hypertropia

Hypertropia is a manifest vertical strabismus in which one eye is displaced upward relative to the other. The latent form of the same upward imbalance is a hyperphoria.¹ The deviation is named for the side of the higher visual line, and a right hypertropia means the right visual line sits above the left.²

Vertical deviations are relative, and a right hypertropia could also be called a left hypotropia. In a tropia the choice of term tells which eye is fixating. Right hypertropia indicates that the lower left eye is fixating, whereas left hypotropia indicates that the higher right eye is fixating.²

A hypertropia may be comitant, with the same deviation in all directions of gaze, or incomitant, with a deviation that grows in the field of action of an underacting or paralytic muscle. A hypertropia may also be constant, or intermittent and manifest only at times of fatigue, illness or stress.²