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Background and Purpose pathological myopia myopia, also known as, is a progressive development of the eye, with the course of development, the axial extension, myopia, and choroidal atrophy, retinal degeneration and various other complications, in cause of blindness in the world accounting for 4 to 7, because of the serious harm to human vision but also makes the prevention and treatment of myopia global attention. Studies on the pathogenesis of myopia than 200 years of history, people have raised many hypotheses, which form deprivation theory that: Impact on normal retinal imaging factors can lead to abnormal growth of the eye, showing excessive axial growth, the formation of myopia . 1977 form deprivation myopia (form-deprivation myopia, FDM) animal model has been successfully established, from basic research in high myopia achieved a breakthrough. During the formation of high myopia, the eye posterior segment pathologic expansion, accompanied by a reduction of retinal nerve cells, and in many degenerative diseases of the nervous system and retinal nerve cell death by apoptosis pathway achieved; addition, XU Ge, also studies have found that humans exist in highly myopic retinal photoreceptor apoptosis phenomenon. Apoptosis (apoptosis) is the body under physiological and pathological processes, due to internal and external environmental changes or death signals triggered in gene regulation under induced cell death process active. Among the many apoptosis genes of Bcl-2 protein family members, such as: Bcl-2, Bax, Bak, Bcl-xL plays such an important role in the formation of the same pass between family members / heterodimer to play its biological functions, regulate cell death process. In this study, guinea pigs FDM model to simulate changes in the human end of high myopia with Ding UNEL retinal cell apoptosis was detected by immunohistochemistry assay Bak, Bcl-xL expression levels, so as to explore the pathogenesis of FDM, Bak, Bcl- xL and apoptosis relationship formed with FDM. Materials and Methods born three days of healthy color guinea pig 60, before the experiment guinea pigs were dilated retinoscopy, excluding congenital myopia, using established methods of form deprivation myopia animal models. Covered with translucent plastic goggles eye guinea pigs were divided into A, B, C 3 groups, respectively, continued to cover the four weeks, eight weeks, 12 weeks, n = 20; left open as normal control group. Both groups were detected retinal retinoscopy refraction; ophthalmic A super-vivo determination of axial length; extraction eye, cut off the soft tissue around the eye, fixation, dehydration, xylene, paraffin-embedded, 4μm serial sections. HE staining, was observed under an optical microscope morphological changes of the retina and the sclera; using TUNEL technique to detect retinal cell apoptosis. By SP immunohistochemical technique to detect retinal Bak, Bcl-xL expression levels. Results 1. With the extension of time to cover, cover the eye axial length guinea pig eyes significant growth compared with the control, negative refraction significantly increased (P <0.05). Axial growth and an increase in negative refraction between the obvious linear correlation (r = -0.855). 2. B group, C group cover the eye posterior pole retinal inner nuclear layer, outer nuclear layer were seen scattered TUNEL-positive cells, the nucleus grainy yellow or brown coloring. B group, C group covering retinal cell apoptosis rates were (0.27 ± 0.14)% and (2.33 ± 0.37)%, the difference was significant (P <0.05). A group cover the eye and the control eye retina group showed no apoptotic cells. 3. Immunohistochemistry showed, Bak expressed mainly in inner segment of photoreceptor cells and outer nuclear layer and ganglion cell layer, Bcl-xL was mainly expressed in retinal photoreceptor cell layer, inner nuclear layer and ganglion cell layer, both of which showed positive cells the cytoplasm brownish yellow or yellow granular coloring, but Bcl-xL staining compared with Bak shallow. Group C covers retina Bak average gray value (113.48 ± 7.77) and its control eyes (94.52 ± 7.10) and group B cover the eye (97.26 ± 7.23) compared to the differences were statistically significant (P <0.05). Bcl-xL protein expression in the two groups covering the eye and no significant difference between the control eyes (P> 0.05). 4. B group, C group covering retinal cell apoptosis rate and Bak protein expression intensity correlation coefficient values ??were 0.79,0.88 plant; and Bcl-xL protein expression intensity values ??of the correlation coefficients were -0.37 plant, -0.31. Conclusions 1. In this study, a method translucent goggles, successful replication of the guinea pig FDM model; extended over time to cover axial growth, myopia gradually deepened, covering 12 weeks can be formed with high myopia. 2. In guinea pigs FDM formation process, fundus degenerative changes in the retina, the outer nuclear layer were seen scattered apoptotic cells were apoptotic cell death in the retina FDM is one of the mechanisms. 3. FDM visible retinal formation Bak, Bcl-xL expression. 4. Retinal cell apoptosis and the expression of Bak into a significant positive correlation between the expression of Bcl-xL with no significant correlation. The high expression of Bak guinea pig FDM may promote apoptosis of retinal reasons.
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