Johns Hopkins School of Medicine

Regulation of Eye Movements

Disorders of the control of eye movements lead to disabling disturbances of vision and balance. Our research aims to understand better the mechanisms by which ophthalmologic, neurologic and inner ear diseases affect ocular eye movements and vision. We apply biomedical engineering techniques to the recording and analysis of eye movements both in normal subjects and in patients with neuro-ophthalmologic or vestibular disorders. Our emphasis is on the mechanisms that ensure optimal performance of the ocular motor control system. Both the immediate visual and vestibular influences on eye movements and the more long-term adaptive processes that permit compensation for disease are investigated. We currently are also studying the effects of the magnetic fields of MRI machines on the inner ear labyrinth and consequently brain function. We are using advanced imaging techniques to visualize movement of fluid within the inner ear. We also are using transcranial magnetic stimulation (TMS) to study vestibular perception, i.e., how the brain develops a sense of upright. Another focus is on the relationship between the molecular biology of ion channels and the genetic and acquired causes of tremor of the limbs as well as oscillations of the eyes. The use of eye movement recordings as diagnostic aids (for example, early diagnosis of stroke, multiple sclerosis, myasthenia gravis) are also being investigated.