The Role of Preoperative Indirect Ophthalmoscopy Under General Anesthesia for Diagnosis of Torsional Strabismus

ABSTRACT

The purpose of this study is to evaluate the status of fundus torsion in 48 patients with unilateral inferior oblique overaction(IOOA) and the results were compared with that in 182 patients who showed normal inferior oblique function by an indirect ophthalmoscope under general anesthesia before strabismic surgery. In 48 eyes with unilateral IOOA, 35 eyes(72.9%) showed extorsion in the same eye. We could also find extorsion in 9 normal fellow eyes(18.7%). Among 182 horizontal strabismic patients(364 eyes) with normal inferior oblique function, there were 23 eyes(6.3%) of extorsion and 1 eye (0.3%) of intorsion. We compared the degree of extorsion with that of IOOA in 48 patients with unilateral IOOA a mild extorsion were observed in 2 of 10 eyes with IOOA+1. A mild and moderate extorsion were observed in 13(72.2%) and 3 (16.7%) of 18 eyes with IOOA+2, respectively. A mild and moderate extorsion were observed in 9(45%) and 8(40%) of 20 eyes with IOOA+3 respectively. These findings showed that the greater IOOA produces the greater extorsion(p<0.01). On our results the fundus indirect ophthamoscopy before strabismic surgery seems to be helpful in the diagnosis of cyclotorsion.