OCT-guided LALAK for KCN

This study is currently recruiting participants. (see Contacts and Locations)
Verified October 2014 by Oregon Health and Science University
Sponsor:
Collaborators:
Information provided by (Responsible Party):
David Huang, Oregon Health and Science University
ClinicalTrials.gov Identifier:
NCT01901614
First received: July 2, 2013
Last updated: October 14, 2014
Last verified: October 2014
  Purpose

The purpose of this study is to determine if a new procedure, called laser-assisted lamellar anterior keratoplasty (LALAK), can achieve the same level of vision with a lower risk of potential complications after surgery compared to another corneal transplant procedure. The current procedure is called Intralase-enabled keratoplasty (IEK) and replaces the entire cornea.

The LALAK procedure involves transplanting only the top layers of the cornea instead of the entire cornea. Only one eye will have this experimental procedure performed. If both eyes need to have surgery your doctor will help you decide on the best non-study option for your other eye.


Condition Intervention
Corneal Opacity
Keratoconus
Procedure: LALAK
Procedure: IEK
Drug: Retrobulbar Block or General Anesthesia
Device: optical coherence tomography (OCT)
Drug: Topical Anesthesia
Device: femtosecond laser

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Treatment
Official Title: RANDOMIZED CLINICAL TRIAL OF OCT-GUIDED LASER-ASSISTED LAMELLAR ANTERIOR KERATOPLASTY IN ADULTS FOR KERATOCONUS

Resource links provided by NLM:


Further study details as provided by Oregon Health and Science University:

Primary Outcome Measures:
  • Does LALAK achieve the same level of post-operative BSCVA as IEK. [ Time Frame: 24 months ] [ Designated as safety issue: Yes ]
    The primary goal of the trial is to determine if LALAK can achieve the same level of postoperative Best Spectacle Corrected Visual Acuity (BSCVA) guided by OCT as IEK


Estimated Enrollment: 94
Study Start Date: August 2013
Estimated Study Completion Date: August 2016
Estimated Primary Completion Date: August 2016 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: LALAK
laser-assisted lamellar anterior keratoplasty. Optical Coherence Tomography, femtosecond laser, topical anesthesia, and Retrobulbar Block or General Anesthesia will be used.
Procedure: LALAK
  1. A "dovetail" shaped cut will be made on the graft using a femtosecond laser at the eye bank. The cut depth will be proportional to the central stromal thickness of the graft. This graft will be separated from stromal bed by eye bank personnel for examination of the cut surface. High-quality graft will be replaced in preservation medium and shipped to the surgeon prior to surgery.
  2. The host cornea will receive femtosecond laser cut consisting of a shallow lamellar cut with angled side cut to match the dovetail graft in a tongue-in-groove fashion. The femtosecond laser treatments will be performed under topical anesthesia in the laser suite. The femtosecond laser is an FDA-approved device for use in this indication (corneal transplantation including lamellar keratoplasty). A protective eye shield is placed over the eye. The graft will be sutured into the host bed.
Device: optical coherence tomography (OCT)
OCT will be used to guide the depth of the graft and donor dissections.
Drug: Topical Anesthesia Device: femtosecond laser
The femtosecond laser system to be used in this study for host cornea preparation will be the Intralase FS system (iFS, AMO, Inc., Santa Ana, CA). The iFS is FDA-approved for corneal surgery including full thickness and lamellar keratoplasty. Eye banks use earlier versions of the Intralase system which are also FDA approved for this indication.
Active Comparator: IEK
Intralase-enabled keratoplasty. Femtosecond laser and Retrobulbar Block or General Anesthesia will be used.
Procedure: IEK
  1. A full thickness graft will be prepared at the eye bank with zigzag side cuts prepared with a femtosecond laser. The graft is separated from the rim, replaced in the preservation medium, and shipped to the surgeon prior to the surgery.
  2. In the laser suite, the host cornea will be cut with the femtosecond laser with zigzag side cuts leaving a 70-100 micron bridge. A protective eye shield is placed over the eye. The graft will be sutured into the host bed.
Drug: Retrobulbar Block or General Anesthesia Device: femtosecond laser
The femtosecond laser system to be used in this study for host cornea preparation will be the Intralase FS system (iFS, AMO, Inc., Santa Ana, CA). The iFS is FDA-approved for corneal surgery including full thickness and lamellar keratoplasty. Eye banks use earlier versions of the Intralase system which are also FDA approved for this indication.

Detailed Description:

Corneal transplantation (keratoplasty) is the most common organ transplant, with 42,606 procedures in the U.S. in 2009. Many surgeons are moving away from full thickness corneal transplantation, also called penetrating keratoplasty (PK), because of risks involving rejection, irregular astigmatism and wound dehiscence. They are moving towards partial thickness (lamellar) transplantations of either the anterior or posterior (endothelial) layers, which can reduce these risks.

The femtosecond laser has been used to create excellent tongue-in-groove junctions between the graft and host in full thickness PK.1 This technique, called IEK (Intralase-enabled keratoplasty), has now become a standard surgical procedure. The tongue-in-groove junction achieved at the circumferential edge of the graft and host leads to a continuous smooth anterior surface and strong wound healing.

The new technique is called dovetail LALAK. In this technique, the femtosecond laser is used to create a 31% anterior lamellar graft with dove tailed side cuts. It is also used to create a shallow anterior lamellar dissection and beveled side cuts on the recipient cornea to match with the dovetail graft.

In the new technique, the depth of the graft and donor dissections will be guided by OCT measurements. The proposed trial will test if the new technique can reproducibly achieve good visual outcomes without the risk of rejection. The outcome of the LALAK procedure will be compared to that of IEK.

  Eligibility

Ages Eligible for Study:   18 Years and older
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • Eyes with keratoconus that cannot be adequately or safely corrected with spectacles, contact lens or excimer laser surface ablation. The cornea must have healthy endothelium (endothelial cell density > 1,500/mm2).

Exclusion Criteria:

  1. Preoperative corneal thickness less than 400 microns.
  2. Corneal edema
  3. Central guttata
  4. Inability to give informed consent.
  5. Inability to maintain stable fixation for OCT imaging.
  6. Inability to commit to required visits to complete the study.
  7. Eyes with concurrent cataract, retinal diseases, glaucoma, or other eye conditions that may limit the visual outcome after surgery.
  8. Patients with severe collagen vascular diseases or ocular surface disorders
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01901614

Contacts
Contact: Janice Ladwig 503-494-8024 ladwig@ohsu.edu
Contact: Denny Romfh 503-494-4351 romfhd@ohsu.edu

Locations
United States, Oregon
Casey Eye Institute, Oregon Health & Science University Recruiting
Portland, Oregon, United States, 97239
Contact: Janice Ladwig    503-494-8024    ladwig@ohsu.edu   
Contact: Denny Romfh    503-494-4351    romfhd@ohsu.edu   
Principal Investigator: Winston Chamberlain, MD, PhD         
Sub-Investigator: David Huang, MD, PhD         
Sponsors and Collaborators
Oregon Health and Science University
Investigators
Principal Investigator: Winston Chamberlain, MD, PhD Oregon Health and Science University
  More Information

Additional Information:
No publications provided

Responsible Party: David Huang, Winston Chamberlain, MD, PhD, Assistant Professor of Ophthalmology, Oregon Health and Science University
ClinicalTrials.gov Identifier: NCT01901614     History of Changes
Other Study ID Numbers: OHSU IRB00009280- PTK, R01EY018184
Study First Received: July 2, 2013
Last Updated: October 14, 2014
Health Authority: United States: Institutional Review Board

Keywords provided by Oregon Health and Science University:
Keratoconus
Corneal Opacity
Keratoplasty

Additional relevant MeSH terms:
Corneal Opacity
Keratoconus
Corneal Diseases
Eye Diseases
Anesthetics
Central Nervous System Agents
Central Nervous System Depressants
Pharmacologic Actions
Physiological Effects of Drugs
Therapeutic Uses

ClinicalTrials.gov processed this record on October 23, 2014