Endoscopic Assisted Anterior Hyaloid Peeling in Boston Type 1 Keratoprosthesis (KPro-HP-Endo) (KPro-HP-Endo)

July 24, 2023 updated by: Centre hospitalier de l'Université de Montréal (CHUM)

Impact of Endoscopic Assisted Anterior Hyaloid Peeling in Boston Type 1 Keratoprosthesis in Reducing Postoperative Complications

Common complications of the Boston keratoprosthesis type 1 (KPro) surgery include retroprosthetic membrane formation, glaucoma, and retinal detachment. Often pars plana vitrectomy (PPV) is performed at the same time as KPro surgery for different indications. It has been shown to reduce postoperative complications in comparison to when it is performed after the KPro surgery. Patients who receive a complete PPV with peeling of the anterior hyaloid membrane have a lower incidence of retroprosthetic membrane formation and less vision loss due to glaucoma when compared to patients with partial PPV or anterior vitrectomy. During a complete PPV, peeling of the anterior hyaloid membrane is a difficult step because visualisation is poor, but it can be improved using endoscopy. The investigators suggest that peeling of the anterior hyaloid membrane assisted by endoscopy during KPro surgery would decrease postoperative complications in comparison to a PPV done after KPro surgery and without endoscopy.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

Boston keratoprosthesis type 1 (KPro) surgery is the most common corneal graft and is used to restore vision in patients with high risk of failure with traditional penetrating keratoplasty. Common complications of KPro surgery include retroprosthetic membrane formation behind the backplate of the KPro. Glaucoma is the most common threat to vision rehabilitation in patients with KPro. Glaucoma is often present before surgery and progresses after KPro, seven times faster than in patients with only glaucoma. Retinal detachment is a common posterior segment complication that arises post-KPro and can lead to a serious loss of vision. Pars plana vitrectomy (PPV) is the standard treatment for patients with vitreoretinal diseases and opacities. PPV can include peeling of the anterior hyaloid membrane to ensure total resection of the vitreous body. PPV allows for example for retroprosthetic membrane excision, installation or revision of a glaucoma drainage device, or repair of retinal detachment. Often PPV is performed at the same time as KPro surgery for different indications. It has been shown to reduce postoperative complications in comparison to when it is performed after the KPro surgery. Patients who receive a complete PPV with peeling of the anterior hyaloid membrane have a lower incidence of retroprosthetic membrane formation and less vision loss due to glaucoma when compared to patients with partial PPV or anterior vitrectomy. Combined surgeries of KPro and PPV offer a complete evaluation of the optic nerve and of the retina, which would not be possible otherwise. During a complete PPV, peeling of the anterior hyaloid membrane is a difficult step because visualisation is poor, especially with a KPro in place. Visualisation can be improved using endoscopy to visualize the inside of the eye over 360 degrees. The investigators suggest that peeling of the anterior hyaloid membrane assisted by endoscopy during KPro surgery would decrease postoperative complications in comparison to a PPV done after KPro surgery and without endoscopy.

Study Type

Interventional

Enrollment (Estimated)

20

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

  • Canada
    • Quebec
      • Montréal, Quebec, Canada, H2X 3E4
        • Recruiting
        • Centre hospitalier de l'Université de Montréal (CHUM)
        • Contact:
        • Principal Investigator:
          • Mona Harissi-Dagher, MD

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

16 years to 78 years (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Aged from 18 to 80 years old
  • Informed consent
  • Boston keratoprosthesis candidate
  • Pars plana vitrectomy candidate
  • Ability to be followed for the duration of the study

Exclusion Criteria:

  • Aged less than 18 or more than 80 years old
  • Inability to give informed consent
  • Repeat Boston keratoprosthesis
  • Repeat pars plana vitrectomy

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Patients with KPro, PPV, and endoscopy
Patients will receive at the same time a Boston keratoprosthesis type 1 (KPro) with a pars plana vitrectomy (PPV) with anterior hyaloid membrane peeling assisted by endoscopy.
Procedure: Boston keratoprosthesis type 1 and anterior hyaloid membrane peeling assisted by endoscopy
Patients will receive at the same time a Boston keratoprosthesis type 1 (KPro) with a pars plana vitrectomy (PPV) with anterior hyaloid membrane peeling assisted by endoscopy.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Rate of retroprosthetic membrane formation
Time Frame: 12 months
Rate of postoperative retroprosthetic membrane formation behind the backplate of the Boston keratoprosthesis. Retroprosthetic membrane formation is diagnosed by the investigator using an examination of the anterior chamber performed at the slit-lamp.
12 months
Rate of retinal detachment
Time Frame: 12 months
Rate of postoperative retinal detachment. Retinal detachment is diagnosed by the investigator using a dilated fundus (retinal) examination performed at the slit-lamp.
12 months
Rate of glaucoma development
Time Frame: 12 months
Rate of development or progression of glaucoma, determined based on intraocular pressure increase of > 21 mmHg, increase of glaucoma medications, optic nerve excavation progression, or need to undergo glaucoma filtration surgery.
12 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Proportion of patients with visual acuity better than 20/200
Time Frame: 12 months
Proportion of patients with visual acuity better than 20/200 after surgery. The visual acuity is measured using the Snellen chart.
12 months
Change of visual acuity
Time Frame: 12 months
Change of visual acuity compared between before and after surgery. The visual acuity is measured using the Snellen chart.
12 months
Time to retroprosthetic membrane formation after surgery
Time Frame: 12 months
Time to retroprosthetic membrane formation, calculated in months from the time of the surgery. Retroprosthetic membrane formation behind the backplate of the Boston keratoprosthesis is diagnosed by the investigator using an examination of the anterior chamber performed at the slit-lamp.
12 months
Time to retinal detachment after surgery
Time Frame: 12 months
Time to retinal detachment, calculated in months from the time of the surgery. Retinal detachment is diagnosed by the investigator using a dilated fundus (retinal) examination performed at the slit-lamp.
12 months
Proportion of participants requiring glaucoma surgery
Time Frame: 12 months
Proportion of participants requiring glaucoma surgery (including glaucoma drainage device, trabeculectomy or cyclophotocoagulation) after the Boston keratoprothesis surgery.
12 months
Proportion of patients with visual field loss of 30% or more
Time Frame: 12 months
Proportion of patients with visual field loss of 30% or more, measured using the automated Humphrey 24-2 visual field. The loss of 30% or more of visual field is calculated using the first two postoperative tests as a reference.
12 months
Proportion of patients with thinning of the nerve fiber layer
Time Frame: 12 months
Proportion of patients with thinning of the nerve fiber layer, determined by Spectral Domain Optical Coherence Tomography (SD-OCT) in average and for each of the four quadrants.
12 months
Rate of Boston keratoprosthesis complications
Time Frame: 12 months
Rate of Boston keratoprosthesis complications. Complications from the Boston keratoprosthesis include: corneal melt, retroprosthetic membrane formation, retinal detachment, cystic macular edema, extrusion, hypotony, choroidal hemorrhage.
12 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Centre hospitalier de l'Université de Montréal (CHUM)

Investigators

  • Principal Investigator: Mona Harissi-Dagher, MD, Centre hospitalier de l'Université de Montréal (CHUM)

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

April 8, 2020

Primary Completion (Estimated)

October 1, 2024

Study Completion (Estimated)

March 1, 2025

Study Registration Dates

First Submitted

April 3, 2020

First Submitted That Met QC Criteria

April 6, 2020

First Posted (Actual)

April 8, 2020

Study Record Updates

Last Update Posted (Actual)

July 27, 2023

Last Update Submitted That Met QC Criteria

July 24, 2023

Last Verified

July 1, 2023

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • CE19.382

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Postoperative Complications

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

CROs by country

CROs in Italy

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

3
Subscribe