Fig. 1

Comparison of ocular biometric parameters between control and dark-reared zebrafish. (A) Using optical coherence tomography (OCT) images of zebrafish eyes, ocular parameters including axial length, lens radius, retinal radius, equatorial diameter and corneal curvature were quantified. Lens (white dashed lines), retina (orange solid line) and retinal pigmented epithelium (RPE; light blue solid line) are highlighted in the representative image. (B) For dark-rearing, zebrafish were reared under a normal light/dark cycle until 4 weeks post-fertilization (wpf), followed by 2 days (2d), 2 weeks (2w) or 4 weeks (4w) of exposure to a constant dark environment. Controls were age-matched fish reared under normal lighting. (C–J) To analyze the impact of dark rearing, ratios of (C) retinal radius to lens radius, (D) equatorial diameter to lens radius, and (E) axial length to equatorial diameter, as well as (F) axial length, (G) lens radius, (H) retinal radius, (I) equatorial diameter and (J) averaged corneal curvature were compared between groups for each dark-rearing duration. In violin plots, dots show data for each individual retina. Thick bars indicate the median, and thin lines indicate interquartile ranges. N = 36, 40 and 40 fish per group for 2d, 2w and 4w of dark rearing, respectively. Two-way ANOVA was performed. *P < 0.05; **P < 0.01; ***P < 0.001; ****P < 0.0001. Asterisks next to the vertical bars indicate the group effect, those above or below the horizontal bracket indicate Fisher's LSD post-hoc comparisons. Given that differences between groups for the tested parameters, if any, were in relatively small ranges, for better visualization, y-axes of figures may not start from 0. (For interpretation of the references to color in this figure legend, the reader is referred to the Web version of this article.)