The Relationship Between Deviation Control and Accommodative Load in Patients with Intermittent Exotropia.

Abstract

Purpose: To investigate the relationship between deviation control and accommodative load in patients with intermittent exotropia (IXT).

Methods: A total of 35 patients with IXT aged 5-21 years (average, 10.46 $\pm$ 4.42 years) with a best-corrected visual acuity of 20/20 or better were included in this study. All examinations, including binocular and monocular refraction, deviation angle, near stereoacuity, and deviation control, were done in patients with the best optical correction.

Results: Of the 35 patients, 16 (45.7%) were male and 19 (54.3%) were female. The results indicated a statistically significant difference in the average distance and near deviation angles between good, relatively good, and poor deviation control levels (P = 0.012). The results also showed that the likelihood of deterioration in deviation control increased significantly with deviation angle (P = 0.012). The accommodative load of the right and left eyes at distance and near fixation did not differ significantly across the three levels of deviation control. Based on the results of univariate logistic regression, no statistically significant relationship was observed between accommodative load (both the right and left eyes at distance and near) and deviation control level. However, there was a significant difference between the accommodative loads of the left and right eyes at near and distance (P $<$ 0.001).

Conclusion: In patients with IXT, deviation control decreased with deviation angle, and accommodative load increased in near fixation compared to distance fixation, but differences were not significant across the three deviation control groups (good, relatively good, and poor).