Relative peripheral refraction in school children with different refractive errors using a novel multispectral refraction topographer.

AIM: To compare relative peripheral refraction (RPR) in Chinese school children with different refractive errors using multispectral refraction topography (MRT). METHODS: A total of 713 eyes of primary school children [172 emmetropia (E), 429 low myopia (LM), 80 moderate myopia (MM), and 32 low hypermetropia (LH)] aged 10 to 13y were analyzed. RPRs were measured using MRT without mydriasis. MRT results showed RPR at 0-15° (RPR 0-15), 15°-30° (RPR 15-30), and 30°-45° (RPR 30-45) annular in the inferior (RPR-I), superior (RPR-S), nasal (RPR-N), and temporal (RPR-T) quadrants. Spherical equivalent (SE) was detected and calculated using an autorefractor. RESULTS: There were significant differences of RPR 15-30 between groups MM [0.02 (-0.12; 0.18)] and LH [-0.13 (-0.36; 0.12)] (P<0.05), MM and E [-0.06 (-0.20; 0.10)] (P<0.05), and LM [-0.02 (-0.15; 0.15)] and E (P<0.05). There were also significant differences of RPR 30-45 between groups MM [0.45 (0.18; 0.74)] and E [0.29 (-0.09; 0.67)] (P<0.05), and LM [0.44 (0.14; 0.76)] and E (P<0.001). RPR values increased from the hyperopic to medium myopic group in each annular. There were significant differences of RPR-S between groups MM [-0.02 (-0.60; 0.30)] and E [-0.44 (-0.89; -0.04)] (P<0.001), and LM [-0.28 (-0.71; 0.12)] and E (P<0.05). There were also significant differences of RPR-T between groups MM [0.37 (0.21; 0.78)] and LH [0.14 (-0.52; 0.50)] (P<0.05), LM [0.41 (0.06; 0.84)] and LH (P<0.05), and LM and E [0.29 (-0.10; 0.68), P<0.05]. A Spearman's correlation analysis showed a negative correlation between RPR and SE in the 15°-30° (P=0.005), 30°-45° (P<0.05) annular (P=0.002), superior (P<0.001), and temporal (P=0.001) quadrants. CONCLUSION: Without pupil dilation, values for RPR 15-30, 30-45, RPR-S, and T shows significant differences between myopic eyes and emmetropia, and the differences are negatively correlated with SE.

Overexpressing NeuroD1 reprograms Müller cells into various types of retinal neurons.

The onset of retinal degenerative disease is often associated with neuronal loss. Therefore, how to regenerate new neurons to restore vision is an important issue. NeuroD1 is a neural transcription factor with the ability to reprogram brain astrocytes into neurons in vivo. Here, we demonstrate that in adult mice, NeuroD1 can reprogram Müller cells, the principal glial cell type in the retina, to become retinal neurons. Most strikingly, ectopic expression of NeuroD1 using two different viral vectors converted Müller cells into different cell types. Specifically, AAV7m8 GFAP681::GFP-ND1 converted Müller cells into inner retinal neurons, including amacrine cells and ganglion cells. In contrast, AAV9 GFAP104::ND1-GFP converted Müller cells into outer retinal neurons such as photoreceptors and horizontal cells, with higher conversion efficiency. Furthermore, we demonstrate that Müller cell conversion induced by AAV9 GFAP104::ND1-GFP displayed clear dose- and time-dependence. These results indicate that Müller cells in adult mice are highly plastic and can be reprogrammed into various subtypes of retinal neurons.

Inhibitor of DNA binding 2 accelerates nerve regeneration after sciatic nerve injury in mice.

Inhibitor of DNA binding 2 (Id2) can promote axonal regeneration after injury of the central nervous system. However, whether Id2 can promote axonal regeneration and functional recovery after peripheral nerve injury is currently unknown. In this study, we established a mouse model of bilateral sciatic nerve crush injury. Two weeks before injury, AAV9-Id2-3×Flag-GFP was injected stereotaxically into the bilateral ventral horn of lumbar spinal cord. Our results showed that Id2 was successfully delivered into spinal cord motor neurons projecting to the sciatic nerve, and the number of regenerated motor axons in the sciatic nerve distal to the crush site was increased at 2 weeks after injury, arriving at the tibial nerve and reinnervating a few endplates in the gastrocnemius muscle. By 1 month after injury, extensive neuromuscular reinnervation occurred. In addition, the amplitude of compound muscle action potentials of the gastrocnemius muscle was markedly recovered, and their latency was shortened. These findings suggest that Id2 can accelerate axonal regeneration, promote neuromuscular reinnervation, and enhance functional improvement following sciatic nerve injury. Therefore, elevating the level of Id2 in adult neurons may present a promising strategy for peripheral nerve repair following injury. The study was approved by the Experimental Animal Ethics Committee of Jinan University (approval No. 20160302003) on March 2, 2016.