Normative Data of Axial Length, Retinal Thickness Measurements, Visual Evoked Potentials, and Full-Field Electroretinography in Female, Wild-Type Minipigs

Purpose: The purpose of this study was to present normative data of optical coherence tomography (OCT), electrophysiological, and ocular biometry parameters and their correlation in minipigs. Methods: Eighty-eight eyes of 44 minipigs underwent full-field electroretinogram (ERG) recording and ocular biometry. However, 10 eyes of 6 minipigs were excluded because of poor OCT image quality. The thickness of the retinal sublayers was measured on a vertical line at 5 locations with a 1 mm interval from the disc margin to the dorsal periphery and at 10 locations on the visual streak. Visual evoked potentials (VEPs) were measured in 15 eyes of 8 minipigs. Results: All minipigs were female with a mean age and axial length of 13.83 +/- 10.56 months and 20.33 +/- 0.88 mm, respectively. The implicit time of the a-wave and b-wave in scotopic 3.0 ERGs was longer than that in photopic 3.0 ERG. The implicit time of the n2-wave and p2-wave in VEP was 25.67 +/- 7.41 ms and 52.96 +/- 10.38 ms, respectively. The total retinal layer (TRL) and nerve fiber layer (NFL) became thinner near the periphery. The inner retinal sublayers near the visual streak were thicker than those at other locations. Central TRL and NFL thickness on visual streak was 223.06 +/- 23.19 mu m and 74.03 +/- 13.93 mu m, respectively. The temporal TRL and NFL on the visual streak were thicker than those on the nasal side. Conclusions: The normative electrophysiological and OCT parameters used in our study can be used as reference data in further pig studies.

Automated summary

This study aimed to present normative data of OCT, electrophysiological, and ocular biometry parameters in minipigs, and found differences in retinal sublayer thickness at various locations. The implicit time of ERGs was longer in scotopic conditions than in photopic conditions, while VEPs showed shorter implicit times in minipigs.