Abstract
Purpose: :
To evaluate the ocular toxicity of increasing doses of intravitreous Omalizumab (Xolair) in the rabbit eye.
Methods: :
Twelve New Zealand pigmented rabbits received unilateral intravitreous injections of 0.1 ml of Omalizumab 0.25 mg (three eyes), 0.50 mg (three eyes), 1.0 mg (three eyes) or 0.1 ml balanced salt solution (BSS, three eyes). Slit-lamp biomicroscopy and fundoscopy were carried out at baseline, day 1, 7 and 14 following intravitreous inyection, while lectroretinography (ERG) was carried out at baseline and day 14. Animals were euthanized on day 14, and histopathological examination of the eyes was performed.
Results: :
Slit-lamp bioimicroscopy and fundoscopy were normal in eyes having received BSS, 0.25 mg or 0.50 mg omalizumab; however inflammation was present in two of the three eyes having received 1.0 mg omalizumab. Similarly, comparison of scotopic and photopic ERG light at baseline and day 14 demostrated no changes in eyes receiving BSS, 0.25 mg or 0.50 mg omalizumab, but two of the three eyes having received 1.0 mg omalizumab showed a greater than 30% reduction in a and b waves. Finally, histopathology demonstrated no differences between eyes receiving BSS, 0.25 mg or 0.50 mg omalizumab, but two of three eyes injected with 1.0 mg demonstrated inflammatory cell infiltration (mainly plasma cells) in the vitreous without gross retinal structural alterations.
Conclusions: :
Increasing doses of intravitreous omalizumab in rabbits eyes caused no detectable functional or structural ocular toxicity up to the dose of 0.50 mg. Administration of 1.0 mg in 0.1 ml was associated with an inflammatory reaction.
Keywords: drug toxicity/drug effects • cell survival • electroretinography: non-clinical