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Femtosecond Laser-Assisted Keratoplasty (FLAK)

This study has been completed.
Information provided by (Responsible Party):
Shahzad Mian, University of Michigan Identifier:
First received: September 27, 2012
Last updated: January 16, 2015
Last verified: January 2015
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 Type: Observational
Study Design: Observational Model: Case Control
Time Perspective: Prospective
Official Title: Femtosecond Laser-Assisted Keratoplasty

Resource links provided by NLM:

Further study details as provided by Shahzad Mian, University of Michigan:

Primary Outcome Measures:
  • Surgical outcomes [ Time Frame: 1 day, 1 week, 1, 3, 6, 12, 18 and 24 months ]
    Wound healing, surgical complications, visual function and endothelial layer assessment

Enrollment: 24
Study Start Date: November 2007
Study Completion Date: December 2013
Primary Completion Date: March 2012 (Final data collection date for primary outcome measure)

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.


Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Probability Sample
Study Population
subjects indicated for corneal transplant surgery

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.
  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.

No Contacts or Locations Provided
  More Information

Responsible Party: Shahzad Mian, Professor, Department of Ophthalmology, University of Michigan Identifier: NCT01695811     History of Changes
Other Study ID Numbers: FLAK-15615
Study First Received: September 27, 2012
Last Updated: January 16, 2015

Keywords provided by Shahzad Mian, University of Michigan:
Keratoconus, PKP, femtosecond laser assisted keratoplasty

Additional relevant MeSH terms:
Corneal Diseases
Eye Diseases processed this record on August 16, 2017