Introduction: Ocular diseases pose a significant health
concern for donkeys. However, studies examining the microanatomy
and cell populations of the donkey retina are
scarce. The current study aimed to describe the vascular
pattern of the donkey retina and document its cellular
components. Methods: The donkey retina specimens were
obtained from different retinal regions and prepared for
semithin sectioning and immunohistochemistry. Results:
The donkey has a paurangiotic retina in which retinal vessels
are confined to a narrow area around the optic disc. Glial
cells coexist with the blood vessels being very numerous in
the vascular region and become scanty in the avascular
ones. S-100-positive astrocytes could be observed in these
avascular areas. Ganglion cells are organized in a single layer
with the least population existing in the peripheral retina.
Acidic fibroblast growth factor (AFGF) is immunoreactive in
amacrine and ganglion cells. A subpopulation of amacrine
cells reacted strongly to tyrosine hydroxylase (TH), and
others reacted positively to S-100 protein. Ganglion cell
nuclei exhibited a strong immunoreactivity to S-100 protein
as well. Furthermore, glial fibrillary acidic protein (GFAP) is
used to identify Müller cells that extend their processes
across the retina from the inner to the outer limiting
membrane. Conclusions: In conclusion, our findings provide
novel insights into the normal retinal organization. The
donkey retina shows the characteristic expression of immunohistochemical
markers for the major cell types. In
addition, the distribution of glial cells is comparable between
the vascular and avascular regions.