A reassessment of infantile esotropia. XLIV Edward Jackson memorial lecture

Comparison of Botulinum Toxin A Injection and Bridge Faden Operation Performed With Bimedial Rectus Recession in Patients With Large-Angle Esotropia

PURPOSE

To compare the results of botulinum toxin A injection and bridge Faden operation performed with bimedial rectus recession in the treatment of large-angle esotropia.

METHODS

The medical charts of patients with large-angle esotropia who underwent bimedial rectus recession combined with the Faden operation or botulinum toxin A injection between January 2018 and March 2022 were retrospectively screened. The degree of deviations measured before surgery and at 1, 3, 6, and 12 months after surgery were compared between the two groups.

RESULTS

The sample consisted of 26 patients, of whom 15 (57.7%) were male and 11 (42.3%) were female. In the botulinum toxin A group (n = 11), the mean age was 42.1 ± 22.6 months at admission and 65.3 ± 17.1 months at surgery, and the mean preoperative near and far distance deviations were 49.8 ± 8.4 and 44.3 ± 9.4 PD, respectively. In the Faden group (n = 15), the mean age was 54.9 ± 21.7 months at admission and 71.3 ± 12.6 months at surgery, and the mean preoperative deviations at near and far distances were 49.3 ± 11.2 and 44.3 ± 9.2 PD, respectively. The complete success rates of the botulinum toxin A and Faden groups evaluated 12 months after treatment were 63.6% and 66.7%, respectively, for the near distance deviation and 72.7% and 73.3%, respectively, for the far distance deviation. After the botulinum toxin A injection, 2 patients developed transient ptosis and 1 developed consecutive exotropia.

CONCLUSIONS

As an alternative to multi-muscle surgery in large-angle esotropia, botulinum toxin A injection and Faden procedures, performed with bilateral medial rectus recession, provide successful results. [J Pediatr Ophthalmol Strabismus. 20XX;X(X):XXX-XXX.].

Bilateral medial rectus recession with or without posterior fixation in large-angle infantile esotropia: a randomized controlled trial

PURPOSE

To compare the results of bilateral medial rectus recession (BMRc) versus bilateral medial rectus recession with Faden operation (BMRF) in the treatment of large-angle infantile esotropia.

STUDY DESIGN

A double blinded, parallel, randomized controlled trial.

METHODS

Patients with large-angle infantile esotropia (≥ 60 prism diopters, [PD]) aged between 3 and 15 years old were included and assigned to either the BMRc or BMRF group. Mean difference and mean reduction of angle deviation between the two groups were compared at 1 week, 1, 3, and 6 months by using generalized estimating equations analysis. Surgical success rates, defined as an esodeviation ≤ 10 PD at near fixation, were evaluated at 6 months postoperatively. Complications from the surgical procedures were observed.

RESULTS

Of 40 enrolled patients, the mean (SD) age of the patients in the BMRc group was 3.4 (1.9), and in the BMRF group, 5.2 (3.8) years old. The overall mean differences of angle reduction between both groups were not significant (-6 PD, 95%CI -14 to 2, P = .12). The surgical success rate at 6 months in the BMRF group (72%) was not different compared to BMRc group (84%, P = .45). Overall consecutive exotropia was 5%, not different between groups (P > .99). There was no difference of complications between the two groups (P = .51).

CONCLUSION

BMRF and BMRc approaches show no difference in treatment of large-angle infantile esotropia. Nevertheless, a long-term assessment for consecutive exotropia should be considered for both surgical procedures.

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.

Response to botulinum neurotoxin injections in large-angle infantile esotropia: a post hoc analysis

PURPOSE

To determine the anticipated reduction of baseline angle of esotropia and identify predictors of change following botulinum neurotoxin (BNT) injections in large-angle infantile esotropia.

METHODS

This was a prospective, longitudinal study of children <10 years of age diagnosed with infantile esotropia of >30^Δ and given either 1, 2, or 3 BNT injections. Post-injection change from baseline deviation was recorded, and predictors of reduction were analyzed. For this study, children were further divided into subgroups based on initial deviation of ≤60^Δ (group 1) and >60^Δ (group 2). The outcomes of subsequent surgeries in failed cases were analyzed.

RESULTS

A total of 117 children were included, 55 in group 1 and 62 in group 2. Mean age was 30.3 ± 18.8 months. Mean baseline deviation was 62.5^Δ ± 13.1^Δ: 51.4^Δ ± 8.4^Δ in group 1 and 73^Δ ± 7.5^Δ in group 2. The mean number of injections was 2.2 ± 0.7. Success was achieved in 25.6% of patients (33.4% in group 1; 16.2% in group 2). The mean percentage reduction of deviation after BNT injection was 55.2% ± 26%, larger in group 1 than in group 2 (61.3% vs 51.1% [P = 0.001]). Five children reverted to baseline deviation. In multivariate analysis, adjusting for number of injections, younger age and larger baseline deviation were significant independent predictors of a larger absolute amount of reduction (P = 0.02, and 0.002, resp.). Thirty-two children had subsequent surgery; 22 were followed for a minimum of 6 months, and 20 were aligned within 10^Δ of orthotropia.

CONCLUSIONS

In large-angle esotropia there was a reduction of approximately 50% of baseline deviation, with greater relative reduction for smaller baseline deviations; the absolute change in angle was greater in younger children. Alignment after subsequent surgery appeared to remain stable and surgery required less recession than would have been needed for the original angle of esotropia.

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.

Botulinum neurotoxin injections in essential infantile esotropia-a comparative study with surgery in large-angle deviations

PURPOSE

To compare botulinum neurotoxin (BNT) injections to surgery as first-line therapy in large-angle essential infantile esotropia (IE).

PATIENTS AND METHODS

Children between the ages 6 months and 6 years with IE of ≥40 prism dioptres (PD) were randomised to either a maximum of three BNT injections or surgical intervention of bimedial rectus muscle recession for angles ≤60 PD and augmented with BNT injection in angles >60 PD. Time taken for each procedure was documented. Orthophoria or misalignment of ≤10 PD was regarded as a complete response (CR). Follow-up visits were done at 3, 6, 12 and 24 weeks.

RESULTS

Mean (SD) age and baseline angle of esotropia were 26.9 (14.5) months and 61.9 PD (12.8), respectively, for the overall cohort. The proportion of children who achieved CR was significantly higher in the surgery arm compared to the BNT injection arm (OR = 4.01, 95% CI 1.74-9.22) but the time taken was six times longer (p < 0.0001). In the BNT arm, 55.2% of children aged ≤24 months and 16% of children >24 months achieved CR. In children with esotropia ≤60 PD, CR was achieved in 50% while those with esotropia >60 PD CR was achieved in 25%.

CONCLUSION

Surgery remains the gold standard for treatment of esotropia but BNT injection is a safe and effective alternative in children ≤24 m and with smaller angles of esotropia ≤60 PD in resource-limited centres.

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.].

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.

Strabismus Surgery for Esotropia, Down Syndrome and Developmental Delay; Is an Altered Surgical Dose Required? A Literature Review

Background and Purpose:

There is a high rate of strabismus, in particular esotropia, in children with Down syndrome or developmental delay, which frequently requires surgical correction. A paper in 1994 advocated that the surgical dose be adjusted due to an altered response in these children. The aim of this literature review is to evaluate the available evidence to establish whether an altered surgical approach is required in either population.

Methods:

A literature review was conducted using PubMed and Web of Knowledge. Only English language papers were eligible for inclusion. The papers were collated in chronological order for analysis, and their references searched for further relevant papers. Forward citation searches were also undertaken.

Results:

A 2 × 2 comparison is made between publications on Down syndrome (in isolation) and developmental delay populations (including Down syndrome) with adjusted versus non-adjusted surgery. Published surgical success rates on esotropia from unaltered surgical doses range from 62.0%–85.7% (four papers) in the Down syndrome cohort, with none of the adjusted surgeries having a successful outcome. Surgical success rates from adjusted surgical doses in developmental delay cohort range from 37.5%–86.0% (seven papers), with one unadjusted surgical success rate of 76.0%. The results across the studies are summarised in a table and discussed.

Conclusions:

An exaggerated surgical effect in individuals with developmental delay has been reported, and this population may benefit from a reduced surgical dose. Published research does not support giving a reduced surgical dose in individuals with Down syndrome, but more research needs to be done to make a definitive conclusion.

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.

Relation between preoperative hyperopia and surgical outcome in infantile esotropia

AIM

To evaluate the relation between preoperative hyperopia and surgical outcomes of infantile esotropia in patients younger than 24 months of age.

METHODS

Medical records of patients who underwent bilateral medial rectus muscle recession for infantile esotropia between November 1, 2002 and December 1, 2011 were retrospectively reviewed. Patients were divided into two groups according to the degree of preoperative hyperopia. Group I had less than +3.0 diopter (D) of hyperopia and group II had between +3.0 and +5.0 D of hyperopia. Postoperative alignments were evaluated 1wk, 3, 6mo, and 1y after surgery. Following the 1-year postoperative visit, patients were monitored yearly. Relationships between preoperative factors including hyperopia and postoperative outcomes were evaluated.

RESULTS

Forty-six patients were included, with 33 patients in group I and 13 patients in group II. The preoperative mean refractive error was +0.88 D in group I and +3.45 D in group II. Surgical outcomes were not significantly different between groups at any postoperative time point examined. Cumulative probability of surgical success, prevalence of inferior oblique overaction, dissociated vertical deviation, and re-operation rate were not significantly different between groups.

CONCLUSION

Preoperative moderate hyperopia (less than +5.0 D) did not affect the surgical outcome of infantile esotropia. Therefore, the surgical correction of esotropia should be considered when the angle of esodeviation is unchanged following hyperopia correction, even in children with moderate hyperopia.

The Functional Benefits of Strabismus Surgery

When performed prior to visual maturity, strabismus surgery can result in the development or recovery of binocularity. When strabismus surgery is performed after visual maturity, the functional benefits of the surgery should be dichotomized according to whether the onset of the strabismus was before or after visual maturity. If the onset was after visual maturity, patients typically are diplopic. Specific success rates for eliminating diplopia vary according to the nature of the strabismus; however, overall the success rate is quite high. There is a common misperception that surgery in adults for strabismus that began prior to visual maturity is merely cosmetic. Numerous studies contradict this misconception. Even if the strabismus has been longstanding, most adults will experience some improvement in binocular function after strabismus surgery. In esotropic patients, this improvement typically takes the form of an expansion of binocular visual fields; however, some patients may also regain stereopsis. There are many psychosocial benefits to adult strabismus surgery. This is reflected in the finding that the majority of adults surveyed with strabismus would trade a portion of their life expectancy to be rid of their strabismus.

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.

Comparison of Surgical Success for Infantile Esotropia and Strabismus Associated with Neurological Impairment

PURPOSE

Surgery for strabismus associated with neurological impairment is assumed to have unsatisfactory results in comparison with other strabismus cases. The aim of this study is to compare the surgical success rates of infantile esotropia (IE) and strabismus associated with neurological impairment.

METHODS

The records of 103 patients that received operations for IE and strabismus associated with neurological impairment between January 1994 and May 2014 were reviewed retrospectively. The angles of deviation and surgical success rates were evaluated at preoperative, 1-month postoperative, and 24-month postoperative visits.

RESULTS

Forty-five patients received operations for strabismus associated with neurological impairment (25 patients with esotropia and 20 patients with exotropia) and 58 patients for IE. Mean preoperative angles of deviation in cases with neurological impairment were 42 prism diopters (PD) for esotropia, 44.7 PD for exotropia, and 44.4 PD for IE. One patient from each group had consecutive deviation at first visit, and at last visit, 3 patients with neurological impairment and 5 patients with IE had consecutive deviations. Surgical success rates at the end of the second year were 52% for esotropia and 50% for exotropia in patients with neurological impairment and 56.8% for IE cases.

CONCLUSION

This study was unable to find the differences between surgical success rates in IE and strabismus associated with neurological impairment.

Stability of the Functional Cure in Congenital Esotropia

PURPOSE

To report the stability of the functional cure in a chart review of patients with congenital esotropia.

METHODS

The charts of 31 patients with congenital esotropia, encountered in 2007-2012 with functional cure, were studied. The stability of the cure and duration of follow-up were determined by comparing the first recorded date of cure with the date of the last examination. The mean age of the patients analyzed was 19.5 years.

RESULTS

Two patients decompensated in the subgroup of 24 patients who did not require hyperopic correction and 1 patient decompensated in the subgroup of 7 patients who required hyperopic correction. All patients with decompensation were realigned by secondary surgery. A small subgroup of 4 patients demonstrated gradual improvement of stereoacuity to 60 arc seconds or better.

CONCLUSIONS

The functional cure of congenital esotropia is relatively stable in patients within the first 20 years. The secondary use of hyperopic correction and secondary surgery increased this stability.

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.

Strabismus surgery for children with developmental delay

PURPOSE OF REVIEW

To describe recent evidence regarding the surgical approach of strabismus in children with various forms of developmental delay.

RECENT FINDINGS

There remains variability in surgical outcomes with or without dose adjustment in strabismus surgery for children with developmental delay. However, this should not deter one from performing surgery - even early surgery, as fusional potential remains possible, which can especially impact the quality of vision and quality of life in developmentally delayed children.Future prospective, comparative, long-term studies with larger sample sizes for strabismus surgery in children with developmental delay are still needed.

SUMMARY

Strabismus is one of the most common ophthalmologic findings in children with developmental delay. Surgical correction of strabismus in children with developmental delay is well tolerated and effective, although it remains slightly less predictable, which can depend on the specific type of delay or underlying neurological deficit. Careful consideration of types and severity of developmental delay and attempts to measure binocular potential can help guide the timing, dosage, and type of treatment.Reoperations tend to be more frequently encountered in this population, and this higher degree of variability should be addressed in the consent process.Considering adjusting the surgical dosage in this population, taking careful preoperative measurements, and checking for fusional potential should be taken into account when managing children with developmental delay.

Comparative study of Y-split recession versus bilateral medial rectus recession for surgical management of infantile esotropia

Aim

This prospective study compares the results of bilateral medial rectus recession versus (vs) Y-split recession of medial recti techniques for surgical management of essential infantile esotropia.

Patients and methods

Thirty patients were included in this study and had preoperative infantile esotropia with large angles (ie, >30 prism diopters [PD]). Patients were divided into Group A, which underwent bilateral medial rectus (BMR) recession and Group B, which underwent bilateral Y-split recession of medial recti muscles. All patients were subjected to complete ophthalmologic examination and met the criteria for inclusion in this study. The degrees of BMR recessions performed ranged from 6.0–7.5 mm. All operations were performed under general anesthesia. Follow-up visits were conducted at 1 and 2 weeks, and 1, 3, and 6 months postoperatively. Rates of reoperation for residual esotropia and consecutive exotropia were determined.

Results

The patients’ preoperative angles of deviation ranged from 30–80 PD. Group A consumed 57% less operative time than Group B. Immediately postoperatively, the Y-splitting technique showed satisfactory results (ie, orthotropic or residual angles ≤15 PD) in 73% of patients vs 67% only for the BMR recession patients. By the end of six months of follow up; 13% of the BMR technique patients vs 27% of the Y-splitting technique patients showed negative change of PD but without reoperation.

Conclusion

Our results suggest that, although the Y-splitting technique is more difficult and time consuming, both procedures are effective and have shown comparable results for the correction of horizontal deviation ≤70 PD.

Anterior segment dysgenesis associated with Williams-Beuren syndrome: a case report and review of the literature

Background

Williams-Beuren syndrome is characterized by mild mental retardation, specific neurocognitive profile, hypercalcemia during infancy, distinctive facial features and cardiovascular diseases. We report on complete ophthalmologic, sonographic and genetic evaluation of a girl with a clinical phenotype of Williams-Beuren syndrome, associated with unilateral anterior segment dysgenesis and bilateral cleft of the soft and hard palate. These phenotypic features have not been linked to the haploinsufficiency of genes involved in the microdeletion.

Case presentation

A term born girl presented at the initial examination with clouding of the right cornea. On ultrasound biomicroscopy the anterior chamber structures were difficult to differentiate, showing severe adhesions from the opacified cornea to the iris with a kerato-irido-lenticular contact to the remnant lens, a finding consistent with Peters' anomaly. Genetic analyses including FISH confirmed a loss of the critical region 7q11.23, usually associated with the typical Williams-Beuren syndrome. Microsatellite analysis showed a loss of about 2.36 Mb.

Conclusions

A diagnosis of Williams-Beuren syndrome was made based on the microdeletion of 7q11.23. The unique features, including unilateral microphthalmia and anterior segment dysgenesis, were unlikely to be caused by the microdeletion. Arguments in favor of the latter are unilateral manifestation, as well as the fact that numerous patients with deletions of comparable or microscopically visible size have not shown similar manifestations.

Why do only some hyperopes become strabismic?

Children with hyperopia greater than +3.5 diopters (D) are at increased risk for developing refractive esotropia. However, only approximately 20% of these hyperopes develop strabismus. This review provides a systematic theoretical analysis of the accommodation and vergence oculomotor systems with a view to understanding factors that could either protect a hyperopic individual or precipitate a strabismus. The goal is to consider factors that may predict refractive esotropia in an individual and therefore help identify the subset of hyperopes who are at the highest risk for this strabismus, warranting the most consideration in a preventive effort.

Decorrelation of cerebral visual inputs as the sufficient cause of infantile esotropia

BACKGROUND AND PURPOSE

Human infants at greatest risk for esotropia are those who suffer cerebral insults that could decorrelate signals from the two eyes during an early critical period of binocular, visuomotor development. The authors reared normal infant monkeys under conditions of binocular decorrelation to determine if this alone was sufficient to cause esotropia, and associated behavioral as well as neuroanatomic deficits.

METHODS

Binocular decorrelation was imposed using prism-goggles for durations of 3-24 weeks (control monkeys wore plano goggles), emulating unrepaired strabismus of durations 3 months to 2 years in human infants. Behavioral recordings were obtained, followed by neuroanatomic analysis of ocular dominance columns and binocular, horizontal connections in the striate visual cortex (area V1).

RESULTS

Concomitant, constant esotropia developed in each monkey exposed to decorrelation for a duration of 6-24 weeks. The severity of ocular motor signs (esotropia angle; dissociated vertical deviation; latent nystagmus; pursuit / optokinetic tracking asymmetry; fusional vergence deficits), and the loss of V1 binocular connections increased as a function of decorrelation duration. Stereopsis was deficient and motion visually evoked potentials were asymmetric. Monkeys exposed to decorrelation for 3 weeks showed transient esotropia, but regained normal alignment, visuomotor behaviors, and binocular V1 connections.

CONCLUSIONS

Binocular decorrelation is a sufficient cause of infantile esotropia when imposed during a critical period of visuomotor development. The systematic relationship between severity of visuomotor signs and severity of V1 connectivity deficits provides a neuroanatomic mechanism for these signs. Restoration of binocular fusion and V1 connections after short durations of decorrelation helps explain the benefits of early strabismus repair in humans.

Outcome of surgery for esotropia in children with down syndrome

BACKGROUND AND PURPOSE

The outcome of surgery for esotropia in children with Down syndrome has not received significant attention.

PATIENTS AND METHODS

We reviewed motor outcomes of esotropia surgery in all patients with Down syndrome in our practice from 1991-2001.

RESULTS

Twenty-one patients had surgery for esotropia. The mean age at surgery was 55 months. The mean preoperative esotropia was 36(Δ). Three patients required a second surgery: two for residual esotropia and one for consecutive exotropia. A second operation was recommended for two additional patients: one with residual esotropia and one with consecutive exotropia. The mean length of follow-up was 39 months. At the last follow-up examination, fourteen patients had a deviation of 0-10(Δ) (thirteen esotropic and one exotropic). Five patients had a final deviation of 11-20(Δ) (four esotropic and one exotropic). One patient had a residual esotropia of 21-30(Δ) and one had greater than 30(Δ) of residual esotropia.

CONCLUSION

The motor outcomes for esotropia surgery in children with Down syndrome were not as good as those in children with acquired esotropia but were comparable to those in children with infantile esotropia. More children had residual esotropia than consecutive exotropia, which may reflect a tendency toward conservative amounts of surgery or an underlying esotropic tendency in Down syndrome. Parents of children with Down syndrome may be counseled to expect good outcomes in the surgical management of esotropia.

Best age for surgery for infantile esotropia

Infantile esotropia (IE) is defined as an esotropia before the age of 6 months, with a large angle, latent nystagmus, dissociated vertical deviation, limitation of abduction, and reduced binocular vision, without neurological disorder. Prematurity, low birth weight, and low Apgar scores are significant risk factors for IE. US standard age of first surgery is 12-18 months, in Europe 2-3 years. The only study to date with prospectively assigned early- and late-surgery groups and evaluation according to intention-to-treat, was the European Early vs. Late Infantile Strabismus Surgery Study (ELISSS). In that study 13.5% of children operated around 20 months vs. 3.9% (P = 0.001) of those operated around 49 months had gross stereopsis (Titmus Housefly) at age 6. The reoperation rate was 28.7% in children operated early vs. 24.6% in those operated late. Unexpectedly, 8% in the early group vs. 20% in the late group had not been operated at age 6, although all had been eligible for surgery at baseline at 11 SD 3.7 months. In most of these children the angle of strabismus decreased spontaneously. In a meta-regression analysis of the ELISSS and 12 other studies we found that reoperation rates were 60-80% for children first operated around age 1 and 25% for children operated around age 4. Based on these findings, the endpoints to consider when contemplating best age for surgery in an individual child with IE should be: (1) degree of binocular vision restored or retained, (2) postoperative angle and long-term stability of the angle and (3) number of operations needed or chance of spontaneous regression. IE is characterized by lack of binocular connections in the visual cortex that cannot develop, e.g. because the eyes squint, or do not develop, e.g. after perinatal hypoxia. As the cause of IE, whether motor or sensory, is a determinant of surgical outcome, a subdivision of IE according to cause is needed. As similarities exist between IE and cerebral palsy we propose to adapt the working definition formulated by the Surveillance of Cerebral Palsy in Europe and define IE as "a group of permanent, but not unchanging, disorders with strabismus and disability of fusional vergence and binocular vision, due to a nonprogressive interference, lesion, or maldevelopment of the immature brain, the orbit, the eyes, or its muscles, that can be differentiated according to location, extent, and timing of the period of development."

An automated Hirschberg test for infants

A novel automated method to measure eye misalignment in infants is presented. The method uses estimates of the Hirschberg ratio (HR) and angle Kappa (the angle between the visual and optical axis) for each infant to calculate the angle of eye misalignment. The HR and angle Kappa are estimated automatically from measurements of the direction of the optical axis and the coordinates of the center of the entrance pupil and corneal reflexes in each eye when infants look at a set of images that are presented sequentially on a computer monitor. The HR is determined by the slope of the line that describes the direction of the optical axis as a function of the distance between the center of the entrance pupil and the corneal reflexes. The peak of the distribution of possible angles Kappa during the image presentation determines the value of angle Kappa. Experiments with five infants showed that the 95% limits of agreement between repeated measurements of angle Kappa are ± 0.61 (°). The maximum error in the estimation of eye alignment in orthotropic infants was 0.9 (°) with 95% limits of agreement between repeated measurements of 0.75 (°).

Update on strabismus and amblyopia

This review analyzes progress in the field of infantile strabismus and amblyopia. Only works which are of clinical interest have been reviewed. A brief survey is provided also of subjects matter of international debate, as surgery for accommodative esotropia, the prism adaptation test and the use of sectors for amblyopia treatment. Mention is made of new developments in the field which are not yet applicable to clinical practice. Finally, progress in the approach towards ocular nystagmus is considered as well.

Intermittent esotropia

Not even half the number of the patients included in this study (N = 46) had been noticed as intermittent. Diplopia (N = 5) is not a reliable criterium. They need surgery with comparatively large amounts, on which behalf we prefer bi-medial rectus recessions. The prevailing result is "subnormal binocular vision," not to be confused with microtropia. Only four patients reached a cure, which means that they could not be differentiated from unaffected individuals any more.

Duration of binocular decorrelation in infancy predicts the severity of nasotemporal pursuit asymmetries in strabismic macaque monkeys

PURPOSE

Strabismus in human infants is linked strongly to nasotemporal asymmetries of smooth pursuit, but many features of this co-morbidity are unknown. The purpose of this study was to determine how the duration of early-onset strabismus (or timeliness of repair) affects the severity of pursuit asymmetries in a primate model.

METHODS

Binocular image decorrelation was imposed on infant macaques by fitting them with prism goggles on day 1 of life. The goggles were removed after 3 weeks (n=2), 12 weeks (n=2) or 24 weeks (n=3), emulating surgical repair of strabismus in humans at 3, 12, and 24 months of age, respectively. Two control monkeys wore plano lenses. Several months after the goggles were removed, horizontal smooth pursuit was recorded using binocular search coils and a nasal-bias index (NBI) was calculated.

RESULTS

Each animal in the 12- and 24-week groups developed a constant, alternating esotropic strabismus and a nasotemporal asymmetry of pursuit when viewing with either eye. Spatial vision was normal (no amblyopia). The 3-week duration monkeys were indistinguishable from control animals; they had normal eye alignment and symmetric pursuit. In the 12- and 24-week monkeys, the longer the duration of binocular decorrelation, the greater the pursuit asymmetry: for 15 degrees /s target motion, the NBI in the 12-week and 24-week animals was 16x and 22x greater respectively, than that in the 3-week animals (ANOVA, P=0.03).

CONCLUSIONS

Binocular decorrelation in primates during an early period of fusion development causes permanent smooth pursuit asymmetries when the duration exceeds the equivalent of 3 months in human. These findings support the conclusion that early correction of infantile strabismus promotes normal development of cerebral gaze pathways.

Why do the eyes cross? A review and discussion of the nature and origin of essential infantile esotropia, microstrabismus, accommodative esotropia, and acute comitant esotropia

PURPOSE

To try to explain the long-term stability of bilateral medial rectus botulinum toxin (botox) chemo-denervation in essential infantile esotropia; to evaluate divergent fusion amplitude in accommodative esotropia and acute comitant esotropia of emmetropes; to look for accommodation anomalies in high AC/A ratio accommodative esotropia and acute comitant esotropia of myopes; and to discuss characteristics of microstrabismus.

METHODS

Retrospective analysis of 61 essential infantile esotropia patients with early treatment with one botox injection in both medial rectus; measurement of divergent fusion amplitude in accommodative esotropia and acute comitant esotropia; measurement of Near point of accommodation in high AC/A ratio accommodative esotropia and acute comitant esotropia of myopes.

RESULTS

Stable results were found in 85.24% of essential infantile esotropia treated patients; reduced divergent fusion amplitude was detected in accommodative esotropia and acute comitant esotropia; hypo-accommodation was found in some patients with high AC/A ratio accommodative esotropia and a convergence spasm in acute comitant esotropia of myopes.

CONCLUSIONS

Very early botox treatment probably eradicates the effect of an excessive convergence tonus in essential infantile esotropia. A prevention of accommodative esotropia with full retinoscopic correction is only mandatory with a significantly reduced amplitude of fusional divergence. A deficit in accommodation should be looked for in high AC/A ratio accommodative esotropia, before bifocal lenses prescription. Early diagnosed acute comitant esotropia of myopic patients can be treated as a convergence spasm. Only surgery treats acute comitant esotropia, in patients with emmetropia or moderate hypermetropia.

Accommodative esotropia following surgical treatment of infantile esotropia: frequency and risk factors

PURPOSE

We aimed to examine the frequency of and risk factors for the development of accommodative esotropia following surgical treatment for infantile esotropia.

METHODS

A total of 29 children were recruited. Potential risk factors for the development of accommodative esotropia included: sex; angle of deviation at initial and final visits; cycloplegic refractive error at initial and final visits; increase in hyperopia; amblyopia; amblyopia treatment; age at surgical treatment; pre- and postoperative latent nystagmus; dissociated vertical deviation or inferior oblique muscle overaction; additional surgical procedures; unstable alignment, and binocular sensory status.

RESULTS

Overall, 14 (48.2%) of 29 children developed accommodative esotropia during the 36- to 132-month postoperative follow-up period. Twelve (85.7%) of the 14 patients developed refractive accommodative esotropia and two developed non-refractive accommodative esotropia. The onset of accommodative esotropia occurred at a mean of 8.8 months (range 6-24 months) after the initial surgical alignment. This corresponded to a mean age of onset for accommodative esotropia of 43.2 months. We determined that, among children with infantile esotropia, those who had hyperopia of > or = 3.0 D and increasing hyperopia after surgery and those who did not develop dissociated vertical deviation during the follow-up period were more likely to develop accommodative esotropia.

CONCLUSIONS

Children who have the established risk factors should be followed closely for the development of accommodative esotropia. The treatment of these children with appropriate glasses may prevent the development of adverse effects of accommodative esotropia on sensory and motor functions.

Effect of preoperative stability of alignment on outcome of strabismus surgery for infantile esotropia

INTRODUCTION

Some strabismus surgeons wait until the angle of deviation stabilizes prior to operating on patients with infantile esotropia. This study evaluated whether a preoperative increase in the angle of deviation affected surgical outcomes.

METHODS

This was a retrospective comparative case series in which records of patients with infantile esotropia, who had surgery performed before age 2 years and who were followed for at least 2 years postoperatively, were reviewed to identify two groups for comparison: the first had </=5(Delta) change in the angle of deviation between the first office visit and time of surgery; the second had a >/=10(Delta) increase in the angle of deviation prior to surgery. In the latter group, surgery was performed for the angle present at the time of surgery. Outcomes were considered successful if the patients had microtropias.

RESULTS

Fifteen patients were identified in each group. The interval between the first office visit and time of surgery was the same in both groups (mean, 2 months). Outcomes were successful in 11 of 15 (73%) in each group (no significant difference, p = 0.659).

CONCLUSIONS

There was no difference in outcome between children whose angles of deviation were stable and those whose angles increased prior to surgery. This indicates that strabismus surgery does not need to be delayed while waiting for the angle of deviation to stabilize. Surgical correction may therefore be achieved at an earlier age, which may have a beneficial effect on outcome.

Changes in the functional binocular status of older children and adults with previously untreated infantile esotropia following late surgical realignment

BACKGROUND

Most studies of infantile esotropia concern patients diagnosed in infancy and treated throughout childhood. This prospective study addresses changes in the functional binocular status of older children and adults with previously untreated infantile esotropia, following late surgical realignment.

SUBJECTS AND METHODS

Seventeen patients aged 8 years or more with a history of untreated esotropia occurring within the first 6 months of life were included in this study. All had monocular optokinetic asymmetry, a visual acuity of 20/30 or better in the worse eye, and binocular function assesment preoperatively and postoperatively. All were surgically aligned within 8(Delta) of orthotropia. None had neurologic disease.

RESULTS

Preoperatively, all 17 patients demonstrated a monocular response to Bagolini lenses, while postoperatively 15 (88%) of the 17 demonstrated binocular function with Bagolini lenses (in that they could constantly perceive the major part of both arms of the X generated by the Bagolini lenses) and 13/17 (76%) demonstrated an increase in the binocular field. All 17 had no sensory fusion, either preoperatively or postoperatively, when tested with the Worth 4-Dot test or synoptophore, and no stereopsis with the Titmus stereo test.

CONCLUSIONS

Older children and adults with previously untreated infantile esotropia derive some functional benefits following late surgical realignment. The degree of binocular function may be lower than that achieved in patients aligned before 24 months of age.

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

BACKGROUND

The optimal age for surgery for infantile esotropia is controversial. Proponents of early surgery believe that further loss of binocular vision can be prevented by early surgery, a minority believes that binocular vision can even be restored by early surgery. The ELISSS compared early with late surgery in a prospective, controlled, non-randomized, multicenter trial.

METHODS

Fifty-eight clinics recruited children aged 6-18 months for the study. Each clinic operated all eligible children either 'early', i.e. at age 6-24 months, or 'late', i.e. at age 32-60 months. At baseline the angle of strabismus, refraction, degree of amblyopia and limitation of abduction were assessed. Intermediate examinations took place every six months. Children were evaluated at age six in the presence of independent observers. Primary endpoints were (i) level of binocular vision, (ii) manifest angle of strabismus at distance and (iii) remaining amblyopia. Secondary endpoints were number of operations, vertical strabismus, angle at near and the influence of surgical technique.

RESULTS

A total of 231 children were recruited for early and 301 for late surgery. Age at entry examination was 11.1 months (SD 3.7 months) in the early group and 10.9 (SD 3.7) months in the late group. Refraction, amblyopia and limitation of abduction were distributed equally in the early and late groups, but the angle of strabismus was slightly larger in the early group. Dropout-rates were 26.0% in the early and 22.3% in the late group. At age six, 13.5% of the early vs. 3.9% of the late group recognized the Titmus Housefly; 3.0% of the early and 3.9% of the late group had stereopsis beyond Titmus Housefly. No significant difference was found for angle of strabismus. 35.1% of the early group and 34.8% of the late group did not have an angle between 0 degrees and 10 degrees , the thresholds set for re-operation. For ratio of the visual acuities (remaining amblyopia) there was a small but significant advantage for the early group. There was hardly any correlation between the baseline parameters and the primary endpoints. Children scheduled for early surgery had first been operated at 20 (SD 8.4) months, but 8.2% had not been operated at age six. Children scheduled for late surgery had been operated at 49.1 (SD 12.7) months, but 20.1% had not been operated at age six. The number of operations per child was 1.18 (SD 0.67) in the early and 0.99 (SD 0.64) in the late group. Age at recruitment, age that strabismus reportedly had started and refraction at entry examination were similar among operated and non-operated children. Only the angle of strabismus at entry predicted, to some extent, whether a child had been operated at age six.

DISCUSSION

Children operated early had better gross stereopsis at age six as compared to children operated late. They had been operated more frequently, however, and a substantial number of children in both groups had not been operated at all.

Can ophthalmologists repair the brain in infantile esotropia? Early surgery, stereopsis, monofixation syndrome, and the legacy of Marshall Parks

Can ophthalmologists repair defects of visual cortex circuitry in infants who have esotropia? The answer to this question encompasses both sensory and motor behaviors because the clinical hallmarks of the disorder are stereoblindness and absence of motor fusion, which manifests as convergently deviated eyes. Functional recovery of sensory and motor fusion in infantile esotropia was a consuming interest, if not career-defining passion, of Marshall Parks. The purpose of this work is to pay tribute to Parks' legacy by showing how human and animal studies, conducted largely during the last 25 years, support both his clinical insights and treatment philosophy.