Evaluation of the posterior fixation plus recession operation with saccadic velocities.

I performed a posterior fixation of the medial rectus in seven patients with convergence excess esotropia and successfully reduced their esotropia at near. Postoperative saccadic velocity testing did not reveal the expected decrease in saccadic velocity as the eye moved increasingly into the field of action of the operated muscle. Posterior fixation of a rectus muscle may enhance the effect of the standard recession operation by increasing the amount of slack created in the functional part of the muscle after recession. Also, it may make a large percentage of the muscle fibers ineffective.