Relationship between strabismus associated with Angelman syndrome and orbital anomaly.

PURPOSE: To investigate the relationship between the details of strabismus and orbital abnormalities determined by ocular motility tests and orbital imaging examinations in 9 cases with Angelman syndrome (AS). STUDY DESIGN: A retrospective, clinical report. METHODS: The 9 AS cases (mean age at initial visit: 4.6 ± 8.0 years) were confirmed by genetic diagnosis of the chromosome 15q11-13 region. In all cases, axial imaging of the orbit in the transverse plane of the horizontal extraocular muscles was obtained. The opening angle between both lateral walls of the orbit (greater wing of sphenoid) was measured as the biorbital angle, and compared with the 95% confidence interval of the orbital angle in normal children. RESULTS: All cases had exotropia with means of the distance and near of angle 32.2 prism diopters (Δ) ± 9.7Δ and 32.8Δ ± 8.3Δ. The mean of the biorbital angle was 107.7° ± 7.6°, greater than the biorbital angle of 94.3° ± 5.1° previously reported in 129 normal children (P < 0.0001, t-test). Except for one biorbital angle of 93° in the 25-year-old patient, all the biorbital angles in the 8 children were larger than the upper 95% confidence interval in normal children. Astigmatic and hyperopic ametropic amblyopia were detected in 3 cases and 1 case, respectively. CONCLUSIONS: The frequency of exotropia in AS is higher than previously reported, with our results strongly suggesting that the enlarged biorbital angle is related to the pathogenesis of exotropia in AS.

Two Pediatric Patients with Acute Acquired Comitant Esotropia as the First Symptom of Brainstem Tumor: A Case Report.

Introduction: Acute acquired comitant esotropia (AACE) is an acquired strabismus with uncrossed sudden-onset diplopia due to esodeviation, comitant esotropia without accommodation factor, or paretic eye movement. The diagnosis of AACE entails differentiation from incomitant esotropia caused by abnormalities in the central nervous system. We present 2 pediatric patients with AACE as the first symptom of brainstem tumor. Case Presentation: The 2 patients were aware of their diplopia and had no other neurological abnormalities. There were no special findings in the anterior segment, ocular media, or fundus. Esotropia with a difference of no more than 10Δ between distant and near fixations was observed. Eye movements were normal, and Hess red-green test under prism neutralization did not reveal abduction restriction. The presumed cause of AACE in both patients was excessive use of digital displays, and brain magnetic resonance imaging (MRI) was performed to confirm the absence of neurological abnormality. Using MRI, a definitive diagnosis of AACE was made based on comitant esotropia associated with diffuse median glioma and medullary pilocytic astrocytoma without abducens nerve palsy. Conclusion: Although the incidence of AACE caused by brainstem tumors may be low, it is necessary to perform head imaging to confirm etiology. Furthermore, Hess red-green test under prism neutralization is considered important for the differentiation of abducens nerve palsy.

Relationship Between Suppression Scotomas and Stereoacuity in Anisometropic Amblyopia With Successfully Treated Visual Acuity.

Purpose: The purpose of this study was to investigate the relationship among suppression scotoma size, stereoacuity, and four-prism base-out test (4ΔBOT) results in anisometropic amblyopia with successfully treated visual acuity. Methods: We included 103 cases of anisometropic amblyopia successfully treated for visual acuity without strabismus. Stereoacuity was measured using a Randot Stereotest. The size of the suppression scotomas was measured using a new device, the polarized four dot (P4D) test. This is a modification of the Worth 4 dot test (W4D) device. The patients were divided into three groups based on the 4ΔBOT results: normal (group A = 29 cases), subnormal (group B = 48 cases), and abnormal (group C = 26 cases) response groups. The horizontal diameter of the suppression scotomas and stereoacuity in logarithmic values with a base of 20 seconds of arc (″) were compared among the 3 groups. Results: The mean age at P4D testing was 8.4 ± 2.1 years. The average horizontal diameters of the suppression scotomas were 0.35 ± 0.79Δ, 2.01 ± 0.82Δ, and 5.50 ± 2.72Δ in groups A, B, and C, respectively, showing significant differences (A versus B: P < 0.0001, A versus C: P < 0.0001, and B versus C: P < 0.0001; 1-way ANOVA). The average logarithmic stereoacuity were 1.07 (24.95″), 1.22 (38.84″), and 1.47 (82.79″) in groups A, B, and C, respectively, thereby showing significant differences between the groups (A versus B: P < 0.0001, A versus C: P < 0.0001, and B versus C: P < 0.0001; 1-way ANOVA). Stereoacuity and horizontal diameter of the suppression scotoma were strongly correlated (r = 0.732, P < 0.0001). Conclusions: The suppression scotoma size measured using P4D correlated significantly with stereoacuity and the 4ΔBOT results.

Surgical Outcomes with and without Prism Adaptation of Cases with Acute Acquired Comitant Esotropia Related to Prolonged Digital Device Use.

Purpose: To analyze surgical results of 32 cases with acute acquired comitant esotropia (AACE) related to prolonged use of digital devices (DDs). Patients and Methods: Medical records of cases with AACE related to prolonged use of DDs that had undergone surgery were retrospectively revised. Complete medical history and full ophthalmological examinations before and surgery were obtained for all cases. All cases also underwent neurological examinations using brain and orbital imaging. Motor success was considered as alignment within 10 prism diopters (Δ) at both near and distance. Sensory success was defined as stereopsis ≤60 arcsec. Nineteen cases (Group S) underwent surgery alone and 13 cases were treated with surgery and prism adaptation (Group S+P). Motor and sensory outcomes were compared between groups. Results: Mean age at first visit was 22.0 ± 9.0 years and mean daily use of DDs use was 6.3 ± 3.4 hours. Mean angle of preoperative alignment for distance and near were 26.5 ± 13.0Δ and 24.6 ± 16.4Δ, respectively. Surgery was performed at a mean of 23.3 ±3.5 years old and mean angle of alignment at final examination for distance and near were 5.8 ± 7.7Δ and 3.5 ± 5.7Δ, respectively. Final motor and sensory success rate were 84% and 53%, respectively. No significant differences in motor or sensory outcomes were evident between groups at initial or last visit. Conclusion: Favorable motor and sensory outcomes were achieved with surgical intervention with and without prism adaptation for AACT related to prolonged use of DDs.

Accuracy and Correlation of the Kinect-Based Semi-Automatic Scoring Method for Measuring Anomalous Head Posture as Compared to the CROM® Device.

Objective: To determine the reliability of the Kinect-based semi-automatic scoring method (KSSM) using Kinect for Windows v2 for head posture compared to the cervical range-of-motion (CROM) device. Methods and Analysis: Head positions between -40° and +40° of chin up/down (X), head turn (Y), and lateral tilt (Z) were measured in 10° increments in healthy volunteers. Their head positions were simultaneously measured using the KSSM and CROM. The following four points were analyzed: the success rate of the KSSM, the correlation between the two methods, the comparison of results by 95% limits of agreement (LA), and proportional error at 95% LA. Results: The measurability of the KSSM for all positions within ±30° of the X, Y, and Z axes was 100%. The correlations for both methods were 0.979 (95% CI: 0.967-0.987), 0.985 (0.976-0.991), and 0.988 (0.981-0.993) for the X-, Y-, and Z-axes, respectively. The simple linear regression analysis equations for 95% LA were Y=-0.024X-0.452 for X axes, Y=0.024X-0.363 for Y axes, and Y=-0.045X+0.217 for Z axes (95% confidence interval for each axis: -0.055-0.007, -0.006-0.050, and -0.071-0.018). However, the proportional biases were small because the predictive values of the differences in head positions from -40° to 40° determined by the equations were within ± 5° for chin up/down and within ± 3° for head tilt. Conclusion: Head posture measurements using the KSSM and CROM were found to be similar when used in clinical settings.

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 ≤10Δ, (2) recurrence: exotropia >10Δ, or (3) overcorrection: esotropia >5Δ. 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.

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.

Developmental change of the biorbital angle in normal Japanese infants.

Purpose: To investigate postnatal changes in the biorbital angle in normal Japanese children. Subjects and methods: Axial imaging of the orbit in the transverse plane of the horizontal extraocular muscles was obtained in 129 ophthalmologically healthy infants (age ranging from a few months to 11 years). The opening angle between both lateral walls of the orbit was defined as the biorbital angle. Results: The mean biorbital angle in 11 infants less than a year of age was 105.0°±6.0°. The mean biorbital angles for each of the subsequent age groups were 97.7°±3.1°, 96.2°±4.0°, 96.3°±4.1°, 92.8°±3.8°, 92.3°±2.3°, 93.1°±2.8°, 91.5°±3.9°, 91.9°±2.3°, 91.4°±2.3°, and 90.9°±3.1°. The mean biorbital angle in infants less than a year old was significantly larger than those found in the groups of infants older than 1 year (P<0.01, Newman-Keuls test). Conclusion: The biorbital angle in infants less than a year old was larger than that found in infants older than 1 year, with this larger biorbital angle potentially the causative factor of the observed exotropia seen in 70%-80% of newborns gradually disappearing in most cases by 2-4 months of age.

Changes in angle of optic nerve and angle of ocular orbit with increasing age in Japanese children.

PURPOSE: To study changes in the opening angle of the optic nerve and the angle of the ocular orbit with increasing age in normal Japanese children. METHODS: We studied 147 normal children (aged 6 months to 18 years) who had undergone CT as a diagnostic procedure. Measurements were performed on axial CT images that included the entire optic nerve of both eyes. The opening angle of the optic nerve was defined as the angle formed by the intersection of a line running through the left optic nerve and a vertical line passing through the centre of the nose. The opening angle of the orbit was defined as the angle formed by the intersection of a line running tangentially along the deep lateral wall of the left orbit and a vertical line passing through the centre of the nose. The relationship between age and these opening angles was analysed by regression analysis. RESULTS: The correlation between age and opening angle of the optic nerve was not significant. In contrast, the opening angle of the orbit decreased relatively rapidly until about 2-3 years of age, and then it stabilised. The decrease in the opening angle of the orbit with increasing age was significant (p<0.001). The relationship between these two parameters was best fitted by a logarithmic regression curve. CONCLUSIONS: Because the opening angle of the orbit decreased significantly with increasing age, this factor must be considered when diagnosing and treating strabismus in children.

Influence of timing of initial surgery for infantile esotropia on the severity of dissociated vertical deviation.

PURPOSE: The purpose of this study was to clarify whether the timing of initial surgery for infantile esotropia contributes to better sensory outcomes and to the severity of dissociated vertical deviation (DVD). METHODS: This retrospective study examined 55 children, aged 8 years and younger, who underwent esotropia surgery. Based on age at the time of the surgery, patients were divided into the very early surgery group (birth to 8 months, N = 14), early surgery group (9-24 months, N = 23) and late surgery group (25 months and older, N = 18). Sensory and motor outcomes of the three groups were statistically evaluated. RESULTS: No significant differences in the incidences of DVD were noted among the three groups at the final visit. However, all DVDs of the very early surgery group were latent, whereas 38.9% of the DVDs for both near and distance of the late surgery group were manifest. Significant differences were found among the three groups for the proportion of patients with manifest DVD, latent DVD and without DVD, and for the incidence of additional surgery for manifest DVD (p < 0.05, G-test). CONCLUSION: Early surgery for infantile esotropia decreases the severity of DVD and lowers the need for an additional operation for DVD.

[Surgical results of unilateral recession-resection for intermittent exotropia in children: multicenter study in Japan].

PURPOSE: To survey the surgical results of unilateral recession-resection surgery for intermittent exotropia of children through a multicenter study in Japan. SUBJECTS AND METHODS: A retrospective study was performed at 6 Japanese hospitals. A total of 377 patients who underwent the first surgery of unilateral recession-resection, at the ages of 4 to 12 years with a follow-up of more than 3 years were included. Those who had amblyopia or vertical deviation were excluded. Ocular deviations before and after surgery, type of exotropia, the age at surgery and the size of the surgical operations were studied. The change in deviation by surgery (surgical effect; PD/mm) and final deviation between 15PD exodeviation and 10 PD esodeviation was categorized as a cure. Factors affecting to the cure were statistically evaluated. RESULTS: The average age at surgery was 6.7 years, the average of preoperative deviation was 31.6 PD and the average size of surgery (recession + resection) was 11.1 mm. The surgical effect and the preoperative deviation were positively related. Two hundred and sixty cases among the 377 cases (69.0%) were determined as being cured. Preoperative deviation of less than 30 PD (p = 0.02) and one-week postoperative esodeviation (p < 0.001) were significantly related to the cure. CONCLUSIONS: The distribution of surgical age and preoperative deviation of intermittent extropia of children were elucidated. Preoperative deviation under 30PD and esodeviation (overcorrection) at one-week postoperative time were significantly related to the cure.

Effects of vertical offsets of the horizontal rectus muscles in V-pattern exotropia without oblique dysfunction.

PURPOSE: To investigate the effects of vertical offsets of the horizontal rectus muscle in V-pattern exotropia without oblique dysfunction. METHODS: A computerized patient database was searched for patients treated with full tendon offsets for V-pattern strabismus from 2002 to 2007. Patients with clinically significant inferior oblique overaction were excluded. Surgery included upward transposition of lateral rectus muscles and/or downward transposition of medial rectus muscles. Medical records were retrospectively analyzed for alignment in the primary position, 30 degrees upgaze, and 30 degrees downgaze before and 3 months after surgery. The main outcome measure was the change in V pattern after surgery. RESULTS: The search identified 11 patients who met inclusion criteria. Of these, 6 underwent bilateral lateral rectus recessions, 1 had 3-muscle surgery, and 4 had monocular recession-resection surgery. The preoperative V-pattern (horizontal) deviation between upgaze and downgaze was 22.2(Delta)+/-5.0(Delta). Postoperative deviation at 3 months was 3.5(Delta)+/-3.9(Delta), a decrease of 18.9(Delta)+/-7.5(Delta). Postoperatively, no patient had an A-pattern deviation or subjective torsional disturbance. The amount of V-pattern correction was closely correlated with the size of the preoperative V pattern (r=0.84). CONCLUSIONS: In patients with V-pattern exotropia without inferior oblique dysfunction, vertical offsets of the horizontal rectus muscles effectively corrected the pattern deviation. The amount of correction was closely correlated with the size of the preoperative V pattern.

Modified method for assessment of the binocular fusional field in patients with suppression.

PURPOSE: To evaluate the usefulness of a new system using a modified Goldmann perimeter and Bagolini striated glasses for quantitative assessment of the binocular fusional field (BFF) in patients with suppression. METHODS: The BFF was assessed quantitatively in ten normal patients aged 10 to 15 years by using a modified Goldmann perimeter equipped with a xenon light source. Subjective perception was elicited with the use of a crossed or single oblique streak through Bagolini striated glasses. The BFF in 15 strabismic patients with suppression were analyzed at their initial visit and at their last visit after therapy. RESULTS: In normal patients, extent points of the BFF on every 15 degrees meridian ranged from 48 degrees to 56 degrees . The normal BFF drawn from these average points was approximately equal to the previously published normal format of binocular single vision for strabismic patients with diplopia. Additionally, this scoring system for BFF provided quantitatively objective information during the course of their extraocular disorder in 15 strabismic patients with suppression. CONCLUSION: This new method of assessing BFF in patients with suppression can be helpful for evaluation of quantitative effects in the course of treatment for an extraocular disorder and compensatory abnormal head position.