PURPOSE: Retinopathy, globe enlarged (RGE) is an inherited genetic disease of chickens with a corneal phenotype characterized by loss of tissue curvature and changes in peripheral collagen fibril alignment. This study aimed to characterize the material behavior of normal and RGE chicken corneas under inflation and compare this with new spatial- and depth-resolved microstructural information to investigate how stromal fibril architecture determines corneal behavior under intraocular pressure (IOP). METHODS: Six RGE chicken corneas and six age-matched normal controls were tested using trephinate inflation and their stress-strain behavior determined as a function of posterior pressure. Second harmonic generation mulitphoton microscopy was used to compare the in-plane appearance and degree of through-plane interlacing of collagen lamellae between normal and mutant corneas. RESULTS: RGE corneas displayed a 30-130% increase in material stiffness [E(tangent)(RGE) = 0.94 ± 0.18 MPa to 3.09 ± 0.66 MPa; E(tangent)(normals) = 0.72 ± 0.13 MPa to 1.34 ± 0.35 MPa] (P ≤ 0.05). The normal in-plane disposition of anterior collagen in the peripheral cornea was altered in RGE but through-plane lamellar interlacing was unaffected. CONCLUSIONS: This article demonstrates changes in corneal material behavior in RGE that are qualitatively consistent with microstructural collagen alterations identified both herein and previously. This study indicates that, in general, changes in stromal fibril orientation may significantly affect corneal material behavior and thereby its response to IOP.
PURPOSE:Retinopathy, globe enlarged (RGE) is an inherited genetic disease of chickens with a corneal phenotype characterized by loss of tissue curvature and changes in peripheral collagen fibril alignment. This study aimed to characterize the material behavior of normal and RGE chicken corneas under inflation and compare this with new spatial- and depth-resolved microstructural information to investigate how stromal fibril architecture determines corneal behavior under intraocular pressure (IOP). METHODS: Six RGE chicken corneas and six age-matched normal controls were tested using trephinate inflation and their stress-strain behavior determined as a function of posterior pressure. Second harmonic generation mulitphoton microscopy was used to compare the in-plane appearance and degree of through-plane interlacing of collagen lamellae between normal and mutant corneas. RESULTS: RGE corneas displayed a 30-130% increase in material stiffness [E(tangent)(RGE) = 0.94 ± 0.18 MPa to 3.09 ± 0.66 MPa; E(tangent)(normals) = 0.72 ± 0.13 MPa to 1.34 ± 0.35 MPa] (P ≤ 0.05). The normal in-plane disposition of anterior collagen in the peripheral cornea was altered in RGE but through-plane lamellar interlacing was unaffected. CONCLUSIONS: This article demonstrates changes in corneal material behavior in RGE that are qualitatively consistent with microstructural collagen alterations identified both herein and previously. This study indicates that, in general, changes in stromal fibril orientation may significantly affect corneal material behavior and thereby its response to IOP.
Authors: Jacek K Pijanka; Baptiste Coudrillier; Kimberly Ziegler; Thomas Sorensen; Keith M Meek; Thao D Nguyen; Harry A Quigley; Craig Boote Journal: Invest Ophthalmol Vis Sci Date: 2012-08-07 Impact factor: 4.799
Authors: Siân R Morgan; Erin P Dooley; Paul M Hocking; Chris F Inglehearn; Manir Ali; Thomas L-M Sorensen; Keith M Meek; Craig Boote Journal: Biophys J Date: 2013-06-18 Impact factor: 4.033
Authors: Ibrahim Seven; Ali Vahdati; Vinicius Silbiger De Stefano; Ronald R Krueger; William J Dupps Journal: Invest Ophthalmol Vis Sci Date: 2016-11-01 Impact factor: 4.799