Characterizing the Collagen Network Structure and Pressure-Induced Strains of the Human Lamina Cribrosa

Abstract

Characterizing the collagen network structure and pressure-induced strains of the human lamina cribrosa. Invest

The Effects of Glaucoma on the Pressure-Induced Strain Response of the Human Lamina Cribrosa

“…1,34 We measured in a prior study of 10 normal human eyes with a similar range of LC area (2.6-4.1 mm 2 ) but a broader age range (26-73 years) that LC strains increased with LC area. 33 This was opposite of the finding in this study that glaucoma eyes with larger LC area exhibited smaller strains, indicating that LC strains would be even less in glaucoma eyes compared to normal eyes if the two groups had similar eye lengths and LC areas.…”

Pressure-Induced Changes in Astrocyte GFAP, Actin, and Nuclear Morphology in Mouse Optic Nerve

“…A series of morphologic smoothing was performed to remove local artifacts owing to binarization, adapted from a previously reported method. 23 , 30 These included using ‘bwmorph’ with the options of ‘clean,’ ‘majority,’ and ‘bridge’ to remove pixel-level noise. Morphologic opening (Matlab function ‘imopen’) was also applied with disk element sizes of three and diamond element size of four in the GFAP and nuclei channels, respectively, to separate regions that were partly connected.…”

“…The resulting dispersion parameter, which signifies the degree of alignment along the average orientation, was defined as the anisotropy. 23 A network with processes aligned in parallel with each other would yield an infinite dispersion value, while a dispersion value of 0 would indicate that the processes are not selectively aligned along any one direction in the imaging plane. Number of nuclear clusters : The number of separated regions in the DAPI-labelled channel was recorded as the number of nuclear clusters per section ( Fig.…”

“…Serial ON sections were imaged after immunolabeling or staining for GFAP, actin, and nucleus. A custom morphologic algorithm 23 was adapted to quantify structural features, including area coverage, process thickness, and aspect ratio of the nuclei. The outcomes were used to examine differences after 3 days of OHT and to assess the effect of IOP level.…”

So-Called Lamina Cribrosa Defects May Mitigate IOP-Induced Neural Tissue Insult

“…A prevailing theory about the function of LC connective tissues is that they provide structural support to the adjacent neural tissues, including LC astrocytes and unmyelinated retinal ganglion cell axons. [6][7][8][9][10][11][12] A focal decrease or absence of connective tissues would compromise this support, aggravating intraoc-ular pressure (IOP)-induced mechanical insult to neural tissues. 5,[13][14][15] This, in turn, would potentially increase the risk of neural tissue damage and vision loss, explaining why these foci of missing connective tissues are regarded as "LC defects."…”