Penetration of Inner Scleral Fibers into Peripapillary Sclera Revealed by Polarization-Sensitive OCT

PurposeTo determine the structural characteristics of the peripapillary sclera in myopic eyes using polarization-sensitive optical coherence tomography (PS-OCT). MethodsPatients with myopia who underwent PS-OCT imaging between April and June 2023 were studied. The intensity, optic axis, and birefringence of PS-OCT images were analyzed to determine the surface of the lamina cribrosa (LC). The direction and arrangement of the scleral collagen fibers in the peripapillary region and scleral ridge were determined. ResultsOne hundred and ten eyes of 59 patients with myopia (mean axial length, 30.00 {+/-} 1.98 mm) were studied. The scleral fibers around the optic nerve were arranged circularly in all eyes regardless of the presence or size of the peripapillary atrophy. Inner scleral fibers that penetrated beneath this circular arrangement were detected in 98 eyes (89.1%). There was a Y-shaped split at the point of penetration in 77 eyes (70.0%). The integrity of the circular arrangement and penetrating scleral fiber complexes remained intact even in cases of severe peripapillary scleral deformation. A scleral ridge was identified in 27 eyes (24.5%), and it appeared as a full-thickness protrusion composed primarily of outer scleral fibers. The ridge was consistently located outside the circular arrangement. ConclusionsThe penetration of the radial inner scleral fibers into the circular arrangement and extension to the LC suggest that they act as stabilizing anchors for the circular structure. The differences of the scleral ridges from those in eyes with dome-shaped macula suggest that unique mechanisms cause the scleral differences.