Study on retinal nerve fibre layer thickness in myopia measured by Cirrus HD OCT

Abstract

AIM:To investigate the characteristics of the retinal nerve fibre layer(RNFL)thickness in myopia measured by Cirrus HD optical coherence tomography(OCT), and the relationship between RNFL thickness and refractive diopter/axial length. METHODS: Totally 106 cases(196 eyes)were divided into low, moderate and high myopia group and 38 cases(60 eyes)as normal group were included in the study. Cirrus HD OCT was used to measure the RNFL thickness. Each eye was performed circular scans around the optic nerve with a circle size of 3.46mm. The average RNFL thickness, the mean RNFL thickness in each quadrant and clock hour in each group were recorded. The difference between each myopia group and normal group and the relationship between RNFL thickness and refractive diopter was researched.RESULTS: Compared to normal group, the average RNFL thickness, the mean RNFL thickness of superior and inferior were thinner in myopia groups, the difference between moderate, high myopia group and normal group were significant(PP>0.05), the temporal quadrant RNFL thickness was thicker and the difference was significant(PPPPCONCLUSION: The average RNFL thickness and the RNFL thickness at superior quadrant, inferior quadrant, 2:00, 6:00, 12:00 position in myopia groups are thinner than normal group; the RNFL thickness at temporal quadrant, 8:00, 9:00 and 10:00 position are thicker. The result shows the characteristics of the RNFL thickness in myopia, which is of instructive significance to guide the diagnosis of disease. Effect of refractive diopter on RNFL should be concerned for a clinical diagnosis; The RNFL thickness at 7:00, 8:00, 10:00 and 11:00 position in myopia group are not thinner than normal group. If they become thinner, glaucoma should be considered.

Keywords

• myopia
• retinal nerve fibre layer thickness
• optical coherence tomography
• spherical equivalent
• spherical equivalent