Medical Information about KeraVision Intacs™

Intacs:  What are they, and how do they work?

Article: Prepare to answer patients' questions about Intacs
requires free registration with Primary Care Optometry News

• What are they?
• Recovery Time
• Advantages and Disadvantages

Article: Intacs implantation takes no more time than LASIK
requires free registration with Ocular Surgery News

• Patient Preparation
• Implantation
• Outcome

Article: Enhancements with the Intacs are 'easy'
requires free registration with Ocular Surgery News

• Intac Removal and/or Replacement
• Intacs after LASIK
• LASIK after Intacs
• Removals during clinical trials: reasons and results

Article: Improvement in visual quality may be obtained with Intacs implantation associated with LASIK
requires free registration with Ocular Surgery News

• "By re-establishing physiological corneal asphericity, Intacs corneal ring segments
  improve visual acuity and contrast sensitivity, reducing glare and halo effects."

Article: To resculpt or implant? That is the question...
requires free registration with Ocular Surgery News

• Ocular Surgery News, March 15, 2000

Diopters and the Snellen Chart

• The Relationship Between Diopters and the "20/20" System

Astigmatism and Myopia

• What is Astigmatism and how does it correlate with Myopia?

Article: Corneal Changes Associated With Intrastromal Corneal Ring Segments

• Iron and Lipid Deposits
• "Fortunately, none of these corneal findings seems to have any visual consequence"

Diurnal Variations: Refraction Variations During the Course of the Day

• Research Abstract: Diurnal variations in keratometry and refraction with intracorneal ring segments
  • "Similar to that observed after radial keratotomy"
• Research Abstract: Diurnal Variation after Implantation with the KeraVision Intacs
  • "The data suggests less diurnal change in vision and refraction after Intac implantation."

Complications from Refractive Surgery

• VISX disclaimer detailing the rate of complications from PRK
• FDA data on LASIK using the Summit Technology laser
• "Intacs use reviewed for complications:" Ocular Surgery News
  requires free registration with Ocular Surgery News

FDA Intacs Documentation:

• Indications and Contraindications
• Device Description
• Potential Adverse Effects
• Clinical Trial Results
• Removals and Exchanges
• Benefits and Risks

Information on Clinical Trials

• Completed Trials Approved for patients with -1.0 to -3.0 diopters of myopia.
  • Graph: Visual Acuity
    • vs. LASIK
  • Two-Year Clinical Results
    • Correction of Myopia is Stable
    • "Intacs, unlike laser procedures, preserve the natural shape of the cornea"
• Future Uses: Intacs for a Wider Range of Myopia Phase IIIb trials underway.
  • Six-Month Data
• Future Uses: Intacs for Astigmatism and Hyperopia
• Experimental Treatment of Keratoconus
  • Article: Pilot trial of ICRS for keratoconus suggests benefit  (4/98)
    requires free registration with Ocular Surgery News
  • Article: Intacs may be useful for select keratoconus correction  (4/99)
    requires free registration with Ocular Surgery News