Measurement of strabismus eyes with a scan ultrasonography

A series of 25 patients with strabismus, of whom 16 had eso and 9 exo deviation were examined by A scan to determine the antero-posterior diameter of the eye. This seemed smaller than the accepted normal being 22.13 mm and with a greater range than normal --17.95 mm to 25.27 mm. In particular there were more small eyes. The fallacy of planning squint operation on the basis of the measurements of a standard eye is stressed --a 5 mm recession may be excessive in a small eye but inadequate in a large one. Two major variables in deciding on squint surgery are the diameter of the globe and the length of the muscles.