Objective To investigate corneoscleral dimensions and sagittal heights in the cornea and sclera using ultra-long scan depth spectral domain optical coherence tomography (UL-OCT). Methods This was a cross-sectional investigation. Forty subjects (80 eyes, 17 men, 23 women; mean age, 25.8±2.8 years) were recruited for the study. UL-OCT image acquisition was taken for each eye. Custom software was used to quantify corneal/scleral sagittal height and dimensions of the corneoscleral junction. The differences in sagittal heights and dimensions of the corneoscleral junction in the four quadrants were analyzed with a paired t test and repeated measures ANOVA. Results There were no significant differences in the X and Y axis coordinates in the corneoscleral junction, the tangential curvature difference between the corneoscleral junction and the mean tangential curvature of the central 3 mm cornea and the corneal/scleral sagittal height (chord distances of 1.5, 3, 5 and 7 mm from the corneal apex) in the same locations between the left and right eyes. Except for the X axis coordinates, other dimensions were larger on the nasal side than the temporal side (P<0.05). There were no significant differences among all dimensions between the superior and inferior sides at the vertical meridian. The values of the X axis coordinates at the vertical meridian were closer to the corneal apex than the horizontal meridian. The values of the Y axis coordinates and the tangential curvature difference between the corneoscleral junction and the mean tangential curvature of the central 3 mm cornea were largest on the nasal side compared to other locations (P<0.05). Conclusion There are no significant differences for any dimensions at the same location between the left and right eyes. The corneosclera presents a larger junction angle on the nasal side than at other locations.
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