Measurement of Axial Length by Applanation Ultrasound Relative to Optical Biometry in Normal Eye

Abstract

The Axial Length (AL) is the distance from the corneal surface to an interference peak corresponding to the retinal pigment epithelium/Bruch's membrane. 1,2 The average newborn's eyeball is about 16 millimeters in diameter, from front to back (axial length). In an infant, the eye grows slightly to a length of approximately 19½ millimeters. The eye continues to grow, gradually, to the length of about 24-25 millimeters. 3 The majority of axial length elongation takes place in the first three to 6 months of life and a gradual reducing rate of growth over the next two years 4 , and by three years the adult eye size is attained. 5 It is considered that the axial length reaches adult length by the age of 13 years. 6