Effects of age and breed on corneal thickness, density, and morphology of corneal endothelial cells in enucleated sheep eyes.
OBJECTIVE
The purpose of the study was to determine corneal thickness (CT), endothelial cell density (ECD), morphology, and morphometry in ovine eyes, and to report the effects of age and breed on these parameters.
Forty-eight healthy ovine eyes were classified into six groups (eight eyes per group) according to animals' age (lambs and adults) and breed (Manchega, Ripollesa, and Rasa Aragonesa). Endothelial cell density (cells/mm(2) ) and CT (μm) were calculated in the central cornea and four peripheral quadrants by means of specular microscopy. Mean cell area (MCA (μm(2) )), pleomorphism (% hexagonal cells), and polymegethism (CV) were evaluated in the central cornea. Statistics consisted of an ANOVA model and a LSD test for the post hoc analysis.


RESULTS
Results in lambs were as follows: ECD = 3532 ± 259, CT = 699 ± 56, MCA = 283 ± 22, % hexagonal cells = 75.64 ± 3.09, and CV = 18 ± 8.4; and in adults: ECD = 2204 ± 261, CT = 804 ± 87, MCA = 473 ± 53, % hexagonal cells = 69.9 ± 3.42, and CV = 18.1 ± 5.2. There were differences (P < 0.001) in all parameters studied between both groups except for the CV (P = 0.962). Regarding the breed, Rasa Aragonesa presented a higher CT (P = 0.001) and CV (P = 0.04) compared to other breeds. Mean values of all groups together showed that central and dorsal areas of the cornea were the thickest, whereas temporal quadrant was the thinnest (P < 0.001).


CONCLUSIONS
This study demonstrates that age and breed influence corneal and endothelial parameters in sheep.
Departament de Medicina i Cirurgia Animals, Facultat de Veterinària, Universitat Autònoma de Barcelona, Bellaterra, Spain.
Natalia
N
Coyo
Departament de Medicina i Cirurgia Animals, Facultat de Veterinària, Universitat Autònoma de Barcelona, Bellaterra, Spain.|Servei d'Oftalmologia de la Fundació Hospital Clínic Veterinari, Universitat Autònoma de Barcelona, Bellaterra, Spain.
Maria Teresa
MT
Peña
Departament de Medicina i Cirurgia Animals, Facultat de Veterinària, Universitat Autònoma de Barcelona, Bellaterra, Spain.
Daniel
D
Costa
Biostatistics and Data Management Core Facility, IDIBAPS - Hospital Clínic, Laboratory of Biostatistics & Epidemiology, Universitat Autònoma de Barcelona, Bellaterra, Spain.
José
J
Ríos
Servei d'Oftalmologia de la Fundació Hospital Clínic Veterinari, Universitat Autònoma de Barcelona, Bellaterra, Spain.
Rodrigo
R
Lacerda
Departament de Medicina i Cirurgia Animals, Facultat de Veterinària, Universitat Autònoma de Barcelona, Bellaterra, Spain. marta.leiva@uab.cat.|Servei d'Oftalmologia de la Fundació Hospital Clínic Veterinari, Universitat Autònoma de Barcelona, Bellaterra, Spain. marta.leiva@uab.cat.
Marta
M
Leiva
D000367:Age Factors; D000818:Animals; D002452:Cell Count; D003315:Cornea; D019781:Corneal Topography / Q000662:veterinary; D042783:Endothelial Cells / Q000166:cytology*; D004728:Endothelium, Corneal / Q000033:anatomy & histology*; D008853:Microscopy; D012756:Sheep; D013045:Species Specificity
endothelium; eye; pleomorphism; polymegethism; sheep; specular microscopy