LALAK for Opacities

Summary

The purpose of this protocol is to compare and develop new surgical technique of partial-thickness corneal transplantation for treating corneal opacity. A newly developed technique, "dovetail" laser-assisted lamellar anterior keratoplasty (LALAK), will be tested and compared with standard full-thickness corneal transplantation, Intralase-enabled keratoplasty (IEK). The new LALAK technique replaces only the front portion of the cornea and does not have the risks associated with conventional IEK. Additionally, optical coherence tomography (OCT) will be used to guide the depth of the graft and donor dissections.

The data will be analyzed to understand whether the new technique (LALAK) can repeatedly achieve good visual outcomes with lower risk from the operation compared to the visual outcomes and risk associated with the current standard of care, IEK.

Conditions

• STROMAL OPACITIES

Interventions

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.

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

optical coherence tomography (OCT)

OCT will be used to guide the depth of the graft and donor dissections. The OCT systems to be used in this study will be the RTVue (Optovue, Inc., Fremont, CA) or the Visante (Carl Zeiss Meditec, Inc., Dublin, CA). Both are FDA-approved for the mapping of corneal thickness.

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.

Sponsors & Collaborators

• National Institutes of Health (NIH)

  collaborator NIH

• National Eye Institute (NEI)

  collaborator NIH

• Oregon Health and Science University

  lead OTHER

Principal Investigators

• Winston Chamberlain, MD, PhD · Casey Eye Institute, Oregon Health & Science University

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

NONE

Model

SINGLE_GROUP

Eligibility

Min Age

18 Years

Max Age

100 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2013-07-31

Primary Completion

2017-08-31

Completion

2017-08-31