Área Técnica: Retina
THE INNER PLEXIFORM LAYER INVOLVEMENT ON RETINAL SPREADING DEPRESSION DEMONSTRATED ON OCULAR COHERENCE TOMOGRAPHY
The aim of the present study is to demonstrate the Inner Plexiform Layer involvement on Retinal Spreading Depression [SD] demonstrated on Ocular Coherence Tomography after the use of brimonidine over Retinal Spreading Depression. Brimonidine is an alpha-2–adrenergic receptor agonist and it is used in the management of glaucoma. The Spreading Depression of neuronal electric activity is a wave of cellular massive sustained depolarization that damages the nervous tissue. Local trauma, pressure, ischemic injuries and other chemical agents as high extracellular potassium concentration or glutamate, can trigger SD, leading to exaggerated focal electrical followed by an electrical silence.
the authors used in this study the chicken retina as model and performed alpha2-receptor detection by Western Blotting and Immunohistochemistry. The electrical signals of SD are obtained by microelectrodes on retina in the absence or presence of Brimonidine. For in vivo visualization the authors observed the retina with Optical Coherence Tomography on normal state, with SD passing, and with SD + Brimonidine.
Our data revealed that OCT demonstrated that SD creates a hyper reflectance at inner plexiform layer, but SD was not visualized when the retinal treatment with brimonidine was realized. The authors also show that the alpha2-adrenergic receptors are present in Müller cells and the treatment with Brimonidine decreases the SD`s velocity as well as the voltage of SD waves.
In this study about brimonidine possible pathways of neuroprotection we observed and firstly demonstrated SD on OCT that the inner plexiform layer is the main optically affected layer on SD; as well as, identified a new cellular target, the Müller cells.