The cornea is the eye’s outermost layer. It is the clear, dome¬shaped surface that covers the front of the eye. It plays an important role in focusing vision. The hyperglycemic state in diabetes promotes formation of advanced glycation end products or AGEs (The non-enzymatic reaction between amino groups of proteins and reducing sugar results in the formation of toxic molecules termed advanced glycation end products that causes proteins to become damaged and dysfunctional) which then produce alteration in structural proteins in the cornea leading to thickening of the corneal stroma & Descemet’s / Bowman’s basal with morphological abnormalities in the epithelial and endothelial layers. These alterations in the diabetic cornea are accompanied by decreased protein stability and increased immunoreactive AGEs. Bowman’s membrane is highly glycated in diabetic patients. Descemet’s membrane is also very susceptible to AGEs. Rosmarinic acid (RA) is a phenolic compound that commonly found in plants of lamiaceae family. RA has various properties such as anticancer, antiviral and etc. The purpose of this study was to investigate the effect of RA on Diabetic Keratopathy.

AGEs effects were studied in vitro. The extent of proteins cornea damage and AGEs formation assessed by UV-Visible, CD, Fluorescence spectroscopy and various tests such as Congo red, DTNB, TNBS and etc.

High level blood sugar (hyperglycemia) leads to formation of AGEs that causes damaged the cornea proteins. These deleterious effects were significantly prevented by Rosmarinic acid.

Rosmarinic acid demonstrate an ability to protect cornea proteins against glycation because of its Anti-Glycation property (inhibits the formation of AGEs), that potentially prevent the formation or to slow the progression of Diabetic Keratopathy.