The Involvement of the Retina in the Development of Myopia in a Model Eye of Chicks

Background: The current concept of eye growth and emmetropization is thought to be dependent on visual stimulation of the mid-peripheral retinal cells. The aim of the current study was to examine whether damage to this part of the retinal tissue can affect the growth and function of the eye during development. Methods: We had two groups of domestic fowl chicks. One group was normal (N) and the other had a laser burn on 10% of the nasal retinal area of one eye. The optical components of the eye were examined by retinoscopy while physical measurements were made using ultrasonography and micrometry. The function of the retina was examined by standard flash ERG test. There were no differences in the refractive and the ultrasonographic results between the two groups. Results: The experimental group (right eye) showed a significant decrease in the amplitude and the latency results of both a and b wave compared to the other eye (left) and to the control group. However, there were no differences in the refractive and the ultrasonographic results between the two groups. Conclusion: This study found that the ERG in damaged eye was significantly affected by the laser as compared to that of control eye, while there was no difference in the refractive status and growth between the experimental and control groups. Therefore we concluded that burning only a 10% of the retina has no influence on the eye's growth or refractive development, notwithstanding the ensuing decrease in retinal function.