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The background and purpose of the last 200 years, the study of the mechanism of myopia has been an important issue in the eyes of scientific research. Since 1977, Wiesel first suture rhesus eyelid successfully induced form deprivation myopia (formdeprivation myopia, FDM), with the establishment of myopia animal model methods are maturing, myopia progression and outcome in-depth research. The current study shows: Form deprivation the main through local retinal mechanism for the regulation adjacent sclera of growth, form deprivation can lead to a change on the retina of a variety of neurotransmitters and growth factor levels, as a messenger role in the retinal pigment epithelium cells and choroidal produce two messengers, and then acting on the sclera, and thus affect scleral extracellular matrix (extracellularmaterial, ECM) synthesis or degradation, so that the re-shaping of the sclera, axial extend the excessive formation of myopia. Subsequent thinning of the sclera in form deprivation myopia is an important feature, the main reason is because the scleral extracellular matrix remodeling. Department of matrix metalloproteinases (matrix metalloproteinase, MMPs) are widely present in plants and animals to a group of zinc-dependent protease degradation of the extracellular matrix (ECM). Experimental chicks and guinea pigs form deprivation eye sclera active MMP-2 was significantly increased reduce convalescence active MMP-2, prompt MMP-2 form deprivation myopia. Nitric oxide (NO) is a newly discovered retinal neurotransmitters in the past 20 years, with the development of the retina, visual excitement and the conduction of the visual information. NO synthesized by nitric oxide synthase (nitric oxide synthase, NOS) catalytic L-arginine (L-Arginine, L-Ag). Fujiis study found that newborn chicken monocular form deprivation process., Retinal pigment epithelium - - the choroidal three NOS isoforms, only inducible nitric oxide synthase (i-NOS) levels were significantly decreased, suggesting that i -NOS may be involved in the formation of form deprivation myopia. INOS and of MMP-2 in the form deprivation myopia in animal models of change were to be confirmed, but in the formation process of form-deprivation myopia is intrinsic link has not yet been studied. This study was to establish the guinea pig form deprivation myopia model, applying immunohistochemical staining study of iNOS and MMP-2 in the form deprivation myopia in guinea pigs posterior pole expression change, as well as both, in order to further reveal the shape deprivation myopia mechanisms, which provide a valuable reference for the prevention and treatment of myopia. Materials and Methods 2-week-old healthy color guinea pig 60, were randomly divided into four groups: Ⅰ group: group uncovered; Ⅱ group: 3 weeks right eye covered; Group: III right eye covered 6 weeks; Ⅳ group: right eye cover nine weeks the group. Ⅱ, Ⅲ and group Ⅳ are in the right eye for the experimental eye diameter 15mm translucent goggles glued on the guinea pig right eye and on the skin around the long, narrow slit for breathable with goggles below left; left eye without any treatment for their own control group. Group of guinea pigs at different time points binocular diopter, axial length, HE staining optical microscope observation of pathological changes of retina sclera, immunohistochemistry staining the retina of iNOS and sclera of MMP-2 protein. All data are used (?) ± s statistical analysis SPSS13.0 statistical software, eyes paired t-test was used to compare the groups were compared using one-way ANOVA, multiple sample mean LSD pairwise comparisons between Pearson correlation analysis the correlation Person, a = 0.05 level of inspection. Results 1 to cover the eye and the control eye diopter axial comparison: cover the eyes for myopia hyperopia gradient before the experiment, along with a cover time, myopia, axial length. Cover the eyes and control eyes (normal eyes and control eyes) compared to the difference was statistically significant (P <0.05), successfully established animal models of experimental myopia. Retina, sclera morphological changes: cover 3,6,9, cover the retina compared with its own control eye and normal control eyes thinning is most obvious to the inner and outer nuclear layer; thinning of the posterior sclera, sparse. Immunohistochemical staining: iNOS in normal and self-control eyes guinea pig retina was expressed at low levels in the form deprivation myopia is mainly expressed in the retinal ganglion cell layer, inner nuclear layer, photoreceptor cell layer and choroidal interstitial tissue, positive staining in the nerve fiber layer and sclera. MMP-2 expression in the sclera, positive staining in the ganglion cell layer, inner nuclear layer, the layer of light-sensitive cells. With the extension of the time covered, retinal iNOS and MMP-2 absorbance values ??into an increasing trend (P <0.01). 4.iNOS and MMP-2 analysis: correlation analysis found in the the form deprivation different stages, the retina of iNOS and sclera of MMP-2 protein expression correlation coefficient r = 0.769, P <0.05, prompted both protein expression was significantly positively correlated. Conclusion 1. Monocular cover can cause guinea pigs to cover the retina in the i-NOS and sclera of MMP-2 expression increased gradually strengthen, with the increase in myopia and axial extension trend consistent extension of time, and with the cover prompted iNOS and MMP -2 may be involved in the formation of form deprivation myopia. Cover retinal iNOS and of MMP-2 expression in the process of form deprivation was a strong positive correlation. Can be speculated that in the process of the development of form deprivation myopia, blurred objects like by stimulating the retina to produce a variety of neurotransmitters including NO, including influence, direct or indirect role in the sclera, the expression and activity of MMP-2, the final result sclera remodeling and the formation of myopia.
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