The Change of Macular Thickness and Retinal Layer Profiles in Spectral Domain Optical Coherence Tomography According to Axial Length in Korea

摘要

Purpose: : To evaluate the change of macular thickness and retinal layer profiles in spectral domain optical coherence tomography (SD-OCT) according to axial length in Korea. Methods: : This study was conducted in accordance with the Declaration of Helsinki recommendations. Informed consent was obtained from all participants. Randomly selected 60 eyes of 60 young, healthy individuals underwent auto-refraction (NRK-8000; Nikon, Tokyo, Japan), IOL Master (Zeiss Humphrey System, CA, USA) to measure axial length, and SD-OCT (OTI, Toronto, Canada). Six retinal layers, which composed of retinal nerve fiber layer (RNFL), inner plexiform layer and ganglion cell layer (IPL+GCL), inner nuclear layer (INL), outer plexiform layer (OPL), outer nuclear layer and photoreceptor inner segments (ONL+PIS), and photoreceptor outer segments (POS), were segmented by manually drawing the boundaries. And the each retinal layer thickness was measured with scale bar in SD-OCT at hyperreflective spot, temporal 1, 2, 3 mm and nasal 1 mm from the hyperreflective spot. Associations between axial length and macular thickness/6 retinal layer thickness were evaluated by linear regression analysis. Results: : The mean age of the patients was 27.1 years (range: 13~40 years). The male/female ratio was 1:1. Mean axial length was 25.41 mm (range: 23.00~28.98 mm) and mean spherical equivalent was -4.40 diopters (range: -10.88~+0.13).Analyzing the association between macular thickness in the topographic map and axial length, center circle and all quadrants of the inner ring macular thickness were positively correlated with axial length(r2=0.068~0.115, P0.05). In the analysis of retinal layer thickness, although the regression coefficient was very low, IPL+GCL in the temporal 2mm from the hyperreflective spot(r2=0.076, P=0.033) and INL in the temporal 3mm from the hyperreflective spot(r2=0.171, P=0.001) were negatively correlated with axial length. Conclusions: : Increasing axial length was associated with increased central macular thickness. Axial length can be associated with the thickness of inner retinal layer. These findings should be considered while evaluating macular thickness.