To compare the keratometry obtained from optical low-coherence reflectometry (Lenstar LS900®), autokeratometer (KR-8100®), and topography (Medmont E300®) in children.

A retrospective study was performed in 316 eyes of 160 subjects. Subjects were divided into 3 groups according to age. Group 1 was younger than 10 years, group 2 was older than 10 years and younger than 18 years, and group 3 was older than 18 years. Subjects were tested using the Lenstar LS900®, KR-8100®, and Medmont E300®. Comparisons were made for steep K, flat K, mean K, and astigmatism among three groups. Agreement among the 3 devices was examined using the Bland-Altman method.

The keratometry measured by Medmont E300® was highest, followed by that of Lenstar LS900® and KR-8100® in all 3 groups. Almost all keratometry was significantly different among the 3 devices except for the flat K measured by LS900® and KR-8100® in all 3 groups and flat K measured by KR-8100® and Medmont E300® in Group 3 ( p < 0.05). With regard to mean K, the agreement between Lenstar LS900® and KR-8100® was better than that between the other two pairs in both Groups 1 and 2, while agreement between Lenstar LS900® and Medmont E300® was better in Group 3. The agreement between KR-8100® and Medmont E300® was worse than that between the other two pairs in Groups 1 and 3, while the agreement between Lenstar LS900® and Medmont E300® was worse in Group 2.

There were significant differences in keratometry among the 3 devices in all 3 groups. In children, Medmont E300® showed relatively less agreement compared with the other two devices. In adults, however, the agreement between 2 devices showed variable results. Consideration of the keratometry measurement from Lenstar LS900®, KR-8100®, and Medmont E300® might be helpful to estimate accurate corneal keratometry in children.