A GYROSCOPE DEVIOMETER FOR MEASUREMENT OF STRABISMUS

We describe a hand-held gyroscope deviometer that an examiner can use to measure strabismic deviations without prisms. The deviometer is ide ally suited for use with small children who will not allow prisms to b e held near their eyes, and adults with poor fixation in one eye. The device consists of a fixation light attached to a gimbal-mounted singl e-axis gyroscope. The gyroscope provides the necessary reference for h orizontal deviations. Gravity provides the reference for vertical devi ations. As the patient observes his or her reflection with the fixing eye in a plane mirror at the end of the room, the examiner positions t he corneal light reflex in the pupil of the deviating eye and presses a rocker switch to the ''reset'' position, zeroing the deviometer. The examiner the aims the deviometer fixation light at a reflection of it self in a plane mirror located on the wall behind the subject and pres ses the rocker switch to the ''read'' position. Horizontal and vertica l deviations are displayed to the nearest degree. The accuracy of the device is dependent upon the examiner's ability to position the cornea l light reflex correctly in the pupil of the deviating eye.