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Objective
To compare the agreement of biometric parameters measured by a new swept-source optical coherence tomography IOLMaster 700 and a new Scheimpflug imaging combined with partial coherence interferometry biometer Pentacam AXL in cataractous eyes.
Methods
A cross-sectional study was performed.A total of 146 eyes from 76 cataract patients were enrolled in Beijing Tongren Eye Center from 2 to 11 in January 2018, including 69 eyes in 36 males and 77 eyes in 40 females, the age ranged from 35 to 88 years, the mean age was (64.52±11.36) years.Axial length (AL), mean keratometry (Km), anterior chamber depth (ACD), central corneal thickness (CCT) and white-to-white (WTW) were measured with IOLMaster 700 and Pentacam AXL, respectively.The differences and correlations of the biometry parameters between the two devices were assessed.Bland-Altman method was used to evaluate the agreement of these parameters between the two devices and the 95% limits of agreement was calculated.This study adhered to the tenets of the Declaration of Helsinki and was approved by an Ethics Committee of Beijing Tongren Hospital (TRECKY2018-049).
Results
The mean values of the AL measured by IOLMaster 700 and Pentacam AXL were (24.03±1.72)mm and (23.98±1.73)mm, Km were (44.04±1.71)D and (43.88±1.72)D, ACD were (3.24±0.47)mm and (3.28±0.47)mm, WTW were (11.82±0.51)mm and (11.49±0.49)mm, respectively.Compared with the values in Pentacam AXL, the AL, Km and WTW were larger while ACD was smaller in IOLMaster 700 with significant differences (t=18.06, 8.94, 23.83, -15.36, all at P<0.01). The mean CCT values from the IOLMaster 700 and Pentacam AXL were (534.18±30.12)μm and (533.42±28.71)μm, respectively, with no significant difference (t=1.04, P=0.30). The AL, Km, ACD, CCT and WTW from IOLMaster 700 were highly correlated with those from Pentacam AXL (r=0.999, 0.992, 0.998, 0.956, 0.942; all at P<0.01). The Bland Altman analysis showed that the 95% limits of agreement of AL, Km, ACD, CCT and WTW were-0.02-0.11 mm, -0.27-0.59 D, -0.10-0.02 mm, -16.5-18.1 μm and 0.00-0.67 mm.
Conclusions
IOLMaster 700 and Pentacam AXL have good agreements and narrow 95% limits of agreement in the measurements of AL, ACD, CCT, which can be clinically interchangeable.The 95% limits of agreement of WTW and Km are out of the clinically acceptable range, so the WTW and Km measured by the two devices are not interchangeable.