Electroretinographic signs of retinal remodeling after experimental induction of retinal pigment epithelium atrophy

: Various animal models of atrophy of retinal pigment epithelium (RPE) are created in order to study certain aspects of geographical atrophy in humans. To study the effects of new methods of therapy, it is necessary to determine the objective functional markers of structural changes in the retina. Purpose: To determine the alterations in activity of the retina that characterize its remodeling in induction of RPE atrophy. Material and

Methods: Full-field electroretinograms (ERG), pattern ERG, and multifocal ERG were recorded according to the ISCEV standards from the right eyes of twenty rabbits of the New Zealand albino breed 6-7 weeks after induction of RPE atrophy by subretinal administration of 0.9% sodium chloride or bevacizumab solution.

Results: Characteristic electroretinographic signs of RPE atrophy and retinal remodeling are described. Changes in ERG indicate a predominant inhibition of the functional activity of photoreceptors compared with bipolar cells, which objectively reflects an impairment of their metabolism associated with RPE pathology. With the injection of bevacizumab, a sharp weakening of the functional symbiosis of Mueller cells with bipolar cells was observed. According to pattern ERG, the function of the retinal ganglion cells was reduced. The reaction of the paired eyes after induction of RPE atrophy included a moderate decrease in the amplitude of b-wave of photopic ERG and activation of glia-neuronal relationships.

Conclusion: Subretinal injections of 0.9% sodium chloride and bevacizumab trigger changes in the retina that reflect specific remodeling of retinal neurons of the second and third orders, which characterizes the used models of RPE atrophy.