Exotropia. Strabismus. Cham: Springer International Publishing; 2017. pp. 73-95. [DOI: 10.1007/978-3-319-63019-9_6]

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

BACKGROUND/AIMS

We evaluate the clinical characteristics of intermittent exotropia with controllability and compare surgical outcomes between patients with and without controllability.

METHODS

We reviewed the medical records of patients aged 6-18 years with intermittent exotropia who underwent surgery between September 2015 and September 2021. Controllability was defined as the patient's subjective awareness of exotropia or diplopia associated with the presence of exotropia and ability to instinctively correct the ocular exodeviation. Surgical outcomes were compared between patients with and without controllability, with a favorable surgical outcome defined as an ocular deviation between ≤ 10 PD of exotropia and ≤ 4 PD of esotropia at distance and near.

RESULTS

Among 521 patients, 130 (25%, 130/521) had controllability. The mean age of onset (7.7 years) and surgery (9.9 years) were higher in patients with controllability than in those without controllability (p < 0.001). The mean control scores of patients with controllability (distance: 1.9, near: 1.5) were lower compared with patients without controllability (distance: 3.0, near: 2.2), reflecting a better level of control. Patients with controllability had a better surgical outcome than those without controllability, as analyzed by log-rank test (p < 0.001). Larger preoperative ocular exodeviation at distance (hazard ratio [HR] = 1.083, confidence interval [CI] = 1.018-1.151, p = 0.012) and near (HR = 1.102, CI = 1.037-1.172, p = 0.002) were significantly related to recurrence in patients with controllability.

CONCLUSIONS

Patients with controllability showed better surgical outcomes, later exotropia onset, and better level of control than patients without controllability. Preoperative ocular exodeviation was a significant factor influencing favorable outcomes in patients with controllable exotropia.

Binocular function in patients with intermittent exotropia accompanied by unilateral congenital ptosis

Patients with intermittent exotropia (IXT) have a wide range of binocular deficits. This study aims to evaluate the effect of ptosis on the binocular function of patients with IXT. Clinical records of 45 IXT patients with congenital ptosis (IXT-ptosis group) and 58 age-matched IXT patients without ptosis (IXT only group) who presented for eye examination between January 2017 and June 2020 were retrospectively reviewed. Patients with amblyopia were excluded to rule out the effects of visual acuity on binocularity. Best-corrected visual acuity (BCVA), the magnitude of exodeviation at distance and at near, stereopsis, and office-based control scores at the first visit were reviewed. The binocular functions of the two groups were compared. The mean ± SD age of the overall patients was 6.6 ± 2.7 years. There were no significant differences in the distribution of age, sex, spherical equivalent refraction, or BCVA between the two groups (all p > 0.05). Although the office-based control scores at distance and near were slightly worse in the IXT-ptosis group, the differences were not statistically significant (at distance, 2.8 ± 1.87 vs. 2.2 ± 1.13, p = 0.08; at near, 1.8 ± 0.67 vs. 1.6 ± 0.74, p = 0.11). Furthermore, the IXT-ptosis group had worse stereopsis at distance (p = 0.01). There were no significant differences between the two groups in near stereopsis or exodeviation magnitude (p > 0.05). A larger proportion of patients had suppression on the Bagolini test in the IXT-ptosis group than in the IXT-only group (p = 0.04). The IXT-ptosis group had worse distance stereoacuity, and a larger proportion of patients had suppression on the Bagolini test than the IXT only group. In IXT patients, the presence of coexisting ptosis can have a further deleterious impact on binocular function.

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

PURPOSE

To evaluate the longitudinal course of consecutive esotropia following surgery for basic-type intermittent exotropia.

METHODS

Patients who underwent surgery (bilateral lateral rectus muscle recession [BLR] or unilateral lateral rectus muscle recession-medial rectus muscle resection [RR]) for the treatment of intermittent exotropia between 2011 and 2017 with a minimum follow-up period of 2 years were retrospectively reviewed. When esodeviation occurred later in patients with orthotropia or exodeviation at postoperative month 1, it was defined as delayed-onset consecutive esotropia. The number of patients with esodeviation at every follow-up and characteristics of patients were evaluated.

RESULTS

A total of 336 patients (6.2 ± 2.1 years; 236 in the BLR group and 100 in the RR group) were included. After surgery, postoperative esodeviation decreased mostly during the 1st postoperative month in both groups. At postoperative year 2, there were 28 patients (8.3%) with consecutive esotropia: six in the RR group and 22 in the BLR group. Among the 284 patients with orthotropia or exodeviation at postoperative month 1, there were 13 patients with delayed-onset consecutive esotropia; they presented larger preoperative angle of exodeviation, poorer stereopsis, younger at the time of surgery and associated with the types of surgeries for exotropia.

CONCLUSIONS

In patients with consecutive esotropia, the angle of esodeviation decreased and patching/prismatic correction helped achieve the good surgical outcomes. However, delayed-onset consecutive esotropia and persistent esotropia also presented, requiring the reoperation. Therefore, postoperative alignment should be carefully monitored after surgery for intermittent exotropia.

Factors associated with the effectiveness of part-time patching for intermittent exotropia in children

PURPOSE

To evaluate the factors associated with the efficacy of low-dose part-time patching in children with intermittent exotropia (IXT).

METHODS

In this prospective observational study, we enrolled 186 patients diagnosed with IXT. Outcome measures included office based control scales, magnitude of exo-deviation, and stereoacuity at near and distance after daily patching for 2 h. We analyzed the clinical data and demographic factors association with improvement of IXT.

RESULTS

The study was completed by 152 subjects of total enrolled patients on a consecutive basis followed up for 1 year. Decrease in the magnitude of exo-deviation, improvement of control, and or gain of stereoacuity were observed in 31.6% patients of the recruited subjects after part-time patching. Multivariate analyses showed that prognostic factors determining improvement to part-time patching included convergence insufficiency (CI) type IXT (p = 0.016), poor distance stereopsis (p = 0.044), and large exotropic deviation at distance (p = 0.025).

CONCLUSIONS

CI-type exotropia, large distance magnitude of exo-deviation, or poor distance stereopsis appear to be associated with a better response to part-time patching. Therefore low dose part-time patching may be a useful non-surgical treatment alternative to delay surgery in these cases.

Comparison Between Parental Observations and Clinical Evaluation Findings in Korean Pediatric Patients With Intermittent Exotropia

PURPOSE

To compare parental observations with the clinical evaluation findings in pediatric patients with intermittent exotropia and evaluate the clinical factors associated with the parental observations.

METHODS

This prospective study included either one or both parents of pediatric patients with intermittent exotropia who visited the clinic between January and May 2019. The parental observations were assessed through a questionnaire that included questions on the age of onset, usually deviated eye, degree of awareness, and frequency of exotropia. These findings were compared with those of the clinical evaluations, including the amount of ocular deviation and level of control.

RESULTS

A total of 100 parents (mean age: 39.7 years; 78 women) of 95 pediatric patients (mean age: 8.2 years; 47 girls) with intermittent exotropia participated in the study. The parental observation and clinical evaluation findings on the usually deviated eye showed good concordance (74%). The degree of parental awareness did not show any association with the amount of deviation. However, it showed a statistically significant increase associated with the worsening level of distance control (P = .04). The parental observations of the frequency of exotropia significantly increased with the worsening of the level of near (P = .037) and overall (P = .019) control.

CONCLUSIONS

Parental observations are more likely to correlate with the level of control than with the amount of ocular deviation in pediatric patients with intermittent exotropia. [J Pediatr Ophthalmol Strabismus. 2020;57(3):199-203.].