Final report of the early vs. late infantile strabismus surgery study (ELISSS), a controlled, prospective, multicenter study

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.].

The incidence, clinical features, and management of essential infantile esotropia in the United Kingdom. A British Ophthalmology Surveillance Unit (BOSU) study

BACKGROUND/OBJECTIVES

A national study was undertaken through the British ophthalmology surveillance unit (BOSU) to determine the incidence, presenting features and management of essential infantile esotropia (EIE) in the UK.

METHODS

Data from a prospective national observational study of newly diagnosed EIE presenting to clinicians in the United Kingdom over a 12-month period were collected. Cases with a confirmed diagnosis by a clinician of a constant, non-accommodative esotropia ≥20 prism dioptres (PD), presenting at ≤12 months, with no neurological or ocular abnormalities were identified through BOSU. Follow-up data were collected at 12 months.

RESULTS

A total of 57 cases were reported giving an incidence of EIE of 1 in 12,828 live births. The mean age of diagnosis and intervention were 7.05 ± 2.6 months (range 2-12) and 14.7 ± 4.9 months (range 6.5-28.1), respectively. Management was surgical in 59.6%, botulinum toxin alone in 22.8%, and 17.5% were observed. The preoperative angle of esotropia was smaller in the observation group (P = 0.04). The postoperative angle of esotropia was not statistically significant between botulinum toxin or surgery (P = 0.3), although the age of intervention was earlier in the botulinum group (P = 0.007). Early intervention (before 12 months of age) did not influence the post-intervention motor outcomes between 0 and 10 prism dioptres of esotropia (P = 0.78).

CONCLUSIONS

The incidence of EIE in the UK is considerably lower than reported in other population-based studies. The preferred method of treatment was surgical with earlier intervention in those treated with botulinum toxin. An early age of intervention (<12 months) did not influence motor outcomes.

Effect of refractive errors on the results of botulinum neurotoxin administration in patients with infantile esotropia

PURPOSE

To investigate the effect of refractive errors on the results of patients followed up with infantile esotropia (IE) and treated with botulinum neurotoxin (BNT) injection.

METHODS

The files of patients with IE who presented to the ophthalmology pediatric ophthalmology unit and underwent BNT injection into both medial rectus muscles between 2019 and 2021 were reviewed retrospectively. Sixty eyes of 30 patients were included in the study. Patients with additional systemic or ocular diseases and those with a history of ocular surgery were excluded. Distance and near deviations were measured (with the prism cover test or Krimsky method) before and at the first, third, and sixth months after BNT injection.

RESULTS

In Group 1 (n = 20) with a spherical equivalent of + 2.0 diopters (D) or less, the mean near and distance deviation value was both 36.8 ± 12.7 prism diopter (PD) before injection. In Group 2 (n = 10) with a spherical equivalent of above + 2.0 D, the near deviation was measured as 35.0 ± 7.1 PD and distance deviation as 31.8 ± 7.9. At six months after BNT injection, the near and distance deviation values were 20.6 ± 12.3 and 20.6 ± 11.6 PD, respectively in Group 1 and 10.1 ± 10.3 and 8.8 ± 10.8 PD, respectively in Group 2. The change in deviation did not statistically significantly differ between the groups (p > 0.05), but the distance and near deviation values were lower in Group 2 at sixth months after BNT injection.

CONCLUSIONS

BNT injection is a preferred method in IE. Higher hypermetropic values seem to increase the success of BNT injection.

Acquired comitant esotropias - comparison of surgical outcomes of accommodative vs non-accommodative types

Purpose: To compare the motor and sensory outcomes of strabismus surgery and the factors affecting surgical success in acquired acute non-accomodative esotropia (ANAET) and partially accommodative refractive esotropia (pARET). Methods: A retrospective chart review of patients with ANAET and pARET who underwent unilateral or bilateral horizontal rectus muscle surgery between January 2020 and December 2021 was conducted. Patients with postoperative follow-up of at least six weeks were included. Patients with pattern deviation, lateral incomitance, and near-distance disparity were excluded. Motor success was defined as a postoperative deviation within eight prism diopters of orthophoria. Sensory success was defined as presence of binocular single vision (BSV) for both distance and near (Worth four dot test). The effect of factors like age at onset, age at surgery, amblyopia before surgery, duration of squint before treatment, presence or absence and magnitude of vertical deviation, preoperative angle of deviation, and spherical equivalent on the motor and sensory success in each group were analyzed and compared. Results: 38 patients with ANAET and 33 patients with pARET were included. The mean age of onset of esotropia was 8.55 ± 4.65 years and 4.39 ± 2.27 years (p < .001) and the mean age at surgery was 10.62 ± 4.99 years and 7.89 ± 2.84 years (p = .006) in the ANAET and the pARET group respectively. The mean duration of the final follow-up was 38.51 weeks in the ANAET and 48.68 weeks in the pARET group (p = .089). Patients were successfully aligned for both distance and near in 81.5% of patients in the ANAET and 78.9% of patients in the pARET group at the final follow-up (p. 0.775). A BSV for both distance and near at the final follow-up was seen in 81.2% vs 66.6% of patients in the ANAET and the pARET group respectively (p = .25). A good near stereoacuity (<120 arcsecs) was seen in 60.6% and 41.9% of the ANAET and the pARET groups respectively (p = .175). The percentage of patients in the ANAET group who had orthophoria, any esodeviation, and any exodeviation for distance at the final follow-up was 63.1%, 34.2% and, 2.6%. The percentage of patients in the pARET group in similar categories was 36.3%, 42.4% and, 21.2%. None of the demographic and preoperative factors were found to affect the surgical outcomes in the two groups. Conclusions: The motor and sensory outcomes were similar in the two groups. A higher proportion of ANAET patients remained orthophoric during the follow-up. The patients in the pARET group showed a tendency toward exodrift.

Comparison of the results of the modified and classical bi-medial hang-back recession in infantile esotropia

PURPOSE

Bi-medial rectus recession, which can also be performed using a hang-back technique, is one of the surgical treatment options for infantile esotropia (IE). This study has modified the surgical approach, with outcomes compared to the traditional hang-back technique.

METHODS

The bi-medial recession was performed with a modified hang-back technique in 120 IE patients and with a traditional hang-back technique in 88 cases. Surgical outcomes were reviewed and compared retrospectively.

RESULTS

The patients in the two groups were compared in terms of surgery time, inferior oblique weakening surgery, and the presence of refractive error. The differences between pre-operative and postoperative first-month, sixth-month, and first-year degrees were statistically significant (p < 0.001).

CONCLUSIONS

This modified novel technique aims to avoid unwanted muscle movement in the horizontal and vertical axes and a gap in the middle of the recessed muscle, as seen in the traditional hang-back technique. Further, the modified technique resulted in less over- and under-correction as well as alphabetic pattern deviation.

Torticollis in Non-Syndromic Unicoronal Craniosynostosis Is Predominantly Ocular Related

(1) Background: Patients with unicoronal craniosynostosis (UCS) often show torticollis which can result from either an ocular cause or contraction of the sternocleidomastoid muscle. For clinicians, it is crucial to know the prevalence of ocular torticollis (OT) to ensure appropriate referral for treatment. Furthermore, associated ophthalmic features with OT in these patients are scarcely described. The aim of this study was to determine the prevalence of OT in non-syndromic UCS patients and investigate its associated ophthalmic features. (2) Methods: In this descriptive cross-sectional study medical records of non-syndromic UCS patients treated between 1994-2022 in one tertiary care hospital in The Netherlands were retrospectively reviewed. Collected data included: diagnosis and type of torticollis, binocular single vision (BSV), strabismus, ocular motility, alphabetical patterns, refractive error, and amblyopia. Patients were classified as OT, based on their ophthalmic and/or orthoptic diagnosis. Prevalence was determined with the 95% CI using the Clopper-Pearson exact test. Associations between OT and the ophthalmic features were determined using Chi-square or Fishers' exact test and its effect size was calculated using Cramer's V. (3) Results: In total, 146 patients were included, of whom 57 had torticollis. An ocular cause for the torticollis was found in 54 patients. The prevalence of OT was 37% (n = 146; 95% CI [0.292-0.454]). Significant associations were found between OT and strabismus (p < 0.001), ocular motility abnormalities (p < 0.001), alphabetical patterns (p < 0.001), and amblyopia (p = 0.002). BSV (p = 0.277) and refractive error (p = 1.0) were not significantly associated with OT. However, in OT the BSV was relatively poor (42.1%) and more frequently absent (26.3%) compared to the non-torticollis group (7% poor and 16.3% absent). In both groups, excyclotorsion was predominantly present (62.3%). (4) Conclusions: In 95% of cases, torticollis in UCS patients is ocular-related. Overall, one in three patients with UCS have OT. This study emphasizes the importance of a timely referral of all patients with UCS with torticollis to an orthoptist and/or ophthalmologist, specialized in diagnosing and treatment of OT, before considering physiotherapy.

Occurrence and subsequent development of vertical deviations in patients treated surgically for infantile esotropia

Purpose

The purpose of this study was to evaluate the onset of dissociated vertical deviation (DVD) and inferior oblique overaction (IOOA), their subsequent development, and their correlation with pre and postoperative parameters.

Methods

Medical records of patients with infantile esotropia who underwent surgery between 2005 and 2017 were retrospectively reviewed. DVD and IOOA were measured before and after surgery. Patients were divided into two groups based on horizontal and vertical deviation at the time of presentation: those with infantile esotropia only (group A) and patients with infantile esotropia who developed vertical deviation (group B).

Results

Out of a total of 102 patients, DVD occurrence was seen in 53 patients (51.9%) and IOOA was seen in 50 patients (48.04%). DVD was seen in 22 patients at the time of initial examination and in 31 patients postoperatively. IOOA at presentation was seen in 45 patients (44.1%) and 5 patients (8.8%) postoperatively. No statistical difference was found in the age of surgery, angle of deviation, mean follow-up, and mean refractive error within both groups. The postoperative motor outcome was statistically comparable between the two groups (P = 0.29). Sensory outcomes of fusion (P = 0.048) and stereopsis (P-value = 0.00063) were better in group A.

Conclusion

No correlation was found between the age of occurrence and development of vertical deviation with refractive error, angle of deviation, age, or type of surgery. We found that motor outcomes are not affected but sensory outcomes are affected in patients with vertical deviations. This indicates that DVD and IOOA are developed due to inherent disruption of fusion and stereopsis.

Effect of Midface Surgery on Ocular Outcomes in Patients with Orbital and Midface Malformations

(1) Background: Orbital and midface malformations occur in multiple craniofacial disorders. Depending on the deformity, surgical corrections include orbital box osteotomy (OBO), Le Fort III (LFIII), monobloc (MB), and facial bipartition (FB). The aim of this study was to determine the effect of these procedures on ocular outcomes. (2) Methods: A retrospective analysis was performed. All patients with craniofacial disorders who had previously undergone midface surgery were included. The Wilcoxon signed ranks test was used for statistical analysis. (3) Results: In total, 63 patients were included: two patients were treated by OBO, 20 by LFIII, 26 by MB, and 15 by FB. Pre-operatively, strabismus was present in 39 patients (61.9%), in whom exotropia was most common (n = 27; 42.9%), followed by esotropia (n = 11; 17.5%). Postoperatively, strabismus significantly worsened (p = 0.035) in the overall population (n = 63). Pre-operative binocular vision (n = 33) was absent in nine patients (27.3%), poor in eight (24.2%), moderate in 15 (45.5%), and good in one (3.0%). Postoperatively, binocular vision significantly improved (p < 0.001). Before surgery, the mean visual acuity (VA) in the better eye was 0.16 LogMAR (Logarithm of the Minimum Angle of Resolution), and 0.31 LogMAR in the worse eye. Furthermore, pre-operative astigmatism was present in 46 patients (73.0%) and hypermetropia in 37 patients (58.7%). No statistical difference was found for VA (n = 51; p = 0.058) postoperatively. (4) Conclusions: Midface surgery has a direct and indirect substantial effect on several ocular outcomes. This study emphasizes the importance of appropriate ophthalmological evaluation in patients with craniofacial disorders undergoing midface surgery.

Interventions for infantile esotropia

BACKGROUND

Infantile esotropia (IE) is the inward deviation of the eye. Various aspects of the clinical management of IE are unclear; mainly, the most effective type of intervention and the age at intervention.

OBJECTIVES

To examine the effectiveness and optimal timing of surgical and non-surgical treatment options for IE to improve ocular alignment and achieve or allow the development of binocular single vision.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, one other database, and three trials registers (November 2021). We did not use any date or language restrictions in the electronic searches for trials.  SELECTION CRITERIA: We included randomized trials and quasi-randomized trials comparing any surgical or non-surgical intervention for IE.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodology and graded the certainty of the body of evidence for six outcomes using the GRADE classification.

MAIN RESULTS

We included two studies with 234 children with IE. The first study enrolled 110 children (mean age 26.9 ± 14.5 months) with an onset of esotropia before six months of age, and large-angle IE defined as esotropia of ≥ 40 prism diopters. It was conducted between 2015 and 2018 in a tertiary care hospital in South Africa. It compared a maximum of three botulinum toxin injections with surgical intervention of bimedial rectus muscle recession, and children were followed for six months. There were limitations in study design and implementation; the risk of bias was high, or we had some concerns for most domains.  Surgery may increase the incidence of treatment success, defined as orthophoria or residual esotropia of ≤ 10 prism diopters, compared with botulinum toxin injections, but the evidence was very uncertain (risk ratio (RR) of treatment success 1.88, 95% confidence interval (CI) 1.27 to 2.77; 1 study, 101 participants; very low-certainty evidence). The results should be read with caution because 23 children with > 60 prism diopters at baseline in the surgery arm also received botulinum toxin at the time of surgery to augment the recessions. There was no evidence of an important difference between surgery and botulinum toxin injections for over-correction (> 10 prism diopters) of deviation (RR 0.29, 95% CI 0.06 to 1.37; 1 study, 101 participants; very low-certainty evidence), or additional interventions required (RR 0.66, 95% CI 0.36 to 1.19; 1 study, 101 participants; very low-certainty evidence). No major complications of surgery were observed in the surgery arm, while children experienced various complications in the botulinum toxin arm, including partial transient ptosis in 9 (16.7%) children, transient vertical deviation in 3 (5.6%) children, and consecutive exotropia in 13 (24.1%) children. No other outcome data for our prespecified outcomes were reported.  The second study enrolled 124 children with onset of esotropia before one year of age in 12 university hospitals in Germany and the Netherlands. It compared bilateral recession with unilateral recession surgeries, and followed children for three months postoperatively. Very low-certainty evidence suggested that there was no evidence of an important difference between bilateral and unilateral surgeries in the presence of binocular vision (numbers with event unclear, P = 0.35), and over-correction (RR of having exotropia 1.09, 95% CI 0.45 to 2.63; 1 study, 118 participants). Dissociated vertical deviation, latent nystagmus, or both were observed in 8% to 21% of participants.

AUTHORS' CONCLUSIONS

Medial rectus recessions may increase the incidence of treatment success compared with botulinum toxin injections alone, but the evidence was very uncertain. No evidence of important difference was found between bilateral surgery and unilateral surgery.  Due to insufficient evidence, it was not possible to resolve the controversies regarding type of surgery, non-surgical intervention, or age of intervention in this review. There is clearly a need to conduct good quality trials in these areas to improve the evidence base for the management of IE.

Strabismus controversies that inspired the foundation of the Donders Society for Strabology and of the journal Strabismus

The Donders Society for Strabology and the journal Strabismus were founded in 1984 and 1992 to (i) stimulate scientific exchange, (ii) bridge the gap between clinical strabismus and neurophysiology by covering the two fields in a single journal and (iii) provide a forum for multicenter studies. They were inspired by two controversies on the treatment of strabismus, whether accommodative esotropia should be treated with glasses or not and whether infantile esotropia should be operated in the first years of life to preserve or reinstate binocular vision. Key assumptions in the theory leading to the former controversy were that the angle between the oblique muscle plane and the sagittal plane was small in strabismus patients causing excyclotropia, that hemiretinal suppression occurred when the left and right halves of the visual fields were no longer aligned because of excyclotropia and that binasal or bitemporal suppression disturbed the balance of the optomotor reflexes and thereby caused esotropia or exotropia. Hemiretinal suppression also disturbed accommodation related to the development of hyperopia, which did not cause esotropia and could worsen by wearing glasses. The Donders Society for Strabismology was founded in 1984, and expanded with Flemish pediatric ophthalmologists and orthoptists two years later. A survey gauging the need for a European journal on strabismus and amblyopia in 1985 got favorable responses from strabismologists from continental Europe. However, a proposal by Aeolus Press to the European Strabismological Association to adopt or endorse such journal was turned down in 1989 and by the International Strabismological Association in 1990. In 1992 candidate editors were invited to start the journal Strabismus without adoption by a professional organization and founding meetings took place in April and May, 1992. Regarding the three goals set, it can be said that both the Donders Society for Strabology and the journal Strabismus have stimulated scientific exchange to a high degree, but they have bridged the gap between clinical strabismus and neurophysiology only modestly. Strabismus did successfully provide a forum for the multicenter Early vs. Late Infantile Strabismus Surgery Study.

Efficacy and safety of adjustable suture in horizontal strabismus: Comparative study of children versus adults

OBJECTIVE

Adjustable suture procedures allow addressing the unpredictability of some postoperative results in strabismus surgery. The purpose of the study was to compare the effectiveness of adjustable and non-adjustable suture in the treatment of horizontal strabismus in children and adults.

METHODS

Prospective study including patients undergoing strabismus surgery to correct horizontal strabismus with fixed hanging suture (non-adjustable suture group) and adjustable suture. Visual acuity, amblyopia, deviation, oblique muscle involvement, previous surgeries, nystagmus, need for adjustment, and complications were recorded. The variables were recorded in the immediate postoperative period, at one week and at 3 and 6 months.

RESULTS

186 patients were included: 157 (84.4%) with adjustable suture and 29 (15.6%) with non-adjustable suture, of which 119 were children and 67 were adults. Postoperatively, 19 children (16.0%) and 19 adults (28.4%) required adjustment (p = 0.044). Of 157 patients with adjustable suture, it was adjusted in 20% (32/157). Success after adjustment was higher for adjustable suture (91.72% vs 79.31%; p = 0.043) and remained for 6 months (p < 0.05). Previous surgery (p = 0.004) and exotropia (p = 0.018) correlated with the need for adjustment.

CONCLUSIONS

20% of patients with horizontal strabismus can benefit from a postoperative adjustment to improve the surgical result. The adjustable suture was shown to be superior to the fixed hanging suture and is an excellent surgical option, both in children and adults.

Profile of infantile strabismus at a tertiary eye care center in India

Purpose

To study the profile, risk factors, and management outcomes of infantile strabismus at a tertiary eye care center.

Methods

We prospectively analyzed the data of infants (children less than 1 year of age) who presented at our institute from August 2018 to December 2019. We excluded infants who did not complete a minimum follow-up of 6 months. Detailed meticulous history based on a set of standardized questionnaires was obtained and a comprehensive ophthalmological examination of the child was performed. Data were collected regarding refractive error (astigmatism; myopia; hyperopia; anisometropia [<1.0 DS or >1.0 DS]; astigmatism [<1.0 DS or >1.0 DS]) and the type of strabismus.

Results

During this period, we saw 4,773 infants, out of which 123 infants were diagnosed to have infantile-onset strabismus (hospital prevalence of 2.6%). Boys and girls were equally affected. Sixty-two patients had esotropia, 37 had exotropia, 2 had hypotropia, and 22 had pseudo strabismus. Prematurity, hypermetropia, and anisometropia had increased odds of developing esotropia, whereas delivery by cesarean section, delayed cry at birth, infantile seizures, parental consanguinity, delayed development of milestones, and myopia had increased odds of developing exotropia. Twenty-nine patients underwent a surgical correction. The mean deviation at the first visit was 42.59 ± 15.40 PD and 8.25 ± 12.70 PD at the last visit. For all patients who underwent a squint surgery, the change in ocular deviation was clinically and statistically significant (P-value <0.0001, paired t-test).

Conclusion

The hospital prevalence of infantile strabismus in our cohort was found to be 2.6%. Our study suggests that esotropia is two-fold more common in our cohort as compared to exotropia. Further, our study highlights risk factors for the development of strabismus in infancy, which must be kept in mind and awareness must be created among pediatricians. Surgical correction should be considered early during the infantile period, because it may lead to promote the development of good binocular vision.

A Novel Method Ensuring an Immediate Target Angle After Horizontal Strabismus Surgery in Children

Purpose

Pediatric strabismus surgery has low success rates and high reoperation rates because of difficult alignment measurements and the nature of different strabismus types. Furthermore, adjustable sutures are not easily employed in children on an OPD basis.

Methods

This was a retrospective comparative case study of children less than 12 years old who underwent strabismus surgery and were followed up at least 6 months postoperatively. We proposed a novel method that combines adjustable sutures and corneal light reflexes in regular strabismus surgery to improve surgical results. Efficacy and safety were evaluated and compared with those in a regular fixed-suture group.

Results

In total, 128 children (88: exotropia and 41: esotropia) in the novel method group (Group 1) and 109 (71: exotropia and 38: esotropia) in the regular fixed-suture group (Group 2) were enrolled. The primary outcome was the immediate target angle (for esotropia within 4 PD of orthotropia and exotropia within 8 PD of esotropia within the first week postoperatively); the secondary outcome was success at the 6-month visit (angle of deviation < 10 PD). Consequently, there was a significantly higher proportion of achieving the immediate target range and success rate in both exotropic and esotropic patients in Group 1 than in Group 2. A significantly lower reoperation rate was also demonstrated in Group 1. No complications were noted in either group.

Conclusions: The novel method enabled a higher proportion of subjects to achieve an immediate target range and success rate and a lower chance of reoperation among both esotropic and exotropic patients.

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.

Infantile Esoropia: Management results and prognostic factors

BACKGROUND

Infantile esotropia is characterized by a significant deviation angle and a marked sensory perversion. Although the motor surgical results are satisfactory, the sensory results remain disappointing.

AIM

Our work aims to describe the methods of surgical management, its motor and sensory results as well as its prognostic factors.

METHODS

Retrospective study of 68 cases of infantile esotropia. All patients underwent a complete ophthalmologic examination and sensorimotor assessment. They were operated on, under general anesthesia, by the same surgeon. We assessed the motor and sensory results. The prognostic factors studied were age of onset, treatment delay, amblyopia severity, strabismus deviation angle, and presence of a vertical element.

RESULTS

The mean minimum angle of deflection was 38.6 ± 13.2D. Inferior oblique muscle hyper action was noted in 73.5% and a dissociated vertical deviation in 5.8%. Bilateral medial rectus muscle recession was the most performed surgery (60.2% of cases). The overall success rate was 94.11%. No patient acquired stereoscopic vision. Multivariate logistic regression analysis showed that preoperative nail (p = 0.007), immediate postoperative outcome (p <0.001) and surgical dosage (p = 0.009) were associated with long-term motor success.

CONCLUSION

The motor results of early esotropia surgery are generally satisfactory; the sensory results are often disappointing. Detecting poor prognostic factors improves operative results.

Surgical outcomes and occurrence of associated vertical strabismus during a 10-year follow-up in patients with infantile esotropia

Purpose:

Authors analyzed long-term surgical outcomes of infantile esotropia and the occurrence of associated strabismus, inferior oblique overaction (IOOA), and dissociated vertical deviation (DVD). Clinical factors related to the occurrence of IOOA and DVD in patients with infantile esotropia were also evaluated.

Methods:

Medical records of patients with infantile esotropia, who underwent surgery between 1995 and 2008, were reviewed retrospectively. Included patients were followed for at least 10 years. The incidence and age at development of IOOA and DVD were analyzed. To evaluate predisposing factors for developing IOOA or DVD, patients were divided into two groups: those with infantile esotropia only (group A) and those who developed IOOA or DVD (group B).

Results:

A total of 122 patients were enrolled and mean follow-up period was 16.0 years (range: 10–32 years). The mean number of surgeries was 1.7 (range: 1–5), and 64 (52.5%) patients achieved optimal horizontal alignment (esotropia <10 prism diopters [PD] and orthotropia). Fifty (41.0%) patients developed IOOA at a median age of 3 years (range: 1–21 years); 54 (44.3%) developed DVD at a median age of 5 years (range: 1–25 years). Patients in group B underwent more horizontal surgeries than those in group A (P = 0.028), and favorable surgical outcomes between the two groups were not different at final visit. There were no other significant differences in clinical factors between the two groups.

Conclusion:

Approximately, 52.5% of patients achieved favorable surgical outcomes through 1.7 surgeries during the 10-year follow-up period. DVD tended to develop at a later age than IOOA, and in some cases, up to 20 years after diagnosis of infantile esotropia. To achieve favorable horizontal alignment at final visit, patients with associated vertical strabismus underwent more horizontal muscle surgeries than patients with infantile esotropia only. The presence of IOOA/DVD may affect horizontal alignment outcomes.

Motor and Visual-spatial Cognitive Abilities in Children Treated for Infantile Esotropia

While many studies have investigated links between motor and visual spatial cognitive abilities in typically developing children, only a few studies have tested this link among children with innate handicaps. Therefore, we assessed motor abilities (using the M-ABC-2) and visual spatial cognitive skills (using the Block Design subtest of the WPPSI-III and a picture mental rotation task, PRT) of 5-7 year old typically developing children (n= 17) and same-aged children with severe deficits in stereopsis due to infantile esotropia (n= 17). Compared to the typically developing children, children with esotropia showed significantly poorer motor performances, especially in manual dexterity and ball skills, and significantly poorer and slower performance on the visual spatial cognitive tasks. Especially the girls treated for infantile esotropia needed more time to mentally rotate the pictures of the PRT correctly. Overall, this study showed that perceptual, motor and cognitive processes are interconnected and that children treated for infantile esotropia had an increased risk of motor and visual spatial cognitive deficits.

Bilateral combined resection-recession of the same rectus muscle versus Fadenoperation for treatment of purely tonic esotropias

PURPOSE

To compare the efficiency of bilateral combined resection-recession surgery of the medial rectus muscle versus using a modified Fadenoperation for surgical management of esotropias that totally resolve under general anesthesia, which we called "purely tonic" esotropias.

METHODS

We included 65 unselected consecutive cases of patients with purely tonic esotropias who underwent surgery between October 2017 and 2018. Patients were divided into group I, who underwent a combined resection and recession of medial recti muscles, and group II, who underwent a bilateral medial rectus Fadenoperation using posterior strapping. A satisfactory outcome was defined as deviation ⩽10 prism diopters (PD), at near and distance fixation, between 3 and 6 months postoperatively.

RESULTS

Mean initial deviation was in group I, 19.6 PD and 32.0 PD, in group II, 23.6 PD and 33.5 PD, at distance and near fixation respectively. Postoperatively, in group I, 31 patients (91.2%) showed satisfactory alignment at near and distance fixation. Post-operatively, in group II, 25 patients (80.6%) showed satisfactory alignment at near and distance fixation.

CONCLUSION

Our results suggest both techniques are good options to treat purely tonic esotropias.

Multiple Short Daily Periods of Normal Binocular Vision Preserve Stereopsis in Strabismus

Purpose

Infantile strabismus impedes the development of stereopsis. In optically strabismic monkeys, 2 continuous hours of normal binocular vision per day has been shown to preserve near-normal stereopsis. In this study, we investigated whether, as in learning, multiple shorter periods of intervention would further boost performance.

Methods

To simulate infantile esotropia, infant monkeys were reared with 30 prism diopters base-in starting at 4 weeks of age. Daily periods of normal binocular vision were provided by replacing prisms with plano lenses. Altogether, 14 monkeys were prism reared: 2 with continuous prism, 2 with 2 continuous hours of normal binocular vision per day, 6 with 2 noncontinuous hours, and 4 with 1 noncontinuous hour of binocular vision each day. Seven normally reared monkeys provided control data. Behavioral methods were employed to measure spatial contrast sensitivity, eye alignment, and stereopsis.

Results

One monkey reared with continuous prism had poor stereopsis, and the other had no stereopsis. Ten of the 12 monkeys reared with periods of normal binocular vision had stereopsis, and those with longer and more continuous periods of binocular vision had stereopsis approaching that of normally reared monkeys.

Conclusions

During early development, multiple short periods of binocular vision were effective in preserving clinically significant stereopsis in monkeys. These results suggest that by providing relatively short multiple daily intervention periods, stereopsis may be preserved in strabismic human children.

[Long term outcomes of botulinum toxin injections in infantile esotropia]

PURPOSE

To evaluate long terms outcomes of botulinum toxin in infantile esotropia by measuring the amount of microtropia 24 months after injection. Secondary purpose was to identify predictive factors of microtropia.

METHODS

A retrospective, single-center study was performed at the university medical center in Bordeaux between 2001 and 2018, including all patients with infantile esotropia greater than 20 D. All patients received 5 or 7,5 IU of botulinum toxin A in each medial rectus, once or twice depending on the angle of deviation after the first injection and after wearing full optical correction at least two months. We noted the angle at 1, 6, 12 and 24 months, the occurrence of any complications and the need for later strabismus surgery. The primary endpoint was the achievement of a microtropia less than 8 diopters (D) at 24 months post-injection. We evaluated the predictive factors for microtropia with a Fischer's test.

RESULTS

We included 30 patients with esotropia greater than 20 D. The mean follow-up after injection was 48 months ±30. The mean age was 16.24 months (7-29 months) with a female predominance in the population (SR=0.43). The mean pre-injection deviation was 41.25±12.17 D. The majority of patients were mildly (40%) or moderately (40%) hyperopic. At 24 months, 46.7% microtropias were obtained (95% CI: 28.9%-64.5%). The change in mean angle at 1, 6, 12 and 24 months post-injection was -8.57±25.21 D; 14.48±13.40 D; 18.38±12.07 D and 21.23±14.97 D, respectively. No factors were predictive of microtropia. Of the 30 children, 3 had transient ptosis requiring strips and 12 showed an exotropia at 1 month. All complications were self-limited and without consequences. 3 children had a second injection of botulinum toxin, which in 2/3 of the cases resulted in a long-lasting microtropia. 26.7% (n=8) of the children underwent secondary surgery. Obtaining a microtropia 24 months after injection statistically significantly reduced the need for secondary strabismus surgery: 92.9% P=0.039% CI 95% (0.002; 1.0606).

CONCLUSION

Botulinum toxin appears to be a less invasive and more conservative alternative to surgery in children with infantile esotropia. In 46.7% of cases, microtropia is achieved. An improvement was noted in 90% (n=27) of the children with a reduction of half (21.23 D) of the mean post-injection angle at 24 months. When effective, it significantly reduces the need for secondary surgery.

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.

A dichoptic feedback-based oculomotor training method to manipulate interocular alignment

Strabismus is a prevalent impairment of binocular alignment that is associated with a spectrum of perceptual deficits and social disadvantages. Current treatments for strabismus involve ocular alignment through surgical or optical methods and may include vision therapy exercises. In the present study, we explore the potential of real-time dichoptic visual feedback that may be used to quantify and manipulate interocular alignment. A gaze-contingent ring was presented independently to each eye of 11 normally-sighted observers as they fixated a target dot presented only to their dominant eye. Their task was to center the rings within 2° of the target for at least 1 s, with feedback provided by the sizes of the rings. By offsetting the ring in the non-dominant eye temporally or nasally, this task required convergence or divergence, respectively, of the non-dominant eye. Eight of 11 observers attained 5° asymmetric convergence and 3 of 11 attained 3° asymmetric divergence. The results suggest that real-time gaze-contingent feedback may be used to quantify and transiently simulate strabismus and holds promise as a method to augment existing therapies for oculomotor alignment disorders.

Effects of Surgical Timing on Surgical Success and Long-term Motor and Sensory Outcomes of Infantile Esotropia

PURPOSE

To investigate the effect of surgical timing on long-term motor and sensory outcomes in patients with infantile esotropia.

METHODS

The medical records of patients who underwent strabismus surgery for infantile esotropia were reviewed retrospectively. The patients were divided into three groups according to age at the time of surgery: early group (6 to 11 months), late group (12 to 17 months), and very late group (18 to 27 months). The main outcome measures were final alignment, surgical success rate (the angle of deviation at final follow-up of ≤ 10 prism diopters [PD] of esotropia, no exotropia and no need for reoperation), stereoacuity, visual acuity, and the number of reoperations required during the follow-up.

RESULTS

A total of 79 patients (44 female, 35 male) met the inclusion criteria. The surgical success rate was 25.9%, 23.1%, and 53.8% in the three groups, respectively (P = .035). After a mean follow-up of 96 months, the average number of operations per child was 1.7 ± 0.9, 1.6 ± 0.6, and 1.4 ± 0.6 in the three groups, respectively (P = .020). The measurable stereopsis rate was higher in the early group (37% vs 3.8% and 3.8%, respectively) (P = .001). The amblyopia rate was similar between groups.

CONCLUSIONS

The results show that performing surgery later in life in patients with infantile esotropia increases the motor success rate of surgery. In addition, orthophoria is achieved with fewer surgical operations. However, earlier surgery may improve stereopsis. [J Pediatr Ophthalmol Strabismus. 2020;57(5):319-325.].

Development of stereo vision in young infants

In this study, infants' visual processing of depth-inducing stimuli was tested using a new method suitable for experimental settings. Stereograms of the Lang-Stereopad^® were presented in a timed preferential-looking paradigm to determine infants' preference for a stereogram as compared to a stimulus not inducing an impression of depth. A total of 80 infants were tested at 7 months of age; of these, a sub-sample of 41 infants were tested longitudinally at 4 and 7 months to characterize the developmental trajectory of their preference. Infants were simultaneously presented with a card showing a random-dot stereogram (800" disparity) and a similar looking dummy card without stereogram. In the total sample, 7-month-olds showed a clear preference for the stereogram regardless of sex. In the longitudinal sample, 7-month-olds but not 4-month-olds looked significantly longer to the stereogram as compared to the dummy card. On individual level, 56% of the 4-month-olds and 85% of the 7-month-olds predominantly looked at the stereogram. The findings yield evidence for a clear developmental progression and show that the test cards of the Lang-Stereopad^® prototype provide a viable instrument to determine the preference for depth-inducing stimuli in young infants when used in a controlled experimental setting.

Automated Diagnosis and Measurement of Strabismus in Children

PURPOSE

Manual measurements of strabismus are subjective, time consuming, difficult to perform in babies, toddlers, and young children, and rely on the examiner's skill and experience. An automated system, based on eye tracking and dedicated full occlusion glasses, was developed to provide a fast, objective, and easy-to-use alternative to the manual measurements of strabismus. This study tested the efficacy of the system in determining the presence of strabismus in children, as well as its type and the amount of deviation, in addition to differentiating between phorias and tropias.

DESIGN

A prospective, masked, inter-rater reliability study.

METHODS

A prospective, masked, cross-sectional study included 69 children, 3-15 years of age. A cover-uncover test and a prism alternating cover test (PACT) for the primary gaze, at a distance of 50 cm, were performed by 2 independent, masked examiners and by the automated system.

RESULTS

A high correlation was found between the automated and the manual test results (R = 0.9 and P < 0.001 for the horizontal deviation, and R = 0.91 and P < 0.001 for the vertical deviations, with 100% correct identification of the type of deviation). The average automated test duration was 46 seconds. The Bland-Altman plot, used to compare the 2 measurement methods, showed a mean value of -2.9 prism diopters (PD) and a half-width of the 95% limit of agreement of ±11.4 PD.

CONCLUSION

The automated system provides precise detection and measurements of ocular misalignment and differentiated between phorias and tropias. It can be used in participants from the ages of 3 years old and up.

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

PURPOSE

To clarify the relationship between stereopsis outcome and timing of surgical alignment in infantile esotropia.

METHODS

The medical records of otherwise healthy patients with infantile esotropia who underwent surgery by 8 years of age were divided into the following groups according to age at time of surgery: very early surgery (≤8 months), early surgery (>8 to ≤24 months) and late surgery (>24 months). Binocular response and stereopsis were compared between groups.

RESULTS

A total of 76 patients were included: 22 in the very early group, 30 in the early group, and 24 in the late group. Binocular response at near was found in 96% of the very early group and in 80% of the early group, significantly higher than the 50% of the late group (P < 0.001 and P < 0.05 [Dunn test], resp.). Stereopsis was present in 77% of the very early group, significantly higher than the 20% of the early group and 13% of the late group (P < 0.001 [Dunn test]). A significant correlation was also found between age (months) at surgery and stereopsis (seconds) outcome (logarithmic fit: y = 2539.4ln(x) + 147.2; R² = 0.2691; P < 0.001).

CONCLUSIONS

In this study cohort, earlier surgery was associated with better binocularity in patients with infantile esotropia. Our results suggest that very early surgery, at ≤8 months, can improve the chance for postoperative stereopsis, with the caveat that some infants might have had spontaneous esotropia resolution.

Long term motor and sensory outcome after surgery for infantile esotropia and risk factors for residual and consecutive deviations

Purpose: To present long-term motor and sensory outcomes after surgery for infantile esotropia and assess risk factors for residual and consecutive deviations.Methods: Data of infantile esotropia patients operated between 2002 and 2016 with minimum follow-up of 2 years were retrospectively reviewed.Results: Among a total of 62 patients, 35 had a successful motor outcome (alignment within 10 PD from orthotropia) after one surgery (Group A), while 27 required horizontal reoperation (Group B). Patients with residual esotropia had larger preoperative angle of deviation (P = .005) and younger age at first surgery (P = .01), while consecutive exotropia was associated with longer follow-up (P = .03) and higher rate of DVD (P = .003) compared to patients in Group A. Stereopsis was present in 30.3% of patients in Group A and associated with younger age at first surgery (P = .03).Conclusions: Successful motor alignment may be obtained with single surgery in infantile esotropia; however, reoperations are common. Younger age at first surgery may be associated with both higher rate of stereopsis and risk of reoperation. Careful preoperative assessment and surgical timing, with long-term postoperative follow-up is required to achieve satisfactory outcome.

The history of the Ostschweizerische Pleoptik und Orthoptik Schule in St. Gallen

In judging the achievements of Alfred Bangerter in treatment and research of amblyopia it is easy to conclude that his pleoptic exercises have been forgotten because occlusion therapy is more effective and cheaper. However, Bangerter introduced the visuscope to determine the point of fixation directly on the retina, he started the first "school" (exercise treatment facility) for pleoptics and orthoptics in St. Gallen only 18 years after Mary Maddox did so in London and he started a training program for orthoptists. In 1957 the Genossenschaft Ostschweizerische Pleoptik-und Orthoptik-Schule, the OPOS Society, was founded, that in the following years built a clinic especially for the treatment of amblyopia. The idea was to treat children not in a clinic but in a home for children that offered optimal treatment but also adequate lodging and care for the children with amblyopia. The Cantonal government contributed by donating a right to build on the premises of the Cantonal Hospital. The new OPOS Clinic measured more than 500 square meters, had 4 floors and a cellar, and contained outpatient treatment facilities, two operating theatres, patient bedrooms, pleoptic and orthoptic exercise rooms with many devices and classrooms for orthoptic students. There were 56 beds for children. After Bangerter retired as chief physician of the Eye Clinic in 1974, he continued and expanded his clinical and surgical activity in the OPOS Clinic next to the Eye Clinic. After his successor in the OPOS Clinic retired in 1987, the OPOS Foundation sold the OPOS Clinic to the Canton that reintegrated it into the Eye Clinic. In the meantime, Bangerter had continued to pursue his ideal of amblyopia treatment and built a new clinic in Heiden in the neighbouring Canton Appenzell Ausserrhoden, for pleoptics, orthoptics, strabismus surgery, plastic eye surgery, but also for controversial treatments for macular degeneration and other retinal disorders. This Rosenberg Clinic opened in 1982 but Bangerter already stepped down in April 1983 and opened a day clinic in the Rosenbergstrasse in St. Gallen some years later instead. Strangely enough, one of the reasons he had moved to the Rosenberg Clinic was that he insisted on lengthy clinical stays for the treatment of amblyopia, but exactly that was one of the main causes of financial problems.

[Unilateral combined strabismus surgery to correct esotropia : Video article on recession of the medial rectus muscle and plication of the lateral rectus muscle]

OBJECTIVE OF SURGERY

The aim of strabismus surgery to correct esotropia is orthotropic alignment or microstrabismus to achieve best possible binocularity, a larger visual field, better appearance, and a frequently connected improved self-esteem. A widely used technique to correct esotropia is combined unilateral strabismus surgery with recession of the medial rectus muscle and plication of the lateral rectus muscle.

INDICATIONS

Indications are esotropia of various origins or decompensating esophoria over 15 prism diopters.

CONTRAINDICATIONS

Absolute contraindications are insufficient optical correction of hyperopia and sixth nerve palsy with unfinished spontaneous regeneration. A relative contraindication in children is untreated amblyopia.

SURGICAL TECHNIQUE

The technique consists of unilateral recession of the medial rectus muscle and tucking of the lateral rectus muscle. The surgical technique is demonstrated in detail in two videos of the operation, which are available online.

FOLLOW-UP

Antibiotic and lubricating eye drops are applied during the first week after surgery. In the early postoperative period, patients should be monitored for postoperative infection, conjunctival dehiscence, or corneal laceration. We review patients 4 months postoperatively for evaluation of the long-term result.

EVIDENCE

Recent randomized controlled studies have shown that unilateral medial rectus muscle recession and resection surgery is comparable to bilateral recession surgery with regards to postoperative results in esotropia. The effect of lateral rectus muscle tuck is comparable to muscle resection with less trauma and potential reversibility during the first days after surgery.

Stereopsis: are we assessing it in enough depth?

The assessment of stereoacuity is an integral part of the ophthalmic assessment, with the responses used to inform clinical management decisions. Stereoacuity impacts on many aspects of life, but there are discrepancies reported where people without measurable stereoacuity report appreciating 3-D vision. This could be due, in part, to the presentation of the stimuli. A literature review was undertaken to evaluate current assessment techniques, how they relate to patient outcomes, identify the limitations of current tests and discuss how they could be improved. Recent evidence has been collated on currently available tests, used commonly within vision clinics, with normative data provided allowing responses to the tests to be interpreted. The relevance of the results is evaluated in relation to a range of outcomes, where a reduced level of stereopsis has a negative impact on the ability of an individual to perform many tasks, and can lead to an increase in difficulty interacting in the world. Current tests are limited in the aspects of stereoacuity they assess and their ability to precisely measure stereopsis. The world is not static, yet clinical tests are limited to measuring static stereoacuity, even though higher grades of depth perception can be identified in the presence of changing depth. Presentation methods of stereoacuity tests have remained similar over time, with a limited number of disparity levels assessed. New assessment methods are becoming available that include automated staircase testing to present multiple levels of disparity using digital technology. Current clinical tests are limited in their presentation, and are poor at detecting/measuring stereoacuity in those with limited stereopsis. Given the relevance of the stereoacuity measurement to management choices and functional outcomes, new testing methods would be beneficial to fully assess stereoacuity, both static and dynamic.

The relationship between abduction deficit and reoperation among patients with infantile esotropia

AIM

To determine the relationship between abduction deficit and reoperation among patients with infantile esotropia (IET).

METHODS

The records of 216 patients (432 eyes) with IET who underwent surgery, from 2010 to 2015 were studied. Patients with IET whose deviation appeared before 6mo of age and had stable preoperative deviation in two examinations with at least 2wk apart and a minimum 3mo postoperative follow up were included. Cases with early onset accommodative esotropia, congenital cataract, retinopathy of prematurity (ROP), manifest nystagmus, fundus lesions, neurologic and ophthalmic anomalies, 6^th nerve palsy and Duane's syndrome were excluded. Preoperative abduction deficit was considered from -1 to -3 grading scale. Three months after surgery, children were classified into no-need reoperation [deviation≤15 prism diopters (PD)], and need-reoperation groups (deviation>15 PD).

RESULTS

In this retrospective study, 117 female and 99 male patients with the mean surgical age of 4.7±6.4y were included. Reoperation rate was 33.3% and 16.0% in IET patients with and without abduction deficit, respectively in patients who had a history of late surgery. Abduction deficit increased the odds of reoperation by 82% [OR=1.82, 95% confidence interval (CI) =1.05 to 3.19, P=0.003] in patients who had a history of late surgery (>2 years old, P=0.021). Abduction deficit was improved significantly after operation (P<0.001).

CONCLUSION

Based on our results, abduction deficit can be considered as a risk factor of reoperation in IET patients who are operated at the age of more than 2y.

Differences in quality-of-life dimensions of Adult Strabismus Quality of Life and Amblyopia & Strabismus Questionnaires

Purpose

The Adult Strabismus Quality of Life Questionnaire (AS-20) and the Amblyopia & Strabismus Questionnaire (A&SQ) both measure health-related quality of life in strabismus patients. We evaluated to what extent these instruments cover similar domains by identifying the underlying quality-of-life factors of the combined questionnaires.

Methods

Participants were adults from a historic cohort with available orthoptic childhood data documenting strabismus and/or amblyopia. They had previously completed the A&SQ and were now asked to complete the AS-20. Factor analysis was performed on the correlation-matrix of the combined AS-20 and A&SQ data to identify common underlying factors. The identified factors were correlated with the clinical variables of angle of strabismus, degree of binocular vision, and visual acuity of the worse eye.

Results

One hundred ten patients completed both questionnaires (mean age, 44 years; range, 38–51 years). Six factors were found that together explained 78% of the total variance. The factor structure was dominated by the first four factors. One factor contained psychosocial and social-contact items, and another factor depth-perception items from both questionnaires. A third factor contained seven items—only from the AS-20—on eye strain, stress, and difficulties with reading and with concentrating. A fourth factor contained seven items—only from the A&SQ—on fear of losing the better eye and visual disorientation, specific for amblyopia. Current visual acuity of the worse eye correlated with depth-perception items and vision-related items, whereas current binocular vision correlated with psychosocial and social-contact items, in 93 patients.

Conclusions

Factor analysis suggests that the AS-20 and A&SQ measure a similar psychosocial quality-of-life domain. However, functional problems like avoidance of reading, difficulty in concentrating, eye stress, reading problems, inability to enjoy hobbies, and need for frequent breaks when reading are represented only in the AS-20. During the development of the A&SQ, asthenopia items were considered insufficiently specific for strabismus and were excluded a priori. The patients who generated the items for the AS-20 had, in majority, adulthood-onset strabismus and diplopia and were, hence, more likely to develop such complaints than our adult patients with childhood-onset strabismus and/or amblyopia.

Esotropia with an accommodative component after surgery for infantile esotropia compared to primary accommodative esotropia

PURPOSE

To compare the clinical outcomes of patients with an esotropia with an accommodative component after infantile esotropia surgery and patients with primary refractive accommodative esotropia.

METHODS

The medical records of patients with postoperative (secondary group) and primary refractive accommodative esotropia (primary group) were reviewed retrospectively. Changes in ocular alignment, refractive error, weaning rate, decompensation rate over time, and sensory outcomes were compared.

RESULTS

The overall change in ocular deviation with glasses correction was -0.5^Δ/year in the secondary group and -0.2^Δ/year in the primary group (P = 0.010). The overall change in spherical equivalent refractive error was -0.2 D/year in the secondary group and -0.3 D/year in the primary group (P < 0.001). The latest stereoacuity result was poorer in the secondary group than in the primary group (P = 0.027). No significant differences in the decompensation or weaning rates were detected between groups.

CONCLUSIONS

The changes in refractive error and the amount of esotropia over time were different between the secondary group and the primary group. Although refractive error was significantly lower and stereoacuity was poorer in the secondary group compared to the primary group, the majority of patients in the secondary group maintained good control of ocular alignment after hyperopic correction.

Outcome of early surgery in infantile esotropia: Our experience in tertiary care hospital

BACKGROUND

Infantile esotropia is a convergent strabismus presenting before 6 months of age and is the most common strabismus disorder presenting in the ophthalmology OPD. The dilemma of whether to go for early surgery and how early has been a matter of research for the last 50 years. We describe our results of surgery in infantile esotropia at variable age groups, as well as with different reoperation rates and compare with the results in western literature.

METHODS

A prospective study was carried out through a review of 113 cases operated for infantile esotropia between February 2013 and August 2014. The variables studied were: age at surgery, type of fixation, refractive error, associated nystagmus, inferior oblique overaction or dissociated vertical deviation (DVD), type of surgery performed and pre- and postoperative deviation angles.

RESULTS

There were 67 male and 46 female cases of infantile esotropia. The age group of patients varied from 6 months to 12 years. Latent nystagmus was seen in 22 cases, inferior oblique overaction in 49 cases and DVD (mild) in 14 cases. Bimedial rectus recession was done in 78 cases and recession-resection in non-dominant eye in remaining 35 cases. The postoperative residual deviation was <10 PD in 102 cases, between 10 and 16 PD in 5 cases and more than 16 PD in 6 cases. Only 6 cases (5.3%) required reoperation for correction of residual deviation.

CONCLUSION

The authors recommend surgery before 12 months in all cases of infantile esotropia. The reoperation rates in the current study were considerably low.

Essential infantile esotropia with inferior oblique hyperfunction: long term follow-up of 6 muscles approach

AIM

To evaluate long term follow-up (10y) of 6 muscle surgical approach in essential infantile esotropia (EIE).

METHODS

A 6 muscle approach to EIE was retrospectively evaluated in patients with inferior oblique (IO) hyperfunction and lateral rectus (LR) pseudoparalysis, who underwent surgery at different ages. Different clinical characters were analyzed pre- and postoperatively, in patients who underwent a 6 muscles approach ≤4 years of age. All patients underwent a multiple muscles approach: bilateral medial recti (MR) recession (4-5 mm), bilateral LR resection (lower than 7 mm) and bilateral IO recession and anteroposition. Of 108 children with preoperative angle ≥+30 prism diopters (PD) and IO hyperfunction were selected from larger cohort of patients (n=213, 103 females and 110 males) after excluding patients with: angle variability, who underwent reoperation and with incomplete follow up. Preoperative assessment and complete orthoptic examination were performed. Follow-up was performed 3mo, 2, 5 and 10y after surgery. Statistical analysis was performes using SAS statistical software package (version 9.1, SAS Institute Inc., Cary, NC, USA).

RESULTS

Ten years follow up data analysis showed the following percentage of orthotropic patients: (0 PD): 3mo, 22.2%; 2y, 16.7%; 5y, 25.0% and 10y, 27.8%. A slight, significant (P<0.01), increase of 2y follow up residual deviation was found when compared to 3mo one. Stationary surgical results is reported during time, with a trend of mean residual deviation reduction (P=0.04).

CONCLUSION

Our results confirm the reliability of multiple muscles surgical approach in the treatment of patients affected by EIE with OI hyperfunction.

Surgical Results of Symmetric and Asymmetric Surgeries and Dose-Response in Patients with Infantile Esotropia

Objectives:

To evaluate the results of symmetric and asymmetric surgery and responses to surgical amounts in patients with infantile esotropia.

Materials and Methods:

The records of patients with infantile esotropia who underwent bilateral medial rectus recession (symmetric surgery) and unilateral medial rectus recession with lateral rectus resection (asymmetric surgery) were analyzed. The results of the cases with symmetric (group 1) and asymmetric (group 2), successful (group 3) and failed (group 4) surgeries were compared, and responses to the amount of surgery were investigated.

Results:

There were no significant differences between group 1 (n=71) and group 2 (n=13) cases in terms of gender, refraction, preoperative distance deviation, anisometropia and postoperative deviation angles, binocular vision, surgical success or follow-up period (p>0.05). The rate of amblyopia, near deviation and amount of surgery were higher in group 2 cases (p<0.05). Between group 3 (n=64) and group 4 subjects (n=20), no significant differences were detected in terms of gender, surgical age, refraction, amblyopia, anisometropia, preoperative deviation angles, the number of symmetric and asymmetric surgeries, the amount of surgery, or postoperative binocular vision (p>0.05). The average postoperative follow-up period was 15.41±19.93 months (range, 6-98 months) in group 3 cases and 40.45±40.06 months (range, 6-143 months) in group 4 cases (p=0.000). No significant difference was detected in the amount of deviation corrected per 1 mm of surgical procedure between the successful cases in the symmetric and asymmetric groups (p>0.05).

Conclusion:

Symmetric or asymmetric surgery may be preferable in patients with infantile esotropia according to the clinical features. It is necessary for every clinic to review its own dose-response results.

Infantile esotropia: risk factors associated with reoperation

The aim of this study was to identify clinical and demographic factors associated with misalignment after first surgery performed on children affected by infantile esotropia to evaluate the reoperation rate. A retrospective study was carried out, analyzing data from 525 children who underwent bilateral medial recti recession, bilateral lateral recti resection, and inferior oblique recession and anteroposition by the same surgeon (AM). Postoperative evaluation included assessment of motor alignment at approximately 3 months, 6 months, 1 year, and 5 years. Statistical analysis was performed with a logistical regression model in which the dependent variable was the presence/absence of reoperation. We found that late surgery (after 3 years of age) and a family history of strabismus are associated with a higher risk of reoperation, while some clinical factors, including some classically associated with worst motor outcome as preoperative angle, dissociated vertical deviation, and amblyopia, did not influence the incidence of reoperation in infantile esotropia. Male patients and patients with hyperopia in preoperative examinations have a significantly decreased reoperation rate.

Essential Infantile Esotropia: Postoperative Sensory Outcomes of Strabismus Surgery

BACKGROUND

The optimum age for Essential Infantile Esotropia surgery is a controversial subject. Sensory status was evaluated in patients who underwent surgery at different ages in a retrospective study. The setting of the study is the ophthalmology department of a teaching hospital.

METHODS

Different clinical characters were analyzed pre- and postoperatively; nine different surgeries were performed. A total of 188 patients presented valid postoperative sensorial data, divided in two groups: surgery at ≤2 years (n=69) or >2 years (n=119). Sensory status was dichotomized in binocular single vision (BSV) and exclusion. Univariate differences were assessed with the chi-square test (or Fisher exact test). To identify the independent role of factors associated with the sensory status, all variables showing in univariate analyses a significant association (p<0.05) with the outcome variable were entered into a multivariate logistic regression model. All statistical tests were two-sided.

RESULTS

Multivariate analysis confirmed that children operated >2 years were 0.4 times less likely to obtain BSV compared with children operated at ≤2 years (AOR. 0.38, 95% C.I. 0.17-0.89, p=0.025). Patients operated on by OO MR rec.+ OO LR res. + OO IO rec.-ap. (intervention type 6) were about 11 times more likely to have BSV than those by OO rec.MR + unilateral res. LR (operation type 2); AOR.: 10.67, 95% C.I.: 1.34 - 85.29, p=0.026). Twenty-nine patients (12.1%) operated at ≤2 years of age underwent a reoperation, compared to 33 (8.6%) who underwent surgery after two years (p>0.05).

CONCLUSIONS

Our findings suggest to perform EIE surgery between age 1 and 2 and, when indicated, to prefer a six-muscle approach in order to achieve a better sensory function.

Botulinum toxin uses in strabismus: A review of the injections performed during one year in a general hospital

OBJECTIVE

To analyse the indications, dosage and efficacy of botulinum toxin A injection performed in patients in a Strabismus Department.

METHODS

In this prospective study, botulinum toxin A was injected into 28 patients diagnosed with strabismus. Data was obtained from the records of patients that were evaluated during 2013 in the Strabismus Unit of Rey Juan Carlos Hospital (Móstoles, Madrid, Spain) in order to assess the indications and dosage of botulinum toxin A use in strabismus, as well as its clinical effect and differences in paediatric and adult patients. The outcomes in the last visit, at least 14 months after the injections, were analysed.

RESULTS

An analysis was performed on the data from 11 children, 6 females (54.5%), and 17 adults, 11 males (64%). The mean age was 4.42±3.48 years and 58.71±18.07 years in the children and adult groups, respectively. The majority of cases in both groups were esotropia (81.8% in children and 47.1% in adults). However the pathologies in the adult group were quite heterogeneous, including 4 patients with exotropia (26.5%), 4 with hypertropia (26.5%), and one with isolated nystagmus (5.9%). The mean number of the botulinum toxin injections in children was 1.45±0.93, although 72.7% received a single injection. In the adult group, the mean number of injections was 3.27±1.41. There was a statistically significant difference between pre- and post-injection in the tropia and phoria measurements in children and adults group (P<.05). In both groups there was a statistically significant improvement in post-injection torticollis when compared with the pre-injection measurement (P<.05). An improvement in the stereoacuity could be detected in 4 children. Two children (18.2%) and 5 adults (29.4%) required subsequent surgical intervention. Eight adult patients (49.1%) complained of diplopia in the primary position, which was resolved in 6 cases with toxin injection, whereas 2 needed surgery for diplopia correction.

CONCLUSIONS

Botulinum toxin is a very useful tool in the management of strabismus, obtaining better sensory and motor results in children, but it is also effective as a symptomatic treatment in some types of strabismus in adults.

An external pilot study to test the feasibility of a randomised controlled trial comparing eye muscle surgery against active monitoring for childhood intermittent exotropia [X(T)]

INTRODUCTION

The evidence base for the treatment of strabismus (squint) is poor. Our main aim is to improve this evidence base for the treatment of a common type of childhood squint {intermittent exotropia, [X(T)]}. We conducted an external pilot study in order to inform the design and conduct of a future full randomised controlled trial (RCT).

METHODS

Children of between 6 months and 16 years with a recent diagnosis of X(T) were eligible for recruitment. Participants were recruited from secondary care at the ophthalmology departments at four UK NHS foundation trusts. Participants were randomised to either active monitoring or surgery. This report describes the findings of the Pilot Rehearsal Trial and Qualitative Study, and assesses the success against the objectives proposed.

RECRUITMENT AND RETENTION

The experience gained during the Pilot Rehearsal Trial demonstrates the ability to recruit and retain sites that are willing to randomise children to both trial arms, and for parents to agree to randomisation of their children to such a study. One child declined the group allocation. A total of 231 children were screened (expected 240), of whom 138 (60%) were eligible (expected 228: 95%) and 49 (35% of eligible) children were recruited (expected 144: 63% of eligible). Strategies that improved recruitment over the course of the trial are discussed, together with the reasons why fewer children were eligible for recruitment than initially anticipated. Attrition was low. Outcome data were obtained for 47 of 49 randomised children.

TRIAL PROCESSES AND DATA COLLECTION

The Trial Management processes proved effective. There were high levels of completion on all of the data collection forms. However, the feedback from the treatment orthoptists revealed that some modifications should be made to the length and frequency of the health service assessment and travel assessment questionnaires, thus reducing the burden on participants in the main trial. Modifications to the wording of the questions also need to be made.

MONITORING OF BIAS

Children who recruited to the trial were older and had more severe strabismus than those children eligible but declining participation. Strategies to account for this in a full trial are proposed.

REASONS FOR PARTICIPATION OR DECLINING STUDY

These were identified using qualitative interviews. The principal reasons for declining entry into the study were strong preferences for and against surgical treatment.

HARMS

There were no serious unexpected adverse events. Two children had overcorrection of their X(T) with reduction in binocular vision following surgery, which is in line with previous studies. No children in the active monitoring arm developed a constant strabismus although two showed some reduction in control.

CONCLUSIONS

The SamExo study has demonstrated that it is possible to recruit and retain participants to a randomised trial of surgery compared with active monitoring for X(T). For longer-term full RCTs, in order to maximise the generalisability of future studies, consideration needs to be given to planning more time and clinic appointments to assess eligibility and to allow consideration of participation; the greater use of research nurses for recruitment; and accommodating the strong preferences of some parents both for and against surgical intervention.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN44114892.

FUNDING

This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 19, No. 39. See the NIHR Journals Library website for further project information.

Altered intrinsic regional brain spontaneous activity in patients with comitant strabismus: a resting-state functional MRI study

OBJECTIVE

To investigate the underlying regional homogeneity (ReHo) of brain-activity abnormalities in patients with comitant strabismus (CS) and their relationship with behavioral performance.

METHODS

Twenty patients with CS (ten men and ten women) and 20 (ten men and ten women) age-, sex-, and education-matched healthy controls (HCs) underwent resting-state functional magnetic resonance imaging scans. The ReHo method was used to assess local features of spontaneous brain activities. Patients with CS were distinguished from HCs by receiver operating characteristic curve. Correlation analysis was performed to explore the relationship between the observed mean ReHo values of the different brain areas and behavioral performance.

RESULTS

Compared to HCs, the patients with CS showed significantly increased ReHo values in the right inferior temporal cortex/fusiform gyrus/cerebellum anterior lobe, right lingual gyrus, and bilateral cingulate gyrus. We did not find any relationship between the observed mean ReHo values of the different brain areas and behavioral performance.

CONCLUSION

CS causes dysfunction in many brain regions, which may explain the fusion compensation in CS.

Stereoscopic perception of 3-D images by patients after surgery for esotropia

PURPOSE

Patients with esotropia (ET) have generally poor stereopsis; however, it is not clear whether they can see the recently developed 3-D images stereoscopically. We investigated the ability of postoperative ET patients to have stereoscopic perception of 3-D attraction images which have large crossed disparities, and also 3-D movies which have generally small uncrossed disparities.

METHODS

Twenty-seven ET patients (infantile ET = 12, late-onset ET = 15) were examined postoperatively. They were examined with the 4-dot test, Titmus fly test, and questionnaires to determine whether they had stereoscopic vision when observing 3-D attraction images and 3-D movies. McNemar tests were used for statistical evaluations.

RESULTS

The number of patients who passed the Titmus fly test was smaller than the number that were able to see 3-D attraction images stereoscopically (fly test 13; 48%, 3-D attraction 22; 81%; P = 0.016). However, the number was not significantly different from that of those who could perceive 3-D movies stereoscopically. The number of patients who passed the Titmus fly test was significantly smaller than the number who can perceive 3-D attraction images stereoscopically in the infantile ET group (fly test 2, 17%, 3-D attraction 10, 83%; P = 0.013) but was not different in the late-onset ET group postoperatively. The minimum angle of fusion for the 4-dot test was smaller in the Titmus fly-positive patients than in the Titmus fly-negative patients (P = 0.03).

CONCLUSIONS

These results suggest that children who cannot pass the Titmus fly test might be able to experience 3-D attractions stereoscopically but not be able to see 3-D movies stereoscopically.

[Surgery for convergent strabismus in childhood: why and when?]

The authors explain the reasons for and the timing of surgery for convergent strabismus, or esotropia, in children as a function of the particular type of strabismus. The goal of surgery is to correct the cross-eyed deviation by choosing the most opportune time so as to obtain the best binocular result with the minimum number of surgeries. The authors take a position in the debate over age at time of surgery for childhood esotropia, which is still controversial. Their arguments are based on recent neurophysiological and clinical data.

Long-term surgical outcomes of infantile-onset esotropia in preterm patients compared with full-term patients

BACKGROUND/AIMS

To compare surgical outcomes between preterm and full-term patients with infantile-onset esotropia.

METHODS

This study included 56 preterm and 162 full-term patients with infantile-onset esotropia who underwent strabismus surgery. The extent of surgery was reduced by 0.5 mm per muscle in preterm patients who were born at <30 weeks of gestation. Surgical outcomes over time, including surgical success, overcorrection rate, undercorrection rate and surgical dose-response were compared between preterm and full-term patients.

RESULTS

The Cox proportional hazards regression model and competing risk analysis showed no statistically significant differences in the rate of surgical success or undercorrection over time between preterm and full-term patients. However, the final overcorrection rate was greater in preterm children than in full-term children (p=0.019). The average surgical dose-response was 3.99 prism dioptres (PD)/mm in full-term children and 4.40 PD/mm in preterm children.

CONCLUSIONS

The results of this study showed a favourable outcome using a mildly reduced amount of surgery in preterm patients with infantile-onset esotropia. Surgical dose-response was significantly greater in preterm patients than in full-term patients.

Strabismus surgery before versus after completion of amblyopia therapy in children

BACKGROUND

Normal visual development occurs when the brain is able to integrate the visual input from each of the two eyes to form a single three-dimensional image. The process of development of complete three-dimensional vision begins at birth and is almost complete by 24 months of age. The development of this binocular vision is hindered by any abnormality that prevents the brain from receiving a clear, similar image from each eye, due to decreased vision (e.g. amblyopia), or due to misalignment of the two eyes (strabismus or squint) in infancy and early childhood. Currently, practice patterns for management of a child with both strabismus and amblyopia are not standardized.

OBJECTIVES

To study the functional and anatomic (ocular alignment) outcomes of strabismus surgery before completion of amblyopia therapy as compared with surgery after completion of amblyopia therapy in children under seven years of age.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (2014, Issue 6), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to July 2014), EMBASE (January 1980 to July 2014), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to July 2014), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 24 July 2014. A manual search for articles from a review of the references of the selected publications and conference abstracts was completed to identify any additional relevant studies.

SELECTION CRITERIA

We searched for randomized controlled trials (RCTs) that provided data on strabismus surgery in children less than seven years of age, performed after initiation of, but before completion of amblyopia therapy, as compared with strabismus surgery after completion of amblyopia therapy.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed studies identified from the electronic and manual searches.

MAIN RESULTS

There were no RCTs that fit our inclusion criteria and so no analysis was possible.

AUTHORS' CONCLUSIONS

As there are no RCTs currently available and the best existing evidence is only from non-randomized studies, there is a need for prospective RCTs to investigate strabismus surgery in the presence of strabismic amblyopia. The optimal timing of when to perform strabismus surgery in children with amblyopia is unknown.

Factors influencing the development and severity of dissociated vertical deviation in patients with infantile esotropia

PURPOSE

To investigate the factors associated with the development and the severity of dissociated vertical deviation (DVD) in patients who underwent surgery for infantile esotropia.

METHODS

The medical records of consecutive patients who underwent surgery from March 1998 to December 2011 for infantile esotropia were reviewed retrospectively. The development, severity, and onset of DVD were assessed. Patients were divided into three groups: spontaneous, latent, and no DVD. The age at the time of the initial surgery, the angle of deviation of esotropia, anisometropia, amblyopia, stereopsis measured at the final visit, and history of prematurity were compared.

RESULTS

A total of 90 patients were included. DVD was detected in 52 (58%). Of these, 34 patients demonstrated spontaneous DVDs and 18 showed latent DVDs. In the spontaneous DVD group, 71% underwent surgery after 24 months and 50% had a large angle of esodeviation (>60(Δ)), compared to the latent DVD group, in which 22% underwent later surgery and 11% had large-angle esodeviations (P < 0.001 and P = 0.002, respectively), and the no DVD group, in which 16% underwent later surgery and 13% had large-angle esodeviations (P < 0.001 each). Multivariate logistic regression analysis between groups revealed that later surgery (OR = 8.23; P < 0.001) and large-angle esodeviation (OR = 6.32; P = 0.003) were associated that greater development of spontaneous DVD.

CONCLUSIONS

Surgical correction for infantile esotropia prior to 24 months of age, especially in cases with a large amount of esodeviation, decreased the incidence of spontaneous DVD.