Histomorphological and Histomorphometrical Postnatal Development of the Retina in White Rabbits (Oryctolagus Cuniculus)

Abstract

The present study aims to elucidate retinal development by analyzing the histomorphological and histomorphometrical parameters in white rabbits (Oryctolagus cuniculus retina). Samples were collected from 25 rabbits divided into five different age groups: 1, 10, 15, 30, and 40 postnatal days (PND). The samples were then sectioned, processed, and stained with Hematoxylin and Eosin stain, as well as Masson's trichrome stain. Some sections were additionally stained with toluidine blue (TB) stain to detect cell density in the outer and inner nuclear layers. Measurements of retinal layers were performed for morphometric comparison among the age groups. The findings revealed that the total thickness of the retina gradually decreased with age. The thickness of the inner and outer nuclear layers, as well as cellular density, also decreased with the development of the photoreceptor layer (rods and cones). This decrement was accompanied by an elevation of the outer plexiform layer thickness and swelling of the ganglion cell layer, particularly after the opening of the eyelids and the differentiation of the different layers of the retina. The histomorphometry results in the retina showed significant differences in the thickness of its different layers among the five age groups. In conclusion, Retina showed highly active histological development and growth with cellular differentiation and significant measurements differences before and after eyelid opening between 10 -15 PNDs.