Abstract
Abstract: :
Purpose: To characterize the multifocal ERG in two nonhuman primate species (Macaca fascicularis and Macaca mulatta), which are frequently used in pressure-induced models of experimental glaucoma. Methods: Multifocal ERGs were obtained from 9 cynomolgus and 9 rhesus monkeys with the use of a standard 13.33-ms base period binary m-sequence of 103 equal-sized hexagonal elements, which subtended ± 44 deg about the central visual axis. Mean luminance of the stimulus display was 100 cd/m2. Pupils were fully dilated. A Jet contact lens electrode or a DTL thread electrode under a contact lens was applied to the corneal surface. Testing was monocular with the nontested eye covered with an opaque occluder. Response density amplitude, implicit time, and root mean square (RMS) response measures of the first- and second-order kernels for the multifocal ERG were averaged in 4 rings radiating from the foveal element. Separate repeated measures analyses of variance for response density amplitude, implicit time, and RMS measures of the first- and second-order kernels, and of the oscillatory potentials, tested the effect of species, eye, retinal eccentricity (ring), and/or waveform component (N1, P1, N2, P2) as factors. Results: Significant 3-way interactions (p<0.05) of species, waveform component, and ring were found for response density amplitude and implicit time. Response amplitudes were larger in rhesus than in cynomolgus monkeys, excluding the P2 component. Delay in implicit times was greater in cynomolgus than in rhesus monkeys. Significant effects were found in all univariate tests of the first- and second-order kernel RMS response measures in comparisons between the cynomolgus and rhesus monkey groups. Conclusion: There are significant differences between cynomolgus and rhesus monkeys in response density amplitude and implicit time, and in RMS measures of the first- and second-order kernels in multifocal ERG responses. These results suggest caution when comparing multifocal ERG data across primate species.
Keywords: 396 electroretinography: non-clinical • 316 animal model