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Objective:To observe the changes of vessel densities (VD) in the macula and optic disc and its correlation with axial length (AL) in pathological myopia (PM).Methods:A retrospective clinical study. A total of 171 eyes from 171 patients admitted to Department of Ophthalmology of Jinshan Hospital of Fudan University from June 2019 to December 2019 were included in this study. Among them, there were 72 males and 99 females; age was 35.0±10.8 years old. The patients were divided into PM group, high myopia (HM) group and non-HM group, 51 cases with 51 eyes, 70 cases with 70 eyes, and 50 cases with 50 eyes, respectively. Optical coherence tomography angiography was used to scan the macular and optic disc areas of all the examined eyes in the range of 6 mm×6 mm. According to the early treatment of diabetic retinopathy study, the 6 mm macular and optic disc scan range was centered on the macular fovea and optic disc, respectively, then divided into two concentric circles with diameters of 1 mm of central area, an annulus between 1-3 mm circles of paracentral area. The paracentral area was divided into superior, inferior, nasal, temporal four quadrants by 2 radiation lines. The VD of superficial capillary plexus (SCP), deep capillary plexus (DCP), outer retina, and choriocapillaris layer were calculated in the central, superior, inferior, nasal, and temporal areas, respectively. The VD of PM, HM and non-HM groups were compared. The variance analysis was used to compare the VD among the three groups; Pearson’s correlation was used to assess the correlation between VD and AL.Results:The perifoveal VD of the SCP, outer retina and choriocapillaris layers were all lower in the PM than those of HM and non-HM group, and the differences were statistically significant ( P<0.05). The VD of DCP macular central was higher in the PM than in the HM group, and the difference was statistically significant ( P=0.020). In the optic disc, the VD were lower in the PM group than in the non-HM group except for the area of DCP superior, inferior, temporal, outer retinal center, and the differences were statistically significant ( P<0.05). The results of correlation analysis showed that the VD in the DCP macular central, ONH superior and the choriocapillaris ONH central were not correlated with AL ( P=0.647, 0.688, 0.146), and the other VDs were negatively correlated with AL ( P<0.05). Conclusion:Compared with HM and non-HM groups, the majority of VDs in macular and ONH are lower in participants with PM.
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Objective To observe the dopamine(DA)concentrations in the lateral geniculate nucleus in guinea pigs with flickering light-induced and form deprivation myopia,and to compare and analyze the pathogenetic mechanisms in the centers of vision of these two different myopia models. Methods Twenty-four two-week-old guinea pigs were randomly assigned to three groups(n=8):flickering light-induced myopia(FLM)group, form deprivation myopia(FDM)group and control group. All the groups were fed for 8 weeks. The refraction and axial length(AL)were measured before and af-ter modeling. After eight-week modeling,the contents of dopamine in the left lateral geniculate nucleus were detected by high performance liquid chromatography with electrochemical detection(HPLC-ECD). Results Before modeling,no sig-nificant difference was found in refraction and AL among the three groups. After eight-week modeling,in contrast with the control group,significant differences were found in changes of both refraction(P<0.001)and AL(P<0.05)in the right eyes of FLM and FDM groups,indicating that the two myopic models were successfully established. The result of HPLC-ECD showed that the contents of DA in the left lateral geniculate nucleus in FLM group were significantly higher than the control group(P=0.01),while in the FDM group it was lower than the control group(P=0.021). The average contents of DA were as follows:(37.04 ± 1.18)pg/μL in the control group;(24.27 ± 3.46)pg/μL in the FDM group; and (45.58 ± 1.98)pg/μL in the FLM group. Conclusions The content of DA in the lateral geniculate nucleus is increased in FLM,while decreased in FDM,indicating that the expression of DA in LGN and the mechanisms of formation of these two experimental myopia are different.