Superior Oblique muscle palsy: a 30-year review of patient characteristics and surgical management from southern Iran
Hajar Farvardin1 *, Majid Farvardin1 , Mohammad Reza Talebnejad1
- Poostchi Ophthalmology Research Center, Department of Ophthalmology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
Abstract: Background: Superior Oblique muscle (SO) palsy is the most common cyclo-vertical muscle palsy encountered by strabismus surgeons. The purpose of this study is to investigate the demographic characteristics of surgically treated SO palsy patients in a tertiary ophthalmology center in Shiraz.
Methods: Methods: All medical records of unilateral SO palsy patients who were treated by a single ophthalmologist during 30 years were retrospectively reviewed. Patients with bilateral involvement, simultaneous other cranial nerve palsy, and those who were previously treated by another surgeon were excluded from our study. For each patient, the following data was retrieved: sex, age at the time of surgery, etiology of palsy, laterality, preoperative vertical deviation in the primary position, and type of operation. The amount of hypertropia correction was calculated for different types of operation in those patients whose follow-up data were available.
Results: Results: In this study, 441 patients with an average age of 15.38 years at the time of surgery were included. The male-to-female ratio was 1.24 and palsy was on the right side in 56.3% of the individuals. The most common etiology in our patients was congenital (85.3%) and head trauma (9.4%). The average preoperative vertical deviation was 15.6 PD in the primary position. Diplopia and abnormal head position were recorded in 13% and 72% of the patients before the operation. Inferior oblique muscle (IO) surgery alone was performed for over 85% of patients. Among various IO weakening procedures, anterior transposition plus resection had the most hypertropia correction. IO anteriorization and IO myectomy were in second and third place; IO recession and IO disinsertion had the least amount of hypertropia correction.
Conclusion: Conclusion: Unilateral superior oblique muscle palsy mostly presents in the second decay and slightly affects male individuals more than females. Among surgically treated patients, congenital etiology is nine times more common than trauma. IO weakening surgery is the most popular approach for surgical correction and among various types of IO weakening procedures, anterior transposition plus resection has the highest degree of vertical correction.
