consecutive strabismus

Consecutive strabismus is a deviation in the direction opposite to an earlier strabismus. Most cases follow surgical overcorrection, and an esotropic eye occasionally changes into an exodeviation on its own.^1,2 Consecutive strabismus is one of the secondary heterotropias, the deviations that result from a known cause.¹

Consecutive esotropia follows surgical overcorrection of an exodeviation.² Smaller overcorrections, usually comitant, are watched, because a postoperative esodeviation of 10 to 15 prism diopters may disappear with time, while larger deviations tend to increase.³ A second operation waits at least 6 months unless limited ductions cause incomitance in lateral gaze.³ After surgery for intermittent exotropia in a child, consecutive esotropia should not persist for more than 6 weeks without further intervention.²

Consecutive exotropia develops spontaneously in an amblyopic eye, or more often after surgical correction of an esodeviation.² Divergence within hours to months of surgery is usually due to muscle slippage, and divergence years later is usually due to a stretched scar.²