High-frequency ultrasound spectral parameter imaging of anterior corneal scars

High frequency (50-MHz) ultrasound allows greater resolution (approximately 30 microns) and improved tissue differentiation of the anterior ocular structures than conventional (8-10 MHz) ultrasonic techniques. Spectral analysis of tissue acoustic backscatter is sensitive to both the concentration and size of tissue inhomogeneities. We studied the healing process of experimentally induced corneal scars using high frequency ultrasound spectral analysis. Scatterer size and concentration parameter images of scarred corneas showed distinctive patterns that were correlated with histology over time. This quantitative technique offers a new, noninvasive, in vivo method for the assessment of the internal microarchitecture of surgically altered corneal tissue and its healing dynamics.