Confocal scanning laser ophthalmoscopy (CSLO) is a new technique that enables ocular fundus image recording and retinal dynamic angiography to be performed. The ocular fundus image is acquired sequentially, point by point, and is reconstructed on a video monitor at the rate of 25 images per second. The feasibility of performing both ocular fundus image recordings and retinal angiography image recordings were tested on two dogs, two monkeys and two minipigs using a 40 degrees field I + Tech CSLO. Fundus area of each dog, monkey and minipig were examined without any additional optical devices. The ocular fundus and angiography images were recorded, stabilized and analyzed under the same conditions. For each species, all images were easily recorded without any additional optical device in a lighted room and the morphology of the retinal images generated was similar to those obtained with a camera or angiography of higher resolution. Capillary phase or venous times are presented. Image recording at 25 frames/second enabled more retinal dynamics to be demonstrated than with use of regular angiography. This technique is noninvasive and easy to perform if the eye is fixed and eyelids maintained open. It also allows exploration of retinal microvascularization and could be utilized for clinical, pharmacologic and toxicologic investigations as well.

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Confocal scanning laser ophthalmoscope (cSLO) is a new technique which enables ocular fundus image recording and dynamic retinal angiography to be performed. The ocular fundus image is acquired sequentially, point by point, and is reconstructed on a video monitor at the rate of 25 images per second. The aim of this paper is to evaluate the feasibility of measuring retinal arterio-venous filling times (AVFT) with a I + Tech cSLO. Three young adult cynomolgus monkeys and three young adult Göttingen minipigs were used as experimental models. All animals were anesthetized using a zolazepam + tiletamine mixture injected intramuscularly; heart rate and rectal temperature were monitored and corneal irrigation was regularly performed. For all subjects, prior to examination, hematocrit and globe axial length were measured. The images were recorded, stabilized and analyzed. The retinal examination consisted of retinal images with 40 degrees field cSLO, retinal fluorescein angiography and arterio-venous 50% filling time measurements. For each subject all images were easily recorded while keeping the animals in a normally lighted room without having to use any additional optical device. AVFT using an I + Tech cSLO is easily performed in monkeys and minipigs. AVFT measurements in minipigs and monkeys are similar. These results suggest that minipigs can replace monkeys as an experimental species for AVFT investigations.

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.

The micropig is viewed by many as one of the best animal models of human system physiology. The purpose of this study was to develop a simple, rapid and reliable method to record clinical electroretinograms from conscious adult Yucatan micropigs. Photopic ERGs were recorded from 18 conscious animals following a 3-h period of preadaptation to a moderate photopic environment. Rectal temperature and blood pressure were monitored throughout the experiment. In order to test the reproducibility of our procedure, the same protocol was repeated (n=6 micropigs) on three different recording sessions each separated by a 48-h period. Our results indicate that the recording of reproducible ERGs, in the conscious Yucatan micropig, is feasible provided that an adequate experimental approach is used. We believe that our method will enable investigators to perform retinal physiology experiments using an approach which is compatible with that used in a human clinical setup thus facilitating the transposition of experimental data from animal to human.