TIMP4 and myopia: In Figure 4B, we present the frequency distribution of collagen fiber diameters, where a notable error bar in Timp4−/− rats suggests heterogeneity and dispersed distribution of fiber sizes, which aligns with the visual trends depicted in Figure 4A. Our study suggests a model wherein Timp4 deficiency may lead to a change of ECM in the retina, which changes the function and structure of bipolar cells, resulting in high myopia.