Association of axial length with retinal thickness and choroidal thickness in diabetic patients

BackgroundUnderstanding the associations of axial length (AL) with retinal thickness (RT) and choroidal thickness (CT) at different subgrids among diabetic participants are of great important in exploring potential protective mechanism and pathogenesis of diabetic retinopathy (DR) in myopic eyes. Therefore, this study aimed to investigate the associations of AL with RT and CT among participants with type-2 diabetes mellitus (T2DM). MethodsParticipants with T2DM and registered with the government-monitored diabetes communities near Zhongshan Ophthalmic Center, Guangzhou, China, were consecutively invited to participate in the current study from October 2017 to April 2019. High-definition retina and choroid images of the macular area were obtained using swept-source optical coherence tomography.AL and other ocular biometrics were measured using Lenstar900. Linear regression models were used to assess relationships between AL and RT as well as CT. ResultsA total of 1378 participants with a mean age of 63.8{+/-}7.75 years and mean AL of 23.6{+/-}1.15 mm were included in the current study. In the multivariate linear regression models, AL was positively associated with the central RT ({beta}=4.11 per mm increased in AL, 95%confidence interval (CI)=2.66 to 5.56, P<0.001), but negatively associated with the RT of the outer ring ({beta}=-3.37 per mm increased in AL, 95%CI=-4.19 to -2.56, P<0.001).Longer AL tended to have thinker CTs in the central ({beta}=-27.4 per mm increased in AL, 95%CI=-31.2 to -23.7, P<0.001),outer ring ({beta}=-20.8 per mm increased in AL, 95%CI=-23.8 to -17.7, P<0.001) and inner ring ({beta}=-24.6 per mm increased in AL, 95%CI=-28.1 to -21.1, P<0.001). ConclusionsMyopic ocular elongation is accompanied by retinal thinning of the outer ring and retinal thickening of the foveal area. The CT of the macular area tended to become thinner with elongated AL among the diabetic subjects.