Effects Of Betagan Solution On Form Deprivation Myopia In Guinea Pig Eye

In recent years, the prevalence of myopia is increasing in many parts of the world; however the pathogenesis of myopia is unclear yet. From the initial theory of accommodation, bioactive substance to circumstance, heredity, many researches on the pathogenesis of myopia presume the forming of myopia is complicated and related to multiple factors. Many contemporary researches infer that the bioactive substance such as retinal transmitter and growth factors manipulates the growth of the eye by parallel and interlacing ways. In the early time, People have paid attention to the relationship between the intraocular pressure and myopia and furthermore observed myopia always companied with the increasing intraocular pressure and the forming of myopia could be inhibited by reducing the increasing intraocular pressure, however the relationship between the intraocular pressure and myopia is still controversial.Objective To study the Effects of betagan solution on Form deprivation myopia in guinea pig eye and observe the relationship between intraocular pressure rhythm and the mechanisms of form deprived myopia.Methods 60 1-week- old guineas were divided into 4 groups randomly. Group I was used as normal control without any treatment. In group II,III,IV , all the right eyes were worn with monocular translucent goggles for 9 weeks. In group III,IV, all the right eyes were treated with normal sodium and 0.5%betagan solution respectively. Before and after experiment, refractive status, axial length, intraocular pressure and its circadian rhythm, electroretinogram and corneal endothelial density were measured, and then eyeballs were removed and observed by light and electron microscope.Results 9 weeks later, compared with group I, the experimental eyes of group IKIII,IV showed myopia- 6.29±2.41D (t=-10.115 P=0.000<0.001),-6.23±2.56D (t=-9.431 P=0.000<0.001) , -1.08±1.91D (t=-2.193 P=0.046<0.05) ,elongating 0.51±0.17mm (t=11.931 P=0.000<0.001), 0.53±0.17mm(t=11.820 P=0.000<0.001), 0.10±0.17mm(t=2.241 P=0.042<0.05), There is significant deference between group IV and group II,III. The IOP of group I was lower than that of group II,III and higher than that of group IV, There is statistical deference between them. The phase of the circadian rhythm in IOP of group II,III were more variable than that of group I,IV; Compared with group I, the corneal endothelial density and the amplitude of b-wave in group II,III,IV decreased. There is significant deference between group IV and group II,III. There is a significant correlation between myopic diopter and axial length (P<0.01).The axial length of myopia went up with diopter increasing. The diopter and IOP in myopia have significant correlation (P<0.01). The IOP in myopia went up with diopter increasing. Under the light microscope and electron microscope, the retinal and sclera of group II,III are much thinner than that of group IV and the morphous of membranous disc, phagosome, mitochondrion are altered much more likewise.Conclusion Betagan solution can't completely inhibit the shaping of form deprivation myopia in guinea pig eye, but it's able to improve negative effects caused by myopia and make the progression of myopia postpone.