Electroretinographic and Ophthalmologic Examinations in the Yucatan Micropig and in the Göttingen Minipig

Abstract

External gross observations of the eye and its adnexae, ocular reflexes, anterior ocular segment biomicroscopic examinations, fundic examinations performed with an indirect ophthalmoscope, and/or electroretinographic investigations (ERG) were carried out on 112 7-12month-old Yucatan micropigs, on 18 6-8-week-old, and 81 2-10-month old Gottingen minipigs to evaluate the incidence of observed ocular abnormalities and to compare the ERG waves. A statistical comparison was performed for these findings.The most important ocular defects were classified as remnants of embryological vascular tissue. The other findings were considered either as embryonic remnants or of nondeterminate etiology. The most noteworthy findings were, in decreasing order of incidence, for Yucatan micropigs, 6-8 week-old and 2-10-month-old Gottingen minipigs, respectively, hyaloid artery remnants (82.1%, 83.3%, and 46.3%), pupillary Cutaneous and Ocular Toxicology Downloaded from informahealthcare.com by The University of Manchester on 12/01/14 For personal use only. 70LOGET AND SAINT-MACARY membrane remnants (66.1%, 19.4%, and 13.0%) and incomplete pigmentation of the fundus with appearance of choroidal vasculature (tigroid fundus: 50%, 72.2%, and 70.4%).Apparently the visual capabilities of the animals were not affected by these findings. Although anatomical fundus differences were noted, the ERG waves were similar in Gottingen minipigs and in Yucatan micropigs.Cutaneous and Ocular Toxicology Downloaded from informahealthcare.com by The University of Manchester on 12/01/14For personal use only.

Nonclinical Safety and Pharmacokinetics of Intravitreally Administered Human-Derived Plasmin in Rabbits and Minipigs

“…18 There are anatomic similarities in the structure of the retina as well, with the pig eye having a macula and a holangiotic type of retinal vasculature that is similar to humans. 19 In vivo, the human retina may be more resistant to enzymatic changes, owing to the greater thickness of its inner limiting membrane (1-2 m), as compared with pigs (0.03 m), therefore optimizing the sensitivity of the minipig model in terms of intravitreal tolerance of plasmin.…”

“…When comparing ocular findings in both animal species, in minipigs no blurred zones were observed at funduscopy, no treatment-related corneal or conjunctival macroscopic changes were noted, and there were no plasmin-related postmortem findings, contrary to rabbits. The minipig, which appears to be a relevant model for humans, based on similarities in the anatomy of the posterior segment, 18,19 was the least sensitive to plasmin-related changes following a single injection. No sexrelated findings were reported in either species.…”

Toxicity and Toxicokinetic Study of Subcutaneously Administered RPh201 in Minipigs

“…Lens opacities, including suture line abnormalities, are described as a normal background lesion in the Göttingen minipig (Loget 1995; Loget and Saint-Macary 2000). According to Loget and Saint-Macary (2000), the background incidence of lens abnormalities in the Göttingen minipig is reported to be 2.8% for suture line abnormality, 8.3% for focal nuclear opacity, 19.4% for posterior cortical pinpoint opacity, and 8.3% for posterior capsular opacity (Loget and Saint-Macary 2000).…”