Use of specular microscopy to determine corneal endothelial cell morphology and morphometry in enucleated cat eyes

Abstract

The purpose of this study was to investigate the effect of age on endothelial morphology and morphometry in cats. The corneal endothelium was studied using a contact specular microscope. A total of 18 cats (Felis catus Linnaeus, 1758) were evaluated in this study. The subjects were divided into three groups of six cats each in function of age: G1 (1 to 3 months old), G2 (5 to 12 months old), and G3 (24 to 40 months old). The examination presented data as endothelial cell density (ECD), average cell area, corneal thickness, polymegathism, and pleomorphism. Results revealed ECD decrease in corneas of normal cats with age, as well as a corresponding increase in endothelial cell area and pleomorphism. The present work suggests that the endothelial parameters evaluated change with advancing age.

Morphology of endothelial cells from different regions of the equine cornea

“…Normally, corneal endothelium is a monolayer consisting mostly of hexagonal cells, but may have four, five, seven, or even eight sides (TUFT & COSTER, 1990;DOUGHTY, 1998). Results of previous studies reported no significant difference in polymorphism according to age (SPERLING 1977;GWIN et al, 1982) and the lack of differences in relation to endothelial parameters obtained from the bulbs of the right and left eyes in dogs, pigs, horses, and cats (GWIN et al, 1982;ANDREW et al, 2001;AMANN et al, 2003;TAMAYO-ARANGO et al, 2009;FRANZEN et al, 2010). Results obtained in this study showed that the normal equine endothelium consisted of a monolayer of hexagonal cells; most, however, have also been observed with cells having four, five, seven, eight and nine sides.…”

“…Using images obtained by specular microscopy, it is possible to examine the corneal endothelium and obtain data related to endothelial cell density and morphology. This technique has been used to quantify endothelial parameters in humans and other animal species including pigs (TAMAYO-ARANGO et al, 2009), rabbits (SAILSTAD & PEIFFER, 1981;OJEDA et al, 2001), dogs (GWIN et al, 1982;PIGATTO et al, 2006;RODRIGUES et al, 2006), horses (ANDREW et al, 2001;LEDBETTER & SCARLETT, 2009), llamas and alpacas (ANDREW et al, 2002), chinchillas (BERCHT et al, 2015), and cats (FRANZEN et al, 2010), among others. The high cost of specular microscopes and the difficulty in obtaining good images in injured endothelial areas are common challenges or barriers to the use of this technique (ANDREW et al, 2001;PIGATTO et al, 2005a;SAAD et al, 2008).…”

“…enucleated eye balls have proven that it is possible to evaluate the corneal endothelium within six hours post-mortem without structural changes occurring (ANDREW et al, 2001;PIGATTO et al, 2006;RODRIGUES et al, 2006;PIGATTO et al, 2008;FRANZEN, et al, 2010).…”

Effects of intracameral brilliant blue on the corneal endothelium of swine: in vitro study

“…The swine corneas in this research were maintained in moist chamber for less than six hours until glutaraldehyde fixation to avoid endothelial damage. This methology has also been used with excellent results in previous studies (Pigatto et al 2005, Franzen et al 2010, Coyo et al 2015. SEM has been widely used to compare the endothelial ultrastructure of vertebrates, and to evaluate the effects of medication, chemicals or surgical procedures on the endothelium (Pigatto et al 2005, Tamayo-Arango et al 2009).…”

“…In humans, corneal tissues for transplants must be used within six hours of the donor's death and need to be safely maintained to avoid endothelial damage (Franzen et al 2010). The swine corneas in this research were maintained in moist chamber for less than six hours until glutaraldehyde fixation to avoid endothelial damage.…”