Effect of myopic anisometropia on anterior and posterior ocular segment parameters

The purpose of this study is to investigate the differences in anterior and posterior segment parameters of more myopic eyes compared to fellow eyes using spectral domain optical coherence tomography and optical biometer device in patients with myopic anisometropia. This prospective cross-sectional study included 42 myopic anisometropic patients with and without amblyopia, aged between 7 and 40 years old. The refractive error and keratometry values, axial length (AL), central corneal thickness (CCT), peripapillary retinal nerve fiber layer thickness (RNFLT), and central macular thickness (CMT) were evaluated. Eighteen of the patients had myopic anisometropia with amblyopia, and the remaining 24 had myopic anisometropia without amblyopia. There were 23 female and 19 male patients with a mean age as 23.67 ± 10.12 years (range 7-40). The right eyes of the subjects significantly had a higher degree of myopia. There was a significant difference in mean best-corrected visual acuity (0.195 ± 0.234 vs. 0.011 ± 0.025 logMAR, p < 0.001), spherical equivalent refraction (-3.95 ± 1.38 vs. -1.04 ± 0.99 D, p < 0.001), AL (25.06 ± 1.27 vs. 23.99 ± 0.98 mm, p < 0.001), and RNFLT (89.24 ± 12.84 vs. 94.57 ± 10.81 μm, p < 0.001) between the more myopic and fellow eyes in all patients. On the contrary, there was no significant difference in CMT and anterior segment parameters including mean keratometry and CCT in all patients and either group. During the development of the myopic anisometropia, more myopic eyes have significantly more myopic refraction, longer AL and thinner RNFLT compared to the fellow eyes.