Two Trabecular Micro-bypass Stents & Postoperative Travoprost to Treat Glaucoma Subjects on Two Hypotensive Agents

Overview

The study objective was to evaluate the intraocular pressure (IOP) lowering effect of two iStent devices in eyes of subjects with primary open-angle glaucoma, washed out of two anti-glaucoma medications (one a Prostaglandin) prior to stent implantation.

Full Title of Study: “A Prospective Evaluation of Open-angle Glaucoma Subjects on Two Topical Hypotensive Medications (One a Prostaglandin) Treated With Two Trabecular Micro-bypass Stents (iStent Inject) and a Postoperative Topical Prostaglandin”

Study Type

  • Study Type: Interventional
  • Study Design
    • Allocation: N/A
    • Intervention Model: Single Group Assignment
    • Primary Purpose: Treatment
    • Masking: None (Open Label)
  • Study Primary Completion Date: April 2015

Detailed Description

The study design is as follows:

- Prospective, single-arm study.

- Subjects with open-angle glaucoma and medicated IOP > 18 mmHg and ≤ 30 mmHg.

- Subjects on two topical ocular hypotensive medications (one a prostaglandin).

- Implantation of two iStent inject devices (if IOP is < 6 mmHg, at any point during the postoperative follow-up, medication will not be prescribed or will be discontinued).

- IOP will be measured by two (2) observers to minimize bias; observer 1 will look through the slit lamp and turn the dial with readings being masked, and observer 2 will document the IOP.

- Follow-up through 60 months postoperative (or up to 61 months if subject needs to undergo terminal washout).

- Descriptive statistics will be tabulated.

- Medical therapy considered necessary for the subject's welfare can be implemented at any time during the study at the investigator's discretion.

Interventions

  • Procedure: Implantation of two iStent inject micro-bypass stents
    • - Implantation of two trabecular micro-bypass stents (iStent inject) in a standalone procedure (i.e., without cataract surgery).
  • Drug: Topical travoprost
    • - Topical travoprost (0.004%, 1 drop each evening in study eye) started on postoperative Day 1.
  • Device: Two iStent inject micro-bypass stents
    • - Two trabecular micro-bypass stents (iStent inject) implanted in a standalone procedure.
  • Drug: Tobramycin
    • Topical antibiotic (tobramycin): 1 drop four (4) times per day in the study eye for one week (in cases of allergy or contraindication, Polytrim (polymyxin B sulfate + trimethoprim sulfate ophthalmic solution, USP, or equivalent) may be used as an alternative medication) .
  • Drug: Dexamethasone
    • Topical anti-inflammatory medication (dexamethasone ophthalmic suspension 0.1%): Week 1: 1 drop four (4) times per day in the study eye Week 2: 1 drop three (3) times per day in the study eye Week 3: 1 drop two (2) times per day in the study eye Week 4: 1 drop one (1) time per day in the study eye

Arms, Groups and Cohorts

  • Other: 2 micro-bypass stents & travoprost
    • Two iStent inject micro-bypass stents and topical travoprost Intervention: Implantation of two iStent inject micro-bypass stents Tobramycin Dexamethasone

Clinical Trial Outcome Measures

Primary Measures

  • Mean intraocular pressure reduction of 20% or more versus baseline with reduction of 1 medication
    • Time Frame: 12 months postoperative

Secondary Measures

  • Mean intraocular pressure of 18 mmHg or less versus baseline with reduction of 1 medication
    • Time Frame: 12 months postoperative

Participating in This Clinical Trial

Inclusion Criteria

Screening Exam Inclusion Criteria:

  • Phakic patients or pseudophakic patients with posterior chamber intraocular lenses (PC-IOLs)
  • Primary open-angle glaucoma (including pigmentary or pseudoexfoliative)
  • C/D ratio ≤ 0.9
  • Visual field defects, or nerve abnormality characteristic of glaucoma
  • Two topical hypotensive medications at time of screening exam
  • IOP > 18 mmHg and ≤ 30 mmHg (medicated) at screening exam
  • Study eye BCVA 20/100 or better
  • Normal angle anatomy as determined by gonioscopy
  • Absence of peripheral anterior synechia (PAS), rubeosis or other angle abnormalities that could impair proper placement of stent

Baseline Exam Inclusion Criteria:

  • Subject has completed appropriate medication washout
  • Mean IOP > 22 mmHg and ≤ 38 mmHg after anti-glaucoma medication washout period
  • A 3mmHg IOP increase over screening mean IOP

Exclusion Criteria

Screening Exam Exclusion Criteria:

  • Aphakic patients or pseudophakic patients with anterior chamber IOLs (AC-IOLs)
  • Prior stent implantations (study eye)
  • Traumatic, uveitic, neovascular, or angle-closure glaucoma; or glaucoma associated with vascular disorders
  • Functionally significant visual field loss, including severe nerve fiber bundle defects
  • Prior incisional glaucoma surgery
  • Prior SLT within 90 days prior to screening
  • Prior ALT
  • Iridectomy or laser iridotomy
  • Ineligibility for ocular hypotensive medication washout period as determined by the investigator.
  • Any active corneal inflammation or edema (e.g., keratitis, keratoconjunctivitis, keratouveitis)
  • Clinically significant corneal dystrophy (e.g., bullous keratopathy, Fuch's dystrophy); any guttata
  • Corneal surgery (prior or anticipated) of any type (including LASIK, LASEK, PRK, etc.) that may interfere with IOP measurement reliability
  • Corneal opacities that would inhibit visualization of the nasal angle
  • Congenital or traumatic cataract
  • Retinal or optic nerve disorders that are not associated with the existing glaucoma condition
  • Elevated episcleral venous pressure such as associated with: active thyroid orbitopathy; cavernous sinus fistula; Sturge-Weber syndrome; orbital tumors; orbital congestive disease
  • Clinically significant sequelae from trauma
  • Chronic ocular inflammatory disease or presence of active ocular inflammation

Baseline Exam Exclusion Criteria:

  • Subject did not complete medication washout
  • Mean IOP < 22 mmHg or > 38 mmHg after anti-glaucoma medication washout
  • Subject does not have a 3mmHg IOP increase over screening mean diurnal

Gender Eligibility: All

Minimum Age: 18 Years

Maximum Age: N/A

Are Healthy Volunteers Accepted: No

Investigator Details

  • Lead Sponsor
    • Glaukos Corporation
  • Provider of Information About this Clinical Study
    • Sponsor
  • Overall Official(s)
    • Lilit Voskanyan, MD, PhD, Principal Investigator, S.V. Malayan Eye Center

References

Berdahl J, Voskanyan L, Myers JS, Hornbeak DM, Giamporcaro JE, Katz LJ, Samuelson TW. Implantation of two second-generation trabecular micro-bypass stents and topical travoprost in open-angle glaucoma not controlled on two preoperative medications: 18-month follow-up. Clin Exp Ophthalmol. 2017 Nov;45(8):797-802. doi: 10.1111/ceo.12958. Epub 2017 Jun 2.

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