Eight Years and Beyond Longitudinal Changes of Peripapillary Structures on OCT in Adult Myopia

Purpose To investigate the long-term changes of peripapillary structures detected by enhanced depth imaging of OCT in adult myopia. Design Observational case series. Methods Myopic participants who had undergone a full baseline ophthalmologic examination and followed up with a minimum of 8 years were included. Using enhanced depth imaging of OCT, scans around the optic disc in the follow-up mode which enabled capturing of the same positions were performed in 65 eyes. The peripapillary parameters including the size of border tissue, Bruch's membrane opening (BMO), peripapillary choroidal thickness, and the angle between peripapillary Bruch's membrane and anterior sclera were manually delineated and measured. Results The axial length showed a significant elongation after a mean follow up time of 9.46±0.92 years. The rates of changes were 0.015±0.011 mm/y in the medium myopia group, and 0.057±0.039 mm/y in the high myopia group. At the last visit, the average border tissue length and BMO diameter were increased. The angle between peripapillary BM did not show significant change, while the angle between peripapillary sclera showed significant rise. In multivariate analysis, the border tissue elongation, BMO enlargement, and increased sclera angle were all associated with the change of axial length. The development of BM defect and inward protrusion of sclera on temporal peripapillary region was observed on 8 (34.8%) eyes in the high myopia group, along with an extreme thinning or disappearing of peripapillary choroid. Conclusion A marked longitudinal changes of peripapillary structures including border tissue, BM, choroid and sclera could be observed in adult myopic eyes, which may impact the biomechanical environment around optic nerve head.