To assess clinical features of sensory exotropia with distant-near disparity, surgical outcome, and compare according to amount of medical rectus resection.

Authors retrospectively reviewed medical records of patients of sensory exotropia with follow-up over 6 months. We defined patients with over 10 prism diopter (PD) disparity as distant-near disparity sensory exotropia (DND-XT) and without dis-parity as basic sensory exotropia (B-XT). First, we analyzed and compared data of visual acuity, cause and age of visual loss, amount of deviation. Second, Surgical failure was analyzed with dividing DND-XT into conventional surgery group as Parks’ for-mula and reduced medial rectus resection group in accordance with disparity. Surgical success was defined as less than 10 PD deviation in distant, near fixation.

B-XT consisted of 58 patients (40 males) and DND-XT of 33 patient (13 males). There was no significant difference be-tween 2 groups in onset and cause of visual loss, deviation at distant fixation. But, log MAR visual acuity of worse eye was better in DND-XT than B-XT (1.74 ± 0.78, vs. 2.10 ± 0.74, p = 0.039). Average deviation in distant fixation in DND-XT was 46.55 ± 16.59 PD in distant and 14.93 ± 8.91 PD in near fixation. All patients underwent surgery of medial rectus resection and lateral rectus re-cession and average deviation was 6.83 ± 7.71 PD at distant fixation, 3.02 ± 0.69 PD at near fixation at last follow-up. Among 33 patients, 16 patients underwent conventional amount of surgery and 17 patients with reduced medial rectus resection. In patient with conventional surgery, 9 patients were surgical failure (8 patients of over-, 1 patient of under-correction) but in patient with re-duced amount of resection, only 1 patient was under-correction.

As a result of medial rectus resection and lateral rectus recession in DND-XT, more surgical failures due to over-correction were observed with conventional resection and higher surgical success was attained in consideration of disparity.