an investigation on the effects of the aloe vera extract on the thickness of the retina in male diabetic rats

retina is a part of the central nervous system derived from the neuroectoderm and made up of 5 layers.in this study, the changes in the thickness of the retinal layers as a consequence of diabetes and effect of aloe vera gel extract in male rats were assessed. thirty sprague dawley adult male rats (175 ± 25 g) in two age groups (4 and 8 weeks) were divided into 6 groups of 5 as control, diabetic and diabetic receiving 400 mg/kg aloe vera extract. diabetes was induced by ip injection of 50 mg/kg of stz (streptozotocin). the animals were weighed and their blood sugar was measured by glucometer before stz administration and 24 h thereafter. animals were anesthetized with sodium thiopental (40 mg/kg) via ip injection. after removal ofeyes on both sides, retina was dissected out precisely and fixed in 4% glutaraldehyde, post fixed in osmiumtetroxid 1%, dehydrated and then embedded in taab resin. thin sections (1 μm) were stained with toluidineblue stain and viewed under light microscope. ten slides were prepared from each animal. the resultsrevealed reduction of the blood glucose levels and body weight in treated rats in comparison to diabeticgroups. the thickness of neural retina and its layers were different as well. in the group treated with aloevera the thickness of retina and its layers retained their normal histologic structures.