AcuTarget measurements: repeatability and comparison to OPD-Scan III.

Purpose: To evaluate repeatability of the AcuTarget (SensoMotoric Instruments, Teltow, Germany) measurements and compare them to those obtained with the OPD-Scan III (NIDEK, Inc., Fremont, CA).

Methods: Measurements were taken with the AcuTarget and OPD-Scan III in 62 eyes of 31 patients. Results were compared using paired Student's t tests, Pearson correlation coefficients, and 95% limits of agreement.

Results: Repeatability of the AcuTarget was good with intraclass correlation coefficients of 0.773, 0.777, and 0.780 for Purkinje-versus-pupil along the x-axis, y-axis, and chord length measurements, respectively. No statistically significant difference was observed between the AcuTarget and OPD-Scan III for Purkinje-versus-pupil measurement along the x-axis (P = .061) and chord length (P = .950). Conversely, a statistically significant difference was observed between the two systems for measurements along the y-axis (P < .001). No statistical difference was found between the mean of the first three acquisitions and the best acquisition obtained with the AcuTarget.

Conclusions: Measurements provided by the AcuTarget have good repeatability and are close to those obtained with the OPD-Scan III. Although controversies remain on where to best center refractive procedures, this may help in analyzing the importance of refractive surgery centration in relation to visual acuity and visual symptoms.