Abstract
Purpose: :
Decorin is a small proteoglycan that binds to collagen fibrils in human cornea helping to stabilize fibrils and orient fibrillogenesis. The purpose of this study was to evaluate stromal penetration of decorin core protein and to determine effects of decorin core protein on corneal hysteresis following application to the corneal surface. The application of decorin core protein to cornea reshaped using orthokeratology lenses may stabilize the cornea to provide extended vision correction, stabilize corneal structure following LASIK procedures reducing the incidence of ectasia and strengthen keratoconic cornea.
Methods: :
Recombinant human decorin core protein was expressed in CHO cell medium in bioreactors and stored in buffered saline solution. To evaluate stromal penetration, decorin was tagged with Oregon Green 488 and applied to the surface of human donor cornea following pretreatment to dissociate epithelial cell junctures. Fluorescent decorin penetration was examined by confocal microscopy. To evaluate effects on corneal hysteresis, untagged decorin core protein was applied to the corneal surface in the feline model following pretreatment to dissociate epithelial cell junctures. Corneal hysteresis was measured using the Reichert Optical Response Analyzer. In addition, corneal tissue was dissected and examined by TEM following quinolinic blue staining to identify decorin structures.
Results: :
Confocal microscopy clearly showed the penetration of decorin core protein into the stroma following pretreatment to dissociate epithelial cell junctures. Fluorescent decorin penetration was not observed in controls without pretreatment. Feline cornea receiving decorin core protein demonstrated increased corneal hysteresis (CH) indicating strengthening of corneal structure. TEM photomicrographs from isolated feline cornea showed increased levels of quinolinic blue stained structures in corneas receiving decorin core protein. In addition, decorin supplemented cornea demonstrated enhanced clarity and matrix structure definition.
Conclusions: :
Methods were developed to increase the biomechanical strength of corneal tissue by administering of decorin core protein to intact cornea following pretreatment to enhance trans-epithelial penetration. Decorin stabilization of cornea stroma may stabilize corneal tissue following LASIK, strengthen keratoconic cornea and extend vision correction following overnight wear of orthokeratology lenses.
Keywords: cornea: clinical science • refractive surgery: other technologies • cornea: epithelium