Accuracy of Ocular Biometry and Postoperative Refraction in Cataract Patients with AL-Scan®

PURPOSE To compare the axial lengths, anterior chamber depths, and keratometric measurements and to predict postoperative refractions of AL-Scan(R), IOL master(R), and ultrasound. METHODS: A total of 40 eyes in 30 patients who received cataract surgery were included in the present study. The axial length, anterior chamber depth, and keratometry were measured by 2 types of partial coherence interferometry (AL-Scan(R) and IOL master(R)) and ultrasound. The SRK/T formula was used to calculate IOL power, and the predictive error which subtracts predictive refraction from postoperative refraction was compared among the ocular biometry devices. RESULTS: Axial lengths were 23.08 +/- 0.62 mm, 23.09 +/- 0.62 mm, and 22.99 +/- 0.62 mm measured by AL scan(R), IOL master(R), and ultrasound, respectively. Axial length measured by ultrasound was statistically significantly shorter than AL scan(R) and IOL master(R) (p < 0.001, p < 0.001, respectively). The anterior chamber depth and keratometry were 3.11 +/- 0.06 mm and 44.82 +/- 1.34 D measured by AL scan(R), and 3.13 +/- 0.06 mm and 44.85 +/- 1.26 D measured by IOL master(R), respectively. The differences of anterior chamber depth and keratometry between the 2 devices were not statistically significant (p = 0.226, p = 0.331, respectively). The mean absolute prediction errors were 0.44 +/- 0.35 D, 0.40 +/- 0.34 D, and 0.39 +/- 0.30 D in AL-Scan(R), IOL master(R) and ultrasound, respectively, and were not statistically significantly different (p = 0.843, p = 0.847, p = 1.000, respectively). CONCLUSIONS: The ocular biometric measurements and prediction of postoperative refraction using AL-Scan(R) were as accurate as IOL master(R) and ultrasound.