B.C. Martins1;A.P. Oriá1; C.P. Soares2; C.B. Neto3;J.A.S. Zuanon3; J.M.B. Duarte1; J.L. Laus1
The ocular surface is composed by the conjunctival, limbic and corneal epithelium, as well as lacrimal glands and pre-ocular tear film. Its integrity is related to the integrity of those structures. The mechanic protection to the eye is made by the conjunctiva, acting as a natural barrier to pathogens. There is no consistent data about ocular conditions of Brazilian deer. The present study aimed to establish the features of the conjunctival epithelium of captive brown brocket deer (Mazama gouazoubira)in São Paulo State, Brazil. ARVO guidelines on the use of animals in experimentation were adhered to and institutional ethics clearance was obtained prior to doing the experimentation. The animals used in this experiment (n=9) were from Animal Husbandry Department of College of Agricultural and Veterinarian Sciences. They were manually retrained and the samples were collected for brush exfoliative cytological and histological examination. Ocular topical proxymetacaine was applied to the eye before brushing and fragment harvesting. The ocular surface was then scraped by several gentle rotations of the brush and the collected material was smeared on slides and fixed by absolute alcohol. Brush samples were stained with Papanicolaou. Fragments for histological evaluation were obtained from the superior bulbar conjunctiva, fixed by 10% formol and stained with Hematoxylin and Eosin. All samples were examined under light microscopy. In cytological examination, a high number of superficial epithelial cells with poliedric shape, abundant and blue cytoplasm, and minimal nuclei were observed. Keratinization was suggested by the pink cytoplasm of some cells. Intermediary cells were less observed, with oval shape and round nuclei. Basal cells were found more frequently than intermediary cells, and their shape was round, as well as their nuclei. The cytoplasm was blue and nuclei were colored in purple. Cytoplasm melanin granules were evident in intermediary and basal cells. Goblet cells were also evident presenting round shape, huge size and blue color. Some of them were observed with mucous in their cytoplasm. The histological evaluation revealed a stratified epithelium composed by two to four layers of cells. The deepest layer was composed by basal cells and the primary layer contained superficial cells. Intermediary cells, if present, were situated between the basal and superficial layer. Globet cells were evident adjacently to epithelial cells. The cytological and histological findings were in agreement with those from domestic species. Keratinizated cells may be present due to minimal inflammation or ambient aggression to the conjunctiva.
Supported by Fundação Coordenação de Aperfeiçoamento de Pessoal de Nível Superior--CAPES, Fundação de Amparo à Pesquisa do Estado de São Paulo-FAPESP, Brazil.
1. Hendrix, D. V. H. Diseases and surgery of the canine conjunctiva. In: GELATT, K. N. Veterinary ophthalmology. 3th ed. Baltimore:Lippincot Williams & Wilkins, 1999. p. 619-634.
2. Rolando, M; Zierhut, M. The ocular surface and tear film and their dysfunction in dry eye. Surv. Ophthalmol., Brookline, v. 45, supl. 2, p. 203-210, 2001.