AIM: To compare differences and consistency of corneal curvatures in adolescent patients with low and moderate myopia measured by Pentacam, IOL Master and corneal topographic.

METHODS: A prospective clinical study. 291 adolescent patients(291 eyes)with low and moderate myopia who underwent orthokeratology in the Affiliated Eye Hospital of Nanjing Medical University from January 2019 to September 2019 were selected. Among them, 141 cases(141 eyes)were low myopia and 150 cases(150 eyes)were moderate myopia. Corneal curvature(K₁, k₂, K_m)and corneal Astigmatism(J₀, J₄₅)were examined by Pentacam, IOL Master, and corneal topography. And then the difference, correlation and consistency of the measurement results of three instruments were analyzed.

RESULTS: Differences analysis showed that in the measurement of J₄₅, there was no difference between Pentacam and corneal topography(P>0.05)in patients with low and moderate myopia; in the measurement of J₀,there was no difference between Pentacam and IOL Master(P>0.05)in patients with low myopia; in the measurement of K₂,there was no difference between Pentacam and corneal topography(P>0.05)in patients with low myopia; in the measurement of J₀,there was no difference between Pentacam and corneal topography(P>0.05)in patients with moderate myopia. But there were significant differences in other measurements among three instruments(P<0.05). Pearson correlation analysis showed that K₁, K₂, K_m, J₀, and J₄₅ were highly correlated among three instruments(r=0.545-0.997, all P<0.001). Bland-Altman consistency analysis showed that three instruments had good consistency.

CONCLUSION: Pentacam, IOL Master and corneal topographic have good consistency and can be used as a mutual reference before orthodontic fitting of low and moderate myopia patients. The measurement difference between Pentacam and corneal topography is the smallest among three instruments, but whether three instruments can be replaced by each other needs to be considered in combination in clinical application.