J Korean Ophthalmol Soc.  2011 Sep;52(9):1128-1134.

Secondary Superior Oblique Overaction after Inferior Oblique Muscle Myectomy in a Patient Misdiagnosed with Inferior Oblique Muscle Overaction

• Kim HK
• Lee YC

Abstract

PURPOSE
To report a case of superior oblique muscle tenotomy in a patient with suspected bilateral inferior oblique muscle overaction. The patient showed secondary superior oblique muscle overaction and inferior oblique muscle underaction after inferior oblique muscle myectomy.
CASE SUMMARY
The patient showed V-pattern exotropia with suspected bilateral inferior oblique muscle overaction. After bilateral lateral rectus muscle recession with bilateral inferior oblique muscle myectomy, the patient showed secondary esotropia and inferior oblique underaction. After the surgery, progressive secondary superior oblique muscle overaction continued and finally, a superior oblique muscle tenotomy was performed. After the superior oblique muscle tenotomy, the superior oblique muscle overaction was corrected but the inferior oblique muscle underaction continued.
CONCLUSIONS
After an inferior oblique muscle myectomy, secondary superior oblique muscle overaction can develop. Thus, caution should be taken in diagnosing inferior oblique muscle overaction in patients who show minimally inferior oblique muscle overaction as well as the surgical methods chosen.

Keyword

Consecutive esotropia; Inferior oblique muscle overaction; Secondary Inferior oblique muscle underaction; Secondary superior oblique muscle overaction; V-pattern exotropia

MeSH Terms

Esotropia
Exotropia
Humans
Muscles
Tenotomy

Figure

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  Figure 1. Preoperative fundus photos. Preoperatively, authors misdiagnosed bilateral excyclotorsions.

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  Figure 2. (A) Postoperative 7 month 9-cardinal photos; Bilateral lateral rectus muscle recession (7.0 mm) with bilateral inferior oblique muscle myectomy. Consecutive esotropia and A-pattern esotropia developed. Right eye showed inferior oblique muscle underaction (−1.5) and left eye showed (−1.0) inferior oblique muscle underaction. (B) Postoperative fundus photo showed bilateral incyclotorsions.

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  Figure 3. (A) Postoperative 3 year 5 months 9-cardinal photos after secondary operation; Right lateral rectus muscle advancement (5.0 mm) and right inferior oblique muscle exploration. Consecutive esotropia and A-pattern esotropia still remained. Both eyes showed inferior oblique muscle underaction (−2.0) and superior oblique muscle overaction (+3.0). (B) Postoperative fundus photo showed marked bilateral incyclotorsions.

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  Figure 4. (A) Postoperative 6 months 9-cardinal photos after tertiary operation; Bilateral superior oblique muscle tenotomy. In primary position, mild esophoria and left hypotropia was noticed. Both eyes still showed inferior oblique muscle underaction (−1.0). Right eye showed mild and left eye had no superior oblique muscle overaction. (B) Postoperative fundus photo showed mild in-cyclotorsion in the right eye and no torsion in the left eye.

Reference

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