Abstract:AIM: To explore Bland-Altman analysis of corneal curvature and astigmatism measured by new swept-source optical coherence tomography(SS-OCT)and Scheimpflug anterior segment analyzer in patients with age-related cataract.
METHODS: A total of 177 patients(282 eyes)with age-related cataract admitted to the hospital between January and December 2021 were enrolled. The steep-axis curvature(Ks), flat-axis curvature(Kf), mean corneal curvature(Km), corneal astigmatism and astigmatism axis of anterior corneal surface, posterior surface and the whole cornea were measured by SS-OCT and Scheimpflug anterior segment analyzer respectively. All parameters were detected by paired sample t-test, intra-group repeatability test, Pearson correlation and Bland-Altman consistency analysis.
RESULTS: There was no significant difference in Ks, Kf and Km of anterior corneal surface measured by SS-OCT and Scheimpflug anterior segment analyzer(P>0.05). Ks, Kf and Km of posterior corneal surface and whole cornea measured by Scheimpflug anterior segment analyzer were all greater than those measured by SS-OCT(P<0.05). There was no significant difference in astigmatism and axial values of anterior corneal surface, posterior surface and whole cornea measured by SS-OCT and Scheimpflug anterior segment analyzer(P>0.05). The intraclass correlation coefficient(ICC)of all parameters was greater than 0.88, indicating a good intra-group repeatability. Ks, Kf, Km, astigmatism and axis of anterior corneal surface, posterior surface and whole cornea measured by SS-OCT were positively correlated with those measured by Scheimpflug anterior segment analyzer(P<0.05). Bland-Altman consistency analysis showed that Ks, Kf, Km, corneal astigmatism and axis of anterior corneal surface, posterior surface and whole cornea measured by SS-OCT were highly consistent with those measured by Scheimpflug anterior segment analyzer(P<0.05).
CONCLUSION: The corneal curvature and astigmatism parameters measured by new SS-OCT are highly consistent with those measured by Scheimpflug anterior segment analyzer, which can be applied in the diagnosis of corneal curvature and astigmatism in patients with age-related cataract.