Working… Menu

Study of the MEL 80 Excimer Laser Using LASIK in the Treatment of Mixed Astigmatism

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00761826
Recruitment Status : Completed
First Posted : September 30, 2008
Last Update Posted : July 19, 2018
Information provided by (Responsible Party):
Carl Zeiss Meditec, Inc.

Brief Summary:
The purpose of this study is to determine whether the MEL 80 Excimer Laser is effective in the treatment of mixed astigmatism up to 6.0 D, when used as part of the Laser In Situ Keratomileusis (LASIK) procedure.

Condition or disease Intervention/treatment Phase
Mixed Astigmatism Device: MEL 80 Mixed Astigmatism Treatment Not Applicable

Detailed Description:
LASIK has become one of the most common refractive eye procedures performed in the country. In the mixed astigmatism procedure, a combination of both a steepening (hyperopic treatment) and a flattening (myopic treatment) occur on the corneal surface. The surgeon will produce a standard keratomileusis flap using a microkeratome, exposing the corneal stroma. Recontouring under the flap is then accomplished by the removal of tissue from the stroma with the laser. This recontouring results in an altering of effective lens power of the central cornea, measured in diopters (D). The MEL 80 Excimer Laser System will be evaluated for its ability to create accurate and stable mixed astigmatic refractive correction results.

Layout table for study information
Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 126 participants
Allocation: N/A
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: A Prospective Multicenter Trial To Evaluate The Safety And Effectiveness Of The MEL 80 Excimer Laser Using LASIK (Laser In Situ Keratomileusis) For The Correction Of Naturally Occuring Mixed Astigmatism Up To 6.0 D
Study Start Date : January 2007
Actual Primary Completion Date : December 2008
Actual Study Completion Date : December 2009

Intervention Details:
  • Device: MEL 80 Mixed Astigmatism Treatment
    Treatment of Naturally Occuring Mixed Astigmatic corrections up to 6.0 D.

Primary Outcome Measures :
  1. At the point of stability, a minimum of 75% of eyes should have an achieved refraction within ± 1.00 D of the intended outcome, and at least 50% of eyes should be within ± 0.50 D of the intended outcome. [ Time Frame: Point of stability ]
  2. A minimum of 85% of eyes should have an uncorrected visual acuity of 20/40 or better at the postoperative interval at which stability has been established. [ Time Frame: Point of stability ]
  3. A minimum of 95% of eyes should have a change of < 1.00 D in manifest refraction spherical equivalent (MRSE) between 2 refractions performed at least 3 months apart, and the mean rate of MRSE change per month should be < 0.04 D. [ Time Frame: Point of stability ]
  4. Distance BSCVA of worse than 20/40 at the postoperative interval at which stability has been established should occur in less than 1.0 % of eyes that had a BSCVA of 20/20 or better before surgery. [ Time Frame: Point of stability ]
  5. Loss of more than 2 lines of BSCVA should occur in less than 5.0 % of eyes. [ Time Frame: Postoperative visits ]
  6. Incidence of adverse events to occur in less than 1% of eyes [ Time Frame: Postoperative visits ]

Secondary Outcome Measures :
  1. Subject Satisfaction: As measured by a subjective questionnaire, and will be considered as a secondary efficacy variable. [ Time Frame: Postoperative visits 3, 6, 9 and 12 months ]
  2. Incidence of complications [ Time Frame: Postoperative visits ]
  3. Patient Symptoms: As measured by a subjective questionnaire, will be considered as a secondary safety variable. [ Time Frame: Preoperative and Postoperative visits 3, 6, 9 and 12 months ]

Information from the National Library of Medicine

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, Learn About Clinical Studies.

Layout table for eligibility information
Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Naturally occurring mixed astigmatism when the magnitude of cylinder (up to 6.0 D) is greater than the magnitude of sphere, and the cylinder and sphere have opposite signs, at the spectacle plane;
  • Have a stable refraction for at least the past twelve months, as demonstrated by a change of less than or equal to 0.50 D preoperative spherical equivalent shift over twelve months prior to surgery;
  • Discontinue use of contact lenses at least 2 weeks for hard contacts and 3 days for soft lenses prior to the preoperative examination;
  • Hard contact lens wearers must have two central keratometry readings and two manifest refractions taken at least one week apart that do not differ by more than 0.50 D
  • Have visual acuity correctable to at least 20/40 in both eyes
  • Have no more than 0.75 D of latent hyperopia as determined by the difference between the preoperative manifest refractive spherical equivalent (MRSE) and cycloplegic refractive spherical equivalent (CRSE);
  • Be at least 18 years of age
  • Corneal topography should be normal;
  • The operative eye must be targeted for emmetropia;
  • Be willing and able to return for scheduled follow-up examinations for twelve months after surgery;
  • and provide written informed consent.

Exclusion Criteria:

  • History of anterior segment pathology, including cataracts (in the operative eye);
  • Clinically significant dry eye syndrome unresolved by treatment;
  • Residual, recurrent, active ocular or uncontrolled eyelid disease, corneal scars within the ablation zone or other corneal abnormality such as recurrent corneal erosion or severe basement membrane disease;
  • Ophthalmoscopic signs of keratoconus (or keratoconus suspect);
  • Required ablation is deeper than 250 microns from the corneal endothelium;
  • Irregular or unstable (distorted/not clear) corneal mires on central keratometry readings;
  • Blind in the fellow eye;
  • Previous intraocular or corneal surgery of any kind in the operative eye(s), including any type of surgery for either refractive or therapeutic purposes;
  • History of ocular Herpes zoster or Herpes simplex keratitis;
  • History of steroid-responsive rise in intraocular pressure, glaucoma, or preoperative IOP >21 mm Hg;
  • Diabetes, diagnosed autoimmune disease, connective tissue disease or clinically significant atopic syndrome;
  • Immunocompromised patients, or use of chronic systemic corticosteroid or other immunosuppressive therapy;
  • Pregnant, lactating, or child-bearing potential and not practicing a medically approved method of birth control;
  • Sensitivity to planned study medications;
  • Simultaneous participation in other ophthalmic drug or device clinical trial.
  • For Fellow (Second) Eyes in Simultaneous Bilateral Treatment Procedures
  • 1. Flap complications during the first eye's surgery such as a free cap, partial flap, thin flap, or irregular flap.
  • 2. Epithelial defect exceeding 2 mm x 2 mm in dimension, or clinically significant debris in the interface between the flap and underlying stroma for the first eye.
  • 3. Severe blepharospasm in the first eye that may have prevented or impeded the completion of the keratectomy and/or the laser ablation procedure.
  • 4. Poor subject cooperation with instructions for the first eye's surgery and/or poor subject fixation on the laser fixation target.
  • 5. Aborted LASIK procedure in the first eye or PRK was performed in the first eye because LASIK was not possible.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00761826

Layout table for location information
United States, California
US Navy Refractive Surgery Center
San Diego, California, United States, 92106
United States, Colorado
Dishler Laser Institute
Greenwood Village, Colorado, United States, 80111
United States, Missouri
Discover Vision Centers
Kansas City, Missouri, United States, 64055
United States, Oregon
Fine, Hoffman, and Packer
Eugene, Oregon, United States, 97401
United States, Wisconsin
Davis Duehr Dean Eye Clinic
Madison, Wisconsin, United States, 53717
Sponsors and Collaborators
Carl Zeiss Meditec, Inc.
Layout table for investigator information
Principal Investigator: John Doane, MD Discover Vision Centers
Principal Investigator: Richard Hoffman, MD Fine, Hoffman, and Packer LLC
Principal Investigator: Howard Fine, MD Fine, Hoffman, and Packer LLC
Principal Investigator: Mark Packer, MD FIne, Hoffman, and Packer LLC
Principal Investigator: David Tanzer, MD US Navy Refractive Surgery Center, San Diego, CA
Principal Investigator: John Vukich, MD Davis Duehr Dean Eye Clinic
Principal Investigator: Jon Dishler, MD Dishler Laser Institute
Layout table for additonal information
Responsible Party: Carl Zeiss Meditec, Inc. Identifier: NCT00761826    
Other Study ID Numbers: MEL 80-2006-2
First Posted: September 30, 2008    Key Record Dates
Last Update Posted: July 19, 2018
Last Verified: January 2018
Keywords provided by Carl Zeiss Meditec, Inc.:
Mixed Astigmatism
Laser In Situ Keratomileusis
Laser Therapy
Laser Corneal Surgery
Refractive Surgical Procedures
Ophthalmologic Surgical Procedure
Operative Surgical Procedures
Additional relevant MeSH terms:
Layout table for MeSH terms
Refractive Errors
Eye Diseases