Histological Study on the Effect of Aminoguanidine on the Cornea of Rat of Streptozotocin Induced Diabetes

Introduction: Diabetes mellitus is increasing worldwide at an alarming rate. Patient morbidity related to diabetic induced ocular complications has increased year on year proportionate with the worldwide increase in the incidence of diabetes. Diabetic keratopathy is a common ocular complication of diabetes. Aim of the Work: The present study tried to investigate the effects of experimentally induced diabetes by Streptozotocin (STZ) on the structure of cornea and the role of aminoguanidine administration to ameliorate these effects. Materials and Methods: Twenty adult male albino rats were divided into four groups five animals each; Group I [control group]. Group II [diabetic]. Group III [diabetic and aminoguanidine]. Group IV [non diabetic and aminoguanidine]. At the end of experiment, the rats were sacrificed and the corneas of different groups were processed for light and electron microscopic examination. Immunohistochemical study was done using caspase -3 to detect the apoptotic changes. The thickness of corneal layers was measured by image analyzer and statistical analysis was done. Results: Light microscopic examination of group II revealed marked histological alteration in the form of degenerative changes. Immunohistochemical reaction showed increased number of apoptotic cells in most layers of the cornea. Statistical analysis of group II revealed a significant increase in thickness of all corneal layers as compared to all groups. Electorn microscopic examination revealed irregularity of the basement membrane of corneal epithelium.The stroma showed focal loss of collagen fibrils. The endothelial cells were enlarged and distorted. Group III showed a more or less restoration of normal histological and morphometric structures of the cornea. Group IV was comparable to control group. Conclusion: Diabetes caused structural alterations in the cornea. However, Aminoguanidine improved structural changes caused by diabetes.