Abstract
Purpose: :
Recently it has been shown in the (avascular) rabbit retina that intravitreal administration of Avastin is followed by mitochondrial damage in the inner segments and an expression of proteins involved in apoptosis. We investigated the safety of intravitreal Avastin in the vascularized retina of the pig.
Methods: :
Under general anaesthesia, Avastin was injected into the vitreous chamber of the right eyes and BSS was injected in the contralateral eyes. The eyes were enucleated 1, 3 and 7 days after injection, and processed for light and electron microscopy. Retinal slices were immunostained against apoptosis-related proteins bax and caspase-3 and -9.
Results: :
In contrast to the study in rabbit eyes, injection of Avastin did not induce glial reactivity or apoptosis of retinal cells at every time point investigated. No pathological changes of retinal cells were observed at light and electron microscopic level. Photoreceptors were not affected and no damage or swelling of mitochodria at the inner segments were observed. We did not detect any morphological changes of retinal neurons and glial cells in the inner nuclear and ganglion cell layers. The microvasculature and the blood-retinal barrier were intact and no changes of the choroid were observed.
Conclusions: :
Intravitreal injection of Avastin did not induce morphological changes in the pig retina or apoptotic death of retinal cells.
Keywords: drug toxicity/drug effects • microscopy: electron microscopy • microscopy: light/fluorescence/immunohistochemistry