Comparison of the effects of myrtus communis (myrtle tree; leaf and trunk) extract, E-PRP (eye platelet rich plasma) and gentamycine on wound healing in experimental alkaline corneal burns in rabbits

The purpose of this study was to evaluate the effects of Gentamicin sulfate (chemical agent), eye platelet rich plasma (E-PRP), and ophthalmic myrtle tree extract (OMTE) on wound healing in rabbits with experimentally induced alkaline cornea burn. The animal material of this study consisted of 42 male New Zealand rabbits. After inducing alkaline burn, rabbits were segregated into six groups such as control (Group I, n=7), Gentamicin (Group II, n=7), E-PRP (Group III, n=7), OMTE (Group IV, n=7), E-PRP + Gentamicin (Group V, n=7), OMTE + Gentamicin (Group VI). Drops were administered four times a day, with a volume of 60 µL on the cornea burn-induced right eyes of the animals during the study period. According to the clinical examinations, prulent discharge were detected in Group I, Group III, and Group IV, however in gentamycin administered groups, no prulent discharge were detected. Intra-ocular pressure fluctuated among all groups, nevertheless, Group IV was measured close to the normal values. There were no statistically significant results among groups in terms of Schirmer tear test I (p>0.05). Corneal lesions were detected to be regressed in all groups, however, there were no significant differences among groups (p>0.05). Hematological and biochemical parameters of all groups were in reference values. When the Total antioxidant status (TAS) of humor aqueous was evaluated, there were no differences among groups. However in Group IV, significant differences were detected on the 0th and 42nd days, and the reason for this difference was determined to be the elevation in TAS levels on the 42nd day. There was no significant difference among groups with regards to total oxidant status in humor aqueous. According to the histopathological examinations, no significant differences were detected among groups, and the obtained results were closest to the healthy corneal thickness in Group IV. There were not any significant differences in vascular endothelial growth factor (VEGF) scoring (p>0.05) according to the immunochemical staining, and the lowest scores were obtained in Group IV. When evaluating matrix metalloproteinase-9 (MMP-9), no statistically significant differences were determined among groups, and in Group IV, the obtained results were the closest to the values of a healthy cornea. As a result, in the experimental model of OMTE preparation on the corneal wound induced by alkaline burn; epithelization, anti-inflammatory, and antioxidant effects were remarkable, and it is concluded that myrtle tree extract can be used as an alternative product in alkaline cornea defects.