INTACS – PKP Comparison X X 180°-0.75 TransplantIntacs

Current Surgical Options - Keratoconus  10% to 20% of Keratoconus Patients Ultimately Require Surgery  Lamellar Keratoplasty Interface haze limits visual result  Penetrating Keratoplasty Most frequent procedure – 4,771 cases in 2004 (US) 80-90% successful Issues  Graft rejection rate 17.9%  Continued astigmatism  Endothelial cell loss (limited longevity of graft)  Recurrence of Keratoconus

Surgical: Central Endothelial Cell Density Studies  Normal: 0.3% - 1.0% Cell loss/Year  PRK: 1.6% - 9.0% Cell loss/Year  LASIK: 0.1% - 1.0% Cell loss/Year  INTACS: 0.2% - 0.5% Cell loss/Year

CORRECTIVE SURGERY: Central Endothelial Cell Density Studies  Cataract: 2.5% Cell loss/Year  Keratoplasty: 7.8% Cell loss/Year

INTACS - PKP Comparison PKP  Irreversible Procedure  Time: 1 Hour  Rehab Time: Months  Intraocular Procedure  Lifetime Follow-up  Complications Cataract, Glaucoma Endophthalmitis Rejection Expulsive hemorrhage Corneal ulcer Neovascularization Induced astigmatism Disease recurrence Risk of viral transference INTACS  Removable Out-Patient Procedure  Time: Minutes  Rehab Time: 1-2 Weeks (Visual Function Immediate)  Corneal Lamellar Procedure  Periodic Follow-up  Complications Unsatisfactory ring placement Segment extrusion Infection (Easily managed with segment removal)

INTACS - PKP Comparison PKP  Significant loss of endothelial cells  Permanently weakened cornea with risk of additional trauma  Outcomes: unpredictable, often unstable INTACS  Endothelial cell loss, not clinically significant 1  Provides structural integrity, PKP still an option without complication  Outcomes: predictable, case dependent 1 Two-Tear Endothelial Cell Assessment following INTACS implantation, Azaretal, J Refract Surg Sept-Oct

Conclusions: INTACS Intervention Superior to Transplant  INTACS restore functional vision Functional refraction with soft, soft-toric, or rigid contact lenses is likely Creates cornea more receptive to contact lenses  INTACS reduce corneal coning Central cone is flattened Asymmetrical cones are repositioned centrally  INTACS post-surgical recovery Visual improvement can be immediate Vision stabilizes in months rather than a year or longer  High potential to defer transplant