Abstract:  Objective To evaluate the distribution of ocular torsion in intermittently exotropic patients. Design Retrospective case series. Participants 108 patients with intermittent exotropia aged 5~16 years presented from October 2021 to July 2022, and 108 patients without strabismus were collected as the control group in Beijing Tongren Hospital. Method All subjects underwent non-mydriatic fundus photography. The disc-foveal angle (DFA) was measured using Image J software. Photographs of the fundus were classified as normal (no torsion) when the fovea lay between the center and the inferior margin of the optic disc. There was an intorsion when the fovea was above the disc center. Extorsion when the fovea was situated below its inferior margin. The correlation between DFA and the Revised Newcastle Control Score (RNCS) and strabismus angle, stereoacuity was analyzed. Main Outcome Measures DFA, ocular torsion and correlation with RNCS, strabismus angle, and stereopsis. Results The mean DFA in the intermittent exotropia group was significantly greater than that in the normal control group (6.17°± 3.18 °; 5.36 °± 2.50°, respectively, P=0.003), and the incidence of ocular torsion (extorsion or intorsion) in the intermittent exotropia group was significantly higher than that in the control group (33 eyes, 15.28%; 14 eyes, 6.48%, P=0.003). DFA size has significant positive correlation with RNCS, strabismus angle and stereoacuity in patients with intermittent exotropia (r=0.634, P＜0.001; r=0.353, P＜0.001; r=0.370, P＜0.001; r=0.271, P=0.005). Conclusion Intermittent exotropia patients exist more obvious the ocular torsion when their control scores were poor, their strabismus angles were larger, and their stereoacuities were poorer. (Ophthalmol CHN, 2023, 32: 425-429)

Key words:  intermittent exotropia, torsion, disc-foveal angle