Precise biometric measurement of the mouse eye using optical coherence tomography based on optic-nerve-head imaging

Due to the availability of various mouse strains with well-defined genomes, mice have become pivotal models for ocular developmental research. Accurate and highly repeatable biometric measurements are crucial for investigating myopia in experimental animals. This study aimed to develop a precise methodology for comprehensive assessment of ocular biometrics in mice. We developed the custom-built spectral domain optical coherence tomography (SD-OCT) system with an axial resolution of 4.3 μm, and an imaging depth of 4.1 mm in tissue. Three-dimensional biometric parameters exhibited superior precision (standard deviation = 5-6 μm, intraclass correlation coefficients (ICC) ≥ 0.78) compared to each two-dimensional parameter (standard deviation = 6-10 μm, ICC ≥0.62). Excellent repeatability was observed in the measurement of anterior chamber depth, vitreous chamber depth, retinal thickness, and axial thickness in mouse eyes, with ICC≥ 0.79 for optic nerve head (ONH) localization results, surpassing the classical non-ONH method (ICC ≥0.62, except for retinal thickness where ICC is 0.33). Notably, ICC and within-subject standard deviation of AL were 0.978 and 5.14 μm, respectively, in ONH localization results, while these values were 0.873 and 11.69 μm, respectively, in classical non-ONH results. Based on the custom-built SD-OCT, this study proposes a precise in vivo ocular biometric measurement method for mouse using the combination of a radial 3D scan mode and novel ONH localization imaging, which provides a useful method for the study of ocular physiology and pathological growth.