A gliacentric view of the human retina

The structure of retina was historically described using light microscopy histological sections. This description placed prime importance on neural elements and their interconnections is establishing retinal structure. Of the 10 retinal layers, 7 are neural elements. This neurocentric description is, however, not the only way to view the retina. After considering various pathological conditions, we believe that an alternative description of the retina exists, based on glial cells. The gliacentric view may better enhance our understanding of vascular pathologies of the retina. In contrast to the classical view of a 10 sheet neurocentric structure, we propose a gliacentric structure composed of two sheet. This model is supported by the embriological development of the retina, originating from two neuroepithelial sheets (the two layers of the optic vesicle). These neuropithelial layers later develop into two monostratified stheets composed of epithelial cells with the following characteristics: a basement membrane at the basal side, villi at the apical side and intercellular junction complexes at the lateral aspects of the cells. The neural network of the retina lies embedded within these sheets. This gliacentric model has not only theoretical implications but bay also explain why various pathologies of the retina are limited to one compartment rather than extending the entire thickness of the retina.