Effect of systemic administration of phytosterol on lacrimal quality of dogs


  • Fernanda Gosuen Gonçalves Dias Universidade de Franca
  • Brenda Martins Cristino Universidade de Franca
  • Claudianara Ávila Silva Universidade de Franca
  • Larissa Fernandes Magalhães Universidade de Franca
  • Cristiane dos Santos Honsho Universidade de Franca
  • Ricardo Andrade Furtado Universidade de Franca
  • Tais Harumi de Castro Sasahara Universidade de Franca
  • Lucas de Freitas Pereira Universidade de Franca
  • Adriana Torrecilhas Jorge Universidade de Franca




Lipids, Veterinary ophthalmology, Lacrimal quality, Tear crystallization test


The tear lipid layer (oily outer layer) reduces evaporation and prevents tear overflow. In dogs, reductions in the lipid components of this layer (cholesterol, triglycerides and phospholipids) can cause eye serious diseases. In this way, the tear crystallization test analyzes the lacrimal quality, however, it is less used in veterinary. As phytosterol reduces blood cholesterol, the objective of this study was to investigate, through the tear crystallization test, whether the systemic administration of this drug influences the lacrimal quality of healthy dogs and, in addition, to verify differences in the interpretation of the ophthalmic test between different evaluators. Eight beagles, healthy, of both sexes, young and adults, without clinical ophthalmic signs apparent were selected. Basal lacrimal samples (D0) were collected from the right and left eye of all animals with glass capillary tube and arranged on a glass slide for scanning the images and subsequent microscopic analysis. Subsequently, all were medicated with the phytosterol (Collestra® 650 mg: 1 capsule, orally, every 12 hours, for 15 days). After seven (D7) and fifteen (D15) days of this systemic administration, the tear crystallization test in both eyes of all dogs was again performed for statistical comparison with the baseline results. The photographs of the slides were classified by four evaluators (AV1 and AV2 with professional experience in ophthalmology and AV3 and AV4 without previous professional experience in ophthalmology), following standards established by Rolando (1984). The results were statistically verified by analysis of simple variance (ANOVA One-Way). There was no statistical difference in the tear crystallization test between the established periods and in relation to the different ophthalmic test evaluators (p≤0.05). Although phytosterols reduce blood cholesterol levels, it was observed in the present study that these drugs when administered systemically did not interfere in the tear lipid layer and, consequently, in the lacrimal quality of healthy dogs, and may be prescribed as lipid-lowering agents for patients with ocular diseases, especially the lacrimal ones.


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How to Cite

DIAS, F.G.G., CRISTINO, B.M., SILVA, C. Ávila, MAGALHÃES, L.F., HONSHO, C. dos S., FURTADO, R.A., SASAHARA, T.H. de C., PEREIRA, L. de F. and JORGE, A.T., 2019. Effect of systemic administration of phytosterol on lacrimal quality of dogs. Bioscience Journal [online], vol. 35, no. 4, pp. 1173–1178. [Accessed1 March 2024]. DOI 10.14393/BJ-v35n4a2019-41782. Available from: https://seer.ufu.br/index.php/biosciencejournal/article/view/41782.



Agricultural Sciences