|
Background and purpose of myopia is a common type of refractive error, occurred in the growth and development of young people, the performance of visual impairment, visual fatigue and eye position deviation. Study of the etiology of myopia has been two hundred years of history, involving racial genetic factors, environmental factors, eye anatomy, physiology, blood supply, nutrition and autonomic nervous system, the immune system, endocrine system, etc., including genetic predisposition, relevant gene mapping, sclera collagen autoimmune doctrine., retina biological active substance disorders doctrines and so on. Form deprivation doctrine: factors affecting the normal imaging of the retina can lead to abnormal growth of the eye, performance for axial excessive growth, the formation of myopia. 1977 form deprivation myopia (Form Deprived Myopia, FDM) animal model has been successfully established, made a breakthrough in basic research from this myopia. Melatonin (melatonin) indole as a by hormones, in the eye pathophysiology play an important role. Most eye tissues of mammals and human eye retina and its outside melatonin receptor MT 1 the MT 2 melatonin through its receptor MT 1 MT 2 adjustable axial length and aqueous humor formation, both of which may be involved in the regulation of intraocular pressure. The formation of myopia and intraocular pressure, IOP was positively correlated with the axial length. The purpose of this experiment is to detect form deprivation myopia in retinal tissue melatonin receptor MT 1 expression as well as changes in intraocular pressure, and thus the study whether the two involved in the formation of form deprivation myopia. Materials and Methods 20 5 ~ 7d guinea pigs born, the cycloplegic retinoscopy before the experiment on guinea pigs, exclude congenital myopia, establish with form deprivation myopia animal models. Covered with translucent goggles guinea pigs right eye and left eye open as normal control group, as the experimental group; The after form deprivation eight weeks, both groups retinoscopy detection diopter; ophthalmic A measured in vivo axial length; were measured before the experiment and cover 8 weeks after IOP of the experimental and control groups. Extraction of the eye, take the equator of the sclera and retina tissue, clear cornea, lens, vitreous and surrounding connective tissue, fixed, dehydrated, xylene, paraffin-embedded, 4μm serial sections. Using the SP immunohistochemical techniques, detection of retinal MT 1 expression levels. Results (1) form deprivation, refraction and axial length of the experimental eyes and control eyes was no significant difference (P> 0.05). Shaped sleep deprivation after eight weeks, compared with the control eyes, the experimental eye induced a -6.65 ± 0.65D (t = 59.035, P <0.01) the relative myopia, axial length than the extended control eyes (0.85 ± 0.24) mm (t = 23.83 , P <0.01). (2) The form deprivation before eyes IOP was no significant difference (P> 0.05). Form deprivation eight weeks after experimental IOP higher than the control eyes (4.06 ± 1.37) mm Hg (t = 21.37, P <0.01). (3) MT 1 immunohistochemical staining results: MT 1 protein immunoreactive products in the guinea pig retina control eyes in the pigment epithelium, the outer nuclear layer and kernel layer, expressed in the nucleus and cytoplasm; mainly expressed in the kernel layer of cytoplasm in the experimental eyes. Experimental eye average gray value and positive area (kernel layer) gray value compared to its own control eyes were reduced, and the difference was statistically significant (P <0.05). Conclusion the guinea pig FDM model successfully established, guinea pigs form deprivation myopia axial growth IOP was significantly higher than the control eyes, MT 1 expression melatonin receptors in the retina than the control eyes. eye, melatonin may regulate growth and development.
|