Comparison of the Biomechanics of the Mouse Astrocytic Lamina Cribrosa Between Glaucoma and Optic Nerve Crush Models.
Korneva Arina, Kimball Elizabeth C, Johnson Thomas V, Quillen Sarah E, Pease Mary E, Quigley Harry A, Nguyen Thao D
AI Summary
This study found glaucoma (high IOP) altered mouse astrocytic lamina mechanics, but optic nerve crush (axon damage) did not, suggesting IOP-induced changes, not just axon injury, affect lamina biomechanics.
Abstract
Purpose
The strain response of the mouse astrocytic lamina (AL) to an ex vivo mechanical test was compared between two protocols: eyes that underwent sustained intraocular pressure (IOP) increase and eyes after optic nerve crush.
Methods
Chronic IOP elevation was induced by microbead injection or the optic nerve was crushed in mice with widespread green fluorescence. After 3 days or 6 weeks, eyes were inflation tested by a published method of two-photon fluorescence to image the AL. Digital volume correlation was used to calculate strains. Optic nerve axon damage was also evaluated.
Results
In the central AL but not the peripheral AL, four strains were greater in eyes at the 3-day glaucoma time point than control (P from 0.029 to 0.049, n = 8 eyes per group). Also, at this time point, five strains were greater in the central AL compared to the peripheral AL (P from 0.041 to 0.00003). At the 6-week glaucoma time point, the strains averaged across the specimen, in the central AL, and the peripheral AL were indistinguishable from the respective controls. Strains were not significantly different between controls and eyes 3 days or 6 weeks after crush (n = 8 and 16).
Conclusions
We found alterations in the ex vivo mechanical behavior in eyes from mice with experimental glaucoma but not in those with crushed optic nerves. The results of this study demonstrate that significant axon injury does not directly affect mechanical behavior of the astrocytic lamina.
MeSH Terms
Shields Classification
Key Concepts6
In mice with experimental glaucoma, four strains in the central astrocytic lamina (AL) were greater than control at the 3-day time point (P from 0.029 to 0.049, n = 8 eyes per group).
In mice with experimental glaucoma, five strains were greater in the central astrocytic lamina (AL) compared to the peripheral AL at the 3-day time point (P from 0.041 to 0.00003).
In mice with experimental glaucoma, strains averaged across the specimen, in the central astrocytic lamina (AL), and in the peripheral AL were indistinguishable from respective controls at the 6-week time point.
Strains in the astrocytic lamina (AL) were not significantly different between controls and eyes 3 days or 6 weeks after optic nerve crush in mice (n = 8 and 16).
Alterations in the ex vivo mechanical behavior of eyes from mice were found with experimental glaucoma but not in those with crushed optic nerves.
Significant axon injury in mice does not directly affect the mechanical behavior of the astrocytic lamina.
Related Articles5
Independent Effects of Axial Length and Intraocular Pressure on the Highly Myopic Optic Nerve Head.
Cross-Sectional StudyThe Strain Response to Intraocular Pressure Increase in the Lamina Cribrosa of Control Subjects and Glaucoma Patients.
Observational StudyAdduction induces large optic nerve head deformations in subjects with normal-tension glaucoma.
Cross-Sectional StudyImpact of Elevated Intraocular Pressure on Lamina Cribrosa Oxygenation: A Combined Experimental-Computational Study on Monkeys.
Basic ScienceLongitudinal Change in Retinal Nerve Fiber Layer Thickness and Intraocular Pressure in Young Adults.
Cohort StudyIs this article assigned to the wrong chapter(s)? Let us know.