Comparative higher-order aberration measurement of the LADARWave and Visx WaveScan aberrometers at varying pupil sizes and after pharmacologic dilation and cycloplegia.
OBJECTIVE
To compare higher-order aberration (HOA) measurements of LADARWave and Visx WaveScan aberrometers, to test the validity of the peripheral wavefront data, and to evaluate the effect of pharmacologic dilation and mild cycloplegia.


METHODS
Thirty-three myopic eyes of 17 volunteers were enrolled and had the ocular HOAs measured and analyzed with varying pupil diameters (PD) controlled by a tunable light intensity source and after instillation of tropicamide 1% and phenylephrine 2.5%.


RESULTS
Higher-order aberrations increased with PD and optical zone (OZ), especially an OZ between 6.0 mm and 6.5 mm. Spherical aberration increased the most, followed by coma, then trefoil and secondary astigmatism. Measurement differences were observed between LADARWave and WaveScan at an OZ of 6.0 mm, although measurement correlations between the 2 machines were high. In the case of the WaveScan, when PD = OZ (6.0 mm), the spherical aberration and, to a less extent, the coma data differed from those obtained with larger PDs and the same OZ. In the case of the LADARWave, at an OZ of 6.0 mm, the HOAs measured in eyes with physiologic pupils were similar to those in pharmacologically dilated pupils when the physiologic pupil center was taken as the reference.


CONCLUSIONS
There were detectable measurement differences between LADARWave and Visx WaveScan. Ensuring that the PD is at least 0.5 mm larger than the desired OZ is very important. Dilation and mild cycloplegia did not clinically affect the wave measurement magnitude or pattern.
Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9057, USA.
Shady T
ST
Awwad
Mohamed
M
El-Kateb
James P
JP
McCulley
D000328:Adult; D003941:Diagnostic Techniques, Ophthalmological / Q000295:instrumentation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009184:Mydriatics / Q000494:pharmacology*; D010656:Phenylephrine / Q000494:pharmacology*; D011680:Pupil / Q000187:drug effects*; D012030:Refractive Errors / Q000175:diagnosis*; D015203:Reproducibility of Results; D014331:Tropicamide / Q000494:pharmacology*
D009184:Mydriatics; D010656:Phenylephrine; D014331:Tropicamide