J.A.T. Pigatto1; A.A. Franzen1; F.C. Abib2; J.L. Laus3; P.M. Guedes4; P.S.M. Barros4
The endothelium is a monolayer of polygonal cells covering the posterior surface of the cornea. The objective of this study was to examine the endothelial surface and to determine density of corneal endothelial cells in normal eyes of Yacare caiman (Caiman yacare) using contact specular microscopy.
Twenty-four normal eyes from 12 Yacare caiman, aged 3 years and whose length, measured from snout to tail tip, ranged from 140 to 160 cm were studied. These eyes were obtained from a licensed Brazilian commercial company that breeds these animals for meat and hide production. All procedures were performed in compliance with the Association for Research in Vision and Ophthalmology statement on the use of animals in ophthalmic and vision research. Both eyes were examined in each yacare. Contact specular microscopy was performed using a Bio-Optics LSM 200 C with software for corneal endothelium analysis and density measurement. The density was evaluated using 3 images of the same cornea with not fewer than 100 cells per image. Density of corneal endothelial cells was calculated and compared using the Tukey test. Values of P < 0.05 were considered statistically significant.
The normal corneal endothelium of Yacare caiman consisted of polygonal cells of uniform size and shape. Mean density of corneal endothelial cells was 1180 ± 231 cells/mm2. Values did not differ significantly between right and the left eyes from the same yacare.
The present work demonstrates that the density of corneal endothelium cells in eyes of Yacare caiman is less than those described in other vertebrates.
The authors would like to thank Pro-Fauna Commercial Ltd. for supplying eyes used in this research.
1. Collin SP and Collin HB. 1998. A comparative study of the corneal endothelium in vertebrates. Clin. Exp. Optom. 81:245-254.
2. Pigatto JAT, et al. 2004. Morphometric analysis of the corneal endothelium of Yacare caiman (Caiman yacare) using scanning electron microscopy. Vet. Ophthalmol. 7:205-208.
3. Yee RW, et al. 1987. Specular microscopy of vertebrate corneal endothelium: a comparative study. Exp. Eye Res. 44:703-714.