Recruiting

Glaucoma Biomarkers

Sponsor:

Centre hospitalier de l'Université de Montréal (CHUM)

Code:

NCT04339907

Conditions

Glaucoma

Corneal Transplantation

Inflammation

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Accepted

Interventions

Sampling of tears

Sampling of aqueous humor

Study Details

Brief summary:

Glaucoma is the most common threat to vision rehabilitation in patients with Boston keratoprosthesis type 1 (KPro) implantation. High intraocular pressure (IOP) is the most important risk factor for glaucoma and may lead to irreversible retinal and optic nerve damage. Glaucoma drainage device (GDD) surgery is used to divert aqueous humor (AH) from the anterior chamber to an external reservoir to regulate flow and decrease the IOP. The AH is in direct communication with any corneal damage or surgery undertaken in the anterior chamber and can serve as a source of potential biomarkers to detect early inflammatory or glaucomatous changes. Tears are also one of the most accessible and non-invasive source of biomarkers, especially in Kpro eyes where the central optic allows communication between aqueous humor and the tears at the surface of the eye. The investigators propose to test the hypothesis that distinct inflammatory mediators in the AH and tears can serve as biomarkers for glaucoma development and progression after CT, making them specifically amenable to targeted treatment strategies to minimize vision loss.

Conditions

Glaucoma

Corneal Transplantation

Inflammation

Study ID

NCT04339907

Start date

May 11, 2020

Status verified date

Mar, 2026

Completion date

May, 2029

Anticipated

Primary completion date

Oct, 2028

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Accepted

Inclusion Criteria:

  • Aged 18 years old or older
  • Informed consent
  • Ability to be followed for the duration of the study
  • Presence of ocular disease specified for each group

Specific criteria for each group:

  • Group 1 : have no glaucoma and no systemic diseases
  • Group 2 : need to have glaucoma filtration surgery without prior corneal transplantation
  • Group 3 : need to have corneal transplantation (penetrating keratoplasty or Boston keratoprosthesis), with or without glaucoma
  • Group 4 : need to have intraocular surgery after prior corneal transplantation (penetrating keratoplasty or Boston keratoprosthesis)
  • Group 5 : need to have glaucoma filtration surgery with prior corneal transplantation (penetrating keratoplasty or Boston keratoprosthesis)

Exclusion Criteria:

  • Aged less than 18
  • Inability to give informed consent
  • Presence of ocular diseases other than those studied herein

Study Design

Enrollment

200 participants

Anticipated

Allocation

Non randomized

Intervention Model

Factorial

Primary purpose

Basic Science

Interventions and Outcome Measures

Arms

sham comparator: Cataract surgery only

Participants needing cataract surgery, without glaucoma or any other corneal diseases.

sham comparator: Glaucoma surgery only

Participants needing glaucoma filtration surgery, without any prior corneal transplantation.

experimental: Corneal transplantation

Participants needing corneal transplantation (penetrating keratoplasty or Boston keratoprosthesis), with or without glaucoma.

This allows analyzing samples at baseline (time 0), at the time of the corneal transplantation procedure.

experimental: Intraocular surgery following corneal transplantation

Participants needing intraocular surgery (cataract, retina or glaucoma), with prior corneal transplantation (penetrating keratoplasty or Boston keratoprosthesis).

This allows analyzing samples during the potential development or progression of glaucoma in participants who have previously undergone corneal transplantation.

experimental: Glaucoma surgery following corneal transplantation

Participants needing glaucoma filtration surgery, with prior corneal transplantation (penetrating keratoplasty or Boston keratoprosthesis).

This allows analyzing samples once glaucoma is confirmed in participants who have previously undergone corneal transplantation.

Interventions

Sampling of tears

Tears will be collected at the start of any of surgery for which the participant presents. It will be collected using a tear-wash method to allow for protein collection. 0.06 ml of saline solution 0.9% will be instilled on the ocular surface. The participants will turn their eyes with eyes closed. The tear-wash fluid will be collected from the inferior fornix of the eye using a micropipette. Tear-was fluid will be placed in codified tubes stored at -150 degrees.

Sampling of aqueous humor

Aqueous humor will be collected at the start of any of surgery for which the participant presents. A paracentesis of the anterior chamber is a common first step in intraocular surgeries. Aqueous humor is then commonly diluted with viscoelastic material injected inside the anterior chamber to avoid collapse of the anterior chamber. This way, the aqueous humor is commonly diluted or replaced entirely by the viscoelastic material injected during intraocular surgeries. A volume of 0.1 ml of aqueous humor will be taken by paracentesis using a 30-gauge needle connected to a 1-ml syringe. It consists of less than half of the total volume of aqueous humor in the eye. Aqueous humor will be placed in codified tubes stored at -80 degrees.

Primary outcome measure

  • Concentration of inflammatory mediators in aqueous humor [ Time Frame: Baseline ]
  • Concentration of inflammatory mediators in tears [ Time Frame: Baseline ]
  • Correlation between tears and aqueous humor [ Time Frame: Baseline ]

Central Contacts and Locations

Central contacts

Marie-Catherine Tessier, M.Sc.

1-514-890-8000marie-catherine.tessier.chum@ssss.gouv.qc.ca

Dominique Geoffrion, B.Sc.

1-514-890-8000dominique.geoffrion@mail.mcgill.ca

Locations

Centre Hospitalier de l'Université de Montréal (CHUM)

Recruiting

Montreal, Quebec, Canada, H2X 3E4

Contacts

Marie-Catherine Tessier, M.Sc.

1-514-890-8000marie-catherine.tessier.chum@ssss.gouv.qc.ca

Principal Investigator:

Younes Agoumi, MD

More Information

Sponsor

Centre hospitalier de l'Université de Montréal (CHUM)

Last update posted

Oct 23, 2026

Last verified

Mar, 2026

Keywords

  • Boston keratoprosthesis type 1
  • Glaucoma
  • Aqueous Humor
  • Tears
  • Inflammation
  • Penetrating keratoplasty

Trial information was received from ClinicalTrials.gov and was last updated on 2026-10-24. This information was provided to ClinicalTrials.gov by Centre hospitalier de l'Université de Montréal (CHUM) on 2026-10-23. Recruitment status is synced daily from ClinicalTrials.gov and may not reflect the sponsor's current status. Confirm during your call.