Postoperative outcomes in children with intermittent exotropia from a population-based cohort

doi:10.1016/j.jaapos.2008.06.001

Journal of American Association for Pediatric Ophthalmology and Strabismus

Volume 13, Issue 1, February 2009, Pages 4-7

Presented in part at the 34th Annual Meeting of the American Association for Pediatric Ophthalmology and Strabismus, Washington, D.C., April 2-6, 2008.

https://doi.org/10.1016/j.jaapos.2008.06.001 Get rights and content

Purpose

To describe the long-term surgical outcomes in a population-based cohort of children with intermittent exotropia.

Methods

The medical records of all children (<19 years) who were diagnosed with intermittent exotropia as residents of Olmsted County Minnesota, from January 1, 1975, through December 31, 1994, and managed with surgery were retrospectively reviewed.

Results

Of 184 patients with intermittent exotropia, 61 (33%) underwent surgery at a mean age of 7.6 years (range, 3.2 to 23 years). Twelve of the 61 children (19.7%) underwent a second surgery (10 for recurrent exotropia and 2 for consecutive esotropia), and no patient received 3 or more surgeries during a mean follow-up of 10 years from the first surgery. The final postoperative measurements were recorded in 56 of 61 patients (92%) at a mean of 7.4 years (range, 0 to 18 years) after the first surgery: 31 of the 56 (55%) were within 9^Δ of orthotropia at distance and 25 of 55 (45%) had better than 60 seconds of stereopsis. The Kaplan-Meier rate of developing ≥10^Δ of misalignment after the first surgery was 54% by 5 years, 76% by 10 years, and 86% by 15 years.

Conclusions

In this population-based study of surgery in children with intermittent exotropia, although only 1 in 5 received a second surgery, after a mean follow-up of 8 years, approximately half were successfully aligned and 45% had high-grade stereopsis.

Section snippets

Subjects and Methods

The medical records of all patients younger than 19 years who, while residents of Olmsted County, Minnesota, were diagnosed by an ophthalmologist as having any form of exotropia between January 1, 1975, and December 31, 1994, were retrospectively reviewed. Institutional review board approval was obtained for this study. Intermittent exotropia was distinguished from other forms of exotropia and defined as an intermittent distance exodeviation of at least 10^Δ without an underlying or associated

Results

During the 20-year study period, 184 new cases of intermittent exotropia were diagnosed in Olmsted County, Minnesota. The historical and clinical characteristic of the 61 (33%) who underwent surgery are shown in Table 1. The mean age at diagnosis for the 61 patients was 4.3 years, and two-thirds were female. Mild amblyopia was found in 4, and the mean initial exotropic angle was 20^Δ at distance and 14^Δ at near. Statistically significant differences between the 61 patients who underwent surgery

Discussion

This study provides population-based data on the surgical outcomes of 61 of 184 children diagnosed with intermittent exotropia during a 20-year period. Successful surgical alignment, defined as <10^Δ from orthotropia, was accomplished in 56% of children after a mean follow-up of 10 years. Although only 20% of the study patients underwent a second surgery, just 45% of patients demonstrated 60 arcsec or better of stereopsis. However, the only clinical factor associated with poor postoperative

Literature Search

All articles involving surgical outcomes of exotropia were reviewed, including those that specifically discussed intermittent exotropia. PubMed was the primary database used. Search terms used included exotropia, surgical, population-based, children, outcomes, bilateral lateral rectus recession, unilateral medial rectus resection, and lateral rectus recession.

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Cited by (123)

Preoperative and Postoperative Clinical Factors in Predicting the Early Recurrence Risk of Intermittent Exotropia After Surgery
2023, American Journal of Ophthalmology
To identify preoperative and postoperative early recurrence risk in intermittent exotropia (IXT) patients after surgery.
Prospective clinical cohort study.
We included 210 basic-type IXT patients who underwent either the bilateral rectus recession or unilateral recession and resection procedure and had complete follow-up until recurrence or for more than 24 months postoperatively. The primary outcome was early recurrence, defined as postoperative exodeviation over 11 prism diopters at any time beyond postoperative month 1 and within 24 months. Survival was estimated by the Kaplan−Meier method. Preoperative and postoperative clinical characteristics were collected from patients, and preoperative and postoperative Cox proportional hazards regression analyses were performed. Preoperative model was fit with 9 preoperative clinical factors (sex, onset age of exotropia, duration of disease, spherical equivalent of the more myopic eye, preoperative distant exodeviation, near stereoacuity, distant stereoacuity, near control, and distant control). Postoperative model was fit by adding 2 factors relevant to surgery (surgery type and immediate postoperative deviation). Corresponding nomograms were constructed and evaluated using the concordance indexes (C-indexes) and calibration curves. Decision curve analysis (DCA) was used to determine the clinical utility.
The recurrence rate was 8.10% for 6 months, 11.90% for 12 months, 17.14% for 18 months, and 27.14% for 24 months after surgery. Younger age at onset, larger preoperative angle, and less immediate postoperative overcorrection were found to increase the risk for recurrence. Although onset age and age at surgery were strongly correlated in this study, age at surgery was not significantly associated with IXT recurrence. The C-indexes for the preoperative and postoperative nomograms were 0.66 (95% CI: 0.60-0.73) and 0.74 (95% CI: 0.68, 0.79), respectively. Calibration plots between predicted and actual observed 6-, 12-, 18-, and 24-month overall survival using the 2 nomograms revealed high consistency. The DCA indicated that both models yielded great clinical benefits.
By relatively accurate weighing of each risk factor, the nomograms offer good prediction for early recurrence in IXT patients and may help clinicians and individual patients make appropriate intervention plans.
Ambulatory Monitoring With Eye Tracking Glasses to Assess the Severity of Intermittent Exotropia
2023, American Journal of Ophthalmology
To explore the utility of eye tracking glasses in patients with intermittent exotropia as a means for quantifying the occurrence of exotropia, defined as the percentage of time that the eyes are misaligned.
Prospective observational study.
Eye tracking glasses were used to obtain 68 recordings in 44 ambulatory patients with a history of intermittent exotropia. Vergence angle was monitored for up to 12 hours to document the occurrence of exotropia.
Intermittent exotropia was present in 31 of 44 patients. They had a mean exotropia of 19.3 ± 5.3° and a mean occurrence of 40% (range 3-99%). There was a moderate correlation between the magnitude of exotropia and its occurrence (r = 0.59). In 13 patients the occurrence of exotropia was <1%; they were deemed to have an exophoria only. In 35 of 44 cases, families reported an occurrence of intermittent exotropia greater than that measured by the eye tracking glasses.
Eye tracking glasses may be a useful tool for quantifying the severity of intermittent exotropia and for defining more precisely its clinical features.
Outcomes of intermittent exotropia surgery
2021, Journal Francais d'Ophtalmologie
Citation Excerpt :
We considered that a stable postoperative binocular fusion and a stereoscopic acuity of less than 60′’ of arc in the TNO test represented a sensory success. The motor success rate reported in the literature ranged between 50 and 79% [24]. In our series, the success rate after a single operative time was of 78.9%, and the final success rate was of 84.2%.
To study the epidemiological and clinical characteristics of intermittent exotropia and to describe our therapeutic choices as well as their results and prognostic factors.
This was a retrospective study including 57 cases of intermittent exotropia. All patients underwent a complete ophthalmological examination with a sensory-motor assessment. Surgery was performed by the same surgeon, and the vertical component was addressed surgically at the same time as the exotropia. Statistical analysis was performed using SPSS software version 21.0.
Our patients were classified as basic exotropia in 46 cases (80.7%), divergence excess in eight cases (14.1%), and convergence insufficiency in three cases (5.2%). Amblyopia was found in 26% of cases. The preoperative maximum angle of deviation was 36.5 DP ± 9.1 DS and a vertical component was found in 16 patients (28%). The most common was V pattern (8 patients). The mean age at the time of surgery was 14.8 years old. After a single surgery, we obtained motor success in 78.9% of the patients. Three patients were re-operated, with an overall motor success of 84.2%.
Motor and sensory success may be achieved in intermittent exotropia. Rigorous, early management is necessary, even if tropic episodes are still rare. The rate of early consultation among children is still low in our country; thus, a national strabismus screening program must be established to obtain the best results.
Étudier les caractéristiques épidémiologiques et cliniques de l’exotropie intermittente et décrire nos indications thérapeutiques, ainsi que leurs résultats et facteurs pronostiques.
Il s’agissait d’une étude rétrospective incluant 57 cas d’exotropie intermittente. Tous les patients ont eu un examen ophtalmologique complet, avec une évaluation sensorimotrice. La chirurgie a été réalisée par le même chirurgien et l’élément vertical a été opéré au même moment opératoire. L’étude statistique a été réalisée à l’aide du logiciel SPSS version 21.0.
Nos patients ont été classés en exotropie de type basique, dans 46 cas (80,7 %), de type excès divergent dans huit cas (14,1 %) et de type insuffisance de la convergence, dans trois cas (5,2 %). L’amblyopie a été retrouvée dans 26 % des cas. L’angle de déviation maximum préopératoire était de 36,5 DP ± 9,1 DS et un facteur vertical a été trouvé chez 16 patients (28 %). Un syndrome V a été note chez huit patients. L’âge moyen au moment de la chirurgie était de 14,8 ans. Après une seule chirurgie, nous avons obtenu un succès moteur chez 78,9 % des patients. Trois patients ont été réopérés avec un succès moteur global de 84,2 %.
Le succès moteur et sensoriel pourrait être atteint dans l’exotropie intermittente. Une prise en charge rigoureuse et précoce est nécessaire, même si les épisodes tropiques sont encore rares. Le taux de consultation précoce chez les enfants est encore faible dans notre pays; ainsi, un programme national de dépistage du strabisme doit être mis en place pour obtenir les meilleurs résultats.
Vision therapy for intermittent exotropia: A case series
2021, Journal of Optometry
We evaluated the effectiveness of office-based vergence/accommodative therapy with home reinforcement for intermittent exotropia in a private practice environment.
This was a retrospective chart review study. Patients who received office-based vision therapy for intermittent exotropia in a private optometric clinic were reviewed. Patients with intermittent exotropia treated with and without strabismus surgery were both included. The pre-therapy baseline data were compared to the re-evaluation data obtained at the last therapy session. All patients received office-based vergence/accommodative therapy administered by a trained therapist during a 60 min office visit every one to two weeks, combined with home reinforcement for a minimum of 15 min, five times per week. The primary outcome measure in this study was the change in the Office Control Score from the pre-therapy visit to the post-therapy visit. The hypothesis was that office-based vergence/accommodative therapy would significantly improve the Office Control Score.
Forty patients aged from 5 to 22 years old fulfilled the inclusion criteria. Eight of them were postoperative patients. After treatment, there was a change of −1.1 ± 1.6 (p < 0.001, z = 3.73, effect size: 0.42) and −1.1 ± 1.4 (p < 0.001, z = 4.26, effect size: 0.48) in distance and near Office Control Score, respectively. In the subgroup analysis, significant improvements in the Office Control Score were observed in both the operated and unoperated intermittent exotropes at distance and near.
This study showed that office-based vergence/accommodative therapy with home reinforcement significantly improved the distance and near control of exodeviation in both operated and unoperated intermittent exotropia patients in a private practice environment.
Analysis of postoperative exodrift according to surgical methods for intermittent exotropia
2024, Acta Ophthalmologica
Office-based vergence and anti-suppression therapy for the treatment of small-to-moderate angle intermittent exotropia: A randomised clinical trial
2024, Ophthalmic and Physiological Optics

View all citing articles on Scopus

: See editorial on page 1.

: This study was conducted at Mayo Clinic Rochester Minnesota.

: Funded in part by an unrestricted grant from Research to Prevent Blindness Inc., New York, New York.

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Major articlePostoperative outcomes in children with intermittent exotropia from a population-based cohort

Purpose

Methods

Results

Conclusions

Section snippets

Subjects and Methods

Results

Discussion

Literature Search

Ophthalmology

Ophthalmology

Am J Ophthalmol

Am J Ophthalmol

Am J Ophthalmol

Ophthalmology

Am J Ophthalmol

Mayo Clin Proc

JAAPOS

JAAPOS

J AAPOS

Major article
Postoperative outcomes in children with intermittent exotropia from a population-based cohort