Comparison efficacy of systemic and intravitreal infliximab treatment in endotoxin induced uveitis model

Purpose: In this study, we aimed to compare efficacy of systemic and intravitreal infliximab treatment in an experimental model of endotoxin-induced uveitis. Methods: Twenty-eight white New Zealand rabbits, weighing 2-2.5 kg, equally divided into 4 groups. Group 1 received intravitreal injection of 0.1 cc saline, group 2 received intravitreal injection of 2 µgr/ 0.1 cc lipopolysaccharide (LPS), group 3 received intravitreal injection of 2 µgr/ 0.1 cc lipopolysaccharide (LPS) and 2 mg/0.1 cc infliximab, group 4 received intravitreal injection of 2 µgr/ 0.1 cc lipopolysaccharide (LPS) and intravenous 5 mg/kg infliximab. Clinical, biochemical (protein levels and TNF-α concentrations in aqueous humour and vitreous) and histopathological evaluation were performed. Results: Clinical examination score was lower in group 4 compared with group 2 (p=0.006); but there was no significant difference between group 2 and group 3 (p=0.016). In group 1, aqueous humour protein levels were significantly lower than the other groups (p<0.001), whereas there were no significantly difference between group 2,3 and 4 (p>0.05). In group 3, aqueous humour TNF-α concentration measured significantly higher than group 4 and 1 (respectively p=0.002, p=0.003). In vitreous protein levels and TNF-α concentrations; there were no significant difference within each group (respectively p=0.026, p=0.101). In histopathological evaluation of uveal tissue and lumen, the highest inflammation was determined in group 3 (p<0.001). In group 4, histopathological evaluation of uveal tissue was lower than group 2 and 3 (p<0.001, p=0.001); whereas there was no diffirence in lumen inflammation between group 4 and 2 (p=1.00). Conclusion: Intravitreal 2 mg/kg infliximab exacerbates inflammation in EIU whereas systemic 5 mg/kg infliximab treatment suppresses inflammation effectively and rapidly. Keywords: Endotoxin, infliksimab, intravitreal, uveitis