Purchase this article with an account.
M. El–Kateb, S.T. Awwad, W. Bowman, D. Cavanagh, J.P. McCulley; VISX WaveScan And LADARWave Aberrometers: A Comparative Higher Order Aberration Capture Study . Invest. Ophthalmol. Vis. Sci. 2004;45(13):2842.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose: To compare VISX WaveScan (VWS) and LADARWave (LW) aberrometer higher order aberration (HOA) capture at same pupillary diameters and evaluate the effect of mild cycloplegia and mydriasis on the HOA degree of capture and pattern and test the validity of the wavefront data captured within 0.25 mm of the pupillary border. Methods:Wavefront capture with VWS and LW aberrometers were done on 23 eyes of 12 pre–custom LASIK candidates at physiologic pupillary diameters of 3, 4, 5, and 6.0 mm and 6.5 mm and after pharmacological mydriasis/cycloplegia with 1% Tropicamide and 2.5% Phenylephrine at a capture zone of 6.0 mm with both instruments and at a 6.5 mm with LW. Results: LW detected more total HOAs and Spherical Aberration (SA) than VWS at physiological pupils of 3, 4, 5, and 6 mm. The differences in Coma and Trefoil (TF) capture were less prominent. At 6.0 mm capture zone, total HOAs were 0.40 for LW and 0.33 for VWS (p<0.05), the SA was 0.18 vs 0.08 (p<0.05), Coma was 0.25 vs 0.21, and TF was 0.12 vs 0.12. Using the VWS and a capture zone of 6.0 mm, a 6.5 mm pupil yielded a very similar total HOAs capture (0.33 vs 0.34), but a different HOAs pattern (Coma: 0.21 vs 0.18, SA: 0.12 vs 0.19, and TF: 0.12 vs 0.16). Pharmacologically dilated pupillary measurements on VWS (all >6.5 mm, average of 8.15 mm) at a capture zone of 6.0 mm produced a HOAs pattern similar to physiologic pupils of 6.5 mm (Coma: 0.21 vs 0.21, SA: 0.14 vs 0.12, and TF: 0.12 vs 0.12). With a capture zone of 6.0 mm on the LW, pharmacologically dilated pupils captured a similar HOA pattern to that of undilated pupils (total HOAs: 0.39 vs 0.40, Coma: 0.25 vs 0.23, p=0.43, SA: 0.18 vs 0.17, TF: 0.13 vs 0.15; p= 0.24). The LW with pharmacologically dilated pupil and 6.5 mm capture zone, however, detected more HOAs than when the capture zone was set to 6.0 mm (total HOAs of 0.50 vs 0.40, p<0.05, Coma of 0.32 vs 0.25, p<0.01, SA of 0.24 vs 0.18 p<0.01, and TF of 0.16 vs 0.12, p<0.01) Conclusions:The LW aberrometer captured more total HOAs than VWS at the same capture zone, with the greatest difference being in SA. The capture of the peripheral wavefront data within 0.25 mm of the pupillary border is inaccurate and introduces an error in the HOA pattern, with under–estimation of Coma and over–estimation of SA and TF. Pharmacological dilation and minimal cycloplegia does not impact the HOA capture pattern or degree of capture.
This PDF is available to Subscribers Only