To evaluate the consistency of the Chinese three-dimensional anterior visual field analysis system (Scansys), the anterior segment analyzer (Pentacam), the frequency-domain anterior segment optical coherence tomography system (CASIA SS-1000), and a new ultra-high frequency digital ultrasound scanning system (Arcscan Insight100) to measure central vault after implantable collamer lens (ICL) implantation in myopic eyes with crystalline lenses.

A diagnostic test study was conducted.Fifty-six myopic patients (56 eyes) who underwent ICL V4c implantation from June to December 2019 were included.Scansys, Pentacam, CASIA and Arcscan were used to measure the central vault after surgery.The vault measurements were compared.Correlations between the measurements of the four instruments were analyzed using Pearson correlation analysis, and consistency comparisons were analyzed using the Bland-Altman method.This study adhered to the Declaration of Helsinki.The study protocol was approved by the Ethics Committee of Henan Eye Hospital (No.HNEECKY-2021[13]). Written informed consent was obtained from each subject.

The central vault measurements by Scansys, Pentacam, CASIA and Arcscan were (481.8±191.6), (476.4±190.6), (619.3±207.5) and (534.0±221.2)μm, respectively, with a statistically significant overall difference (F=143.301, P<0.001). The vault measurements by Scansys and Pentacam were significantly lower than CASIA and Arcscan, and Arcscan was lower than CASIA, with statistically significant differences (all at P<0.001). There were strong positive correlations in vault measurements between Arcscan and CASIA, Arcscan and Pentacam, Arcscan and Scansys, CASIA and Pentacam, CASIA and Scansys, Pentacam and Scansys (r=0.982, 0.933, 0.931, 0.942, 0.941, 0.989; all at P<0.001). Intraclass correlation coefficients of vault measurements by Scansys, Pentacam, CASIA and Arcscan were 0.985, 0.975, 0.998, 0.992, respectively.The 95% limits of agreement of vault measurements differences were -170 to 0, 0 to 280, 0 to 280, -110 to 210, -100 to 220 μm, between CASIA and Arcscan, CASIA and Scansys, CASIA and Pentacam, Arcscan and Scansys, Arcscan and Pentacam, respectively, and the maximum absolute value of the difference was beyond the clinically acceptable range, showing poor agreement.The 95% limits of agreement of vault measurement difference was -60 to 50 μm between Scansys and Pentacam, showing a good agreement.

The repeatability of the vault after ICL V4c implantation in myopic eyes measured by the four instruments is good.Among them, the vault measurements of Scansys and Pentacam are smaller, showing good consistency, and their results could be substituted for each other.The measurement of CASIA is the largest, followed by Arcscan, which have a large difference from each other, and their results can not be substituted for each other, which should be comprehensively analyzed with the actual situation in clinical work.

Myopia; Implantable collamer lens; Vault; Bio-measurement; Ultrasonic, digital, UHF; Optical coherence tomography, anterior segment, frequency domain; Three-dimensional anterior segment panoramic analyzer; Agreement