Related Experiment Video
Updated: Jul 14, 2026

Whole Mount Imaging to Visualize and Quantify Peripheral Lens Structure, Cell Morphology, and Organization
Published on: January 19, 2024
Force and geometry determine structure and function of glaucoma filtration capsules
1Biology Department, United States Air Force Academy, 2355 Faculty Drive 2N224, HD USAFA/DFB, Colorado Springs, CO 80840, USA. mike.wilcox@usafa.af.mil
Background/Aims:
Glaucoma shunts vent aqueous humor to orbital tissue across a fibrous capsule. The capsule consists of collagen and fibroblasts, and its formation was assumed to be a cicatricial process. Capsule fibrosis remains the leading cause of device failure. We tested the wound healing hypothesis using morphometry and polarization microscopy and found the capsule consists not of scar tissue but rather highly organized extracellular matrix.
Methods:
Polarization microscopy reveals collagen orientation within the extracellular matrix. Rotation of the specimen in the plane of polarized light reveals collagen bundle orientation with respect to capsule surface geometry. Capsule thickness was measured and correlated with device dimension.
Results:
Capsule collagen is highly organized and not scar tissue. Relative orientation is predictable from simple engineering principles and shows tissue deposits reinforcing collagen parallel to its principle stress axes along the capsule surface. Capsule thickness and collagen orientation correlate with device dimension and surface geometry.
Conclusion:
The corollary is true. Geometry can be used to manage the amount, distribution and orientation of collagen and thus control hydraulic conductivity and surface area of the filtration capsule.
Related Concept Videos
Glaucoma: Overview
Renal Corpuscle
Glomerulus: Structure and Function
The glomerulus is a tiny, intricate network of capillaries located at the beginning of the nephron. It's enveloped by the Bowman's capsule and receives its blood supply from an afferent arteriole, which divides into numerous capillaries...
Glomerular Filtration
Components of the Filtration Membrane
The filtration process involves three key layers: the glomerular endothelial cells, the basement membrane, and the podocyte-formed filtration slits.
Glomerular Filtration: Net Filtration Pressure
GBHP, with an average value of 55 mmHg, promotes filtration by pushing water and solutes through the filtration membrane. This is balanced by two opposing forces: CHP, a "back pressure" exerted against the filtration membrane by fluid already in the capsular space and renal tubule,...
Open Angle Glaucoma: Treatment
Drugs such as carbonic anhydrase inhibitors, α2- and...
Angle Closure Glaucoma: Treatment
