Tenectomy and Posterior Tenectomy of the Superior Oblique for Superior Oblique Overaction

PURPOSE: The authors of the present study compared the effects of tenectomy and posterior tenectomy of the superior oblique for treating superior oblique overaction (SOOA). METHODS: The records of 30 eyes of 19 patients who underwent tenectomy or posterior tenectomy of the superior oblique alone or in combination with surgery on other horizontal rectus muscles from April 2005 through November 2010 were reviewed. The review was performed in 3 patients who underwent unilateral superior oblique tenectomy, 5 patients who underwent unilateral superior oblique posterior tenectomy, 3 patients who underwent bilateral superior oblique tenectomy, 6 patients who underwent bilateral superior oblique posterior tenectomy, and 2 patients who underwent superior oblique posterior tenectomy and tenectomy. RESULTS: The mean age of the patients was 14.2 years, and the mean follow-up period was 20 months. Through superior oblique tenectomy (11 eyes) and superior oblique posterior tenectomy (19 eyes), the amount of SOOA decreased from +2.27 to +0.09 and from +1.84 to +0.93, respectively. Except for 1 out of 11 eyes with superior oblique tenectomy, SOOA was completely corrected, although SOOA remained in 6 eyes after posterior tenectomy. Therefore, the correctional effects of the 2 methods differed; both procedures showed insignificant correctional effects on vertical strabismus. CONCLUSIONS: Superior oblique tenectomy has a superior long-term weakening effect; however, posterior tenectomy showed a comparable effect in the patient with moderate to severe SOOA. Both of these methods had few complications and are considered to be effective superior oblique weakening procedures.

Reunion of the Rabbit Superior Oblique Tendon After Weakening Procedures

PURPOSE: To investigate the degree of reunion in rabbit eyes of the superior oblique tendon after several surgical weakening procedures. METHODS: A total of 32 rabbits (64 eyes) were used in this study. The rabbits were randomly assigned to four groups, eight rabbits (16 eyes) in the tenotomy group, eight rabbits (16 eyes) in the tenectomy group, eight rabbits (16 eyes) in the disinsertion group and eight rabbits (16 eyes) in the recession group. The degree of reunion or reattachment of the superior oblique tendon on the globe were examined on four eyes in each group at postoperative weeks two, four, six and eight. RESULTS: At eight weeks, the newly created insertion site remained at the same site in all eyes in the recession group, and the distal end of the superior oblique tendon was reattached at the medial border of the superior rectus muscle in all four eyes in the tenotomy and disinsertion groups, and in three of four eyes in the tenectomy group. CONCLUSIONS: From this experimental study, it was speculated that superior oblique recession is more effective than other superior oblique weakening procedures. This result could be helpful in the prediction of time of recurrence for superior oblique overaction after superior oblique weakening procedures.

The Clinical Characteristics of Dissociated Vertical Deviation Combined with Exotropia

PURPOSE: The clinical characteristics and post-operative prognosis of dissociated vertical deviation (DVD) combined with exotropia was evaluated. METHOD & MATERIALS: The clinical appearance such as the frequency of DVD, vision, amount of deviation, stereoacuity, sensory abnormality, the presence of latent nystagmus, head tilting and operation results were evaluated in patients who were diagnosed with comitant exotropia followed by surgical correction with 3 month follow-up. RESULTS: Eight (16.0%) patients had exotropia combined with DVD, the combined DVD showed an angle of vertical deviation 15.88+/-7.26 delta, for the right eye and 13.50+/-6.55 deltafor the left eye in the primary position. All but 1 patient showed subnormal stereoacuity in the Titmus stereopsis test and most showed suppression in near and far in the Worth 4 dot test. Four (50%) patients were associated with latent nystagmus and one (12.5%) patient showed head tilting. Three months after the operation, all patients showed a residual DVD under 8 delta. CONCLUSION: DVD is frequently combined with exotropia and is associated with decreased stereoacuity, latent nystagmus, head tilting, inferior oblique overaction (IOOA), and superior oblique overaction (SOOA). DVD showed no relation to the amount of deviation of exotropia but was usually associated with a small angle of exotropia ( or =50 delta). The correction of DVD with exotropia showed satisfactory results.

Posterior Tenotomy and Tenectomy of Superior Oblique Muscle in "A" Pattern Strabismus

In 7 patients with "A" pattern strabismus with superior oblique overaction, we performed superior oblique posterior tenotomy and tenectomy(PTT) and horizontal rectus muscle surgery for horizontal strabismus, uni- or bilaterally, and analysed the status in degree of postoperative correction of "A" pattern, horizontal and vertical deviation in the primary position for availability of PTT in correction of superior oblique overaction. The average correction of "A" pattern was 10.4 prism diopter(PD). 6 of 7 patients showed eso- or exotropia under 6 PD in the primary position. Two of four patients in bilateral surgery and 2 of 3 patients in unilateral surgery showed the change of vertical deviation in the primary position but there were no problems cosmetically except one. From these results, we think that posterior tenotomy and tenectomy of superior oblique muscle is one of the useful methods for correction of superior oblique overaction in "A" pattern strabismus.

Superior Oblique Tenotomy with Silicone Expander for Superior Oblique Overaetion and Brown Syndrome

Standard procedures for weakening the superior oblique muscle have been associated with significant complications in the treatment of superior oblique overaction and Brown's syndrome. Authors performed a technique for weakening the superior oblique muscle by lengthening the superior oblique tendon with silicone. Lengthening was accomplished by a nasal superior oblique tenotomy and inserting a segment of silicone 240 retinal band between the cut ends of the tendon. This technique was performed on 6 patients (8 eyes), 2 (4 eyes) with superior oblique overaction (SOOA), and 4 (4 eyes) with Brown's syndrome. Preoperatively patients with SOOA demonstrated A-patterns of 26 and 29 prism dioptersrespectively, and versions of +2 or +3 SOOA. Patients with Brown's syndrome demonstrated version of -3 or -4 elevation on adduction. Postoperatively, the A -patterns disappeared and SOOA was improved to 0 or +1, and underaction on adduction improved to 0 or -0.5 in Brown's syndrome. Based on these results, the superior oblique tenotomy with silicone expander is useful in patients with SOOA and Brown's syndrome.

Effect of the Superior Oblique Tendon Silicone Expander for Superior Oblique Overaction

Authors analysed the surgical results of superior oblique silicone expander for the treatment of superior oblique overaction in 8 patients (15 eyes) who were operated at St Mary's Hospital, Catholic University Medical College from October 1990 to December 1991. The results were as follows: 1. Preoperatively, the patients demonstrated versions of +2 overaction in 6 eyes (40%) and +3 to +4 overaction in 9 eyes (60%), And demonstrated A-patterns between 20 delta to 55 delta with a mean of 33 delta. 2. Postoperatively, of the 9 eyes with +3 to +4 overaction, 6 eyes (66.7%) showed no overaction and 3 eyes (33.3%) had +1 residual overaction. Of the 6 eyes with +2 overaction, 4 eyes (66.7%) showed no residual overaction, while 2 eyes (33.3%) had +1 residual overaction. 3. Postoperatively. reduction of A-pattern was from 16 delta to 51 delta with a mean of 27 delta. Bases on these results, it appears that the silicone expander technique is useful for the treatment of superior oblique overaction.