Biomechanical Behaviour of Lamina Cribrosa Influenced by Various Substances
Spoerl E., Boehm A. G., Pillunat L. E.
Dept. of Ophthalmology, University Hospital Carl Gustav Carus, Dresden
Purpose: Structural changes in the lamina cribrosa (LC) might be related to changes of optic disc excavation. The aim of the study was to investigate whether the application of different substances influences the biomechanical properties of the LC.
Method: Porcine eyes stripes of 1 mm width were cut from the posterior sclera through the LC and incubated in DULBECCOs hat medium with different substances: group 1 with 20 % uric acid for 6 days; group 2 with 20 % glutamate for 2 days; group 3 with 0.5 M glyceraldehyde for 3 days; group 4 with 0.1 % glutaraldehyde; group 5 with collagenase A for 1days and group 6 with 20% pepsin. Each group consisted out of 10 stripes. 10 untreated LC stripes and 10 sclera stripes without LC were used as controls. The stress strain relation was measured in the stress range of 2 600 x 104 N/m2 by a biomaterial tester.
Results: Stress values in 105 N/m2 at 20% strain are 12.9±8.8 for the LC, 33.1±12.1 for the sclera, 12.4±5.1 for uric acid,9.9±5.6 for glutamate, 18.6±7.8 for glyceraldehyde, 27.5±7.4 for glutaraldehyde, 5.4±2.5 for collagenase and 4.5±2.6 for pepsin. The LC is about 2.5 times more extensible than the sclera. Uric acid and glutamate do not direct influence the biomechanical properties of the LC. Glyceraldehyde as a representant of sugar derivates leads to an increase of stiffness (factor 1.6). The same
Zurück | Back