title: A gyroscope deviometer for measurement of strabismus.
abstract: We describe a hand-held gyroscope deviometer that an examiner can use to measure strabismic deviations without prisms. The deviometer is ideally suited for use with small children who will not allow prisms to be held near their eyes, and adults with poor fixation in one eye. The device consists of a fixation light attached to a gimbal-mounted single-axis gyroscope. The gyroscope provides the necessary reference for horizontal deviations. Gravity provides the reference for vertical deviations. 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 the corneal light reflex in the pupil of the deviating eye and presses a rocker switch to the "reset" position, zeroing the deviometer. The examiner then aims the deviometer fixation light at a reflection of itself in a plane mirror located on the wall behind the subject and presses the rocker switch to the "read" position. Horizontal and vertical deviations are displayed to the nearest degree. The accuracy of the device is dependent upon the examiner's ability to position the corneal light reflex correctly in the pupil of the deviating eye.
authors: Wilmer Ophthalmological Institute, Johns Hopkins University School of Medicine, Baltimore, Md.
authors: K M
authors: KM
authors: Miller
authors: K L
authors: KL
authors: Cooper
authors: D L
authors: DL
authors: Guyton
mesh_terms: D001767:Blinking / Q000502:physiology; D002675:Child, Preschool; D006801:Humans; D008027:Light; D009885:Ophthalmology / Q000295:instrumentation*; D011680:Pupil / Q000502:physiology; D015203:Reproducibility of Results; D013285:Strabismus / Q000175:diagnosis*