Abstract
Abstract: :
Purpose: To observe the changes of Egr–1 and c–fos gene expression in the visual cortex of infant rhesus monkeys experiencing form deprivation and optical defocus–induced myopia. Methods: Thirty healthy infant rhesus monkeys (Macaca mulatta) ranging in age from 20 to 40 days were randomly divided into three groups. The monkeys from group A (n=13) and B (n=9) were unilaterally treated with diffuser and –3.00D lenses respectively. Eight monkeys (group C) reared with plano lenses in front of both eyes provided control data. The monkeys’ refractive error, corneal topography, vitreous chamber depth were measured at the start of lens wear and at 2, 4, 6, 8 ,12 weeks post–treatment. After 12 weeks exposure, Egr–1 and c–fos expression in the visual cortex were quantified by means of immunoreactive neurons counting and western blot analysis. Results: Axial myopia was induced both in form deprivation group and optical defocus group animals. Form deprivation caused a marked decrease in the level of Egr–1 and c–fos protein expression and immunoreactivity in the primate visual cortex. Significant reduction of c–fos expression was apparent whereas no remarkable changes in Egr–1 expression was detected in the visual cortex of optical defocus monkeys. Conclusions: The results suggest that changes of Egr–1 and c–fos expression in primate visual cortex might play a role in the onset and development of myopia in the susceptible period. It is implied that visual cortex might participate in the pathogenesis of myopia when receiving abnormal visual experience such as form deprivation or optical defocus.
Keywords: gene/expression • myopia • refractive error development