CHANGES IN RETINA IN STREPTOZOTOCIN-INDUCED DIABETES AND THE POSSIBLE PROTECTIVE ROLE OF SELENIUM: A HISTOLOGICAL AND HISTOMORPHOMETRIC STUDY IN ADULT MALE ALBINO RAT Soheir H. Ahmed, Fayza Abdel Raouf, Sherif F. Arsanyous, Walaa M. Sayed and Suzan M. Soliman* Department of Anatomy, Faculty of Medicine, Cairo University and MSA University*
Background: Diabetic retinopathy (DR) is a leading cause of acquired blindness. DR is rarely detected in the first few years of diabetes. Although DR has long been recognized as a vascular disease, recently it has been observed that retinal cells are also affected by diabetes, resulting in dysfunction and degeneration of neuronal cells. Aim of the work: is to study the histopathological changes in the retina of the diabetic rats and to study the possible protective role of selenium. Material and Methods: Sixty male albino rats were divided into 5 groups (12 rats each): Group I (Normal control), Group II (Sham control, Group III (STZ - induced diabetic group), Group IV (Curative- diabetic receiving selenium concomitantly), Group V (Prophylactic- diabetic receiving selenium 2 weeks before STZ injection). Each of the previous groups was subdivided into two subgroups; group a (sacrificed after 2 weeks) and group b (sacrificed after 8 weeks). The animals were sacrificed by cervical dislocation and the eye balls were enucleated and processed for histological and histomorphometric examination. Results: It was found that diabetes caused marked degenerative changes of the retinal cells which progressively increased with the disease with late vascular changes. Concomitant administration of selenium decreased the rate of retinal neuronal loss, while the prophylactic use of selenium succeeded in delaying the onset of DR. Conclusion: selenium has the ability to ameliorate the pathological events of diabetes and delay the development of subsequent diabetic retinopathy, especially if used before the induction of diabetes as a prophylactic drug.