Explaining the current role of high-frequency ultrasound in ophthalmic diagnosis

Ultrasound has become as indispensable as indirect ophthalmoscopy or slit lamp in the evaluation of the eye. It is an important adjuvant for the clinical assessment of a variety of ocular and orbital diseases. Advances in instrumentation, higher frequencies and better sensitivity and resolution have resulted in continuous improvement in image quality. Very high-frequency ultrasound uses frequencies in the range of 35-100 MHz to show greater detail of the anterior segment. Penetration is limited for these higher frequencies to only a few millimeters and, thus, only the anterior vitreous behind the ciliary body and lens can be imaged. High-frequency ultrasound in the range of 20-30 MHz has a penetration of approximately 10 mm and can be used for posterior pole evaluation of the retina and choroid.