Femtolaser Assisted Keratoplasty Versus Conventional Keratoplasty
Primary Purpose
Keratoconus, Fuchs Dystrophy, Corneal Disease
Status
Unknown status
Phase
Not Applicable
Locations
United Kingdom
Study Type
Interventional
Intervention
Femtosecond Laser
Trephine blade
Sponsored by
About this trial
This is an interventional treatment trial for Keratoconus focused on measuring Femtolaser, Corneal Transplant, Keratoplasty, Corneal Graft, Laser, Trephine
Eligibility Criteria
Inclusion Criteria:
- Eyes with corneal opacities owing to previous corneal pathology.
Exclusion Criteria:
- Eyes with concomitant ocular pathology which may affect visual acuity.
- Eyes who received previous corneal grafts.
Sites / Locations
- Southampton Eye UnitRecruiting
Arms of the Study
Arm 1
Arm 2
Arm Type
Active Comparator
Experimental
Arm Label
Conventional keratoplasty group (Control)
Femtolaser group
Arm Description
This group will undergo conventional penetrating keratoplasty with a trephine blade.
This group will undergo femtosecond laser-assisted penetrating keratoplasty.
Outcomes
Primary Outcome Measures
Best Corrected Visual Acuity
Measure of clarity of vision
Subjective refraction
A measure of refractive error
Intraocular pressure
Fluid pressure inside the eye
Corneal hysteresis
Measure of biomechanical stability of the cornea. Will be done by one machine (Ocular Response Analyser)
Corneal topography
A visual outcome measure assessing corneal curvature. Will be done using a pentacam.
Endothelial cell density
A measure of healing in the new graft
Corneal Resistance Factor
Measure of biomechanical stability of the cornea. Will be done by one machine (Ocular Response Analyser)
Keratometry
A visual outcome measure assessing corneal curvature. Will be done using a pentacam.
Pachymetry
A visual outcome measure assessing corneal thickness. Will be done using a pentacam,
Corneal irregularity index
A visual outcome measure assessing corneal curvature. Will be done using a pentacam.
Astigmatism
A visual outcome measure assessing corneal curvature. Will be done using a pentacam.
Secondary Outcome Measures
Full Information
NCT ID
NCT03619434
First Posted
July 23, 2018
Last Updated
December 18, 2020
Sponsor
University of Southampton
1. Study Identification
Unique Protocol Identification Number
NCT03619434
Brief Title
Femtolaser Assisted Keratoplasty Versus Conventional Keratoplasty
Official Title
Pilot Study of Femtolaser Assisted Keratoplasty Versus Conventional Keratoplasty
Study Type
Interventional
2. Study Status
Record Verification Date
December 2020
Overall Recruitment Status
Unknown status
Study Start Date
February 1, 2019 (Actual)
Primary Completion Date
December 26, 2021 (Anticipated)
Study Completion Date
December 26, 2021 (Anticipated)
3. Sponsor/Collaborators
Responsible Party, by Official Title
Sponsor
Name of the Sponsor
University of Southampton
4. Oversight
Studies a U.S. FDA-regulated Drug Product
No
Studies a U.S. FDA-regulated Device Product
No
Data Monitoring Committee
No
5. Study Description
Brief Summary
This pilot study will compare upto 15 patients undergoing femtolaser assisted keratoplasty (using CE[Conformité Européene] approved femtolaser apparatus) with upto 15 patients undergoing conventional keratoplasty with a manual trephine. Patients will be randomly assigned to either group. All keratoplasties will be penetrating keratoplasties. The following aims of this research is detailed below:
Does femtosecond laser assisted keratoplasty ( FLAK ) yield faster visual recovery and better long term BCVA (Best Corrected Visual Acuity)?
Does FLAK offer a biomechanically stronger cornea and thereby more safety and less risk of wound dehiscence?
Is there any difference between FLAK and conventional keratoplasty in terms of graft failure or rejection?
Follow up in best corrected visual acuity, various refraction/astigmatism measurements, intraocular pressure, graft rejection/failure rates, pachymetry and corneal hysteresis and resistance factor will be recorded at 1 day, 1 week, 1, 3 and 6 months and 1 year and 18 months postoperatively.
This study, to the investigators' knowledge will be the first randomised controlled trial in this area, the first to provide an empirical measurement to biomechanical stability of the cornea with the femtolaser, and the first done in an NHS (National Health Service) setting.
Detailed Description
Introduction The femtosecond laser has had a profound effect on refractive surgery and, more recently, on cataract surgery and cornea transplantation. The superior precision and control offered by femtosecond laser and its potential use in cornea transplantation show promise in terms of wound stability and strength.
By doing this research project the investigators aim to answer the following questions:
Does femtosecond laser assisted keratoplasty ( FLAK ) yield faster visual recovery and better long term BCVA?
Does FLAK offer a biomechanically stronger cornea and thereby more safety and less risk of wound dehiscence?
Is there any difference between FLAK and conventional keratoplasty in terms of graft failure or rejection?
There have been other studies that have compared femtolaser to the manual trephine in corneal transplant keratoplasty surgery. The investigators' study, to their knowledge, will be the first randomised controlled trial in this area. The majority of interventional studies comparing the two procedures are retrospective case controls. This study, will also be the first to provide an empirical measurement to the biomechanical stability of corneas that have undergone femtolaser corneal transplant. Although theorised to be better with the femtolaser, there has yet to have been a comparative study that has utilised quantitative evidence supporting this. By measuring postoperative corneal hysteresis and corneal resistance factor using an ocular response analyser, the investigators hope to be able to do that.
Recruitment, inclusion/exclusion and method Patients attending the cornea firm at the eye unit in University Hospitals Southampton who are indicated for penetrating keratoplasty as a result of corneal disease or pathology will be recruited. The participants have no connection to the university or the researcher that is known before the research starts. The aim for this study is to have a minimum of 10 patients recruited altogether and a maximum of 30.
Inclusion criteria: • Eyes with corneal opacities owing to previous corneal pathology.
Exclusion criteria: • Eyes with concomitant ocular pathology which may affect visual acuity.
• Eyes who received previous corneal grafts. Only after the patient has given their informed consent and confirmation that they meet the criteria will they be formally included in the study.
After inclusion in the study participants will be randomised into two groups of equal numbers to either undergo femtolaser-assisted penetrating keratoplasty or to undergo conventional keratoplasty. Other than the use of instrument to make incisions for the graft on the host cornea, all other aspects of the surgery will be kept as homogenous as possible.
Patients will stay overnight or have this operation done as a day case depending on time of day the operation is done. They will then be followed up at 1 day, 1 week, 1 months, 3 months, 6 months, 12 months and 18 months in various different visual outcome measurements as well as biomechanical measures of corneal healing. The two groups will be statistically compared at each timepoint.
This study also has a further role as a pilot study to assess the feasibility of doing a study like this on a larger scale, as a randomised, controlled trial.
Consent Patients who are deemed to not have capacity will not be eligible for this study as they cannot proceed with the consent form. All staff involved in the study have appropriate training in how to judge capacity.
For those with capacity, they will read the patient information sheet first. The patient information sheet contains in layman's terms full details for potential research participants, covering issues from why the researchers are doing the study, what the researchers expect from them, the possibility of adverse effects and anonymity and confidentiality. If patients are still interested after that they will receive a consent form to be signed by them. They will be given a copy of the signed consent form to keep.
Risks, burdens and benefits Risks are explained in the patient information sheet so patients have a fully informed decision about whether to take part in the study. From the investigators point of view it is important to note these patients for this study are indicated for corneal transplant surgery - that is it is felt the benefits of a conventional surgery outweighs the normal risks of corneal transplant surgery. Femtolaser keratoplasty is not known to add any risks that is not present in conventional keratoplasty. It is CE approved for the use in creating cuts in the cornea, as the surgeons are doing for corneal transplants.
Confidentiality The nature of this study means that their details will be known to the surgeons and staff performing the surgery in data collection but these will be coded/anonymised for members of the team involved in other parts of the study, leaving the number of people who know linking details to a minimum. Any documents linking the patient's details to the code will only be the responsibility of the surgeons and their staff. The consent forms themselves will be kept inside a locked storage unit in the Southampton Eye Unit. The patients will be reassured their personal details will not be known to any of the researchers other than the surgeons and their staff that will carry out the surgery.
6. Conditions and Keywords
Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Keratoconus, Fuchs Dystrophy, Corneal Disease
Keywords
Femtolaser, Corneal Transplant, Keratoplasty, Corneal Graft, Laser, Trephine
7. Study Design
Primary Purpose
Treatment
Study Phase
Not Applicable
Interventional Study Model
Parallel Assignment
Model Description
This is a prospective cohort study where a maximum of 30 patients attending the cornea firm at the eye unit in University Hospitals Southampton who are indicated for penetrating keratoplasty as a result of corneal disease or pathology will be recruited.
All patients will receive a complete ophthalmological examination preoperatively.
Subjects will then be divided randomly into 2 groups of 15, should we get 30 patients;
Masking
None (Open Label)
Masking Description
No masking as the investigators are assessing differences in surgical technique
Allocation
Randomized
Enrollment
30 (Anticipated)
8. Arms, Groups, and Interventions
Arm Title
Conventional keratoplasty group (Control)
Arm Type
Active Comparator
Arm Description
This group will undergo conventional penetrating keratoplasty with a trephine blade.
Arm Title
Femtolaser group
Arm Type
Experimental
Arm Description
This group will undergo femtosecond laser-assisted penetrating keratoplasty.
Intervention Type
Procedure
Intervention Name(s)
Femtosecond Laser
Intervention Description
The laser will be used to make incisions in the cornea for the graft.
Intervention Type
Procedure
Intervention Name(s)
Trephine blade
Intervention Description
A trephine blade will be used to make incisions in the cornea for the graft
Primary Outcome Measure Information:
Title
Best Corrected Visual Acuity
Description
Measure of clarity of vision
Time Frame
Followed up periodically for upto 18 months
Title
Subjective refraction
Description
A measure of refractive error
Time Frame
Followed up periodically for upto 18 months
Title
Intraocular pressure
Description
Fluid pressure inside the eye
Time Frame
Followed up periodically for upto 18 months
Title
Corneal hysteresis
Description
Measure of biomechanical stability of the cornea. Will be done by one machine (Ocular Response Analyser)
Time Frame
Followed up once at 3 months
Title
Corneal topography
Description
A visual outcome measure assessing corneal curvature. Will be done using a pentacam.
Time Frame
Followed up periodically for upto 18 months
Title
Endothelial cell density
Description
A measure of healing in the new graft
Time Frame
Followed up periodically for upto 18 months
Title
Corneal Resistance Factor
Description
Measure of biomechanical stability of the cornea. Will be done by one machine (Ocular Response Analyser)
Time Frame
Followed up once at 3 months
Title
Keratometry
Description
A visual outcome measure assessing corneal curvature. Will be done using a pentacam.
Time Frame
Followed up periodically for upto 18 months
Title
Pachymetry
Description
A visual outcome measure assessing corneal thickness. Will be done using a pentacam,
Time Frame
Followed up periodically for upto 18 months
Title
Corneal irregularity index
Description
A visual outcome measure assessing corneal curvature. Will be done using a pentacam.
Time Frame
Followed up periodically for upto 18 months
Title
Astigmatism
Description
A visual outcome measure assessing corneal curvature. Will be done using a pentacam.
Time Frame
Followed up periodically for upto 18 months
10. Eligibility
Sex
All
Minimum Age & Unit of Time
16 Years
Maximum Age & Unit of Time
90 Years
Accepts Healthy Volunteers
No
Eligibility Criteria
Inclusion Criteria:
Eyes with corneal opacities owing to previous corneal pathology.
Exclusion Criteria:
Eyes with concomitant ocular pathology which may affect visual acuity.
Eyes who received previous corneal grafts.
Central Contact Person:
First Name & Middle Initial & Last Name or Official Title & Degree
Parwez N Hossain, MB ChB, PhD
Phone
02381204270
Email
P.N.Hossain@soton.ac.uk
Overall Study Officials:
First Name & Middle Initial & Last Name & Degree
Parwez Hossain, B ChB, PhD
Organizational Affiliation
University of Southampton
Official's Role
Principal Investigator
Facility Information:
Facility Name
Southampton Eye Unit
City
Southampton
State/Province
Hampshire
ZIP/Postal Code
SO16 6YD
Country
United Kingdom
Individual Site Status
Recruiting
Facility Contact:
First Name & Middle Initial & Last Name & Degree
Parwez Hossain, MhCHb, PhD
Phone
02381204270
Email
P.N.Hossain@soton.ac.uk
First Name & Middle Initial & Last Name & Degree
Parwez Hossain, MhCHb, PhD
First Name & Middle Initial & Last Name & Degree
Joshua Adeyoju, Student
First Name & Middle Initial & Last Name & Degree
Omar El-Haddad, Corneal Research Fellow
12. IPD Sharing Statement
Plan to Share IPD
Undecided
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Femtolaser Assisted Keratoplasty Versus Conventional Keratoplasty
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