Comparison of IOL-Master 700 and IOL-Master 500 biometers in ocular biological parameters of adolescents

AIM: To compare the differences and consistency of IOL-Master 700 biometers applying swept optical coherence tomography with the conventional IOL-Master 500 applying partial coherence interference in terms of the ocular biological parameters in adolescents with ametropia. METHODS: A total of 110 adolescents (110 eyes) with ametropia were collected, including 55 males and 55 females; age 10.69 +/- 2.81y. Ocular biological measurements were taken by IOL-Master 700 and IOL-Master 500 respectively to obtain biological parameters including axial length (AL), mean corneal anterior surface keratometry (K-m), anterior chamber depth (ACD), and horizontal corneal diameter (WTW). Paired t-test was used to compare the differences between the two instruments. The intra-group correlation coefficient (ICC) and the Bland-Altman analysis were used to evaluate the consistency of parameter measurements between the two instruments for the four biological parameters. RESULTS: Statistical analysis showed that there was no significant difference in the K-m value measured by IOL-Master 700 and IOL-Master 500 (t=-1.644, P=0.116). The average differences of the AL, ACD, and WTW distances between the two instruments are 0.028, 0.101 and 0.064 mm respectively, and the differences are statistically significant (t=2.644, 12.505, 3.911, P<0.001). The consistency study results indicated high correlation in the measurement of AL, K-m, ACD and WTW between the two instruments (ICC=0.994, 0.873, 0.927, 0.912). CONCLUSION: The novel biometric instrument IOL-Master 700 makes no difference with IOL-Master 500 in the measurement of K-m. There are some differences in the values of AL, ACD, and WTW. However, the two instruments show good consistency in these four biological measurements. The measured values of K-m are interchangeable between the instruments. These two types of biometrics can be used as mutual reference in consideration of that the differences in AL, ACD, and WTW measurements are not sufficient to produce clinically meaningful differences.