Relationship Between Motor Alignment at Postoperative Day 1 and at Year 1 After Symmetric and Asymmetric Surgery in Intermittent Exotropia

doi:10.1016/S0021-5155(00)00351-8

Japanese Journal of Ophthalmology

Volume 45, Issue 2, March–April 2001, Pages 167-171

https://doi.org/10.1016/S0021-5155(00)00351-8 Get rights and content

Abstract

Purpose: To evaluate the relationship between the motor alignment at postoperative day 1 and at year 1 following bilateral lateral rectus recession (BLR, symmetric surgery) and unilateral lateral rectus recession-medial rectus resection (R&R, asymmetric surgery) for the treatment of intermittent exotropia, X(T).

Methods: Forty-six patients with basic or pseudo-divergence excess type of X(T) underwent BLR and 57 patients underwent R&R. The motor alignment at postoperative day 1 was classified as overcorrected by 11–20 prism diopters (PD), overcorrected by 1–10 PD, orthotropic, or undercorrected by 1–10 PD of exotropia.

Results: There was a statistically significant relationship between the alignment at postoperative day 1 and at year 1 following both R&R and BLR surgery (r = 0.74, r = 0.51, respectively, P < .05). Patients overcorrected by 1–20 PD had a significantly higher success rate than those undercorrected by 1–10 PD on postoperative day 1 (P < .05). For R&R, a postoperative day 1 alignment of 1–10 PD resulted in the highest success rate of 73.7%. For BLR, a postoperative day 1 alignment of 11–20 PD showed the highest success rate of 76.9%. There were no significant differences in the success, undercorrection and overcorrection rates between the two surgical procedures after a 1-year postoperative period.

Conclusions: The alignment at postoperative day 1 can be a predictive factor of the surgical outcome in X(T). A postoperative day 1 overcorrection of 11–20 PD following BLR surgery and an overcorrection of 1–10 PD following R&R can lead to good results.

Introduction

Of the various specific factors which contribute to the variability of the surgical results for intermittent exotropia, X(T), an initial postoperative overcorrection is known to be a major contributor.1, 2, 3, 4, 5, 6, 7 An initial postoperative overcorrection is believed to eliminate not only suppression and stimulate fusional vergence but also to reduce postoperative exotropic drift. In cases of basic X(T), the choice between bilateral lateral rectus recession surgery (BLR, symmetric surgery) and unilateral lateral rectus recession-medial rectus resection surgery (R&R, asymmetric surgery) is largely a matter of preference. Moreover, the amount of initial postoperative overcorrection differs between surgeons. In BLR surgery, Raab and Parks⁷ advised a 10 to 20 prism diopters (PD) of overcorrection, while Scott et al⁵ advised a 4 to 14 PD of overcorrection. McNeer⁸ recommended a 0 to 10 PD of overcorrection.

In R&R surgery, Parks⁹ advised a few prism diopters of immediate postoperative overcorrection. Souza-Dias and Uesugui² recommended a 5 to 10 PD overcorrection; however, they cautioned that overcorrections and undercorrections sometimes are the result of greater or lesser amounts of initial overcorrection.

Therefore, the purpose of this study was to determine the relationship between the alignment of the eyes at postoperative day 1 and at year 1. In addition, we attempted to predict the success, undercorrection, and overcorrection rates at postoperative year 1 by examining the alignment at postoperative day 1 following BLR and R&R surgery.

Section snippets

Materials and Methods

This study includes 103 intermittent exotropes comprising 93 with the basic type and 10 with the pseudo-divergence excess type. Between January of 1993 and March of 1998, 46 patients underwent BLR surgery and 57 patients underwent R&R surgery at the Keimyung University Hospital. Of these patients, 45 were boys and 58 were girls. Their ages ranged from 3 to 17 years with a mean age of 7.1 years.

All patients met the following criteria: basic or pseudo-divergence excess type of X(T), a range of

Results

Preoperatively, the mean alignment and age of the patients who underwent BLR was 27.2 PD and 7.3 years old, respectively, and those who underwent R&R was 28.4 PD and 6.9 years old, respectively. There were no significant differences between the mean alignment or the age of the patients who underwent the two surgical procedures.

Discussion

Almost all patients with X(T) require surgical correction at some time. The surgical results are more satisfactory if the operation is done while the patient still exercises fusion during some portion of the day. Moreover, many known variable factors, such as surgical method, age at onset, age at surgery, preoperative distance and near deviation, preoperative difference in the near and distance deviation angle, duration of the exodeviation, presence of amblyopia, anisometropia, and associated

References (15)

R.V Keech et al.
The surgical overcorrection of intermittent exotropia
J Pediatr Ophthalmol Strabismus
(1990)
C Souza-Dias et al.
Postoperative evolution of the planned initial overcorrection in intermittent exotropia61 cases
Binocular Vis Eye Muscle Surg Q
(1993)
E.L Cooper
Purposeful overcorrection in exotropia
Raab EL, Parks MM. Immediate postoperative overcorrection after recession of lateral recti: effect on the final...
W.E Scott et al.
The postoperative results and stability of exodeviations
Arch Ophthalmol
(1981)
G.K von Noorden
E.L Raab et al.
Recession of lateral recti
Arch Ophthalmol
(1969)

There are more references available in the full text version of this article.

Cited by (51)

Outcomes for maximal bilateral lateral rectus recession in large-angle exotropia
2024, Journal of AAPOS
Surgical treatment for large-angle exotropia can be challenging. The aim of this study was to evaluate short-term surgical outcomes of patients with large-angle exotropia (≥50^Δ) undergoing maximal bilateral lateral rectus muscle recession of 10 mm.
This was a retrospective study of consecutive patients at our institution who underwent maximal bilateral lateral rectus muscle recession for exodeviation ≥50^Δ from January 1, 2008, to July 22, 2022. We subdivided the cohort into large-angle exotropia (largest amount of exodeviation at near and/or distance ≥50^Δ and <65^Δ) and very large–angle exotropia (largest exodeviation ≥65^Δ). Patients with a history of prior eye muscle surgery, neurologic deficits, and three- or four-muscle surgery were excluded.
A total of 22 patients were included. Mean preoperative exodeviation at distance was 51.9^Δ in the large-angle group and 67.5^Δ in the very-large-angle group (P = 0.001). Outcomes for the large-angle and very-large angle groups were, respectively, as follows: mean follow-up, 31.1 weeks and 11.8 weeks (P = 0.97); success, 75.0% and 16.7% (P = 0.02); undercorrection rates, 18.7% and 83.3% (P = 0.01); and mean postoperative exodeviation at distance, 3.7^Δ ± 6.3^Δ and 28.0^Δ ± 13.5^Δ (P = 0.001).
Our study identified good surgical outcomes (75%) with maximal bilateral lateral rectus muscle recession of 10 mm in treating patients with large-angle exotropia between 50^Δ and <65^Δ. Other surgical techniques such as recession-resection and three- or four-muscle surgery may result in better outcomes when treating patients with exotropia ≥65^Δ.
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.
An analysis of strabismus reoperations in Northern Alberta, Canada from 1995 to 2015
2019, Canadian Journal of Ophthalmology
To report the reoperation rate in a large group of pediatric and adult strabismus patients over a 21-year period in Northern Alberta, Canada.
A retrospective review of 6177 strabismus surgeries from July 1995 to June 2015 on 5125 pediatric and adult patients was conducted to determine the reoperation rate at a single major referral centre. A set of guidelines was implemented in November 2014 recommending delaying reintervention for at least 12 weeks from the initial surgery, with specific exceptions.
The historical strabismus reoperation rate over a 21-year period was 15.7%. Of those surgeries requiring reoperation, 77.7% required only 1 reoperation, 17.1% required 2 reoperations, 3.1% required 3 reoperations, and 2.1% required 4 or more reoperations. The mean time between surgeries for patients undergoing reoperation was 2.3 years and the median time was 1.0 years.
Our study provides insight into the strabismus reoperation rate and the number of subsequent surgeries performed for patients over a 21-year period. Although preoperative ocular alignment, comorbidities, and the status of the operative eye modify the probability of reoperation, our results from a large cohort of patients provide an impression of the rate of reoperation and may be of benefit in the preoperative counseling of patients. Furthermore, we highlight the scarcity of guidelines for the appropriate timing of reoperation. The implementation of specific guidelines may encourage future investigation into trends in reoperation over time and promote ways to avoid unnecessary surgeries, lower health care costs to stakeholders, and ultimately improve patient care.
Présenter un rapport sur le taux d’interventions supplémentaires au sein d’un vaste groupe de sujets – enfants et adultes – atteints de strabisme sur une période de 21 ans dans le nord de l’Alberta, au Canada.
Il s’agit d’un examen rétrospectif de 6177 interventions visant à corriger le strabisme effectuées entre juillet 1995 et juin 2015 auprès de 5125 patients (enfants et adultes), réalisé pour déterminer le taux d’interventions supplémentaires dans un centre spécialisé d’envergure. Des lignes directrices mises en place en novembre 2014 recommandent de retarder toute nouvelle intervention pendant au moins 12 semaines après l’intervention initiale ou précédente, sauf exception.
Du point de vue historique, le taux d’interventions supplémentaires dans le strabisme pendant les 21 ans de l’étude s’élevait à 15,7 %. De ce nombre, 77,7 % des sujets ont dû subir une seule intervention supplémentaire; 17,1 % ont dû en subir 2; 3,1 % ont dû en subir 3; et 2,1 % ont dû en subir 4 ou plus. Le délai moyen entre les interventions chez les patients qui devaient subir une intervention supplémentaire était de 2,3 ans, pour une médiane de 1,0 an.
Notre étude approfondit les connaissances sur le taux d’interventions supplémentaires dans le strabisme et sur le nombre d’interventions subséquentes réalisées au cours de cette période de 21 ans. Bien que l’alignement oculaire préopératoire, les affections concomitantes et l’état général de l’œil à opérer puissent influer sur la probabilité d’intervention supplémentaire, nos résultats chez cette importante cohorte donnent une idée du taux d’interventions supplémentaires et peuvent contribuer à mieux préparer les patients dans le cadre d’une consultation préopératoire. De plus, nous soulignons la rareté des lignes directrices portant sur le moment approprié où réaliser une intervention supplémentaire. L’implantation de lignes directrices explicites pourrait encourager la réalisation de nouvelles études sur les tendances en matière d’interventions supplémentaires au fil du temps, et favoriser la mise au point de méthodes permettant d’éviter les interventions inutiles, de réduire le coût des soins de santé et, au final, d’améliorer les soins offerts aux patients.
Analysis of postoperative exodrift according to surgical methods for intermittent exotropia
2024, Acta Ophthalmologica
Factors Associated with Surgical Outcomes after Bilateral Lateral Rectus Recession in Children with Intermittent Exotropia
2024, Journal of Clinical Medicine
Factors Associated with Surgical Outcomes of Intermittent Exotropia in Children
2023, Research Square

View all citing articles on Scopus

View full text

Laboratory investigationsRelationship Between Motor Alignment at Postoperative Day 1 and at Year 1 After Symmetric and Asymmetric Surgery in Intermittent Exotropia

Abstract

Introduction

Section snippets

Materials and Methods

Results

Discussion

The surgical overcorrection of intermittent exotropia

J Pediatr Ophthalmol Strabismus

Postoperative evolution of the planned initial overcorrection in intermittent exotropia61 cases

Binocular Vis Eye Muscle Surg Q

Purposeful overcorrection in exotropia

The postoperative results and stability of exodeviations

Arch Ophthalmol

Recession of lateral recti

Arch Ophthalmol

Laboratory investigations
Relationship Between Motor Alignment at Postoperative Day 1 and at Year 1 After Symmetric and Asymmetric Surgery in Intermittent Exotropia