Extraocular muscle size comparison between normal and myopic eyes using standardized A scan echography.

The aim of this study was to establish the range of diameters of extraocular muscles in myopic patients and to obtain the baseline data to follow progression or regression of pathologies involving them. Standardized A scan and B scan ultrasound was used to measure the thickness of straight extraocular muscles at the muscle belly. No statistical differences were seen between right and left eyes. We found no consistent correlation with age or with axial length in the control or in the myopic patients (p>0.05). Diameters in myopic and control eyes were similar. This lack of difference between myopic and control muscle sizes means that we can obtain accurate measurements also from myopic patients.