Abstract
Purpose:
Recently, dual Scheimpflug analyzer (DSA) which could measure axial length and calculate intraocular lens (IOL) power were developed. However, the optical biometry and IOL power were not compared with the previous optical biometry device such as optical low-coherence reflectometry (OLCR). This study was conducted to compare ocular biometry and IOL power obtained by DSA and OLCR in patients with cataract.
Methods:
Sixty-nine cataractous eyes of 51 subjects were evaluated with DSA (Galilei G6™; Ziemer, Port, Switzerland) and OLCR (Lenstar®; Haag-Streit, Koeniz, Switzerland). Mean keratometry (K), axial length (AL), anterior chamber depth (ACD), lens thickness (LT), white-to-white (WTW) and IOL power calculated using the SRK/T formula were obtained with each device. Ocular biometry and calculated IOL power were compared with paired t-test. Correlations of the measurements were evaluated with Pearson correlation test. And, agreements of the measurements were analyzed with Bland-Altman plot.
Results:
Mean K, AL, and IOL power showed no statistically significant differences between the two devices (all p values > 0.05). However, ACD, LT and WTW showed statistically significant differences between the two devices (p < 0.001, p < 0.001, p = 0.001, respectively). Except for the WTW (r = 0.70, p < 0.001), mean K, AL, ACD, LT and IOL power showed very high correlations with each other (all r > 0.80, all p values < 0.001). The 95% limits of agreements of mean K, AL, ACD, LT, WTW, and IOL power were 2.87 diopter (D), 0.59 mm, 1.00 mm, 1.29 mm, 3.41 mm, 1.36 D, respectively.
Conclusions:
Although highly correlated, DSA and OLCR systems cannot be used interchangeably for optical biometry and IOL power in patients with cataract.