Date of Award
Master of Science in Vision Science
Patrick J. Caroline
PURPOSE: This study evaluated how contact lens induced corneal warpage stabilizes upon discontinuation of lens wear and further evaluated whether the waiting periods for laser refractive surgery now in use can be safely shortened.
METHODS: Using corneal topography, both retrospective and prospective analyses were conducted for 16 soft lens eyes and 8 rigid lens eyes. Corneal maps were taken prior to discontinuation of lens wear, serial maps taken during the waiting period (if an RGP wearer), and again on the date of surgery. Using the Humphrey PathFinder Analysis software, comparisons were made of the CIM, Shape Factor, and TKM to evaluate the changes over time.
RESULTS: There is very little corneal reshaping once soft lens wear is discontinued. However, statistically significant changes in SF (Shape Factor) and TKM (Mean Toric Keratometry) before and after the waiting period were found for subjects wearing RGP (rigid gas permeable) lenses.
CONCLUSION: Careful topographic analysis should allow many long-term RGP wearers without signs of corneal warpage to forego the long waiting period dictated by current standards in refractive surgery. Short waiting periods for soft lens wearers may be a prudent precaution, but is not a necessity.
Fechtel, Mark E. and Gussenhoven, Julie, "Evaluation of waiting periods prior to laser refractive surgery after discontinuing wear of rigid and soft contact lenses" (2000). College of Optometry. 1339.