Growth of the human retinal pigment epithelium (RPE) was studied in whole mount preparations from the fourth month of gestation through the seventh decade. Development of the ora serrata and the adult characteristics of the oral and macular regions is described. From the decline in cell densities with maturation, growth rates were determined for the main geographic areas in the RPE. These rates appeared to be a valid index of posterior segment growth postnatally. They showed the oral region continuing to enlarge at almost the fetal rate until 2 years of age. Each successive area behind it grew at a slower rate. Beyond a sagittal ocular diameter of 23 mm, usually 3 to 6 years, growth was largely confined to the oral-equatorial region. This late growth was substantial, especially in large globes, and could be of importance in degenerative processes of the peripheral retina.
Streeten BW. Development of the Human Retinal Pigment Epithelium and the Posterior Segment. Arch Ophthalmol. 1969;81(3):383-394. doi:10.1001/archopht.1969.00990010385017