Purpose:
To compare the insertion of the lamina cribrosa into the neural canal wall in normal human eyes.
Methods:
8 eyes from 4 donors collected within 6 hours postmortem underwent endoscopic vitrectomy and maintained at 10mmHg for 30 minutes with a balanced salt solutions infusion, and then fixed with 2% Glutaraldehyde/1% Paraformaldehyde. Optic nerve head and peripapillary sclera were trephinated and serial sectioned, 3-D reconstructed, 3-D delineated, and parameterized. Anterior laminar insertion position (ALIP), Posterior laminar insertion position (PLIP), laminar insertion length (LIL, distance between the anterior and posterior laminar insertions), the Scleral insertion length (SIL), and the Scleral thickness at the anterior subarachnoid space (SCtn ASAS) were calculated in the four quadrants (inferior, nasal, superior, and temporal) (Yang H et al, IOVS 2011 Sep 9;52(10):7109-21 )(1). All the mean measurements between the four quadrants were compared with ANOVA testing.
Results:
Lamina cribrosa inserts into the pia in all regions and in all eyes. Significant regional variation in ALIP was seen in left eyes (Range: -95 ± 64 µm to -276 ± 134 µm, p<0.05), with the lowest insertion located in nasal quadrant. No significant regional variation in PLIP was seen. The lowest insertion was seen in temporal (-98 ± 65 µm, OD) and inferior (-83 ± 81 µm, OS) regions. Significant regional variation was not found in LIL, SCL, and SCtn ASAS. (Table 1).
Conclusions:
Regional posterior lamina insertion into the pia occurs in all normal eyes, most frequently in the temporal quadrant, but the largest regions of pial insertion were located in the nasal quadrant.
Keywords: lamina cribrosa • optic nerve • optic disc