Search

Uveitis is a major cause of vision loss. Methotrexate (MTX) has been widely used in uveitis due to its relatively safe profile. The purpose of this study was to evaluate the effects of two different dosages of MTX via intra-vitreal administration for treatment of endotoxin induced uveitis (EIU) in an experimental model. Thirty-five healthy rabbits were randomly divided into four groups and all animals were tolerated intra-vitreal injections. The first group received normal saline (NS), the second group received normal saline plus Salmonella typhimurium lipopolysaccharide endotoxin (LPS), (NS+LPS), the third group received 400 μg MTX plus LPS (LPS+MTX 400) and the fourth group received 800 μg MTX plus LPS (LPS+MTX 800). Intra-ocular inflammation was evaluated by clinical examination scoring during 7 post-injection days and histopathological examination at the end of study. Kruskal-Wallis and Mann-Whitney U tests were used to compare the histopathological and clinical scores. According to the clinical examinations, all groups demonstrated higher uveitis score than group 1 on first post-injection day. Also, groups 2 and 3 showed greater uveitis score than group 4. On the third, fifth and seventh post-injection days, clinical uveitis score in groups 2, 3 and 4 was significantly higher than group 1. The mean histopathological inflammation intensity scores in groups 2, 3 and 4 were significantly higher than group 1. Single intra-vitreal injection of 400 μg and 800 μg of MTX did not show significant anti-inflammatory effects on EIU in rabbits.

The objective of the present study was to investigate the clinical and histopathological effects of intravitreal injection of pentoxifylline (PTX) the management of an experimental model of uveitis. Fifty-two rabbits were divided randomly into six intravitreal treated groups as below: 1) Balanced salt solution (BSS), 2) Salmonella typhimurium lipopolysaccharide endotoxin (LPS) + BSS, 3) LPS + PTX 100 μg, 4) LPS + PTX 500 μg, 5) BSS + PTX 100 μg and 6) BSS + PTX 500 μg. Inflammation was evaluated by clinical examinations using slit lamp on days 1, 3, 5 and 7 post injections and histopathological examinations were also performed at the end of the study. Clinical examinations demonstrated a statistically significant difference between group 1 and group 2 on day 5 and day 7. Moreover, the comparison of clinical severity scores of group 1 with groups 3, 4, 5 and 6, on third, fifth and seventh post-injection days showed statistically significant differences. The mean histopathological inflammation intensity score in groups 5 and 6 was significantly higher than group 1. The mean histopathological inflammation intensity score in groups 3, 4, 5 and 6 was significantly higher than group 2. Intravitreal injection of PTX in an experimental model of uveitis in rabbits not only does not reduce inflammation but also leads to inflammation when used alone or in combination with LPS.