Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT01950598 |
| Other study ID # |
FvF 08.275 |
| Secondary ID |
|
| Status |
Completed |
| Phase |
N/A
|
| First received |
|
| Last updated |
|
| Start date |
September 2013 |
| Est. completion date |
November 2020 |
Study information
| Verified date |
January 2021 |
| Source |
Centre hospitalier de l'Université de Montréal (CHUM) |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
The purpose of this study is to determine whether frozen corneas are as safe and effective as
fresh corneas for use as carriers with the Boston Keratoprosthesis type I (KPro) over long
term follow-up.
Corneal transplantation is typically performed using fresh, transparent corneas. With KPro
surgery, the corneal transplant only serves as a carrier to suture the KPro in place. The
cornea used in KPro surgery does not need to be clear like a normal transplant. Frozen
corneal tissue can be used to repair the cornea in cases of emergency but the tissue is not
transparent and does not allow good vision. We hypothesize that frozen grafts are equivalent
as fresh grafts when used as carrier for the KPro.
Description:
The Boston Keratoprosthesis (KPro) is a collar-button shaped device made from a specialized
clear plastic material. This device is used to replace a diseased and opaque cornea with a
clear window so that vision can be improved. KPro surgery is an alternative to a traditional
corneal graft and is used when a traditional corneal graft has failed or has a very poor
probability of success.
During KPro surgery, the KPro needs to be incorporated into a corneal graft before it is
sutured to the patient's cornea. The corneal graft serves as a support to the KPro and helps
to re-establish vision. The corneas typically used as carriers for the KPro are fresh corneas
provided through donors. These fresh corneas are also used in traditional corneal
transplantation, without KPro implantation.
Due to shortage of fresh corneas in the province of Quebec, this project is interested in
evaluating if corneas that have been previously frozen can act as carriers to the KPro. The
frozen corneas cannot be used in traditional corneal transplantation surgery because they are
not transparent. However, they can act as a support to the KPro, as in this case, it is the
KPro and not the corneal graft that re-establishes vision. The use of frozen corneas for KPro
surgery has the potential to improve access to corneal donor tissue and improve the
wait-times for KPro surgery.
37 patients were be recruited from the Centre Hospitalier de l'Université de Montréal (CHUM),
Notre-Dame Hospital between October 2008 and November 2009. Participants were divided into 2
groups: the first group will receive a KPro in a fresh corneal carrier graft while the second
group will receive a KPro in a frozen carrier graft. The use of a fresh or frozen corneal
graft depended on the availability of fresh tissue on the morning of surgery. 19 patients
received a fresh carrier graft and 18 received a frozen carrier graft.
Patients were followed on postoperative day 1, week 1 and 2, month 1, 3 and 6 and every 1 to
3 months thereafter up to 2 years. At each follow-up visit, a complete ophthalmological
examination was performed, including best-corrected Snellen visual acuity and slit lamp
assessment for leaks, tissue necrosis, melts, extrusion, inflammation, retroprosthetic
membrane formation and infectious endophthalmitis.
The current study aims re-consent patients previously enrolled in this study to prospectively
evaluate the long-term outcomes of KPro surgery using either a fresh or frozen carrier graft.
IRB approval was obtained from the CHUM. Written informed consent from the concerned patients
will be obtained for this extension study during their routine visits at the CHUM
Ophthalmology department.
Patients in this study will continue their routine follow-up at the frequency determined by
their surgeon, which may vary from every 3 to 6 months.
Outcome measures include surgical feasibility, level of preoperative and postoperative visual
acuity (VA), retention of the device and complications as stated above. Outcomes will be
compared at 5 and 10 years.
