Abstract
Purpose :
While elevated IOP is often associated with glaucoma, many patients develop glaucoma with normal IOPs or experience ocular hypertension without developing glaucoma, indicating that other factors contribute to the disease. Evaluating these factors in vivo can be difficult and costly, though, so we have developed a model using decellularized posterior poles to aid in studying glaucoma biomechanics.
Methods :
Posterior poles were isolated from fresh porcine eyes, and the retina and choroid were removed. The dissected tissue was then subjected to a mild, detergent-based decellularization process. Histology was performed to show that decellularization removed cells while maintaining the architecture and basement membrane of the tissue. To evaluate the ability of the model to mimic dissected tissue, we subjected the tissue to 5 and 15 mmHg of pressure and imaged the lamina cribrosa at each pressure using two-photon microscopy both before and after decellularization. To ensure that the decellularized tissue was still able to hold pressure, which is needed to image pressure-induced structural changes, the entire tissue was infiltrated with a bioinert PEG-based gel or the optic nerve was coated with super glue prior to pressurization. The gel-infiltrated decellularized tissue could then be seeded with human cells.
Results :
Histology and two-photon imaging confirmed that decellularization was successful in removing cells and maintaining the structural architecture of the posterior poles. Gel-infiltrated and glue-coated tissues produced displacements 34 ± 4% and 69 ± 2% different than dissected tissues, respectively. While both types of coatings produced strains significantly different than those of the dissected tissues (p < 0.0001), all gel and glue coated optic nerves were able to hold both 5 and 15 mmHg of pressure, indicating their potential to be used to model pressure-induced structural changes similar to those experienced by glaucomatous optic nerve heads.
Conclusions :
Our decellularized optic nerve head model is capable of maintaining the structural qualities of dissected optic nerve heads, and gel infiltration is able to help partially restore the biomechanical properties of the tissue prior to decellularization. Therefore, this biomimetic model offers an alternative in vitro platform to study cellular factors that could contribute to glaucoma development and progression.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.