Morphological study of the eye and adnexa in capuchin monkeys (Sapajus sp.)

Abstract

The objective of this study was to describe the anatomic and histologic features of the Sapajus sp. eye, comparing similarities and differences of humans and other species of non-human primates for biomedical research purposes. Computed tomography (CT) of adnexa, eye and orbit live animal, as well as formolized pieces of the same structures of Sapajus sp. for anatomical and histological study were also performed. The anatomical description of the eye and adnexa was performed using the techniques of topographic dissection and exenteration. Histological fragments were fixated in buffered formalin 10%, processed by the routine paraffin inclusion technique, stained with hematoxylin-eosin and special stains. CT scan evaluation showed no differences between the live animal and the formolized head on identification of visual apparatus structures. Anatomic and histologic evaluation revealed rounded orbit, absence of the supraorbital foramen and frontal notch, little exposure of the sclera, with slight pigmentation of the exposed area and marked pigmentation at the sclerocorneal junction. Masson's Trichrome revealed the Meibomian glands, the corneal epithelium and Bowman's membrane; in the choroid, melanocytes and Bruch's membrane were observed; and in the retina, cones and rods as well as, optic nerve, the lamina cribrosa of the nerve fibers bundles. Toluidine blue highlighted the membranes: Bowman, Descemet and the endothelium; in the choroid: melanocytes; and in the retina: nuclear layers and retinal pigment epithelium. In view of the observed results Sapajus sp. is an important experimental model for research in the ophthalmology field, which has been shown due to the high similarity of its anatomical and histological structures with the human species.

Anatomical, histological and computed tomography comparisons of the eye and adnexa of crab-eating fox (Cerdocyon thous) to domestic dogs

“…CT allowed identification mainly of the adnexa; and a detailed study was only possible in the live animal, regardless of the presence of iodinated contrast. This is in agreement with Nascimento et al [17], who reported no influence of iodinated contrast for the interpretation of Sapajus sp. CT images in the soft tissue window.…”

“…The influence of habitat was also noted by the brownish coloration of the bulbar conjunctiva of crab-eating foxes, also noted for Sapajus sp. and capybara eyes [15, 17], but present only in exposed areas of the canine conjunctiva, or in abnormal or chronic conditions [20–22]. Species inhabiting temperate forests, such as the American beaver, possess pigmentation limited to the limbal-based region, since those animals does not receive the same amount of sunrays in their natural environment, compared to neotropical species [15, 23].…”

Anatomia encefálica comparativa de primatas humanos e não-humanos: uma revisão

“…Os PNM estão distribuídos na América Central e do Sul e apresentam uma grande diversidade em padrões de coloração, localização e tamanho das espécies. Por outro lado, os PVM são de ocorrência dos continentes asiático e africano (Nunes & Catão-Dias, 2014;Guimarães, 2007;Rylands, 2014;Lynch et al, 2014;Silva et al, 2017).…”

Comparative Morphological and Computed Tomographical Measurements of the Orbit in Cattle and Pig Eyes

“…G.Orbital Area (OA). 22/7 ab, where a and b are half the orbital length and width, respectively (Silva et al, 2017;Lantyer-Araujo et al, 2019). H. Interorbital distance CT3D:…”

“…Morphometric Assessments.Three heads of cattle compared to three heads of domestic pigs were fixed using 0.1 mL of 10 % buffered formalin (Lantyer-Araujo et al, 2019). Macroscopic evaluation of the visual system was performed using a topographic dissection and exenteration method, with a Digital Vernier Caliper (Silva et al, 2017) the eye was sectioned in the sagittal plane, including the optic nerve. All steps were photographed with a camera.…”