Focal Lamina Cribrosa Defects Associated With Glaucomatous Rim Thinning and Acquired Pits

Figure 1. Schematic diagrams of the optic nerve heads with laminar hole (arrow) (A) and laminar disinsertion (arrow) (B). Thick dotted lines indicate unclear laminar surfaces in the optical coherence tomographic images. Thin dotted lines indicate the expected laminar surfaces that were extrapolated from their visible portions (B). Note that the visible anterior laminar surface ends below the extrapolated posterior laminar surface.

Figure 2. Three-dimensional reconstruction process (A-D) and superimposition of the reconstructed 3-dimensional image and optic disc photograph (E-H). The anterior laminar insertion points (aqua dots), the edges of the laminar hole (A) or disinsertion (C) (blue dots), and retinal vessels (green areas) are manually marked. Sample 3-dimensional images with a laminar hole (arrow) (B) and laminar disinsertion (arrows) (D) are reconstructed using serial optical coherence tomographic images. The reconstructed 3-dimensional image and color optic disc photograph are superimposed (E-G), and the superimposed image with retinal vessels removed allows for better visibility (H).

Figure 3. Structural and spatial relationships between laminar holes and acquired pits of the optic nerve in 2 cases, showing reconstructed images of laminar holes (A and G), optic disc photographs of the corresponding eyes (arrows indicate acquired pits of the optic nerve) (B and H), superimposed images of the reconstructed laminar holes and optic disc photographs (arrows indicate the locations and directions of the enhanced-depth imaging [EDI] optical coherence tomographic [OCT] scans shown in E and K) (C and I), magnified images of the laminar hole areas (note that the laminar holes almost exactly correspond to the acquired pits of the optic nerve) (D and J), EDI-OCT images showing laminar holes as labeled in Figure 2 (yellow lines indicate anterior laminar surfaces; arrows, prelaminar tissue dimpling; aqua dots, anterior laminar insertion points; and blue dots, edges of laminar holes) (E and K), the same images as E and K without labels (F and L), and magnified EDI-OCT images of the laminar hole areas with remnant lamina cribrosa tissue inside the dotted circles (M shows the EDI-OCT image approximately 60 μm temporal to E; N shows the same image as K).

Figure 4. Structural and spatial relationships between laminar disinsertions and acquired pits of the optic nerve (APON) in 2 cases, showing reconstructed images of laminar disinsertions (A and G), optic disc photographs of the corresponding eyes (arrows indicate APON) (B and H), superimposed images of the reconstructed laminar disinsertions and optic disc photographs (arrows indicate the locations and directions of the enhanced-depth imaging [EDI] optical coherence tomographic [OCT] scans shown in E and K) (C and I), with no APON observed in the area corresponding to the superior laminar disinsertion in C, magnified images of the laminar disinsertion areas (note that laminar disinsertions enclose the APON) (D and J), EDI-OCT images showing laminar disinsertions as labeled in Figure 2 (yellow lines indicate anterior laminar surfaces; arrows, prelaminar tissue dimpling; aqua dots, anterior laminar insertion points; and blue dots, edges of laminar disinsertions) (E and K), the same images as E and K without labels (F and L), a magnified EDI-OCT image approximately 30 μm temporal to E showing the remnant lamina cribrosa tissue (dotted circle) in the laminar disinsertion area (M), and a magnified image of K showing unspecified tissue (red line) covering the prelaminar tissue dimpling (N).

Figure 5. Laminar holes and disinsertions without corresponding acquired pits of the optic nerve in 3 cases, showing reconstructed images of the laminar hole (A) and disinsertions (G and M), optic disc photographs of the corresponding eyes (arrows indicate neuroretinal rim thinning) (B, H, and N), superimposed images of the reconstructed laminar defects and optic disc photographs (arrows indicate the locations and directions of the enhanced-depth imaging [EDI] optical coherence tomographic [OCT] scans shown in E, K, Q, and T) (C, I, and O), magnified images of the laminar defect areas (D, J, and P), EDI-OCT images showing laminar defects as labeled in Figure 4K (E, K, Q, and T) (Q and T show the EDI-OCT images along the aqua and blue arrows in O, respectively), the same images as E, K, Q, and T without labels (F, L, R, and U), and a magnified EDI-OCT image approximately 120 μm nasal to Q showing the remnant lamina cribrosa tissue (dotted circle) in the laminar disinsertion area (S).