Dramatic Decrease in Ocular Deviation 1 Day before Surgery in Patients with Intermittent Exotropia

Abstract

Purpose To evaluate the clinical characteristics of patients with intermittent exotropia who exhibited a dramatic decrease in ocular deviation 1 day before surgery. Methods This study retrospectively enrolled patients with intermittent exotropia who underwent surgery between December 2013 and December 2019. Those who exhibited a decrease in ocular alignment ≥10 prism diopters (PD) at the last examination (1 day before surgery) compared with the largest previous angle of deviation were included. A monocular occlusion test was performed to re-confirm the largest angle of ocular deviation. Results Among 547 patients with intermittent exotropia, 10 (six females; mean age, 8.6 years) exhibited a dramatic decrease in ocular deviation before impending surgery. The mean largest angle of deviation was 31.0 PD (range, 20 to 50 PD) at distance and 34.5 PD (range, 20 to 55 PD) at near. The mean control scores using the LACTOSE (Look and Cover then Ten Seconds of Observation Scale for Exotropia) scoring system were 2.5 at distance, 1.8 at near, and 4.3 when combined. Mean ocular deviation prior to the impending surgery decreased to 7.4 PD (range, 0 to 10 PD) at distance and 6.2 PD (range, -10 to 10 PD) at near. The largest angle of ocular deviation was re-confirmed using the monocular occlusion test in all patients. All patients underwent surgery as planned, and none exhibited postoperative overcorrection. Conclusions A relatively small number of patients with intermittent exotropia exhibited a dramatic decrease in ocular alignment 1 day before surgery but demonstrated a relatively better level of control. The monocular occlusion test was helpful in re-confirming the largest angle of ocular deviation.

The subjective controllability of exotropia and its effect on surgical outcomes in patients with intermittent exotropia

“…Lim and Kim showed a higher possibility of dramatic decreases in ocular alignment before impending surgery caused by anxiety in pediatric patients with controllability [ 12 ]. These patients had relatively better level of control [ 12 ]. Lee et al reported better surgical outcomes of exotropia in patients with increased ocular deviation after the monocular occlusion test [ 13 ].…”

“…Patients with controllability showed a relatively later onset of exotropia than those without controllability, possibly because patients with better binocularity can maintain normal ocular alignment for a longer time, leading to older mean ages of onset and surgery. Similarly, patients with better binocularity may hide the total amount of ocular exodeviation, leading to variability in ocular exodeviation during follow-up [11][12][13]. Lim and Kim showed a higher possibility of dramatic decreases in ocular alignment before impending surgery caused by anxiety in pediatric patients with controllability [12].…”

“…Similarly, patients with better binocularity may hide the total amount of ocular exodeviation, leading to variability in ocular exodeviation during follow-up [11][12][13]. Lim and Kim showed a higher possibility of dramatic decreases in ocular alignment before impending surgery caused by anxiety in pediatric patients with controllability [12]. These patients had relatively better level of control [12].…”

The Association between Level of Control and Exodeviation after the Monocular Occlusion Test in Pediatric Patients with Intermittent Exotropia

“…This may increase anxiety, which in turn leads to a temporal increase in the level of control and a decrease in ocular deviation. The level of control in pediatric patients with controllability may be easily affected by intrinsic factors, such as anxiety, and may result in a decrease in ocular deviation at initial examination [ 4 ]. Clinicians should be aware of the possibility of hidden ocular deviation, especially in pediatric patients with controllability.…”

“…The level of control is associated with fusional capacity and variability in the exodeviation of patients with intermittent exotropia [ 3 ]. The level of control in patients with intermittent exotropia can be affected by several factors including general health, alertness, attention span, and level of anxiety [ 1 , 4 ]. The results of the MO may be affected by and differ according to the level of control [ 3 ].…”