Strabismus and Sensory-motor Function of Eye Muscles

Paul Bach-y-Rita and coworkers at the Smith-Kettlewell Institute of Visual Science of San Francisco were among the first to record activity in the muscle fibers of the eye muscles in animals. With their newly developed methods, they could describe fast and slow muscle fibers types and present possible patterns of recruitment of the fibers in different eye movements. These studies have been critical for continued animal research on eye muscle fibers and motor units in different species and in animals of different ages. Bach-y-Rita and coworkers also recorded from receptors in the muscles and demonstrated stretch reflexes different from those of skeletal muscles. Further research in animals revealed that it was difficult to delineate the functional role of the muscle receptors in oculomotor control. However, recent studies on sensory functions of human extra ocular muscles have suggested that proprioception participates in space localization, and the functions may differ in normal and strabismic subjects. The eye muscle studies initiated by Bach-y-Rita have enabled analysis of the sensory-motor components of strabismus or squint in greater detail than before.