Abstract
Purpose :
To investigate thickness changes of the peripapillary tissues during high myopia development in juvenile tree shrews.
Methods :
Juvenile tree shrews were randomly assigned to two groups: normal visual experience (n=9) and monocular -10D lens treatment to induce high myopia, where the other eye served as a control (n=12). Lens treatment started at 24 days of visual experience (DVE). Refractive and biometric measurements were obtained daily. Optical coherence tomography (OCT) of optic nerve head was performed weekly (Spectralis, Heidelberg Engineering). A deep learning algorithm was used for auto-segmentation of sclera, choroid-retinal pigment epithelium complex (Ch-RPE), retinal nerve fiber layer (RNFL) and remaining retinal layers (RRL) after nonlinear distortion correction. Thickness values were obtained from 3D reconstructed tissues, and quantified over a 50-µm band starting at 1000 µm from anterior scleral canal opening centroid.
Results :
The thickness of all tissues significantly decreased during high myopia development. Using one-way ANOVA with post hoc Tuckey test, relative thickness changes from baseline were significantly different in myopic eyes compared to control and normal eyes at 59 DVE for the sclera (2.6±5.1%, 4.4±6.4% and -9.2±4.9% in normal, control and myopic eyes, respectively; P<0.05), Ch-RPE (-3.5±5.3%, -4.01±9.8% and -13.4±8.3% in normal, control and myopic eyes, respectively; P<0.05), RRL (-3.3±2.7%, -2.3±2.7% and -6.2±1.9% in normal, control and myopic eyes, respectively; p<0.05), and compared to control eyes only for RNFL (-4.9±2.2%, -2.2±3.7%, -5.9±1.8% in normal, control and myopic eyes, respectively; P<0.05). In myopic eyes, significant time-thickness interactions were found for all tissues (repeated measures ANOVA, P<0.001). Post hoc analysis with Bonferroni adjustment revealed significant thinning from baseline to 31 DVE for all tissues, and from 31 to 38 DVE for RRL only, but not from 38 DVE to any subsequent follow-up while refractive changes were progressing until 59 DVE.
Conclusions :
Juvenile high myopia is associated with simultaneous but heterogeneous thinning of peripapillary tissues, with scleral and Ch-RPE thinning were more pronounced than retinal thinning. Peripapillary tissue thinning occurrs early during high myopia development and may contribute to increased risk for glaucoma later in life prompting early screening of myopic eyes.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.