title: The parameters of the porcine eyeball.
abstract: BACKGROUND
  The eye of the domestic pig (Sus scrofa domestica) is an ex vivo animal model often used in vision sciences research (retina studies, glaucoma, cataracts, etc.). However, only a few papers have compiled pig eye anatomical descriptions. The purpose of this paper is to describe pig and human eye anatomical parameters to help investigators in their choice of animal model depending on their study objective.
  
  
  METHODS
  A wide search of current medical literature was performed (English language) using PubMed. Anteroposterior axial length and corneal radius, astigmatism, vertical and horizontal diameter, and pachymetry (slit-scan and ultrasound) were measured in five enucleated pig eyes of animals 6 to 8 months old.
  
  
  RESULTS
  Horizontal corneal diameter was 14.31 ± 0.25 mm (CI 95% 14.03 mm-14.59 mm), vertical diameter was 12.00 ± 0 mm, anteroposterior length was 23.9 ± 0.08 mm (CI 95% 23.01 mm-29.99 mm), central corneal ultrasound pachymetry was 877.6 ± 13.58 μm (CI 95% 865.70 μm-889.50 μm) and slit-scan pachymetry was 906.2 ± 15.30 μm (CI 95% 892.78 μm-919.61 μm). Automatic keratometry (main meridians) was 41.19 ± 1.76D and 38.83 ± 2.89D (CI 95% 40.53D-41.81D and 37.76D-39.89D respectively) with an astigmatism of 2.36 ± 1.70D (CI 95% 1.72D-3.00D), and manual keratometry was 41.05 ± 0.54D and 39.30 ± 1.15D (CI 95% 40.57D-41.52D and 38.29D-40.31D respectively) with an astigmatism of 1.75 ± 1.31D (CI 95% 0.60D-2.90D).
  
  
  CONCLUSIONS
  This paper describes the anatomy of the pig eyeball for easy use and interpretation by researchers who are considering their choice of animal model in vision sciences research.
authors.affiliation: IOBA-Eye Institute and CIBER-BBN, University of Valladolid, Spain. isanchezp@ioba.med.uva.es
authors.forename: Irene
authors.initials: I
authors.lastname: Sanchez
authors.forename: Raul
authors.initials: R
authors.lastname: Martin
authors.forename: Fernando
authors.initials: F
authors.lastname: Ussa
authors.forename: Ivan
authors.initials: I
authors.lastname: Fernandez-Bueno
mesh_terms: D000717:Anatomy, Comparative; D000818:Animals; D019781:Corneal Topography; D005123:Eye / Q000033:anatomy & histology*; D006801:Humans; D023421:Models, Animal; D034421:Sus scrofa