Study The Cornea Changes Of Diabetic Rabbit By Laser Confocal Microscopy

OBJECTIVE1.To investigate the pathological formation process of diabetic cornealkeratopathy by confocal microscopy in vivo diabetic rabbit model.2.To analyse thepathogenesis of diabetic keratopathy in the level of biological overall,we combine thevivo confocal microscopy observations and hematoxylin-eosin staining of diabeticrabbit corneal tissue sections.3.To study the relationship between the apoptosis ofcornal cell and the expression of caspase-3and the molecular mechanism of diabetickeratopathy in protein levels by immunohistochemical methods.METHODS1.18New Zealand white rabbits were intravenous injection of alloxanand given high glucose and fat diet to duplicate the diabetes model.3New Zealandwhite rabbits were giving the same dose of saline injection and the normal diet incontrol group.2.Using corneal confocal microscopy in vivo observation respectivelyprior to the administration and4w,8w,12w after the disease model.3.3rabbits wererespectively sacrificed after4w and8w of the establishment of disease model.Other12diabetic rabbits and3rabbits in control group were sacrificed after12w.All cornealtissue were deal with paraffin,HE staining and observed under the microscope.4.Acomprehensive of the immunhistochemical observation of the expression of caspase-3in corneal tissue sections,with the results of the community focus observation in vivoand HE staining in the tissue section of corneal disease to study the molecularpathogenesis of diabetic keratopathy.RESULTS1.The blood glucose of diabetic rabbit were significantlyhigher,17.3mmol/L of the minimum glucose,31.2mmol/L of the highest and22.97±4.03mmol/L on average.2.The epithelial of corneal tissue gradually exfoliation and the area was also increased in diabetic group.The number of stromal cells reduced with stromaledema and morphological changes in stromal cell nuclear.The number of endodermispleomorphic cells increased and endothelial cells reduced.Subepithelial(Brownlayer)nerve fibers appear bent,distored and other morphological changes.Branching ofthe stromal nerve fibers reduced and fractured.3.Caspase-3were expression in theepithelium and stroma of the corneal tissue of diabetic rabbits,and it increased as toextend the duration of diabetes.CONLUTIONS Diabetis will cause the occurrence of the diabetic keratopathy.As theextension of the diabetes time,corneal nerve fibres and epithelial cells degenerationwith the apoptosis and loss of epithelial cells.Corneal stromal cells loosely arrangedwith stromal edema and deformation and apoptosis of stromal cells nuclear.Thepathological changes of corneal epitheal cells and stromal cells may be associated withcorneal nerves,while the earliest morphological changes of the corneal tissue should beendothelial cells which may be directly related to the contact of aqueous humor.