<qa>  What is the first time macular retinal structure has developed?It is reported that it takes a period form 22 weeks pregnant to the first 45 months of life for macular region to develop from structural formation to functional integrity. However, children are still in the critical period of plastic visual development, for their visual acuity has not yet reached the level of adults. Similarly macular retinal structure may develop with age. It is very important to study in macular thickness of this period and to have a proper cognition of it and the relation between macular thickness and other ocular parameter for the research of retinal development and diseases and the early screen of fundus diseases. 