Abstract: Objective  To analyze the cup and disc structure and morphology of high myopia and glaucoma using a fundus camera optic nerve head analysis system, and observe the differences in cup and disc structure and morphology characteristics. Design Retrospective case series study. Participants 85 highly myopic patients (85 eyes) and 29 patients (29 eyes) with a definite diagnosis of glaucoma who underwent fundus photography and optic nerve head analysis, were enrolled in this study. Methods All participants underwent intraocular pressure, fundus imaging examination, optic nerve head analysis system analysis, and ocular biological measurement. To compare the differences in ocular biological parameters and cup-disc related indices between the high myopia group and the glaucoma group, and perform correlation analysis. Main Outcome Measures Axial length, intraocular pressure, optic disc and cup related indicators, and ocular biological indicators. Results In the high myopia group, the intraocular pressure was 15.9 (14.0, 19.0) mmHg, anterior chamber depth was 3.25 (2.96, 3.40) mm, axial length was 27.1 (26.5, 27.6) mm, and pupil diameter was 5.48 (4.45, 6.67) mm. In the glaucoma group, the intraocular pressure was 23.9 (19.0, 26.0) mmHg, anterior chamber depth was 2.89 (2.67, 3.13) mm, axial length was 24.9 (23.9, 25.4) mm, and pupil diameter was 4.73 (4.16, 5.51) mm. The differences in all above parameters between the two groups were statistically significant (Z=-5.164, P<0.001; Z=-3.725, P<0.001; Z=-8.019, P<0.001; Z=-2.756, P=0.006). For optic disc related indicators, the glaucoma disc edge related indicators were smaller than those in the high myopia group in all regions, and the glaucoma group was significantly higher than the high myopia group in the main optic disc and cup indicators. Age, lens thickness, and average corneal curvature radius were negatively correlated with the rim width index in both groups, and positively correlated with some optic disc and cup indices, indicating that older age leads to thicker lenses, larger average corneal curvature radius, narrower rim, and deeper cup. The axial length is positively correlated with the volume of the optic disc, and negatively correlated with the volume of the optic cup and rim, indicating that the longer the axial length, the larger the volume of the optic disc, while the volume of the optic cup and rim are smaller. The intraocular pressure is positively correlated with the average depth of the optic cup. The higher the intraocular pressure, the deeper the optic cup. The highly myopic group with the narrowest edge of the disc is mainly distributed on the temporal side, while the glaucoma group is mainly distributed below and above the temporal side. Conclusions It was found that the cup area of glaucoma patients was generally larger than that of high myopia patients, and the axial growth of high myopia patients made the optic disc larger and the cup shallower. And there is also a difference in the distribution of the narrowest part of the disc between the two groups, which can more accurately distinguish high myopia and glaucoma, providing important basis for clinical differential diagnosis.

Key words: High myopia, Glaucoma, Optic nerve head analysis system