Infantile exotropia

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

PURPOSE

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

METHODS

The medical records of patients who had undergone unilateral lateral rectus recession-medial rectus resection for infantile constant exotropia who were followed up postoperatively for a minimum of 4 years were reviewed retrospectively.

RESULTS

A total of 20 patients were included. The mean age at surgery was 3.21 ± 1.54 years (range: 1.25 to 6.00 years). The mean duration of exodeviation was 2.99 ± 1.61 years (range: 9 months to 6 years). The mean angle of exodeviation was 70.1 ± 20.9 prism diopters (PD) (range: 35 to 90 PD). The median postoperative follow-up was 9.1 years (range: 4 to 24 years). Overall, 12 patients (60%) had surgical success at their last follow-up visit. Age at first surgery, cycloplegic refraction, strabismus duration, preoperative angle of deviation, presence of amblyopia, and the number of exotropia surgeries did not predict motor outcome after surgery. At the last follow-up visit, 20% of patients had residual exotropia and 15% had recurrent exotropia. Peripheral binocular single vision was achieved in 25% of patients and stereopsis in none. Age at first surgery, strabismus duration, and surgical outcome had no effect on sensory outcome.

CONCLUSIONS

In this study, 60% of patients achieved a successful long-term motor outcome and 25% achieved peripheral binocular single vision after unilateral recession-resection for infantile constant exotropia. Stereopsis outcome was nil. Age at surgery and duration of strabismus had no effect on motor and sensory outcomes. [J Pediatr Ophthalmol Strabismus. 20XX;XX(X):XXX-XXX.].

Effects of Bilateral Medial Rectus Resection on Motor Outcomes in Infantile Exotropia

Purpose

To evaluate the effects of bilateral medial rectus resection (BMRres) on motor outcomes in infantile exotropia.

Methods

We evaluated 19 cases of infantile exotropia surgery. The mean age at surgical alignment was 4.8±3.4 years (range, 1.5–11.8 years). The surgical procedures included BMRres (5 cases), BMRres with unilateral lateral rectus recession (ULRR) (3 cases), bilateral lateral rectus recession (BLRR) (8 cases), unilateral lateral rectus recession and medial rectus resection (uniRandR) with contralateral lateral rectus recession (2 cases), and uniRandR (1 case). After dividing the cases into two groups (BMRres group, n=8; other group, n=11), the outcomes at 1 day and at 1, 3, and 6 months after surgery were compared. Surgical outcomes were defined as (1) success: distant esotropia ≤5 prism diopters (^Δ) or exotropia ≤10^Δ, (2) recurrence: exotropia >10^Δ, or (3) overcorrection: esotropia >5^Δ.

Results

Although postoperative distant deviations at 1 day were not different between the two groups, the BMRres group showed smaller distant deviations at 1, 3, and 6 months than the other group (p=0.015, 0.019, and 0.006, respectively). Success rates of the BMRres and other groups were 88% and 73% at 1 day, 100% and 36% at 1 month, 88% and 27% at 3 months, 88% and 18% at 6 months, respectively. Although there were no significant differences between the two groups within 3 months after surgery, surgical outcomes in the BMRres group 6 months after surgery were significantly better than those in the other group (p=0.003).

Conclusion

BMRres is a better procedure than others for infantile exotropia to achieve desirable motor outcomes after surgery.

Abnormal biorbital angle in children with infantile exotropia

PURPOSE

The causative factors of infantile exotropia are unknown. The purpose of this study was to investigate the relationships between the biorbital angle and the pathogenesis of infantile exotropia.

STUDY DESIGN

Retrospective.

METHODS

Of all patients diagnosed as infantile exotropia with onset prior to 12 months of age between 2010 and 2017, 31 patients without any neurological disorders or developmental delay were identified. The angle between both lateral walls of the orbit, defined as the biorbital angle, was measured in the horizontal plane at the optic nerve and where the horizontal extraocular muscles appeared on axial magnetic resonance imaging (MRI) or computed tomography (CT) of the orbit. These patients' data were compared with those of 129 ophthalmologically normal children. All subjects of this study were Japanese.

RESULTS

The mean biorbital angle was significantly larger in patients with infantile exotropia than in the normal children (106.6 ± 5.7° vs 94.2 ± 5.1°, p < 0.001). Of the patients with infantile exotropia, 21 (68%) had an angle outside the 95% confidence interval calculated in normal children. All cases were divided into a constant (15 cases) and intermittent (16 cases) group; there was no significant difference between them in the mean biorbital angles (107.9 ± 5.6° vs 105.4 ± 5.8°, p = 0.224). No correlations were identified between the biorbital angle and the angle of exodeviation, either distant or near.

CONCLUSIONS

Children with infantile exotropia have a larger biorbital angle. This anatomical abnormality may be an associate factor of infantile exotropia.

Infantile Exotropia and Developmental Delay

PURPOSE

To evaluate a group of infants with this disorder to determine the long-term outcome of surgery and to assess the need for neurologic evaluations.

METHODS

This interventional case series reviewed the records of infants who underwent surgery for the treatment of exotropia with onset during the first year of life. The preoperative ophthalmic and systemic findings, treatment, and developmental and ophthalmic outcomes were reviewed. Surgery was considered successful if the horizontal deviation was less than 10 prism diopters (PD). Developmental assessments were obtained at each visit.

RESULTS

Twenty-six patients presented between age 2 and 10 months with exotropia ranging from 20 to 95 PD. Ten (38%) patients had a developmental delay that was recognized at the first visit, 9 of whom had a systemic diagnosis at that time; the other patients remained developmentally normal during a mean follow-up of 7 years. Age at surgery ranged from 4 to 18 months. Surgery was successful in 10 (38%) of 26 patients after 1 surgery and in an additional 13 (50%) of 26 patients after a second surgery.

CONCLUSIONS

In this study, the need for more than 1 surgery was higher in infantile exotropia when compared to other forms of childhood strabismus, but most children achieved good alignment with one or two surgeries. Developmental delay is common in patients with infantile exotropia, but this was usually recognized at the time of the initial evaluation. In the current patients, routine neurologic screening or imaging of these otherwise developmentally normal infants was not required. [J Pediatr Ophthalmol Strabismus. 2018;55(4):225-228.].

The clinical effect of surgical timing in infantile exotropia

PURPOSE

To review the association of postoperative ocular alignment, sensory outcomes, and need for reoperation after surgical management of infantile exotropia.

METHODS

The clinical records of patients who presented with constant infantile exotropia of >25^Δ and subsequently underwent strabismus surgery at a single center from 2004 to 2014 were reviewed retrospectively. Postoperative binocular sensory status was assessed using Worth 4-Dot and Titmus stereoacuity tests. Patients with postoperative exotropia of >10^Δ or esotropia of >5^Δ were advised to undergo additional surgery.

RESULTS

A total of 49 cases were included (28 boys; age at diagnosis, 1-12 months). The patients who underwent reoperation were younger at the time of first surgery (mean age, 13.15 ±1.68 vs 18.58 ± 0.92 months [P = 0.005]). Patients who developed consecutive esotropia were younger at the time of initial operation (P = 0.039). Among 20 patients who were testable for sensory outcome assessment, only 4 patients developed stereopsis, whereas 15 patients achieved bifixation by Worth 4-Dot test. All of the 4 patients with measurable postoperative stereoacuity had initial surgery after 1 year of age.

CONCLUSIONS

In this patient cohort, earlier surgery did not necessarily lead to better sensory outcomes, and reoperation was associated with younger age at time of first surgery.

Early versus late surgery for infantile exotropia

PURPOSE

To determine whether age at surgery influences postoperative outcome in infantile exotropia.

METHODS

This longitudinal, retrospective study included children who underwent bilateral lateral rectus recession between 2004 and 2012 for an exotropia with onset by 12 months of age. Surgical outcomes were considered failures if recurrence with exodeviation of >8^Δ or overcorrection with esodeviation of >5^Δ developed during postoperative period. Univariate and multivariate analyses were conducted to compare the association of age at surgery with development of recurrence and overcorrection.

RESULTS

A total of 93 children were included. Mean age at surgery was 3.2 years. At a mean follow-up of 3.6 years, 19 of 93 patients (20.4%) experienced recurrence and 3 (3.2%) had overcorrection. In the multivariate analyses, increased age at surgery was associated with higher risk for recurrence (OR = 1.031 per 1-month; 95% CI, 1.003-1.060). In subgroup analyses, the association was significant only in the constant exotropia group (OR = 1.410; 95% CI, 1.037-1.917) and not in the intermittent exotropia group (OR = 0.995; 95% CI, 0.938-1.056). In both groups, overcorrection was not associated with any factors, including age at surgery.

CONCLUSIONS

Older age at surgery was associated with risk of recurrence in infantile exotropia with constant deviation, but it was not correlated with surgical outcomes for patients with intermittent exotropia in this study.

Clinical Features and Surgical Outcome of Triad Exotropia

PURPOSE

To describe the clinical features and surgical outcome of A-pattern exotropia combined with dissociated vertical deviation and superior oblique overaction.

METHODS

The medical records of patients with A-pattern exotropia combined with dissociated vertical deviation and superior oblique overaction who underwent horizontal muscle surgery alone or in combination with superior oblique muscle weakening surgery were retrospectively reviewed. The patients were divided into two groups according to their surgery: the horizontal muscle surgery alone group and the horizontal muscle surgery with bilateral superior oblique weakening surgery (combined surgery) group. The preoperative clinical features and postoperative surgical outcomes at the patients' final follow-up visits were analyzed.

RESULTS

A total of 40 patients were included. The mean age at diagnosis was 5.5 ± 4.6 years. Amblyopia and latent nystagmus were observed in 18 (45%) and 10 (25%) patients, respectively. Six (15%) patients were associated with delayed development and hemiplegia. The mean angle of exodeviation was 27.7 ± 11.2 and 28.5 ± 10.9 prism diopters (PD) for distance and near, respectively. The mean degree of superior oblique overaction was 1.9 ± 1.1 and asymmetrical dissociated vertical deviation was observed in 24 (60%) patients. At the final follow-up visit, the horizontal angle of deviation was not significantly different between the groups. The success rates were 57.1% and 80% in the horizontal muscle surgery alone and combined surgery groups, respectively. These differences were statistically significant (P = .04).

CONCLUSION

Amblyopia was common and the prognosis of binocularity was poor in triad exotropia. Some patients had neurological deficits. The surgical success rate in this study was variable, ranging from 57.1% to 80%. [J Pediatr Ophthalmol Strabismus. 2017;54(6):363-368.].

Strabismus-associated myopia. Review

INTRODUCTION

The treatment of strabismus associated with myopia is often a therapeutic challenge for the ophthalmologist. The strabismus associated with myopia has certain peculiarities and there are even certain types of strabismus that occur exclusively in myopia, such as strabismus fixus, requiring treatments with specific surgical techniques.

MATERIALS AND METHODS

It is important to make a correct differential diagnosis, because there are many conditions described with this association. A review is presented of strabismus associated with myopia, together with its treatment adjusted to refractive error.

RESULTS

Measurements of strabismus may be altered by the prismatic effect of the spectacles. Surgical results may be unpredictable if myopia is not taken into account. Better results were obtained with the techniques of anatomical replacement described by Yokoyama than with traditional retro-insertion-resection.

CONCLUSION

For the diagnosis and appropriate treatment of strabismus, it is important to make a correct measurement of the angle of deviation, and perform image tests prior to surgery in certain cases. The anatomical characteristics of the myopic eye should also be taken into account during surgery.

The Effect of Preoperative Occlusion Therapy on Long-term Outcome after Surgery for Early-onset Exotropia

PURPOSE

To investigate the effect of preoperative part-time occlusion therapy on long-term surgical success in early-onset exotropia.

METHODS

The medical records of patients who underwent surgery for exotropia with onset before the first year of age and who were followed for ≥3 years were reviewed. Patients were divided into two groups according to the degree of compliance with part-time occlusion therapy: the good compliance group (>50% adherence rate) and the poor compliance group (≤50% adherence rate). Surgical success was defined as orthophoria to exodeviation less than 10 prism diopters both at distance and near. The level of postoperative stereopsis was compared between the two study groups among total enrolled patients and among those with constant exotropia.

RESULTS

Of the 51 patients, 26 were assigned to the good compliance group and the remaining 25 patients to the poor compliance group. The surgical success rate was significantly higher in the good compliance group than in the poor compliance group (80.8% vs. 52.0%, p = 0.040). Among 24 constant exotropia patients (12 patients for each group), the success rate was insignificantly higher in the good compliance group than in the poor compliance group (75.0% vs. 58.3%, p = 0.448). The good compliance group had a better level of stereopsis than the poor compliance group (p = 0.045 for all 44 patients, p = 0.020 for 19 patients with constant exotropia).

CONCLUSIONS

Preoperative part-time occlusion therapy was useful for improving the surgical outcome of early-onset exotropia and postoperative stereopsis.

The Incidence of Reoperation and Related Risk Factors Among Patients With Infantile Exotropia

PURPOSE

To determine the incidence and related risk factors of reoperation among patients with infantile exotropia who were operated on at Imam Hossein Medical Center, Tehran, Iran, from 2001 to 2015.

METHODS

In this study, 82 children (55 girls and 27 boys) with infantile exotropia were divided into two groups 3 months after their first operation: children with horizontal deviation of 10 prism diopters (PD) or less (n = 64; success group) and those with horizontal deviation greater than 10 PD (n = 18; failure group). Patients with deviation of 20 PD or greater were indicated for reoperation. Factors including age at the first operation, preoperative angle of deviation, inferior oblique muscle overaction, dissociated vertical deviation, and A- or V-pattern in relation to reoperation were studied. Sensory status of children older than 5 years was also evaluated using Worth 4-dot and Titmus tests.

RESULTS

Reoperation was indicated in 18.3% (n = 15) of patients after 11.5 ± 19 months of follow-up. Preoperative angle of deviation (P < .001) and surgical approach (P = .017) were statistically different between the failure and success groups. The majority of patients (71%) achieved fusion and gross stereopsis (< 3,000 seconds of arc) after surgery.

CONCLUSIONS

According to the results, 18.3% of patients with infantile exotropia, especially those with more preoperative exotropia, needed reoperation to achieve good alignment. Although the recession-resection method had better motor results, the authors could not recommend it as a first operation for all patients with infantile exotropia because it was only performed on patients with amblyopia. Gross stereopsis and binocular fusion were seen in the majority of patients. [J Pediatr Ophthalmol Strabismus. 2017;54(1):22-30.].

Comparison of Clinical Features and Long-term Surgical Outcomes in Infantile Constant and Intermittent Exotropia

PURPOSE

To evaluate the long-term surgical outcomes and the clinical features between infantile-onset constant and intermittent exotropia.

METHODS

The medical records of 67 patients diagnosed as having infantile exotropia before 12 months of age who underwent surgery were reviewed retrospectively. Patients were divided into intermittent exotropia and constant exotropia groups based on presentation before surgery. All patients underwent bilateral lateral rectus recession. Preoperative and postoperative clinical features were investigated.

RESULTS

There were 37 children in the intermittent exotropia group and 30 children in the constant exotropia group. The cumulative probabilities of success 3 years after bilateral lateral rectus recession were 91.9% in the intermittent exotropia group and 70% in the constant exotropia group. Constant deviation was more closely associated with both dissociated vertical deviation (DVD) and inferior oblique muscle overaction (IOOA) (P = .009 and P = .009, respectively) and related to poor stereopsis outcome (P = .002) and distance suppression (P = .029).

CONCLUSIONS

Constant deviation was associated with the development of recurrence, DVD/IOOA, and poor stereopsis after surgery. Constancy of exotropia is a reliable factor for predicting poor surgical outcomes in infantile exotropia at long-term follow-up.

Optimal surgical timing in infantile exotropia

OBJECTIVE

To evaluate age at surgery and duration of misalignment, which affect surgical outcomes of infantile exotropia in healthy children younger than 1 year.

METHODS

The charts of 39 patients who have at least 1 year of follow-up period after surgery with a diagnosis of early-onset exotropia were reviewed retrospectively. Patients were divided into 2 groups (preoperative deviation [PD]): success (exodeviation ≤8 PD or esodeviation ≤5 PD at 1 year postoperatively without reoperation in the whole follow-up period) or failure (exodeviation >8 PD or esodeviation >5 PD at 1 year postoperatively, or reoperation for recurrence or overcorrection during the follow-up period). We evaluated the age at surgery and the duration of misalignment divided into 5 categories-before 6, 12, 18, 24, and 30 months-to suggest appropriate surgical timing affecting surgical outcome and compared between the 2 groups.

RESULTS

Overall, 74% of the patients comprised the success group and 26% the failure group. There was no statistically significant difference in the age of alignment between 2 groups (p = 0.91). The mean duration of misalignment was 16.7 months in the success group and 20.1 months in the failure group, with no significant difference (p = 0.52). There were 4 patients (14%) with a misalignment duration of ≥24 months in the success group and 5 such patients (50%) in the failure group; the difference was statistically significant (p = 0.024). Therefore, with a duration of misalignment of up to 24 months as the reference level, the odds of having a successful outcome decreased significantly over 24 months, with the multiple logistic regression model yielding a risk estimate over 6-fold of failure (odds ratio 6.25; p = 0.024).

CONCLUSIONS

The postoperative surgical outcome was influenced by the duration of the misalignment, rather than the age at surgery. Surgery within 24 months of misalignment favourably affected the percentage of patients who achieved successful outcome in the treatment of infantile exotropia.

Traditional and reduced recession surgical dosage for bilateral lateral rectus recession for infantile exotropia

BACKGROUND

To investigate the optimal surgical dose for treating infantile exotropia.

METHODS

In this retrospective study, clinical records of 44 children who had undergone bilateral lateral rectus recessions before 4 years of age for an exotropia present before 12 months of age were studied. Children had 1 year of follow-up after surgery. Patients were separated into those who had traditional surgery and those who received a reduced recession of their lateral recti.

RESULTS

The traditional surgery group comprised 36% of the patients and the reduced recession group, 1-2 mm reduction in the recession, comprised 64% of the study group. There was borderline significance (p=0.074) when the postoperative angle of deviation was compared in the early postoperative period. The traditional group had a mean deviation of 5.25 prism dioptres (PD) of esodeviation compared with the reduced recession group having a 2.91 esodeviation. There was no statistical difference at the 1-year evaluation of the alignment. The traditional group had a mean exodeviation of 2.63 PD compared with the reduced recession group having a 2.91 PD exodeviation.

CONCLUSIONS

Postoperative surgical outcome was not affected by a reduction in the amount of recession by 1-2 mm from traditional tables used for treatment of exotropia. Reducing the recession of the lateral recti reduces the risk of overcorrection in this sensory labile population.

Modified inferior oblique transposition considering the equator for primary inferior oblique overaction (IOOA) associated with dissociated vertical deviation (DVD)

PURPOSE

Inferior oblique anterior transposition (IOAT) should be done only in patients with inferior oblique overaction (IOOA) and dissociated vertical deviation (DVD) without fusional potential because the procedure can cause anti-elevation syndrome. This study reports the results of modified inferior oblique transposition onto the equator in 7 patients diagnosed with infantile exotropia or esotropia associated with IOOA and DVD.

METHODS

We performed modified inferior oblique (IO) transposition onto or considering the equator on 7 patients who had infantile exotropia or esotropia associated with IOOA and DVD. Five patients had infantile exotropia, and the other two patients had infantile esotropia. Six patients had undergone bilateral rectus--Bilateral Lateral Rectus (BLR) or Bilateral Medial Rectus (BMR)--recession previously and one patient underwent BLR recession and IO transposition simultaneously. They had more than +1.5 IOOA with DVD in both eyes. IO was transposed vertically onto the equator in this study. The mean distance between the lateral border of the inferior rectus insertion and the equator was 5.6 mm (range: 4.5 to 6.5 mm). Three months after the operation, degree of IOOA and DVD in each eye was evaluated.

RESULTS

IOOA and DVD were markedly reduced in all patients (+0.5 ∼+1 for IOOA postoperatively). Mild contralateral IOOA was noted but the motility disturbance was successfully corrected in all cases postoperatively.

CONCLUSION

Bilateral IO transposition onto the equator could minimize antielevation and corrected IOOA and DVD successfully in patients with infantile exotropia or esotropia.

Outcomes of surgery in children with early-onset exotropia

OBJECTIVE

To evaluate the clinical characteristics and surgical outcomes of early-onset exotropia and to compare differences between constant and intermittent exotropia at presentation.

METHODS

The medical records of 45 exotropia patients with a reported onset before 1 year of age who were operated on between 2008 and 2011 were reviewed, and the clinical characteristics and surgical outcomes of these patients were analyzed retrospectively. Patients were then divided into two groups according to type of exotropia at presentation: a constant (XT) group and an intermittent (X(T)) group. Clinical features and surgical results of exotropia were then compared between these two groups.

RESULTS

The mean age of onset of exodeviation in 45 patients was 9.3±3.8 months. Mean age at surgery was 4.5±2.4 years, and the mean postoperative follow-up period was 17.3 months (range, 6-37 months). Of the 45 patients, 67% showed alignment of less than±10 prism diopters (PD) at final visit. Gross stereopsis was achieved in all 34 testable patients, and bifixation developed in 10 patients (29%). Eleven patients were included in XT group and 34 patients in X(T) group. No significant intergroup difference was found between surgical success rates and binocularities.

CONCLUSION

Surgical outcomes, both motor and sensory, were not poor in early-onset exotropia patients, even in patients with constant deviation. Good binocular results following surgery can be achieved in children presenting with apparently constant early-onset exotropia.

Cerebral Palsy for the Pediatric Eye Care Team Part II: Diagnosis and Treatment of Ocular Motor Deficits

INTRODUCTION

Cerebral palsy is a term used to describe a spectrum of neurological deficits resulting from damage to the developing nervous system. This paper, the second in a series of three articles, will present frequency, diagnosis, and management of the ocular motor deficits associated with CP. Topics for discussion will include the prevalence and type of strabismus, the effect of CP on eye movement systems, the efficacy of vision therapy for eye movement deficits, and strabismus surgery.

METHODS

In 2002, a retrospective chart review of all cases of cerebral palsy referred to the St. Louis Children's Hospital Eye Center was done. Detailed data on the sensory and motor deficits documented in these children was collected. Also recorded was the management strategy and response to treatment.

RESULTS

Of the 131 cases reviewed (mean age 5.2 years at presentation), 84 (64%) had strabismus: 55% esotropia and 27% exotropia. Of those patients tested for eye movement disorders 67 (61%) had evidence of instability of fixation; 85% of the patients had a pursuit deficit; and 80% had some type of deficit in performing saccades. Vergence was affected in 45% of our patients. Of the patients who underwent strabismus surgery, 67% achieved success after a mean number of 2.1 surgeries. Surgical success was associated with mild or moderate CP (P <.0005), and a stable preoperative angle. Six percent of our patients underwent vision therapy for strabismus or eye movement anomalies under the direction of an outside optometrist.

CONCLUSION

Infantile strabismus is significantly more common in children with CP than in the general pediatric population. Disorders of eye movements are also very common. Based on our experience and review of the literature there is no convincing evidence that vision therapy significantly improves eye movements or visual functioning. Approximately 2 of every 3 cases of nonaccommodative strabismus associated with CP can be successfully managed with conventional strabismus surgery, though most children will require at least two surgeries to achieve alignment.

Comparison of clinical features between two different types of exotropia before 12 months of age based on stereopsis outcome

PURPOSE

To compare the clinical outcomes and characteristics of 2 different types of early-onset exotropia on the basis of stereopsis outcome.

DESIGN

Retrospective case series.

PARTICIPANTS

A total of 24 patients with newly diagnosed exotropia before 12 months of age and at least 1 year of follow-up after surgery.

METHODS

The clinical records of all patients were reviewed. Patients were divided into 2 groups according to stereopsis. The presumable early-onset intermittent exotropia (EIE) group was composed of 6 patients (25%) who showed excellent stereopsis of ≥60 arc seconds. The primary infantile exotropia (PIE) group was composed of 18 patients (75%) who showed stereopsis of ≤100 arc seconds. We compared the preoperative and postoperative clinical features of the 2 groups.

MAIN OUTCOME MEASURES

The age at onset and visit, age at surgery, constancy before surgery, preoperative and postoperative angles of deviation, distant suppression, reoperation rate, and presence of dissociative vertical deviation (DVD) and inferior oblique overaction (IOOA).

RESULTS

The age at the stereopsis test was 6.8 years in the EIE group and 6.4 years in the PIE group (P=0.41). There was no statistical difference in the mean preoperative exodeviation (32.8 prism diopters [PD] in the EIE group vs. 34.7 PD in the PIE group, P=0.58) and postoperative deviation at the stereopsis test (1.0 PD in the EIE group vs. 2.0 PD in the PIE group, P=0.97). The reoperation rate was 33% in the EIE group and 27% in the PIE group (P=1.00). There was no statistical difference in constancy between the EIE and PIE groups (33% vs. 56%, respectively, P=0.64). However, DVD (61%) and IOOA (56%) were noted only in the PIE group (P=0.016, P=0.024, respectively), and distant suppression was noted only in the PIE group (61%, P=0.016).

CONCLUSIONS

The results indicate that excellent sensory outcome was observed in only 25% of patients with exotropia before 12 months of age, but motor outcome and reoperation rate were not different between the 2 types of exotropia. We observed DVD, IOOA, and distant suppression only in the PIE group.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Long-term ocular alignment after bilateral lateral rectus recession in children with infantile and intermittent exotropia

PURPOSE

To compare postoperative drift after bilateral lateral rectus recession for infantile exotropia (XT) and for intermittent XT and to compare initial postoperative alignment with long-term motor outcome.

METHODS

Medical records of all patients with infantile exotropia or intermittent exotropia who had undergone bilateral lateral rectus muscle recession surgery with a follow-up longer than 3 years were reviewed. The pre- and postoperative angles of deviation at distance and at near and postoperative drift at distance were compared. Surgical outcome was categorized as "success" (esotropia <6(Δ) or exotropia <11(Δ)), "recurrence" (>10(Δ) exotropia), or "overcorrection" (>5(Δ) of esotropia).

RESULTS

The overall mean postoperative exotropic drift at 3 years was 10.4(Δ) in the infantile XT group and 7.2(Δ) in the intermittent XT group (P = 0.05). Both groups had a low success rate at 3 years: 41% in the infantile XT group and 51% in the intermittent XT group (P = 0.270). For patients with an initial esotropia of 0(Δ) to 10(Δ), the success rate at 3 years was 86% in the infantile XT group (12 of 14) and 65% in the intermittent XT group (28 of 43).

CONCLUSIONS

Postoperative exotropic drift is clinically similar in patients with intermittent versus infantile exotropia. Esotropia of 0(Δ) to 10(Δ) during the early postoperative period may be associated with the best long-term ocular alignment.

The tendon width of lateral rectus muscle in predicting the effect of recession: is it just age-related artifact?

PURPOSE

The tendon width of the lateral rectus muscle is known to be a useful indicator for estimation of the effect of lateral rectus recession in intermittent exotropia. This study was conducted to investigate whether the tendon width of the lateral rectus would differ according to different age groups.

PATIENTS AND METHODS

We studied 133 patients ranging from 0 to 51 years of age who had undergone bilateral lateral rectus (BLR) recession for the basic type of intermittent exotropia. A total of 133 patients were divided into four groups; 16 patients who were younger than 2 years old (group 1), 20 patients who were 2-5 years old (group 2), 75 patients who were 5-13 years old (group 3), and 22 patients who were older than 13 years (group 4). Under general anesthesia and before dissection of the muscle tendon from the sclera, the tendon width of the lateral rectus of both eyes near insertion was measured with calipers.

RESULTS

The tendon width of each group was as follows: in group 1, 7.84 ± 0.35 mm in the right eye and 7.66 ± 0.44 mm in the left eye; in group 2, 7.70 ± 0.50 mm and 7.65 ± 0.52; in group 3 8.11 ± 0.36, 7.95 ± 0.48. In group 4, measurements were 8.14 ± 0.49 mm and 8.05 ± 0.38 mm, respectively. The difference of tendon width in both eyes was statistically significant in all four groups (P<0.01) and the tendon widths of group 1 and 2 were narrower than that of group 3 and 4.

CONCLUSION

Measurement of tendon width of the lateral rectus muscle for prediction of the effect in intermittent exotropia should be applied in patients ≥ 5 years of age.

Clinical features and the risk factors of infantile exotropia recurrence

PURPOSE

To evaluate the clinical features and the risk factors of recurrence in infantile exotropia.

DESIGN

Retrospective, observational case series.

METHODS

The clinical records of 20 infantile exotropia patients who underwent exotropia surgery were reviewed retrospectively. Patients were divided into 2 groups according to the amount of exodeviation present at 1 year after surgery. Preoperative patient characteristics and postoperative alignments were evaluated at 1 day and 1, 3, 6, and 12 months after surgery.

RESULTS

The successful group was composed of 12 patients with an alignment of less than 10 prism diopters (PD) of exodeviation, and the recurrent group was composed of 8 patients with an alignment of 10 PD or more of exodeviation (range, 10 to 18 PD) at 1 year after surgery. The incidences of dissociated vertical deviation, inferior oblique overaction, and rates of constancy before operation were not significantly different in the 2 groups (P = .603, P = .158, and P = .347, respectively), and postoperative deviations were not significantly different at 1 day after surgery. However, postoperative deviations were significantly different in the 2 groups at 1 month (P = .069) and 3 months (P < .001) after surgery, and this difference was maintained at 12 months after surgery. Furthermore, correlation between initial alignments at 1 month after surgery and final alignments was significant in successful group (P = .012).

CONCLUSIONS

No single factor affecting the surgical outcome was identified in infantile exotropia, but the recurrence of infantile exotropia was apparent from the first postoperative month.

Timing of Surgery for Primary Exotropia in Children

OBJECTIVE

To compare postoperative alignment and sensory functions in children with primary exotropia who were operated at an early age (< 7 years) with patients who were operated at an older age (> 7 years).

METHODS

In a consecutive retrospective cohort study, 112 patients who had a surgical intervention for primary exotropia between 1997 and 2003 were evaluated for postoperative results. After applying criteria for eligibility, the group of patients was divided into two groups: those who had surgical intervention before the age of seven years (n = 24) and those who had surgery after the age of seven years (n = 36). Age at surgery, preoperative alignment and sensory functions were correlated with the postoperative status. The follow-up was at least one year (1.0 year to 7 years; median: 2.3 and 3.5 years, respectively).

RESULTS

Children who had surgery before the age of seven had significantly better alignment and sensory functions. The univariate logistic regression model confirmed a statistically significant association between motor outcome (exodeviation less than 10 prism-diopters) and age at the time of surgery (before or after the age of seven; p = 0.002). In the multivariate model, the association between age at time of surgery and motor outcome was even stronger. The number of reoperations in the group operated before the age of 7 years was significantly less than in the group operated after the age of seven (2 versus 12, p = 0.023).

CONCLUSION

The postoperative alignment and sensory functions in patients with primary exotropia who had surgical intervention before the age of seven years were, in this study, better than in patients who had surgery after the age of seven years.

Dissociated vertical deviation in patients with intermittent exotropia

PURPOSE

To determine whether the age of strabismus onset and the degree of stereopsis are related to the development of dissociated vertical deviation (DVD) in patients with intermittent exotropia and to describe the characteristics of DVD in patients with intermittent exotropia and DVD.

METHODS

Retrospective record review of patients with (1) intermittent exotropia with DVD; (2) infantile esotropia with DVD; and (3) intermittent exotropia without DVD. Age of strabismus onset, stereopsis, strabismus measurements, and the response of DVD to the Bielschowsky head-tilt test were compared among the three groups.

RESULTS

Fifty-two children with intermittent exotropia and DVD were identified. In patients with intermittent exotropia with DVD and intermittent exotropia without DVD group, the mean age of strabismus onset was 12.7 months and 28.9 months, respectively (p = 0.03), and mean stereopsis was 147 arcsec and 65 arcsec (p = 0.02). In patients with intermittent exotropia with DVD and infantile esotropia with DVD, the mean amount of DVD was 9.7(Delta) and 17.2(Delta), respectively (p < 0.01). Bielschowsky head-tilt test showed an increase of DVD on ipsilateral head tilt in 91% and 63.3%, respectively.

CONCLUSIONS

Intermittent exotropia with DVD is characterized by earlier onset of strabismus and worse stereopsis, suggesting that these factors may be related to the development of DVD in patients with intermittent exotropia. Unlike DVD in infantile esotropia, DVD in intermittent exotropia was smaller in amount and demonstrated a more uniform response to the Bielschowsky head-tilt test.

Sensory results after lateral rectus muscle recession for intermittent exotropia operated before two years of age

INTRODUCTION

Early surgical treatment of early-onset intermittent exotropia is controversial. The condition does not always progress, and postoperative esotropia can produce adverse consequences, such as suppression, amblyopia, and loss of binocular vision, particularly stereopsis. It is not known whether surgery before age two years affects the sensory outcome.

METHODS

Using a noncomparative (nonrandomized, uncontrolled) interventional case series, we reviewed the medical records during a 14-year period of 24 patients with intermittent exotropia with onset before age 1 year who also received bilateral lateral rectus muscle recessions before two years of age. Twelve patients were identified who received follow-up examinations at ages > or =4 years, when testing with Worth 4-Dot and Titmus stereo circles would likely be reliable.

RESULTS

Mean age of the patients at last follow-up examination was 87 months. Stereoacuity was measured at 40 arcsec in 2 patients, 100 arcsec in 3 patients, 140-400 arcsec in 2 patients, and none in 5 patients. Among the 5 patients without demonstrated stereopsis, 1 had a history and clinical course consistent with congenital exotropia, and 1 had a nonstrabismic explanation for poor stereopsis. Overall, 7 patients (58%) ultimately obtained favorable motor alignment, defined as a phoria or intermittent tropia <10(Delta) at distance and near. No patient required treatment for amblyopia.

CONCLUSIONS

Early-onset intermittent exotropia usually responds well to surgical treatment, and high-grade stereopsis can be achieved in some cases. More than one clinical entity presenting as intermittent exotropia in infancy probably exists.

Timing of surgery for primary exotropia in children

OBJECTIVE

To compare the postoperative alignment and sensory functions in patients with primary exotropia who had been operated at an early age (< 7 years) with those in patients who had been operated at an older age (> 7 years).

METHODS

In a consecutive retrospective cohort study, 112 patients who had had a surgical intervention for primary exotropia between 1997 and 2003 were evaluated for postoperative results. After applying criteria for eligibility, the group of patients was divided into two groups: those who had had surgery before the age of seven years (n = 24) and those who had had surgery after the age of seven years (n = 36). Age at surgery, preoperative alignment and sensory functions were correlated with the postoperative status. The follow-up was at least one year (1.0 year to 7 years; median: 2.3 and 3.5 years, respectively).

RESULTS

Patients who had had surgery before the age of seven had significantly better alignment and sensory functions. The univariate logistic regression model confirmed a statistically significant association between motor outcome (exodeviation less than 10 diopters) and age at the time of surgery (before or after the age of seven; p = 0.002). In the multivariate model, the association between age at time of surgery and motor outcome was even stronger. The number of re-operations in the group operated before the age of 7 years was significantly less than in the group operated after the age of seven (2 versus 12, p = 0.023).

CONCLUSION

The postoperative alignment and sensory functions for patients with primary exotropia who had had a surgical intervention before the age of seven years were, in this study, better than those in patients who had had surgery after the age of seven years.

Cortical visual impairment: etiology, associated findings, and prognosis in a tertiary care setting

PURPOSE

To evaluate the etiology, prognosis, and associated neurological and ophthalmologic findings of children with cortical visual impairment (CVI) at a tertiary care referral facility.

METHODS

Records from patients visiting the Vanderbilt University Pediatric Ophthalmology Center during 2002 to 2005 were reviewed, and 98 patients were identified with an International Classification of Disease (9th ed.) coding of CVI (377.75). The charts were reviewed to assess presenting symptoms. The clinic and imaging notes were correlated with visual function (graded on a scale of I to VI).

RESULTS

The most common etiologies were perinatal hypoxia (35%), prematurity (29%), hydrocephalus (19%), structural central nervous system abnormalities (11%), and seizures (10%). Many children (69%) had multiple etiologies. Associated ophthalmic abnormalities included esotropia (19%), exotropia (40%), nystagmus (21%), and optic atrophy (42%). Significant refractive error (> +3.00 D or < -2.00 D) was common (20%). Associated neurological findings included seizures (60%), cerebral palsy (37%), periventricular leukomalacia (12%), hemiparesis (21%), and hearing loss (11%). Fifty-three percent of children initially diagnosed with CVI were followed for a period of 0.5 to 10 years. Forty percent of the patients showed no improvement in visual function; 34% had minimal improvement, and 17% had mild improvement. Only 6% of the patients had significant improvement in visual function. Eight patients had fixing and following or better acuity at last follow-up.

CONCLUSIONS

The major risk factors for CVI are perinatal hypoxia, premature birth, and hydrocephalus. Most patients have associated serious neurological and ophthalmologic abnormalities. While many patients have some recovery in vision acuity, most never see well. Patients with the most improvement in visual function were those having better initial acuity.

Binocular status after surgery for constant and intermittent exotropia

PURPOSE

To investigate whether constant exotropia patients with a previous history of intermittent exotropia X(T), like X(T) patients, can achieve postoperative bifixation, and whether they have a better postoperative sensory outcome than those without previous history of X(T).

DESIGN

Prospective comparative clinical study.

METHODS

Sixty-three consecutive patients with intermittent or constant exotropia were divided into three groups: X(T) (group 1), constant exotropia with a previous history of X(T) (group 2), and constant exotropia without previous history of X(T) (group 3). The surgical outcomes were assessed and compared in motor and sensory terms separately between the three groups. Successful motor alignment was defined as within 8 prism diopters (PD) (exo or eso). A stereoacuity < or =60 seconds of arc was considered as bifixation, and a stereoacuity < or =800 seconds of arc was considered as gross stereopsis.

RESULTS

The successful motor alignment rates of group 1, group 2, and group 3 were 79%, 71%, and 67%, respectively (group 1 vs group 2, P = .826; group 1 vs group 3, P = .551; group 2 vs group 3, P = 1.000). Twenty-five (74%) patients in group 1 achieved bifixation and none achieved in group 2 or group 3 (group 1 vs group 2, P = .001; group 1 vs group 3, P = .001). Meanwhile, 34 patients (100%) in group 1, 11 (79%) in group 2, and 5 (33%) in group 3 achieved gross stereopsis (group 1 vs group 2, P = .021; group 2 vs group 3, P = .025; group 1 vs group 3, P = .001). Compared with patients in the two constant exotropia groups, patients in X(T) group had a significantly better sensory outcome in both bifixation and gross stereopsis. Patients in group 2 had a better sensory outcome than those in group 3 in gross stereopsis.

CONCLUSIONS

Constant exotropia patients with a previous history of X(T) have a better postoperative sensory outcome in gross stereopsis than those without previous history of X(T), but a worse surgical sensory outcome when compared with X(T) patients in both bifixation and gross stereopsis. Constant exotropia patients decompensated from X(T) may have missed the best time for treatment.

Ultrastructural study of extraocular muscle tendon axonal profiles in infantile and intermittent exotropia

PURPOSE

To investigate the ultrastructures of tendon axonal profiles in infantile and intermittent exotropia. Tendon axonal profiles are composed of myotendinous nerve endings that are presumed to serve as sensorial receptors in ocular proprioception.

METHODS

The study subjects included 10 patients with exotropia who had undergone surgery in one eye (recession and resection). They were divided into two equal groups. Five patients with infantile exotropia that had developed at under 12 months of age were allocated to group A. Another five, with intermittent exotropia that had developed at over 12 months of age, were allocated to group B. In all patients, medial recti were resected by 3-4 mm in order to obtain tissue samples, which were then examined under an electron microscope.

RESULTS

In group A, we noted many axonal degenerative findings, such as the retraction of axons from myelin sheaths with considerable shrinkage, axonal disintegration, and Schwann cell proliferation. On the other hand, we identified three unique findings in group B: intact axons with incomplete Schwann cell wrapping; intact Schwann cells not associated with axons, and disorganized Schwann cells with shrunken axons.

CONCLUSION

Different patterns of tendon axonal profiles were seen in association with the two types of exotropia. These differences may be related to the pathogenesis of these exotropia types.

Common forms of childhood exotropia

OBJECTIVE

To determine the most common forms of childhood exotropia.

DESIGN

Retrospective, consecutive, observational case series.

PARTICIPANTS

All exotropic children (with >/=10 prism diopters) younger than 19 years from a predominantly rural Appalachian region evaluated from August 1, 1995 through July 31, 2001.

METHODS

Demographic and clinical data were collected on all patients.

MAIN OUTCOME MEASURES

The relative proportion of the various forms of childhood exotropia.

RESULTS

Two hundred thirty-five consecutive children without prior surgical treatment were evaluated for exotropia. Of the 235 study children, the specific forms of exotropia diagnosed and numbers were as follows: intermittent exotropia, 112 (47.7%); exotropia associated with congenital or acquired abnormalities of the central nervous system (CNS), 50 (21.3%); convergence insufficiency, 27 (11.5%); sensory exotropia, 24 (10.2%); paralytic exotropia, 5 (2.1%); congenital exotropia, 4 (1.7%); neonatal exotropia that resolved after 4 months of age, 3 (1.3%), whereas the remaining 10 (4.3%) had an undetermined form of exodeviation.

CONCLUSIONS

Intermittent exotropia was the most common form of divergent strabismus in this population. Exotropia associated with an abnormal CNS, convergence insufficiency, and sensory exotropia were also relatively common, whereas the congenital, paralytic, and late-resolving neonatal forms were uncommon.

A cost-utility analysis of therapy for amblyopia

OBJECTIVE

Evaluation of the incremental cost-effectiveness of therapy for amblyopia.

DESIGN

Cost-utility reference-case analysis.

METHODS

A cost-utility analysis was performed from a third-party insurer perspective by using decision analysis, evidence-based data from the literature, and patient preference-based time trade-off utility values.

DATABASE

Patient-derived time trade-off ocular utility values and the American Academy of Ophthalmology Preferred Practice Pattern guidelines for the treatment of amblyopia.

INTERVENTION

Treatment of childhood amblyopia using medical and surgical therapies per the American Academy of Ophthalmology Preferred Practice Pattern.

MAIN OUTCOME MEASURE

Dollars (year 2001 nominal U.S. dollars) expended per quality-adjusted life-year ($/QALY) gained.

RESULTS

Treatment for amblyopia resulted in a $/QALY gained of $2281 with a discount rate of 3% for costs and outcomes. Sensitivity analysis, varying costs and utility values by 10%, resulted in a $/QALY gained range from $2053 to $2509.

CONCLUSIONS

When compared with other interventions in health care, therapy for amblyopia seems to be highly cost-effective. This information is increasingly important for health care policy makers.

Long-term outcome of uncomplicated infantile exotropia

PURPOSE

The term congenital exotropia (XT) is typically reserved for patients presenting in the first year with a large, constant angle, however, no published study provides a rationale for this restrictive definition. In this study, the present classification system for XT was evaluated and differences between infants with constant versus intermittent XT at presentation were characterized.

METHODS

Medical records of all patients diagnosed with XT before 12 months of age between 1980 and 1994 were identified by computer search. Exclusion criteria included previous eye muscle surgery, resolution of the XT by 3 months of age, and concomitant systemic or ocular disease. Patients were separated into intermittent XT and constant XT groups. The clinical characteristics and outcomes of these two groups were compared.

RESULTS

Of 2018 patients examined on our service during the first year of life for all causes, 23 (1.1 %) met the inclusion criteria. Follow-up data of more than 1 year was available for 13 patients, and of these, 46% had constant XT. The 2 groups had similar clinical features at presentation except for a larger initial angle in the constant XT group (P =.02). Average follow-up was 58 months (range: 13-158 months). Twelve patients (92%) required surgery. The reoperation rate was 27%, and 82% had final horizontal deviations of less than 10 PD. The incidence of A/V-patterns (38%), dissociated vertical deviation (46%), and binocularity (70%) was similar between groups.

CONCLUSION

Half of infantile XT patients may present with intermittent XT, with similar clinical outcomes regardless of presentation. Surgical intervention resulted in successful alignment in most cases. More than half the patients developed measurable stereopsis, but none achieved bifixation.

Prevalence of systemic and ocular disease in infantile exotropia: comparison with infantile esotropia

OBJECTIVE

Exotropia in infancy is believed to be associated with an increased prevalence of neurologic, ocular, and craniofacial abnormalities; however, the prevalence of coexisting ocular and systemic disease in these patients is unknown. In this study, the prevalence of ocular disease and systemic illness was determined in patients diagnosed with exotropia in infancy.

DESIGN

Observational comparative case series.

PARTICIPANTS

Medical records of 70 patients diagnosed with exotropia in the first year of life were reviewed and compared with records of 136 patients diagnosed with esotropia before 1 year of age.

INTERVENTION

Patients with no disorders (other than latent nystagmus, dissociated vertical deviation, or oblique muscle overaction) were grouped as "simple" strabismus. Patients with systemic disorders (including prematurity, neurologic disease, and genetic disease) and patients with ocular disorders (including congenital nystagmus, other strabismus, ptosis, and any condition associated with loss of vision [except amblyopia]) were grouped as "complex" strabismus.

MAIN OUTCOME MEASURES

Prevalence of coexisting systemic and ocular disorders. The demographics, strabismus measurements, and types of coexisting disease in the simple and complex groups were compared.

RESULTS

A high percentage of both exotropia (67%) and esotropia (49%) patients had a coexisting ocular or systemic abnormality. Exotropia patients with a constant strabismus were more likely to have coexisting ocular or systemic disease than those with an intermittent strabismus. Smaller angles of exotropia or esotropia were associated with a higher likelihood of coexisting ocular or systemic diseases. Systemic disorders were found more frequently than ocular disorders in both the exotropia and esotropia groups. In 25% of all patients referred for evaluation of strabismus, an additional ocular or systemic abnormality was discovered by the ophthalmologist.

CONCLUSION

Patients presenting to a university hospital-based practice in the first year of life with exotropia were more likely than those presenting with esotropia to have coexisting ocular and systemic disease. Both groups had a notably high prevalence of associated disorders. The percentages measured in this population may not be applicable to other practices because of referral bias. However, clinicians should consider that children presenting with infantile exotropia and esotropia appear to be at risk for coexisting ocular or systemic disease.

Common ophthalmologic concerns in infants and children

Pediatric ophthalmology differs from adult eye care in many aspects. Some disorders are seen only in children although others may be found in adults as well. A major difference between pediatric and adult ophthalmology is the impact that almost any disorder may have on the developing visual system. This article addresses common pediatric eye disorders and their potential effects on the visually impaired immature child. Referral guidelines and vision screening are also discussed.

Dissociative phenomena in congenital monocular elevation deficiency

INTRODUCTION

Monocular elevation deficiency is characterized by unilateral limitation of elevation in both adduction and abduction and is usually present at birth. Dissociative phenomena such as dissociated vertical deviation are well recognized in association with conditions such as congenital esotropia but much less so in association with conditions such as congenital monocular elevation deficiency.

METHODS

All 129 patients given the diagnosis of monocular elevation deficiency or double elevator palsy in the Pediatric Ophthalmology and Strabismus Clinic at the University of Iowa Hospitals and Clinics between 1971 and 1995 were reviewed. After those with history of trauma, myasthenia gravis, thyroid eye disease, orbital lesions, Brown syndrome, or monocular elevation deficiency with acquired onset were excluded, 31 patients with congenital monocular elevation deficiency remained for retrospective study.

RESULTS

First diagnosed at median age 2.6 years (although all were noted by parents at less than 6 months of age) with mean follow-up of 5.0 years (up to 15.5 years), 9 of 31 (29%) developed dissociated vertical deviation in the eye with monocular elevation deficiency, all of whom had undergone strabismus surgery 0 to 9.7 years previously (mean 3.5 years). Those who developed dissociated vertical deviation were generally younger, were followed up longer, and had more accompanying horizontal strabismus than did those who did not develop dissociated vertical deviation. The results did not reach significance.

CONCLUSION

The current study demonstrates that dissociated vertical deviation occurs in association with monocular elevation deficiency.