Corneal topography in corneal refractive therapy (CRT): a 1-month follow-up.

Purpose: To evaluate visual outcome and corneal shape change during the first month of wearing corneal refractive therapy (CRT) reshaping contact lenses to correct myopia in otherwise healthy eyes.
Methods: Twenty-nine eyes were fit with Paragon CRT contact lenses, which were worn nightly. Before and after CRT fitting, uncorrected visual acuity was measured, and corneal topography was performed and evaluated with the Holladay Diagnostic Summary EyeSys 2000 Videokeratoscope. To evaluate the visual outcome, refractive yield (achieved/attempted correction) was calculated and accounted for distance or monovision.
Results: Uncorrected visual acuity improved in all patients. In 1 month, refractive yield was 96.7%. Corneal uniformity index and predicted corneal acuity index were maintained, and the Q value changed from -0.08 to +0.38 (P < 0.05).
Conclusions: CRT lenses are effective in improving visual acuity. They significantly changed the corneal from prolate to oblate while maintaining corneal quality.