Repeatability and reproducibility of swept-source optical coherence tomography biometer for measuring the biological parameters of the eyeballs in healthy people

Objective

To evaluate the repeatability and reproducibility of swept-source optical coherence tomography biometrics (Tomey OA-2000) for measuring the biological parameters of the eyeballs in healthy people.

Methods

A diagnostic test was carried out in this study.One hundred and three healthy volunteers who were recuited from July to September 2018 in Affiliated Hospital of North Sichuan Medical College were included, and the right eyes were examined.Two examiners used OA-2000 for 3 consecutive measurements, respectively.One week later, the first examiner used OA-2000 for 3 consecutive measurements.The ocular biological parameters including axial length (AL), anterior chamber depth (ACD), corneal curvature (K), lens thickness (LT), central corneal thickness (CCT), pupil diameter (PD), and white to white (WTW) were measured.The repeatability and reproducibility of each parameter based on within-subject standard deviation (S_W), repeatability limit of standard deviation (2.77S_W), coefficient of variation (CoV) and intra-class correlation coefficient (ICC) was evaluated.This study followed the Declaration of Helsinki.This study protocol was approved by Ethic Committee of the Affiliated Hospital of North Sichuan Medical College (No.2018ER[A]019).

Results

Of the ocular biological parameters measured by OA-2000, CoV was less than 2% while ICC was greater than 0.950, except PD and WTW.The repeatability and reproducibility of K, AL and ACD were all good.For K₁(ø=2.5 mm and 3.0 mm), the S_W was less than 0.120 D, the 2.77S_W was less than 0.350 D, the CoV was less than 0.293%, and the ICC was greater than 0.990; For K₂ (ø = 2.5 mm and 3.0 mm) , the S_W were less than 0.175 D, the 2.77S_Wwere less than 0.485 D, the CoV was less than 0.396%, the ICC was greater than 0.980; for K_m (ø = 2.5 mm and 3.0 mm), the S_W were less than 0.099 D, 2.77S_W were less than 0.275 D, CoV was less than 0.227%, ICC was greater than 0.996; ACD S_W was less than 0.024 mm, 2.77S_W was less than 0.066 mm, CoV was less than 0.668%, ICC were greater than 0.993; the S_W of AL was less than 0.014 mm, the 2.77S_W was less than 0.038 mm, the CoV was less than 0.057%, and all of the ICCs were 1.000.

Conclusions

Except PD and WTW, the ocular biological parameters measured by OA-2000 have good repeatability and reproducibility, in which the accuracy of AL measurement is the highest.