Xu Chen1, Yi Lu, Jin-hui Dai, Lin Wang. 1. Department of Ophthalmology, Eye and ENT Hospital, Fudan University, Shanghai 200031, China.
Abstract
OBJECTIVE: To assess the repeatability and difference of ocular wavefront aberrations measured with ray-tracing, dynamic skiascopy, and Hartmann-Shack aberrometers. METHODS: It was an agreement study. Ocular aberrations data obtained by using iTrace (Tracey Technologies), OPD SCAN (Nidek) and WASCA (Zeiss) wavefront aberrometers were analyzed. Eighty six eyes of 45 patients were measured three times. The difference between the measurement and the mean of three consecutive measurements were analyzed to verify the reproducibility. The difference in sphere, cylinder, spherical equivalent (SEQ) and high order aberration (HOA) errors obtained from different aberrometers were evaluated. RESULTS: Repeatability errors of these three wavefront analyzer were found to be low. Comparisons on the same eye showed that there was a significant difference (P < 0.01) in sphere and cylinder between ray-tracing aberrometer and the others in high SEQ group (>or= -6.00 diopter). For HOA, all aberrometers obtained similar results in low SEQ group (< -6.00 diopter). In the high SEQ group, the ray-tracing aberrometer showed statistically higher data in HOA and coma (P < 0.01), and there was no significant difference between the skiascopy and the Hartmann-Shack aberrometer. The iTrace-OPD and iTrace-WASCA HOA difference correlated with spherical equivalent in the high SEQ group (r = -0.418, -0.399, P < 0.01). CONCLUSION: All devices produced similar results of reproducibility, but showed varying results in the ocular total wavefront reading.
OBJECTIVE: To assess the repeatability and difference of ocular wavefront aberrations measured with ray-tracing, dynamic skiascopy, and Hartmann-Shack aberrometers. METHODS: It was an agreement study. Ocular aberrations data obtained by using iTrace (Tracey Technologies), OPD SCAN (Nidek) and WASCA (Zeiss) wavefront aberrometers were analyzed. Eighty six eyes of 45 patients were measured three times. The difference between the measurement and the mean of three consecutive measurements were analyzed to verify the reproducibility. The difference in sphere, cylinder, spherical equivalent (SEQ) and high order aberration (HOA) errors obtained from different aberrometers were evaluated. RESULTS: Repeatability errors of these three wavefront analyzer were found to be low. Comparisons on the same eye showed that there was a significant difference (P < 0.01) in sphere and cylinder between ray-tracing aberrometer and the others in high SEQ group (>or= -6.00 diopter). For HOA, all aberrometers obtained similar results in low SEQ group (< -6.00 diopter). In the high SEQ group, the ray-tracing aberrometer showed statistically higher data in HOA and coma (P < 0.01), and there was no significant difference between the skiascopy and the Hartmann-Shack aberrometer. The iTrace-OPD and iTrace-WASCA HOA difference correlated with spherical equivalent in the high SEQ group (r = -0.418, -0.399, P < 0.01). CONCLUSION: All devices produced similar results of reproducibility, but showed varying results in the ocular total wavefront reading.