Optical Biometry.

Precise biometry is essential for accurate outcomes in cataract and refractive surgeries. The measurement of axial length by ultrasound was the gold standard for many years. With the introduction of optical biometry in the United States in the year 2000, this technology has become more and more popular and is now the most common method for the measurement of axial length. Optical biometry presents an accurate alternative for precise ocular measurements, used not only for axial length, but anterior chamber depth, lens thickness, pachymetry and retinal thickness measurements.

Lens Constants

Haag Streit LENSTAR®

Zeiss IOLMaster®

Optical biometry uses a partially coherent wave that has approximately 9x the resolution of a 10 MHz sound wave, making the measurement of axial length very precise. The measurement technique also helps to avoid operator variations in the measurements. Also increasing the accuracy is the fact that contact with the cornea is not needed, eliminating variations due to compression on the cornea. Since optical biometry measures to the center of the macula, it gives the refractive axial length versus the anatomic axial length achieved with ultrasound biometry.