaukos. Jane Ellen Giamporcaro and Dana Hornbeak are employees of Glaukos. The authors report no other conflicts of interest in this work.

Figures

Figure 1

Subject flowchart through 37-month follow-up period. Abbreviation: LTFU, lost to follow-up.

Figure 2

IOP reduction ≥20% versus baseline IOP with reduction of 1 medication.a Note:aExcludes IOP after secondary surgery. Abbreviation: IOP, intraocular pressure.

Figure 3

IOP ≤18 mmHg with reduction of 1 medication.a Note:aExcludes IOP after secondary surgery. Abbreviation: IOP, intraocular pressure.

Figure 4

Mean IOP over time.a Notes:aExcludes IOP after secondary surgery. bIOP measured after medication washout. cTrabeculectomy for 1 subject at 24 months. dTwo subjects not included in analysis had second medication added at 36 months. Abbreviations: IOP, intraocular pressure; SD, standard deviation; M, month.