Relationship between stereopsis outcome and timing of surgical alignment in infantile esotropia

A Comparative Analysis of Surgical Outcomes for Infantile Esotropia With and Without Prior Botulinum Toxin A Injection

PURPOSE

To compare the surgical outcomes in patients who had a failed botulinum toxin A injection before surgery versus those who had surgery as primary treatment (primary surgery) for infantile esotropia.

METHODS

The files of patients who had strabismus surgery in the Strabismus Unit of Beyoglu Eye Training and Research Hospital between January 2012 and March 2022 were reviewed. This study included 104 eyes of 52 patients with infantile esotropia. The angle of deviation before and 1, 3, and 6 months after botulinum toxin A injection or surgery, complications, pattern deviations, family history, abnormal head position, history of prematurity, intensive care unit admission, and consanguineous marriage were noted. A successful outcome was defined as ocular alignment of 10 prism diopters (PD) or less.

RESULTS

The study population consisted of 52 patients: 27 (52%) boys and 25 (48%) girls. In the botulinum toxin A group (n = 26), the mean age at admission was 14.0 ± 6.8 months, whereas the mean preoperative near and far angle of deviation were 41.92 ± 12.2 and 41.3 ± 13.0 PD, respectively. The mean age at the time of surgery was 40.6 ± 18.1 months. In the primary surgery group (n = 26), the mean age at admission was 34.0 ± 15.9 months. The mean preoperative near and far angle of deviation were 37.3 ± 8.0 and 35.3 ± 10.5 PD, respectively. The mean age at the time of surgery was 48.1 ± 18.5 months. The success rates 6 months after treatment in the botulinum toxin A group and the primary surgery group were 76.9% and 88.5% in near (P > .05) and 80.8% and 88.5% in far (P > .05), respectively. Three patients had transient ptosis and one had consecutive exotropia after botulinum toxin A injection.

CONCLUSIONS

In infantile esotropia treatment, strabismus surgery after failed botulinum toxin A injection compared to primary surgery has statistically comparable surgical success rates. [J Pediatr Ophthalmol Strabismus. 2024;61(4):245-251.].

Long-term Motor and Sensory Outcomes After Unilateral Medial Rectus Recession-Lateral Rectus Resection for Infantile Esotropia

PURPOSE

To report long-term motor and sensory outcomes after unilateral medial rectus recession-lateral rectus resection for infantile esotropia.

METHODS

The medical records of patients who had undergone unilateral medial rectus recession-lateral rectus resection for infantile esotropia and were followed up postoperatively for a minimum of 10 years were reviewed retrospectively.

RESULTS

A total of 100 patients were included. The mean age at surgery was 2.9 ± 2.2 years (range: 2.5 months to 9.0 years). The mean postoperative follow-up was 15.7 ± 4.4 years (range:10.0 to 27.5 years). Overall, 54 patients (54%) had surgical success at their last follow-up visit. Age at first surgery, strabismus duration, degree of hyperopia, preoperative size of deviation, presence of dissociated vertical deviation, inferior oblique overaction, or both dissociated vertical deviation and inferior oblique overaction, and the number of esotropia surgeries did not predict motor outcome after surgery. Consecutive exotropia developed in 43% of patients (constant in 18% and intermittent in 25%). Residual and recurrent esotropia occurred in 20% and 21% of patients, respectively. Refractive accommodative esotropia developed in 17% of patients and there was a high accommodation convergence/accommodation ratio esotropia in 2%. Peripheral binocular single vision was achieved in 54% of patients and stereopsis in 1%. Patients with 1.5 years or less of strabismus duration had better chances of achieving peripheral binocular single vision.

CONCLUSIONS

Nearly half of the patients with infantile esotropia achieved a successful long-term motor outcome and peripheral binocular single vision. Consecutive exotropia occurred frequently. Recurrent esotropia and refractive accommodative esotropia developed in some patients, and a high accommodation convergence/accommodation ratio esotropia in a few. Stereopsis outcome was extremely poor. [J Pediatr Ophthalmol Strabismus. 2024;61(2):106-113.].

Long-Term Effects of Botulinum Toxin A for Horizontal Concomitant Strabismus in Chinese Children

INTRODUCTION

For childhood strabismus, early surgical intervention improves both motor and sensory outcomes. Botulinum toxin type A (BTX-A) injection is an alternative to incisional surgery that is fast, less invasive, and preserves a more normal biomechanical construct. This study was undertaken to assess the safety and effectiveness of BTX-A for horizontal concomitant strabismus in children in our institution.

PATIENTS AND METHODS

Records of all children less than age 18 years with follow-up at least 12 months who were treated with BTX-A for horizontal concomitant strabismus at Beijing Children's Hospital between December 2014 and February 2021 were reviewed retrospectively. Bilateral injections of BTX-A (Henli, 1.25 IU to 5 IU/0.1 ml) were made into the medial or lateral rectus muscles according to the angle of deviation. Reinjection was permitted if the initial alignment was not satisfactory within 1 to 6 months post-injection. Motor success was defined as a final misalignment ≤10 PD. Sensory success was defined as the presence of any evidence of sensory fusion, distance stereopsis, or near stereopsis at the last visit.

RESULTS

Seventy-one patients were included. Fifty-two had esotropia, and 19 had exotropia. There was a significant decrease in the angle of deviation in all treated patients. The overall motor success rate was 60.6%. The motor success rate was highest in children with esotropia <50 PD (81.5%). Motor success was better for children with partially accommodative esotropia and acquired non-accommodative esotropia (80%, 83.3%, respectively) than for children with infantile esotropia (47.4%). Compared with the esotropia group, the fusion was significantly higher in the exotropia group (p = .007), and the proportion of patients with stereoacuity of better than 100 sec arc was higher also in the exotropia group (71.4%, p = .007), evidence of sensory outcomes were significantly better in the exotropia group. Complications were few. Twenty patients (28.2%) developed transient ptosis after injections; transient vertical deviations were seen in 3 patients (4.2%); and subconjunctival hemorrhage was seen in 5 patients (7%).

CONCLUSIONS

BTX-A appears to be an effective treatment for the management of horizontal strabismus with motor outcomes best in children with acquired smaller-angle esodeviations. Children with exodeviations had better sensory outcomes in this cohort. A randomized controlled study comparing incisional surgery to BTX-A will be important for guiding future treatment decisions.

Development and Validation of a Nomogram for Predicting Second Surgery in Patients with Concomitant Esotropia

INTRODUCTION

This study developed and validated a nomogram for predicting the risk of second surgery in patients with concomitant esotropia (CE) based on a cohort in Beijing.

METHODS

In this retrospective cohort study, the inpatient and outpatient medical records of 419 patients with CE who underwent surgery at the Peking University First Hospital between January 1, 2005 and December 31, 2009 were collected. A total of 357 CE cases were included. For those cases 70% were randomly assigned to the training set (n = 234) and 30% to the validation set (n = 123). Demographic and clinical variables were ascertained at hospital admission and discharge and screened using multivariate Cox proportional hazards regression analysis to construct predictive models and generate a 1-, 4-, and 8-year overall survival nomogram. This nomogram provided an estimate of the risk of second surgery in patients with surgically treated CE. Internal validation was conducted using the concordance index (C-index) and calibration curve for the training and validation sets.

RESULTS

Six independent prognostic factors were identified, namely age at surgery, age at onset, amblyopia, deviation angles, surgical amount, and deviation angles 1 week after surgery, and these were entered into the nomogram. The proposed nomogram showed favorable discrimination and accuracy in the training and validation sets. The C-indexes of the training and validation sets were 0.84 (95% CI 0.79-0.89) and 0.80 (95% CI 0.78-0.82), respectively.

CONCLUSIONS

The proposed nomogram can serve as a predictive tool for prognostic evaluation of CE surgery.

Timing of surgery in essential infantile esotropia - What more do we know since the turn of the century?

This review summarizes the results and interpretations of studies pertaining to the long-standing debate regarding the timing of surgery in infantile esotropia, more recently referred to as essential infantile esotropia. A systematic search of studies from the year 2000 onward pertaining to the timing of surgery in infantile esotropia as listed in PubMed, Google Scholar, and the Cochrane database was performed. Appropriate cross-references from the articles were also included. Data collected included demographics, presentation, time of surgery, complications, and outcomes. Very early surgery, that is, within 6 months of the onset of infantile esotropia, offers significant advantages in terms of the quality of stereopsis and binocular vision as well as promoting the development of cortical visual processing, thereby benefiting cortical development in human infants. However, the postoperative alignment was not found to be significantly different in the very early, early, or late surgery groups. The reduction in the incidence of manifest dissociated vertical deviation postoperatively in the very early surgery group also showed measurable benefits. The results of this recent literature review demonstrated that very early surgery, within 6 months of misalignment, showed demonstrable benefits in essential infantile esotropia.

Essential Infantile Esotropia: A Course of Treatment From Our Experience

Background: Essential infantile esotropia (EIE) is the most common type of childhood esotropia. Although its classical approach is surgical, less invasive techniques have been proposed as an adjunct or alternative to traditional surgery. Among them, chemodenervation with botulinum toxin (BT) has been investigated, showing variable and sometimes conflicting results. Objectives: To compare the outcomes of bilateral BT injection and traditional surgery in a pediatric population with EIE in order to optimize and standardize the therapeutic approach. Other purposes are to evaluate whether early intervention may prevent the onset of vertical ocular deviation (which is part of the clinical picture of EIE) and/or influence the development of fine stereopsis, and also to assess changes in refractive status over time among the enrolled population. Methods: A retrospective consecutive cohort study was conducted in 86 children aged 0-48 months who underwent correction of EIE. The primary intervention in naïve subjects was either bilateral BT injection (36 subjects, "BT group") or strabismus surgery (50 subjects, "surgery group"). Results: Overall, BT chemodenervation (one or two injections) was effective in 13 (36.1%) subjects. With regard to residual deviation angle, the outcomes at least 5 years after the last intervention were overlapping in children receiving initial treatment with either injection or surgery; however, the success rate of primary intervention in the surgery group was higher, and the average number of interventions necessary to achieve orthotropia was smaller. Both early treatment with chemodenervation and surgery at a later age were not found to prevent the onset of vertical ocular deviation, whereas, surprisingly, the percentage of subjects developing fine stereopsis was higher in the surgery group. Finally, with regard to the change in refractive status over time, most of the subjects increased their initial hyperopia, whereas 10% became myopic. Conclusions: Our data suggest that a single bilateral BT injection by age 2 years should be considered as the first-line treatment of EIE without vertical component; whereas, traditional surgery should be considered as the first-line treatment for all other cases and in subjects unresponsive to primary single BT injection.