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GDD Timing with Boston KPro for Glaucoma
(GDD-KPro Trial)

Recruiting in Palo Alto (17 mi)

Overseen byMona Harissi-Dagher, MD, FRCSC

Age: 18+

Sex: Any

Travel: May Be Covered

Time Reimbursement: Varies

Trial Phase: Academic

Recruiting

Sponsor: Centre hospitalier de l'Université de Montréal (CHUM)

Disqualifiers: Terminal glaucoma, terminal retinal diseases

No Placebo Group

Approved in 2 Jurisdictions

Trial Summary

What is the purpose of this trial?

Boston keratoprosthesis (KPro) is a piece of specialized plastic that replace sick cornea (transparent structure at the front of the eye) in patients who have failed or those who are expected to have poor results with traditional corneal transplantation. While the Kpro can offer dramatic improvement in vision, it is also associated with several complications. Glaucoma (optic nerve damage due to high pressure inside the eye) is one of the most common complications after KPro surgery and can potentially cause irreversible vision loss. The implantation of a glaucoma drainage device (GDD), a tiny tube that drains the liquid inside the eye by bypassing the natural drainage system, is an effective option to lower the eye pressure in patients with KPro. Given the frequency and potentially devastating effects of glaucoma among KPro patients, some surgeons recommend to put in a GDD as a preventative measure. However, there is no consensus on when is the best timing to perform such surgery in relation to the Boston Kpro surgery. Hypothesis: For patients undergoing the Boston KPro surgery, implanting a GDD simultaneously, at the time of surgery, is more efficacious than at 6 months later, in the prevention of the progression of glaucoma and in maintaining better visual functions. Methods: The investigators aim to recruit 40 patients over 4 years. Recruited patients will be randomly assigned to 2 groups: 1) simultaneous GDD implantation at the Boston KPro surgery, and 2) GDD implantation 6 months after the Boston KPro surgery. Once recruited, patients will be followed before the KPro surgery, postoperative day 1, week 1, month 1, 3, 6 and 12. Standard ophthalmological exam will be performed at each visit. Additional non-invasive glaucoma tests and evaluation (visual fields and optic nerve photo) will be performed on day 1, month 1, 3, 6 and 12. For patients assigned to group 2, a GDD will be implanted 6 months after the KPro surgery. They will have additional follow-ups on post-GDD surgery day 1, week 1 and month 1. Results of visual acuity, visual fields, optic nerve evaluation and complications will be compared between the two groups to determine the better timing of GDD implantation.

Will I have to stop taking my current medications?

The trial information does not specify whether you need to stop taking your current medications. It's best to discuss this with the trial coordinators or your doctor.

What data supports the effectiveness of the treatment Boston KPro and GDD for glaucoma?

Research shows that combining a Boston type I keratoprosthesis (KPro) with a glaucoma drainage device (GDD) can be effective in managing severe eye conditions, as it addresses both corneal issues and glaucoma simultaneously. Studies have reported positive outcomes in terms of vision improvement and glaucoma management when these procedures are performed together.¹ ² ³ ⁴ ⁵

Is the combination of Boston KPro and glaucoma drainage device safe for humans?

Research shows that using the Boston KPro with a glaucoma drainage device is generally safe, but there can be complications. These complications may affect vision, so it's important to discuss potential risks with your doctor.² ³ ⁵ ⁶ ⁷

How is the Boston KPro treatment different from other treatments for glaucoma?

The Boston KPro treatment is unique because it involves the implantation of an artificial cornea (keratoprosthesis) along with a glaucoma drainage device (GDD) in a single procedure, which can help manage both corneal and glaucoma issues simultaneously, unlike traditional treatments that address these conditions separately.³ ⁴ ⁵ ⁶ ⁸

Research Team

Mona Harissi-Dagher, MD, FRCSC

Principal Investigator

Department of Ophthalmology, Centre Hospitalier de l'Université de Montréal

Eligibility Criteria

This trial is for adults over 18 who've had a failed corneal transplant and have poor vision (20/80 or worse) in the affected eye. They should be physically fit for surgery but not have end-stage glaucoma or terminal retinal diseases.

Inclusion Criteria

I am 18 years old or older.

I am fit for surgery.

Pre-operative visual acuity of ≤20/80 or worse in the surgical eye

See 2 more

Exclusion Criteria

I have been diagnosed with terminal glaucoma.

I have a severe eye condition that affects my vision.

Trial Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

1 visit (in-person)

Preoperative Evaluation

Complete medical and ophthalmological history, thorough ophthalmological evaluation, A-scan and B-scan ultrasound

1-2 weeks

1 visit (in-person)

Surgery and Initial Postoperative Follow-up

Boston KPro surgery with simultaneous or delayed GDD implantation, followed by initial postoperative evaluations

1 month

Visits on postoperative day 1, week 1, and month 1

Ongoing Postoperative Monitoring

Standard ophthalmological exams, visual fields, and optic nerve evaluations

12 months

Visits at months 3, 6, and 12

Follow-up

Participants are monitored for safety and effectiveness after treatment

4 weeks

Treatment Details

Interventions

Boston keratoprosthesis type 1 (Other)
Glaucoma drainage device (Other)

Trial OverviewThe study tests if getting a Glaucoma Drainage Device (GDD) at the same time as Boston Keratoprosthesis (KPro) surgery is better than waiting 6 months. The goal is to see which timing best prevents glaucoma progression and maintains vision.

Participant Groups

2Treatment groups

Active Control

Group I: Simultaneous implantationActive Control2 Interventions

Simultaneous implantation of a glaucoma drainage device at the time of Boston keratoprosthesis type 1 surgery

Group II: Implantation at post-Kpro at 6 monthsActive Control2 Interventions

Implantation of a glaucoma drainage device 6 months after Boston keratoprosthesis type 1 surgery

Find a Clinic Near You

Research Locations NearbySelect from list below to view details:

Centre Hospitalier de l'Université de Montréal (CHUM)Montreal, Canada

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Who Is Running the Clinical Trial?

Centre hospitalier de l'Université de Montréal (CHUM)

Lead Sponsor

Trials

389

Recruited

143,000+

Findings from Research

The Boston type I keratoprosthesis (KPro) showed significant improvement in visual acuity for patients with corneal graft failure, with a median best-corrected visual acuity improving from hand motions to 20/330 at 9 months post-surgery.

However, 50% of patients experienced increased intraocular pressure postoperatively, with 23% developing or progressing glaucoma, highlighting the need for careful management of eye pressure to ensure long-term success.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Glaucoma associated with Boston type I keratoprosthesis.Kamyar, R., Weizer, JS., de Paula, FH., et al.[2022]

In a study of 137 keratoprosthesis (KPro) procedures involving 129 patients, concurrent implantation of a glaucoma drainage device (GDD) did not increase the risk of serious vision-threatening postoperative complications compared to KPro alone.

Over an average follow-up of 44 months, none of the GDDs placed with KPro became exposed, indicating that the combination procedure is safe and effective for managing both corneal and glaucoma issues.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Safety of Concurrent Boston Type I Keratoprosthesis and Glaucoma Drainage Device Implantation.Lenis, TL., Chiu, SY., Law, SK., et al.[2022]