Multielectrode array recording detected light-induced field potentials and provided topographic information about regional photoreceptor function. The electrodes were classified into three groups according to their distances to ONH: the central channels, midperipheral channels, and peripheral channels (Fig. 2A). Moreover, the global recording field was divided into four quadrants: superior temporal (ST), superior nasal (SN), inferior temporal (IT), and inferior nasal (IN). Representative field potential waveforms of the examined eyes are shown in
Figure 2B. The mean amplitude of field potentials in the sham group significantly decreased compared with normal controls (0.228 ± 0.033 vs. 0.012 ± 0.010 mV,
P < 0.01;
n = 10,
Fig. 2C). Conversely, the field potential waveforms in the TES100 and TES200 groups were effectively preserved (0.088 ± 0.023 vs. 0.012 ± 0.010 mV,
P < 0.01; 0.119 ± 0.029 vs. 0.012 ± 0.010 mV,
P < 0.01;
n = 10). Moreover, the mean amplitude of field potentials in the TES200 group was significantly larger than in the TES100 group (0.088 ± 0.023 vs. 0.119 ± 0.029 mV,
P < 0.05;
n = 10). Intriguingly, the field potential responses in the TES200 group were not uniformly equal and formed a topographic gradient across retina: The field potentials in the central region were retained with larger amplitudes than in the other two regions (0.148 ± 0.025 vs. 0.123 ± 0.020 mV,
P < 0.05; 0.148 ± 0.025 vs. 0.100 ± 0.021 mV,
P < 0.01;
n = 10,
Fig. 3A). Additionally, the mean amplitude of field potentials in the midperipheral region was significantly larger than in the peripheral region (0.123 ± 0.020 vs. 0.100 ± 0.021 mV,
P < 0.05;
n = 10). Similar disproportions among positional regions were also found in the TES100 group (0.122 ± 0.021 vs. 0.094 ± 0.019 mV,
P < 0.01; 0.122 ± 0.021 vs. 0.073 ± 0.017 mV,
P < 0.01; 0.094 ± 0.019 vs. 0.073 ± 0.017 mV,
P < 0.05;
n = 10). Topographic photoreceptor function of TES-treated retinas was quantified and compared with the normal controls: 61.3%, 50.1%, and 41.8% of the photoreceptor function, respectively, was retained in the central, midperipheral, and peripheral regions of the TES200 group. Meanwhile, 50.8%, 39.8%, and 31.5% of photoreceptor function, respectively, was retained in the central, midperipheral, and peripheral regions of the TES100 group.