Femtosecond Laser-Assisted Keratoplasty (FLAK)

The purpose of this study will be to determine optimal surgical technique for performing FLAK including laser parameters, keratoplasty shape and suture technique in order to standardize surgical technique and to collect safety and efficacy data. This will be compared to data of patients with full thickness PKP to measure visual outcomes, refraction, astigmatism, surgical methods and wound healing.

Study Overview

• Status: Completed
• Conditions: Keratoconus

Detailed Description

FLAK Instrument: The Femtosecond Laser (IntraLase Corporation, Irvine, CA) is a focusable infrared laser, similar to the more familiar neodymium-yttrium-aluminum-garnet (YAG) laser, but uses shorter pulses in the hundred-femtosecond (100 X 10-15 seconds) duration range. There is minimal postoperative inflammation and collateral tissue damage.

Subjects: We will be enrolling subjects 18 years or older that need keratoplasty based on clinical findings. Subjects will be enrolled regardless of race or gender on a first come first serve basis. Subjects will be recruited from the physicians own clinic.

PKP Subjects: We will do a retrospective chart review on subjects who have undergone traditional PKP. FLAK eyes will be age and gender matched to these PKP eyes to compare visual outcomes, wound healing and complications.

• Study Type: Observational
• Enrollment (Actual): 24

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Probability Sample

Study Population

subjects indicated for corneal transplant surgery

Description

Inclusion Criteria:

1. Corneal opacification.
2. Reduced ETDRS-measured, best corrected, distance visual acuity to 20/40 or worse.
3. Ability to participate in follow-up visits..

Exclusion Criteria:

1. Corneal opacification adequately dense to obscure visualization of iris.
2. ETDRS-measured, best-corrected, distance visual acuity of 20/30 or better.
3. Corneal thickness greater than 1200 µm at the 9 mm peripheral zone.
4. Severe corneal thinning including descemetocoele with impending corneal rupture.
5. Prior PKP or incisional surgery that may provide a potential space into which the gas produced by the procedure can escape.
6. Poor visual potential in the non-study eye (VA of 20/100 or less, without potential for improvement by the examining ophthalmologist's judgment).
7. History of glaucoma, including steroid response rise in intraocular pressure.
8. Active intraocular inflammation or infection.
9. Age 18 or younger (consideration will be given to an upper age limit).
10. Unable to return for scheduled follow-up examinations.
11. Other medical condition(s) that will likely prevent long term follow-up.

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort
FLAK
PKP; Retrospective

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Surgical outcomes	Wound healing, surgical complications, visual function and endothelial layer assessment	1 day, 1 week, 1, 3, 6, 12, 18 and 24 months

Collaborators and Investigators

• Sponsor: University of Michigan

Study record dates

Study Major Dates

• Study Start: November 1, 2007
• Primary Completion (Actual): March 1, 2012
• Study Completion (Actual): December 1, 2013

Study Registration Dates

• First Submitted: September 27, 2012
• First Submitted That Met QC Criteria: September 27, 2012
• First Posted (Estimate): September 28, 2012

Study Record Updates

• Last Update Posted (Estimate): January 21, 2015
• Last Update Submitted That Met QC Criteria: January 16, 2015
• Last Verified: January 1, 2015

More Information

Terms related to this study

• Keywords: Keratoconus, PKP, femtosecond laser assisted keratoplasty
• Additional Relevant MeSH Terms: Eye Diseases; Corneal Diseases; Keratoconus
• Other Study ID Numbers: FLAK-15615