The results of surgical treatment of esotropia

Short-Term Motor and Sensory Outcomes in Acquired Nonaccommodative Esotropia of Childhood

Information on the management of acquired nonaccommodative esotropia (ANAET) of childhood is incomplete. Most prior reports combine the results of patients with both accommodative and nonaccommodative esodeviations. The primary objective of this study was to describe the early postoperative motor and sensory results of children with acquired nonaccommodative esotropia. The medical records of 72 consecutive children with ANAET who underwent surgical correction at East Tennessee State University College of Medicine from August 1, 1995 through October 1, 2001 were retrospectively reviewed. The median age at surgery for the 72 study patients was 43.8 months with a median angle of deviation of 30 prism diopters (PD) at both distance and near. Ten patients (13.9%) required a second surgical procedure while one patient (1.4%) required a third. The cumulative probability of a second surgery within two years of the first procedure was 24% (95% CI 4-43%). During a median postoperative follow-up period of 7.1 months, 64 (88.9%) patients were within 8 PD of orthotropia on the last postoperative examination. Normal postoperative stereoacuity was achieved in several children whose deviation began after 30 months of age, as well as in one child who was misaligned for at least two years prior to surgery. Although the postoperative follow-up on these patients with acquired nonaccommodative esotropia managed without prism adaptation is short, the motor results are similar to other studies on patients with acquired esotropia, with sensory outcomes superior to those obtained in children with congenital esotropia.

Results in 50 cases of strabismus after graduated surgery designed by A scan ultrasonography

Of 50 cases of strabismus having surgical operations designed on the basis of A scan ultrasonography 45 (90%) had less than 10 dioptres eso- or exodeviation two months postoperatively; 22 eso-, 25 exo-, and 3 vertical deviations were included in the series. A scan ultrasonography is done preoperatively to find the diameter and thus the circumference of the globe. This is used with the angle of deviation to estimate the amount of recession and/or resection necessary to correct the deviation. Attention is drawn to the oculomotor axis, which is 10-12 degrees divergent to the anteroposterior axis and around which the recti muscles act. The oculomotor equator is at right angles to this axis and is closer to the limbus medially than laterally, so that excessive recession of the medial rectus is more likely than of the lateral rectus.

The use of ultrasonography in determining the amount of extraocular muscle surgery in strabismus

In twenty strabismus patients using ultrasonography a measurement was taken from the apex of the orbit through the centre of rotation of the eye to the front of the eye along the oculomotor axis which is at an angle of approximately 10 degrees to the anteroposterior axis of the eye. From this and from the diameter of the eye average values were derived for the distance from the equator of the medial rectus insertion of 6.27 mm (range 3.96-8. 92 mm) the lateral rectus insertion 8.77 mm, the length of the medial rectus 35.32 mm (range 32. 40-40. 25 mm) and the lateral rectus 37.82 mm (range 34. 79-42. 75 mm). There are sources of error in these measurements but they are probably not great, though corneal diameter and muscle position should be checked at operation. In addition a recession/muscle length ratio may be calculated and it is probably wise not to exceed a ratio of of 0.20 for the medial rectus and 0.25 for the lateral rectus with similar resection muscle length ratios suggested. The variability of the distance of the muscle insertions from the equator is greater than the muscle lengths and it seems important not to recess beyond the equator while alteration of muscle length may be less important. This suggests maximal recession of the medial rectus may vary from 4 up to almost 9 mm and from 6.5 to almost 11.5 mm for the lateral rectus. The value of making these measurements pre-operatively seems obvious and the considerable variation is the amount of squint surgery is stressed, particularly for muscle recessions.