In this study, alkali damage was created using 2 N NaOH in a total of 80 eyes belonging to 40 New Zealand rabbits. Two different models of alkali damage were obtained, of which one was in the whole of the ocular surface in the left eye and only in the cornea in the right eye of the subjects. Each model was separated into 4 groups of 10 subjects and the first groups were left as control groups. In order to restrain the collagenase enzyme, polysulphate glycosaminogiycan was administered locally to the second groups, doxycycline was given per os to the third groups and EDTA was administered locally to the fourth groups. To prevent infection, antibiotic pomade was used twice a day in all subjects. Drug administration was continued until day 21. The clinical changes seen in the subject were observed for 21 days. On days 0, 7, 14 and 21 the clinical appearance of the subjects were photographed and the depth of the cornea lesions were evaluated.
The Schirmer tear test was applied to all subjects on days 0. 7, 14, 21. Findings were statistically evaluated. Samples taken from the cornea, conjunctiva and third eyelid of the subjects, which were destroyed on day 21, were histopathologically examined. A decrease in the amount of tears on day 7 and an increase, which caused the tear amount to lose its statistical meaning, on days 14 and 21 was determined, which had statistical significance only in the PSGAG and EDTA groups.
According to the results of our study, it was seen that PSGAG, which we assumed could have an anticollagenase effect, did not have an adequate anticollagenase effect and that doxycycline, which is known to have a anticollagenase effect, was not effective enough on the ocular surfaces when administered per os in accidents with alkali. In the model where primary alkali damage was created in the corneal surface, it was seen that in comparison to the control group. EDTAs treatment effect was very significant (p<0.01). Following histopathological examination, it was determined that the most severe destruction had been made in the model with damage to the whole of the ocular surface and to the control groups. In the light of the clinical and histopathological findings which were obtained, it was determined that alkali burns and collagenase activity of the ocular surface developed and that in deep progressive cornea ulcers EDTA proved to be an anticollagenase substance which supported the treatment.