Clinical Manifestations of Delayed-onset Consecutive Esotropia after Surgical Correction of Intermittent Exotropia

Abstract

Consecutive esotropia (ET) is a persisting or variable esodeviation after surgery to correct exotropia. The prevalence of such surgical overcorrection in patients with exodeviation ranges from 6% to 20% [1,2]. Risk factors for consecutive ET include lateral incomitancy [3], high ac-Purpose: To evaluate the clinical features and prognosis of a delayed-onset consecutive esotropia (ET) after surgical correction of intermittent exotropia. Methods: Thirty-four patients who developed consecutive ET after primary bilateral lateral rectus recession for the surgical correction of intermittent exotropia were evaluated retrospectively and were divided into two groups: delayed-onset consecutive ET group and the continuous consecutive ET group. Patients who developed esodeviation after once recovering to orthotropia within 1 month after the operation were included in the delayed-onset consecutive ET group, and patients with continuous esodeviation after the operation were included in the continuous consecutive ET group. We evaluated preoperative and postoperative angle of deviation, suppression, stereopsis, and follow up periods between the two groups and compared re-operation and success following non-surgical treatment between the continuous consecutive ET group and the delayed-onset consecutive ET group. Results: Among 34 patients with consecutive ET, 27 patients (79.4%) were included in the delayed-onset consecutive ET group, and seven patients (23.3%) were included in the continuous group. Success rate of non-surgical treatment was not statistically significant between two groups (p = 0.55), but it was higher in the delayed-onset group with 37.5%, and 25% of patients in continuous group were successfully recovered to straight alignment. Duration of orthotropia in delayed-onset group was 7.4 ± 6.0 months (range, 2-29 months). Age, sex, preoperative refractive error, preoperative exodeviation, suppression, and near steroacuity were not statistically significant between two groups (p > 0.05, all). In the delayed-onset group, three patients (11.1%) underwent re-operation, while three patients (42.9%) in continuous consecutive ET group underwent re-operation (p = 0.048). Conclusions: Re-operation rate of delayed-onset consecutive ET after surgical correction of intermittent exotropia was lower than that of continuous consecutive ET.

Longitudinal course of consecutive esotropia in children following surgery for basic-type intermittent exotropia

“…In addition, high AC/A ratios or lateral rectus underaction and/or stronger MR tension following release of tension from recession of the lateral recti could be associated with this phenomenon. Baik et al [22] recently asserted that the cause of delayed-onset consecutive esotropia is unknown, but an increase in "near work" in the current generation during the unstable postoperative period within several early months after surgery may be playing a role. In addition, as children undergo emmetropisation or myopic shift, changes in the refractive error should be considered during the follow-up period.…”

Study on Binocular Accommodative Function in Children With Different Types of Intermittent Exotropia

“…However, to maintain eye position, the non-fixing eye may use convergence. This will lead to a difference in binocular accommodation, resulting in bilateral eye competition, which will cause a decrease in AF and accommodative response ( 12 ). This is consistent with the results of this study, in which it was found that the AMP of non-fixing eyes in patients with IXT is higher than that of their fixing eyes, suggesting that their fixing eyes should exhibit clear vision in everyday use.…”

How to Better Treat Patients with Intermittent Exotropia: A Review of Surgical Treatment of Intermittent Exotropia

“…Kim and Choi [115] reported that the divergence-excess type X (T), amblyopia, BLR, esodeviation ≥ 20 PD at postoperative day 1, younger age at diagnosis and surgery, and shorter duration from onset to surgery Surgical Treatment of Intermittent Exotropia were risk factors for consecutive esotropia. Baik et al [112] found that 79% of consecutive esotropia were patients who underwent BLR that were orthotropic after 1 month, then later developed esodeviation within 7.4 ± 6.0 months (range, 2 to 29 months). Lee and Kim [113] also found that 5% (13/284) of the patients developed consecutive esotropia after showing orthotropia or exodeviation at postoperative 1 month.…”

“…Residual exotropia at postoperative 1 week and 1 month led to recurrence [ 25 , 26 , 104 ]. However, few patients may manifest delayed consecutive esotropia after showing orthotropia to exotropia at postoperative 1 month, especially after BLR [ 112 , 113 ]. Therefore, surgeons should recognize the possibility of delayed development of consecutive esotropia.…”