title: Comparison of the characteristics in hen and quail corneas as experimental models of refractive surgery.
abstract: OBJECTIVE
  To compare the histological, morphological and the biophysical measurements between hen and quail corneas, in order to determine which of them were better suited for use as an animal model for research into corneal refractive surgery.
  
  
  METHODS
  A study was performed using the biophysical measurements of the cornea (curvature, thickness, refraction, and axial length) of 20 animals (10 hens and 10 quails). The corneas were then prepared for histological analysis under microscopy light.
  
  
  RESULTS
  The analysis showed that both groups have the same number of corneal layers as the human cornea and with an evident Bowman's layer. The thickness of the hen cornea and axial length of the eye, 225.3±18.4μm and 12.8±0.25mm, respectively, were larger than that of the quail (P<.01 and P<.001, respectively). The radius of curvature for the hen central cornea, 3.65±0.08mm, was greater than that for the quail (P<.001), but the refractive power of each cornea was similar. The proportion of total corneal thickness of the hen stroma, 82.6%, was more similar to that of the human than was the quail stroma, 72.5%. Within the hen stroma, the density of keratocytes, 8.57±1.49 per 5,000μm(2), was about half that in the quail stroma (P<.005).
  
  
  CONCLUSIONS
  Because of the large size of the hen cornea, the stromal thickness and proportional similarity of the corneal layers with human cornea, the hen maybe better than the quail as an alternative species suitable for use in studies of corneal refractive surgery.
authors.affiliation: Departamento de Histología, Facultad de Medicina, Universidad de Valladolid, Valladolid, España. Electronic address: gisele@ferrararing.com.br.
authors.forename: G C
authors.initials: GC
authors.lastname: Gonçalves
authors.affiliation: CSIC, Madrid, España.
authors.forename: P
authors.initials: P
authors.lastname: Pérez-Merino
authors.affiliation: Departamento de Histología, Facultad de Medicina, Universidad de Valladolid, Valladolid, España.
authors.forename: M C
authors.initials: MC
authors.lastname: Martínez-García
authors.affiliation: Servicio de Investigación y Bienestar Animal, Universidad de Valladolid, Valladolid, España.
authors.forename: A
authors.initials: A
authors.lastname: Barcía
authors.affiliation: Fundación de Investigación Oftalmológica Fernández-Vega, Oviedo, Asturias, España.
authors.forename: J
authors.initials: J
authors.lastname: Merayo-Loves
mesh_terms: D000818:Animals; D001699:Biometry; D050476:Bowman Capsule / Q000648:ultrastructure; D002645:Chickens / Q000033:anatomy & histology*; D003315:Cornea / Q000033:anatomy & histology*; D063171:Corneal Pachymetry / Q000662:veterinary; D003370:Coturnix / Q000033:anatomy & histology*; D019573:Epithelium, Corneal / Q000648:ultrastructure; D023421:Models, Animal; D012029:Refraction, Ocular; D054140:Refractive Surgical Procedures; D013045:Species Specificity
keywords: Bowman; Cirugía refractiva; Codorniz; Cornea; Córnea; Gallina; Hen; Quail; Refractive surgery