The aberrometers showed more agreement at a pupil diameter of 6 mm compared to 4 mm. These results suggest that in healthy eyes, the two aberrometers may vary in some details. The iTrace and OPD Scan showed the largest number of differences for aberrations of internal optics rather than total aberrations for both pupil diameters. Aberrations of the internal optics showed significant differences in the mean values of total RMS, spherical aberration (Z4,0), and coma (Z3,-1) between the two devices (p<0.001, p=0.01, p<0.001). At a pupil diameter of 6 mm, the two instruments showed a similar number of total aberrations. Aberrations of the internal optics showed significant differences in the mean values of total RMS, coma (Z3,-1), and trefoil (Z3,3) between the iTrace and OPD Scan (p<0.001, p=0.01, p<0.001) for the same pupil diameter of 4 mm. To learn more about bringing the iTrace into your practice, you can contact us to request more information or schedule a demo. These parameters, together with the refractive parameters, were then analyzed and complimented by paired t-tests.Īt a pupil diameter of 4 mm, the number of total aberrations in the entire eye showed significant differences for the mean values of spherical aberrations (Z4,0) obtained with the OPD Scan and iTrace aberrometers (p=0.001). For each aberrometer and each eye, the averaged Zernike data were used to calculate various root-mean-square (RMS) data. Aberrations of internal optics and total aberrations were compared for the two aberrometers. Following pupil dilation, aberrations were measured with the iTrace and OPD Scan. Methods: A total of 54 healthy eyes were enrolled in the study. We compared the aberrations obtained from measurements obtained at pupillary diameters of 4 mm and 6 mm with the OPD Scan and iTrace. Purpose: To compare and evaluate the total and internal aberrations measured by two aberrometers: the laser ray tracing aberrometer (iTrace, Tracey Technology) and the automatic retinoscope aberrometer (OPD Scan, Nidek). The iTrace system provides repeatable measurements of the spherocylindrical refraction at near and distance, but consistency of aberrometric and optical quality measurements seems to be limited.To compare and evaluate the total and internal aberrations measured by two aberrometers: the laser ray tracing aberrometer (iTrace, Tracey Technology) and the automatic retinoscope aberrometer (OPD Scan, Nidek).Ī total of 54 healthy eyes were enrolled in the study. The Sw values for the distance and near modulation transfer function parameters were low when compared with their corresponding mean values. No significant differences between the distance and near values of Sw for the power vector components of refraction were found (p ≥ 0.08). Additionally, Sw for vertical coma was significantly larger at near (p = 0.01). This patient came for consultation because of poor visual acuity to far distances, which had been observed practically since childhood. The main impulse to create the above group was the case of a 40-year-old man. However, a more pronounced variability was observed for the coefficients associated with higher order aberrations, with the poorest repeatability for the vertical coma at near, Sw of 0.011 μm for a mean value of 0.018 μm. examined using iTrace due to an unclear cause of poor visual acuity to far distances that could not be corrected in any way. Low values of within-subject standard deviation (Sw) were found for sphere and cylinder at distance and near and for the power vector components of refraction. Three consecutive aberrometric measurements were obtained with the iTrace system (Tracey Technologies) by an experienced examiner at distance (5 m) and near (40 cm). All eyes achieved a best spectacle corrected visual acuity of 20/20, and had not undergone previous ocular surgeries. To evaluate the repeatability of ocular aberrometry at distance and near vision conditions provided by the latest version of a ray tracing aberrometer.Ī total of 22 healthy eyes of 22 patients with ages ranging from 21 to 65 years were included in this study.
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