Measurements of Three Ocular Parameters in the Göttingen Minipig

Abstract

The use of laboratory pigs has increased dramatically in the last decade, and this study supplements the  basic ocular anatomical and physiological characterisations already carried out on laboratory pigs. Pigs are  frequently used as models of human ocular diseases due to the similar anatomy and physiology of the ocular  structures of the pig as compared to humans, but refractive error has not been investigated systematically  in the Göttingen minipig. We measured refractive status, corneal power and axial length in a sample  of 30 adult Göttingen minipigs including both sexes. The uncorrected mean refractive error was +1.3 dioptres  (D) with a standard deviation (SD)± 2.3 D.The mean corneal power was 44.1 D (SD±1.5D) and mean  axial length less than 19 mm. No statistically significant difference was detected between the right and left  eye values, with respect to colour of iris, or between genders (p<0.05). In spite of the smaller axial length,  measures of refractive error and corneal power in the Göttingen minipig are comparable to human values.  This information should prove useful when using Göttingen minipigs as models for human ocular conditions  or in research involving vision or other ophthalmic aspects of the Göttingen minipig. Also, the refractive  status of the animal can be of importance when using pigs in cognitive tasks, mainly because of the  probable lack of accommodative reflex in pigs. If visual stimuli are presented at a short distance, clinical,  emmetropia or myopia in the experimental animals would be desirable; in the present cohort of examined  pigs, 60% fulfilled these criteria.