Perfil de eletrólitos e padrões de cristalização da lágrima de aves, répteis e humanos

Abstract

To describe the electrolytes presented in tears of some species of birds and reptiles, and associate these values to the tear film crystallization pattern. Ten animals of each species: Ara ararauna, Amazona aestiva, Tyto alba, Rupornis magnirostris, Chelonoidis carbonaria and Caiman latirostris; five Caretta caretta and 10 human subjects were submitted to tear sampling using the Schirmer tear test. Aliquot were put in a pool to assess concentrations of total proteins, chloride, phosphorus, iron, sodium, potassium, calcium and urea. To the tear ferning test, samples of about 2µL of each species were dried on a clean microscope glass slide at room temperature and humidity, and observed under a polarized light microscope. Crystallization patterns were classified according Rolando and Masmali scales. There was higher amount of total proteins in humans, followed by owls and caimans. Regarding tear urea, higher values were obtained for sea turtles, followed by caimans and owls. The electrolyte values showed similar electrolytic balance between species, with higher results of sodium, chloride and iron. The grading of tear crystallization patterns using Rolando scale ranged from I to II and ranged from 0 to 2 using Masmali scale in birds; and from II to IV (Rolando) and 2 to 4 (Masmali) in reptiles. Crystallization arrangements of some species had higher scores; however this condition could not be attributed to disease states, possibly being derived from the tear composition. There were no similarities in the tear crystallization patterns between phylogenetically-related species or exposed to the same environment. However, marine and lacustrine species presented increased grading scales. The lacrimal fluid ionic balance in birds and reptiles possess a similar balance to described for humans, with increased presence of sodium and chloride. However, the tear crystals had different arrangements between species, when compared to humans. Crystallization classification revealed that higher grades and types were not necessarily related to tear film disease states in wild animals.