Comparison of the effects of ketogenic diet and western diet on cornea and retina in diabetes induced rats

Purpose:To compare the effects of different diets on cornea and retina in diabetic rats Materials and Methods:In the study,28 male 8-10 week old Long Evans rats were selected randomly and divided into four groups. For the study,a total of 4 groups were formed: healthy and normal nutrition (Group 1), diabetic normal nutrition (Group 2), diabetic ketogenic nutrition (Group 3),diabetic western-type nutrition (Group 4).To create diabetes in rats, a single dose of 60 mg/kg of streptozotocin was dissolved in phosphate buffered saline (PBS) and administered intraperitoneally, thosewith a glucose level above 200 mg/dl in the blood taken from the tail vein 72 hours after the administered was considered diabetic. At the end of ten weeks, eyes were enucleated after exsanguination under anesthesia. Immunobhistochemical staining method was used for vascular endothelial growth factor (VEGF) and Caspase-3 immunoreactivity from the tissue sections embedded in paraffin blocks.Histoscoring was performed based on the extent and intensity of immunoreactivity in the cornea and retina. The thicknesses of retinal layers stained with hematoxilen-eosin were compared. Results: Less intense staining was higher in group 3 in retinal staining with VEGF(p: 0,018).There was no significant difference between the groups in retinal staining with caspase 3 (p: 0,65). When the retinal layers are compared; innernuclear, innerplexiform, outernuclear and ganglion layers were found to be significantly thicker in group 4 than other groups. When the choroidal thickness was compared, no significant difference was found between the groups (p: 0,118). In corneal staining with VEGF, very intense staining was found at a higher rate in group 4 and less intense in group 3 (p <0,001). There was no significant difference between the groups in corneal staining with caspase 3 (p: 0,121). Conclusion: It can be said that western type diet increases apoptosis, vascular permeability, inflammation and thus cellular edema, and consequently causes tissue thickening. It can be said that the ketogenic diet is beneficial or less harmful than the western type diet. However, although positive results have been reported in the shortterm regarding the ketogenicdiet, it is a type of diet whose effect in the longterm is unknown. Longer studies are needed to determine its long-termeffects.