Figure 3

Morphological changes in Iba-1+ cells. The idealized schematic drawing illustrates the morphological types of Iba-1+ cells in the different retinal layers in naïve (A, D, G, J), contralateral (B, E, H, K) and OHT eyes (C, F, I, L). Proportions between cell sizes were established taking into account the scale value of the microphotographs. In NFL-GCL (A-C), both in contralateral (B) and in OHT eyes (C), perivascular cells (a) and ramified cells (b) showed a retraction of their cellular processes in comparison with naïve eyes (A). Ameboid cells (c), absent from naïve eyes (A), were observed in contralateral (B) and in OHT eyes (C). Only in OHT eyes (C) were two additional morphological types of Iba-1+ cells observed: rounded cells (d) and rod-like cells (e). In the IPL (D-F) ramified cells (a) and dendritic-like cells (b) exhibited signs of activation (process retraction in (a) and increased secondary and higher-order processes (a, b)) in contralateral (E) and in OHT eyes (F). In the OPL (G-I) ramified cell processes were retracted and were increased in contralateral (H) and in OHT eyes (I) in comparison with naïve eyes (G). In the OS (J-L), cell orientation of type 1 OS Iba-1+ cells (a) changed from perpendicular in naïve eyes (J) to parallel to the retinal surface in contralateral (K) and in OHT eyes (L). Processes of type 2 OS Iba-1+ cells (b) had a retraction of their processes and a hairy appearance in contralateral (K) and in OHT eyes (L). Ameboid cells (c) were observed in contralateral (K) and OHT eyes (L) but not in naïve eyes (J). Only in OHT eyes (L) appeared rounded Iba-1+ cells (d) and cells with a dendritic-like appearance (e) in the OS. (NFL-GCL: nerve fiber layer-ganglion cell layer; IPL: inner plexiform layer; OHT: ocular hypertension; OPL: outer plexiform layer; OS: photoreceptor outer segment).