Iba-1+ cells in the OS after 15 days of unilateral laser-induced OHT. Iba-1 immunostaining. Retinal whole-mount. Type 1 (A, C, E) and type 2 (B, D, F, G) Iba-1+ cells in the OS. The retinal-like section effect produced by the pressure exerted by the cover slip on one edge of the tissue (A) allowed us to observe that in type 1 OS Iba-1+ cells numerous processes emerged from the same point of the soma, like the roots of a tree. In naïve eyes these processes extended across the thickness of the OS perpendicularly to the retinal surface. Consequently, soma and processes of type 1 OS cells were located on a different focal plane and therefore both cell structures could not be focused simultaneously during whole-mount analysis (A inset). In contralateral (C) and OHT eyes (E) type 1 OS Iba-1+ cells orientation changed from perpendicular to parallel to the retinal surface. In contralateral (D) and OHT eyes (F) type 2 OS Iba-1+ cells had a retraction of their processes and a hairy appearance. Ameboid Iba-1+ cells were observed in contralateral (D inset, arrow) and OHT eyes (arrow in H). Only in OHT eyes were two additional morphological types of Iba-1+ cells observed (G, H): cells with a dendritic-like appearance (blank arrowhead in G) and rounded Iba-1+ cells (arrowhead in H and inset). (OHT: ocular hypertension; ONL: outer nuclear layer; OS: photoreceptor outer segment).