Purpose: To investigate the characteristics of the lamina cribrosa (LC) depth in healthy eyes using enhanced depth imaging (EDI) spectral-domain optical coherence tomography (SD-OCT).
Methods: Serial horizontal B-scans of the optic nerve head were obtained using EDI SD-OCT for both eyes of 150 healthy subjects. Anterior LC surface (ALCS) depths were measured with B-scan images from equidistant planes in each eye and defined as the distance from the Bruch's membrane opening plane to the anterior LC surface. The ALCS depths were compared between eyes within each subject. A linear mixed model was used to identify factors associated with the ALCS depth.
Results: The average ALCS depth was 402.06 ± 101.46 μm (range, 193.08-826.81). The ALCS depth was not significantly different between the right and left eyes (Ps > 0.05 at all planes). There was a strong intereye correlation within subjects (Rs ≥ 0.808 at all planes, Ps < 0.0001 at all planes). The ALCS depth was largest in the superior periphery and smallest in the central inferior plane. ALCS depth was larger in males (P < 0.05) and also larger in eyes with shorter axial length (P = 0.029).
Conclusions: This study reports the range of ALCS depth in healthy subjects. These data suggest that ALCS depth is related to sex and axial length.
Keywords: enhanced depth imaging optical coherence tomography; lamina cribrosa depth; normative data base.