Corneal Biometric Parameters and Refractive Properties in Microcornea With Normal Axial Length

The purpose of this study was to evaluate the features of and relationships among corneal diameter, central corneal thickness (CCT), endothelial cell density (ECD), and corneal refractive properties in cases of microcornea (MC) with normal axial length.

We included 22 patients (35 eyes) with MC and cataracts and 41 patients (48 eyes) with isolated cataracts as age-matched controls. They were divided into patients with MC younger than 18 years (MC-child), patients with MC 18 years or older (MC-adult), children with congenital cataracts (CCs), and adults with senile cataracts (SCs). Corneal diameter, axial and anterior chamber length, and keratometry were measured; central corneal endothelial cell imaging was performed.

The mean horizontal corneal diameter was 7.71 ± 1.51 and 8.78 ± 0.52 mm in MC-child and MC-adult groups, respectively, and 11.89 ± 0.59 and 11.52 ± 2.42 mm in child and adult controls, respectively. The mean CCT was 641.26 ± 63.37 (MC-child) and 617.38 ± 45.40 mm (MC-adult), and 554.92 ± 34.64 (CC) and 551.58 ± 28.47 mm (SC). The mean ECD was 2898.47 ± 443.90 (MC-child) and 2825.81 ± 484.65 cells/mm 2 (MC-adult), and 3155.13 ± 372.67 (CC) and 2749.33 ± 399.63 cells/mm 2 (SC). The average keratometry was 44.22 ± 3.14 D (MC-child) and 43.86 ± 2.59 D (MC-adult), and 44.19 ± 1.44 D (CC) and 43.94 ± 1.34 D (SC).

Patients with MC and normal axial length possess specific parameters, including significantly smaller corneal diameter and thicker CCT than the patients in the control groups. There were no significant differences in ECD and average keratometry. These parameters should be taken into account in the follow-up and treatment.