Surgical management of Helveston syndrome (triad of A- pattern exotropia, superior oblique overaction and dissociated vertical deviation) using 'Four Oblique' procedure

Purpose: To report the surgical outcomes in six patients of Helveston syndrome using a 揻our oblique� procedure. The popular methods for surgical management include superior rectus recessions alone or combined with superior oblique tenectomy. However, large angle exotropia correction would entail a higher risk of anterior segment ischemia when the superior rectus needs to be operated along with the horizontal recti. Hence, we evaluated the long-term results of this uncommon procedure. Methods: This was a retrospective review of six patients diagnosed to have manifest dissociated vertical deviation (DVD) with A pattern exotropia with bilateral superior oblique over action. All patients underwent horizontal muscle recessions/resections for exotropia along with bilateral posterior tenectomy of the superior oblique with inferior oblique anterior transpositioning. Results: The median age was 10 years (Range 5� years). The mean postoperative follow-up was 26 � 14.02 months (Range 12� months). The mean reduction in exotropia was from 36.5 � 21.06 PD (Range 15� PD) to 6.1 � 3.06 PD (Range 3� PD). The procedure corrected the A pattern from a mean 23 � 7 PD (Range 15� PD) to 7.6 � 3.2 PD (Range 3� PD). The average DVD in the right eye reduced from 14 � 4.3 PD (Range 8� PD) to 5.3 � 1.2 PD and in the left eye from 14.33 � 3.6 PD (Range 10� PD) to 4.1 � 1.1 PD. The DVD asymmetry reduced from 6.33 � 3.4 PD to 1.5 � 1.3 PD. Conclusion:擣our oblique� procedure with horizontal muscle surgery seems to be an effective method for significantly correcting the A pattern as well as reducing the DVD with good long-term outcome in our case series.

Clinical characteristics and surgical management in A-pattern exotropia / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To survey the pathogenesis, clinical characteristics and surgical treatment for the correction of A-pattern exotropia.METHODS: The case history and surgical effect of 62 A-pattern exotropia in 1825 strabismus were studied. The superior oblique muscles weakening or the horizontal muscles procedures were performed in all patients according to the dysfunction of the superior oblique muscles, horizontal deviation, with or without binocular vision. Follow-up after surgery was 6-18months with mean duration of 9 months.RESULTS: A-pattern exotropia accounts for 3.4% of all strabismus. A-pattern exotropia accounts for 21.2% of A-V syndrome. After surgery, 52 cases got alignment, 56 cases gained A-sign correction and 54 cases recovered binocular vision.CONCLUSION: A-pattern exotropia is a common type in strabismus, its etiology is mainly oblique muscle dysfunction.Different surgical procedures should be selected according to overaction degrees of oblique muscle and binocular vision function, which can acquire the satisfied results.