Fig. 5: Scleral birefringence in non-pathologic patients with myopia.

a–f, Representative TRIPS-OCT images of an emmetropic eye (40-yr-old female, OS, 0 D, Caucasian) (a,a’, a”,c, c’,e,e’) and a myopic eye (28-yr-old female, OS, −6.75 D, Caucasian) (b,b’,b”,d,d’,f,f’). Cross-sectional images containing the ONH (a,b), fovea (c,d) and en face images (e,f) are shown in intensity (a–d,e,f), birefringence (a’–d’,e’,f’) and optic axis (a”,b”) contrasts. Dotted lines in e and f indicate locations of cross-sectional images. g, Zoomed-in view of the box in f’ and corresponding optic axis image showing the circumferential ring-like structure. h, Cross-sectional intensity (left) and birefringence (right) images indicated by the white dashed line in f’ showing the uneven choroidal–scleral interface (orange dashed line) resulting in the petaloid birefringence pattern (black arrowheads in f’ and h). En face birefringence and optic axis images were obtained from an average projection of a 200 µm slab centred at the manually labelled choroidal–scleral interface (blue dashed line). Scleral birefringence values were calculated by averaging specific fundus areas indicated by orange annular (OPSB) and hatched segment (PPSB) in e. i–k, Correlation analysis of OPSB vs SE (i), PPSB vs SE (j) and PPSB vs AL (k). l, Pearson correlation coefficients of PPSB vs SE and PPSB vs AL at different fundus locations. *P ≤ 0.01. m, Correlation matrix of biometrics of the eyes in the emmetropia or low myopia group. Scatterplots (i,j,k) show 69 eyes from 42 individuals, regression (lines) and 95% confidence intervals (shaded areas). r values were calculated using Pearson correlation. P values were calculated using F-test against a constant model. Inter-eye correlation was addressed by cluster bootstrapping. Histogram equalization was applied to a, b, c, d and h (left panel). S, superior; I, inferior; N, nasal; T, temporal. Scale bars: a,a”,c, vertical: 300 µm, horizontal: 1 mm; e, 1 mm.