Abstract
Abstract: :
Purpose: To determine the accuracy and reproducibility of the InterWave Scanner, a visual aberrometer which is based upon spatially resolved refractometry, and report the first clinical experiment with this instrument. Method: The InterWave Scanner, an interactive wavefront sensor which uses the Scheiner principle to directly measure visual aberrations, is introduced. We determined the accuracy of the device in measuring test lenses, its test-retest reproducibility in a normal cyclopleged subject and the correlation between InterWave measurements and standard measurements of visual acuity and manifest refraction. Two case studies using InterWave measurements to create customized multistage-multizone LASIK treatment with the Nidek EC-5000 laser are reported. Results: The accuracy of the InterWave Scanner was measured by testing 18 lenses of known power between -15.00 and +7.00 diopters and comparing their nominal values to the scanner predicted values. An R-Squared (R2) of 0.9999 was found. Testing the correlation between the predicted refraction of the device and the measured manifest refraction revealed an R2 of 0.9650. The reproducibility tests revealed consistent results with standard deviation of the sphere and cylinder ranging between 0.04 and 0.07 diopter. Standard deviation of the axis ranged between 5 and 28 degrees. In case studies of InterWave guided LASIK treatment, reduced RMS Blur Angle and visual aberrations were found. Conclusion: The InterWaveSM Scanner accurately measures test lenses and provides good reproducibility in normal subjects. InterWaveSM technology can provide customized laser treatment programs that minimize visual aberrations.