Intermittent Exotropia Research Articles

Effect of office-based vergence and anti-suppression therapy on binocular vision and accommodation in small-to-moderate angle intermittent exotropia: A randomised clinical trial.

To evaluate the short-term (1 week after completion of treatment) effect of office-based vergence and anti-suppression therapy (OBVAT) on binocular vision and accommodative function when compared to observation alone in children with small-to-moderate angle intermittent exotropia (IXT). In this single-masked (examiner masked), two-arm, single-centre randomised clinical trial, 40 participants, 6 to <18 years of age with untreated IXT were randomly assigned to OBVAT or observation alone. Participants assigned to therapy received 16 weeks of OBVAT (60 min per visit, once per week) with home reinforcement (15 min per day, 5 days a week). Therapy included vergence, accommodation and anti-suppression techniques. This paper reports the results of clinical measures of binocular vision and accommodation, including fusional vergence, near point of convergence, vergence facility, amplitude of accommodation, the Worth 4-dot test and the Fusion Maintenance Score (FMS). Treatment group differences at the primary outcome visit significantly favoured the OBVAT group (n = 20) over the observation group (n = 16) in negative fusional vergence break point at both distance (p ≤ 0.001; r = 0.58) and near (adjusted mean difference: 12.3 Δ; 95% CI: 5.3-19.3 Δ; p = 0.001; partial eta squared: 0.28), positive fusional vergence break point at both distance (p = 0.009; r = 0.43) and near (adjusted mean difference: 20.6 Δ; 95% CI: 11.8-29.4 Δ; p ≤ 0.001; partial eta squared: 0.41), vergence facility (adjusted mean difference: 5.6 cpm; 95% CI: 1.9-9.4 cpm; p = 0.005; partial eta squared: 0.22) and the FMS (p = 0.007; r = 0.44). In this randomised clinical trial of participants aged 6 to <18 years with IXT, those in the OBVAT group had a significantly better fusional vergence range, vergence facility, near Worth 4-dot test result and FMS than the observation group at the 17-week visit. The improvement in these areas further support the effectiveness of OBVAT for improving IXT.

Types of refractive errors in a sample of Iraqi children with Intermittent exotropia

Background One of the most common strabismus types in children is intermittent exotropia, which masks the deviation of one eye outward, mostly in children aged 2-4 years. It may affect visual development and often coexists with refractive mistakes. Unlike esotropia, which usually links to hyperopia, intermittent exotropia might have a different relationship with refractive errors and thus lead to myopia. Methods In this cross-sectional study from August 2021 to December 2023, 179 patients diagnosed with intermittent exotropia were recruited via an outpatient clinic of Najah Al-Quraishi, Baghdad, Iraq. The refractive errors were compared by autorefractometry and retinoscopy after cycloplegic dilation. Data analysis was constructed under the use of IBM SPSS V.26 for the determination of emmetropia, myopia, and hyperopia prevalence. Results The most expected refractive error among the 179 patients was emmetropia, which occurred in 68 patients (38%). Low hyperopia and low myopia were also common, with 64 and 40, respectively. A limited number of patients had moderate/high myopia and moderate/high hyperopia; in detail, the prevalence was following: 5% of patients had moderate myopia, while 0.5% of patients suffered from high myopia; symmetrically, 5% were moderate to high hyperopia. From the data collected, a trend emerged for a low refractive error and symmetric refractive error in both eyes. Conclusion Contrasted to prior conventional wisdom about refractive error in strabismus, it established the greater incidence of emmetropia in patients with intermittent exotropia. The findings call for specific management strategies to be applied in this population.

Automated Fiber Quantification Analysis Identifies Tract-specific Microstructural Alterations in Brain in Intermittent exotropia

BackgroundGrowing evidence of neuroimaging has indicated brain microstructural abnormalities in comitant strabismus. Nonetheless, few studies have investigated neuropathological alterations in patients with intermittent exotropia (IXT). This study aimed at examining the characteristics of brain microstructure along major fiber tracts in IXT patients using an automated fiber quantification analysis. MethodsA total of 25 patients with IXT as well as 25 healthy participants matched for age and gender finished the diffusion tensor imaging scanning and the ophthalmic examination. Automated fiber quantification analysis of 20 major fiber tracts was carried out for IXT patients and healthy subjects, respectively. Diffusion metrics of 100 equidistant nodes resampled along each tract were measured for every subject and compared between two groups. Effect size analysis was performed to identify the most affected fiber tracts in IXT. ResultsWidely declined mean diffusivity was noted in IXT along major tracts containing bilateral thalamic radiations, bilateral corticospinal fasciculi, bilateral cingulum cingulate, left inferior fronto-occipital fasciculus, right arcuate fasciculus and superior longitudinal fasciculus. Local reduction in fractional anisotropy was observed in IXT along left cingulum hippocampus, right inferior longitudinal fasciculus and right uncinate fasciculus, in contrast to the regionally increased fractional anisotropy along bilateral thalamic radiation, left corticospinal tract and left arcuate fasciculus. Among the tracts with significantly changed diffusion metrics in IXT, right inferior longitudinal fasciculus was the most affected one in fractional anisotropy while left thalamic radiation was the most influenced one in mean diffusivity. ConclusionsAbnormalities in microstructural properties along visual-related fiber tracts are likely to contribute to difficulties in visual information processing in IXT patients, which could serve as the neural basis of underlying pathological mechanism of IXT.

Characteristics of horizontal saccades in children with intermittent exotropia

PurposeTo analyze the peak velocity and gain of horizontal saccades in children diagnosed with intermittent exotropia (IXT) and to compare these measurements with those obtained from children without strabismus. MethodsParticipants included children ≤12 years of age with IXT and no history of strabismus surgery and children without strabismus. The peak velocity and gain of horizontal saccades recorded using an eye tracker were analyzed. ResultsA total of 48 children (including 38 with IXT) were included. In the IXT group, the angles of deviation at near were 30.3Δ ± 13.5Δ; at distance, 30.6Δ ± 10.5Δ. Stereopsis was ≤60 arcsec in 29 patients and 80–400 arcsec in 9 patients. In the IXT group, the peak velocity and gain of the adduction saccade tended to be greater than those of the abduction saccade, but not significantly. The no-strabismus group exhibited a similar trend, with a stronger tendency in the dominant eye, reaching statistical significance. ConclusionsBoth the children with IXT and children without strabismus showed a dominance of adduction in their saccades; however, this dominance was weaker in children with IXT.

Comparison of ganglion cell-inner plexiform layer thickness among patients with intermittent exotropia according to fixation preference: a retrospective observational study.

This study was performed to compare the thickness of the ganglion cell-inner plexiform layer (GCIPL) depending on the presence or absence of fixation preference in patients with intermittent exotropia (IXT) with refractive values close to emmetropia and with no amblyopia. The study recruited pediatric patients diagnosed with IXT with a spherical equivalent within ±1.25 diopter and no amblyopia. The patients were categorized into two groups: a monocular exotropia group with fixation preference and an alternating exotropia group without fixation preference. GCIPL thickness was measured using spectral domain optical coherence tomography, and the macula was divided into nine sectors according to the Early Treatment Diabetic Retinopathy Study (ETDRS). GCIPL thickness in each sector was compared between the monocular and alternating exotropia groups. In the monocular exotropia group, GCIPL thickness was significantly thinner in the dominant eye than in the nondominant eye in the S1 sector (91.2±7.4 μm vs. 93.3±5.2 μm, p=0.019). However, in the alternating exotropia group, there were no significant differences between the eyes across all ETDRS sectors. When comparing the interocular differences in GCIPL thickness between the two groups, the monocular exotropia group (absolute value of the dominant eye minus the nondominant eye) exhibited significantly greater differences in several ETDRS sectors than the alternating exotropia group (absolute value of the right eye minus the left eye). The significant interocular difference in GCIPL thickness in the monocular exotropia group suggests that fixation preference may influence the anatomical structure of the macula in patients with IXT.

Long-term Outcomes of Bilateral Lateral Rectus Recession Using a Modified Normogram for Targeting Small Overcorrection in Intermittent Exotropia.

To evaluate the surgical outcomes of a modified normogram for bilateral lateral rectus recession in the surgical management of intermittent exotropia, with a focus on achieving small overcorrection. A retrospective medical chart review of 242 patients who underwent surgery for intermittent exotropia between October 2014 and June 2020 was performed. Our modified normogram reducing amount of recession targeted for small postoperative overcorrection within 5 prism diopters (PD). Patients were observed for at least 3 years. Esodeviation was denoted by negative numbers and positive values indicated exodeviation. A satisfactory outcome was defined as if distant angle of deviation ranged between ≤10 PD of exotropia and ≤5 PD of esotropia. Recurrence was defined as an exodeviation of >10 PD at distance. Overcorrection was defined as an esodeviation of >5 PD at distance. The mean preoperative deviation angles were 29.32 ± 3.92 PD at distance and 29.88 ± 4.41 PD at near. At postoperative day 1, the mean deviation angles at distance and near were -6.22 ± 1.44 and -6.22 ± 1.49 PD, respectively. Overcorrection within 6 PD of esodeviation was seen in 168 patients (69.42%), undercorrection with exophoria was noted in 11 patients (4.55%), and overcorrection by more than 6 PD of esodeviation was seen in 63 patients (26.03%) at postoperative day 1. The long-term success rate at postoperative 3 years was 77.27% (187 of 242), with a recurrence rate of 19.83% (48 of 242) and an overcorrection rate of 2.89% (7 of 242). A positive correlation between the angle of deviation at postoperative day 1 and 3 years was observed (r = 0.22, p = 0.001). The final success rate at the final examination after a mean follow-up of 38.60 ± 7.99 months was 83.06%. Our modified normogram for bilateral lateral rectus recession in intermittent exotropia surgery resulted in successful surgical outcomes with small overcorrection, reducing the risk of consecutive esotropia due to excessive overcorrection.

Postoperative Changes of Fusional Vergence in Children Intermittent Exotropia

: This study aimed to evaluate changes in fusional vergence after strabismus surgery and to explore predictive parameters and the impact of fusional vergence on surgical outcomes. All patients diagnosed with intermittent exotropia (IXT) between March 2015 and October 2017 were included. Orthoptic assessments, including visual acuity, cover test, and mean fusional vergence (breakage/recovery, both negative and positive), were measured using a synoptophore. Subjects with symptomatic exotropia who underwent strabismus surgery were included. The primary outcome measure was the surgical success (SS) rate at a 6-month follow-up, with adverse effects such as over-correction and under-correction also evaluated. Data were analyzed using SPSS version 20.0. Surgical success was achieved in 62 patients (75.61%) at the 6-month follow-up. The postoperative fusional divergence breakpoints for the SS group and the surgical failure (SF) group were -7.52 ± 4.14 degrees and -10.00 ± 5.96 degrees (P = 0.040), respectively. The postoperative fusional convergence breakpoints for the SS group and the SF group were 10.03 ± 4.36 degrees and 4.65 ± 7.27 degrees (P &lt; 0.001), respectively. The postoperative amplitude of fusional divergence was higher in the SS group compared to the SF group (P = 0.008). There was a significant difference in the duration of deviation (2.08 ± 0.84 vs. 4.23 ± 1.36, P &lt; 0.001) between the groups, suggesting that the success rate of surgery is affected by the cumulative disease duration. Subjective deviation (-8.00 vs. -11.00, P = 0.049) and the amplitude of fusional divergence (6.52 ± 4.10 vs. 4.80 ± 2.59, P = 0.032) were also significantly different between the SS and SF groups. Postoperative breakpoints of fusional divergence and convergence, as well as the amplitude, were distinct between the SS and SF groups. Duration of deviation, angle of deviation, and subjective deviation were independent factors for (SS). Subjective deviation exhibited a predictive index for (SS) and may also reflect the severity of strabismus.

Characteristic differences between full-term and premature infants with intermittent exotropia

Strabismus is prevalent among preterm infants of low gestational age and birth weight in Southeast Asian countries, with intermittent exotropia (IXT) being the most common type in South Korea. In this retrospective, cross-sectional study, we investigated the differences between full-term and premature infants with IXT. IXT patients with available childbirth history were divided into two groups: preterm vs. full-term and low birth weight (LBW) vs. normal birth weight (NBW). Parameters related to exotropia including parental heredity, surgical history, and treatment options were investigated. In univariate regression for gestational age, a result of ≥ 100 s in the Titmus test was 1.352 times more frequent in preterm than in full-term infants. When birth weight was considered instead, a result of ≥ 100 s in the Titmus test was 1.412 times more frequent in the LBW compared to the NBW group. In multivariate regression for birth weight, the frequency of a result of ≥ 100 s in the Titmus test for the LBW group was 2.032 times higher than that for the NBW group. It is particularly important to examine stereopsis in preterm and LBW patients affected by IXT to ensure timely surgical planning and avoid potential recurrence after surgery.

Altered functional connectivity of resting-state networks and the correlation with clinical characteristics in intermittent exotropia adult patients: a resting-state magnetic resonance imaging study

BackgroundThe pathogenesis of intermittent exotropia (IXT) remains unclear. The study aims to investigate alterations of resting-state networks (RSNs) in IXT adult patients using resting-state functional magnetic resonance imaging (rs-fMRI) data to explore the potential neural mechanisms.MethodsTwenty-six IXT adult patients and 22 age-, sex-, handedness-, and education-matched healthy controls (HCs) underwent fMRI scanning and ophthalmological examinations. Brain areas with significant functional connectivity (FC) differences between the IXT and HC groups were selected as regions of interest (ROI) and mean z-scores were calculated to control for individual differences.ResultsCompared with HCs, IXT patients exhibited altered FC in various brain regions within RSNs involved in binocular fusion, stereopsis, ocular movement, emotional processes and social cognition, including the default mode network (DMN), the dorsal attention network (DAN), the visual network (VN), the sensorimotor network (SMN), the executive control network (ECN), the frontoparietal network (FPN) and the auditory network (AN). The degree of exodeviation was positively correlated with FC value of left middle occipital gyrus (MOG) within the VN. Correspondingly, we found a negative correlation between the degree of exodeviation and the FC value of left angular gyrus (AG) within FPN (P < 0.05). The FNC analysis between different RSNs also provides evidence on visual-motor cortical plasticity.ConclusionsIXT patients showed widespread changes of brain activity within RSNs related to binocular fusion, stereopsis, oculomotor control, emotional processes, and social cognition. These findings extend our current understanding of the neuropathological mechanisms of IXT.Trial registrationBeginning date of the trial: 2021-09-01. Date of registration:2021-07-18. Trial registration number: ChiCTR 2,100,048,852. Trial registration site: http://www.chictr.org.cn/index.aspx.

The effect of sunglass filters on contrast sensitivity, monocular eye closure, and blinking rate in people with intermittent exotropia

ABSTRACT Clinical relevance Transient monocular eye closure and photosensitivity under bright light have been reported in people with intermittent exotropia (IXT). The exact mechanism of these symptoms has not been established. Background This study examines the effect of sunglass filters on contrast sensitivity (CS), transient monocular eye closure, and blinking rate under bright light in people with IXT. Methods Forty participants with IXT and complaints of photosensitivity were included in the study. The binocular CS test was performed under mesopic and photopic conditions with and without glare, and with and without two filters with different grades of light transmission (filter 1: 44–80%; filter 2: 20–43% light transmittance). The effect of two filters on transient eye closure, contrast sensitivity, and blinking rate was assessed under bright light. Also, participants were divided into 3 groups based on their degree of control of fusion (good, fair, and poor control). Results The mean age of the participants was 12.0 years ± 8.0 (standard deviation) (range: 7–40 years). There was no significant difference between the age (p = 0.139), stereopsis (p = 0.134), as well as the near and far degree of deviation (p = 0.516, and p = 0.237) between the three groups of fusion control. Under mesopic conditions with glare, mean binocular CS was significantly higher with filters (p < 0.001). Without filters, 57.5% of the participants exhibited monocular eye closure under a photopic setting with additional glare. No participant showed eye closure using filter 2. People in the poor control group showed exodeviation before monocular eye closure (62.5% without filter and 12.5% with filter 1, p = 0.01). The blinking rate decreased from 36.0 ± 4.0 blinks per minute without filter to 21.0 ± 3.0 using filter 1, and 20.0 ± 3.0 with filter 2. Conclusion In people with IXT, wearing sunglass filters of different transmittance reduces monocular eye closure and blinking rate under bright light. To improve these symptoms, sunglasses can be considered for IXT.

Corneal changes after large (9mm) lateral rectus muscle recession measured with Pentacam®

ABSTRACT Introduction: The aim of this study was to evaluate alterations in corneal astigmatism, axial anterior corneal curvature, anterior chamber depth, and central corneal thickness (CCT) two months after the unilateral recession of lateral rectus muscle in children. Methods: This prospective study included 37 children with intermittent exotropia who would undergo unilateral lateral rectus muscle recession. All measurements were performed using Pentacam®. Comparisons were made between the operated and fellow unoperated eyes, pre- and post-operatively. The assessment was made for changes in the radius of axial curvature on major meridians at 3 and 3.5 mm from the optical corneal center in the mid-peripheral zone. Astigmatism changes of the anterior and posterior corneal surface were calculated using vector analysis software (astigMATIC®). The interaction between age or CCT and postoperative changes in anterior and posterior surface corneal astigmatism were examined with ANOVA model. Results: In the intervention group, changes in anterior and posterior corneal surface astigmatism were statistically significant, with a mean increase of 0.56Dx90 and 0.08Dx87, respectively. In the mid-peripheral corneal zone, an increase was observed in the radius of anterior corneal axial curvature, more evident temporal 3 and 3.5 mm from the corneal center on the horizontal meridian, with corresponding decrease superiorly and inferiorly at 3 and 3.5 mm from the corneal center on the vertical meridian. Discussion: The changes in total astigmatism of the operated eyes are mainly attributed to the anterior corneal surface. These changes are associated with flattening in the 180 meridian of the cornea, leading to a shift to “with-the-rule” astigmatism.

Transient eye closure and ocular preference in patients with intermittent exotropia

PurposeTo assess the relationship of sensory and motor ocular dominance to transient eye closure (TEC) under bright light conditions in patients with intermittent exotropia. MethodsForty patients (age range, 7-40 years) with intermittent exotropia were included in this prospective study. Motor and sensory ocular dominance were evaluated using the hole-in-the-card and Worth 4-Dot tests. Presence of any outward eye deviation or TEC was assessed and recorded in all participants under bright light conditions. Based on the fusion control grade of exodeviation, patients were assigned to good, fair, and poor control groups, and the results were compared. ResultsA total of 23 patients (58%) showed TEC under bright light: 18 (45%) in the good control group, 14 (35%) in the fair control group, and 8 (20%) in the poor control group. Eighteen patients (56%) with good and fair control showed TEC in the dominant eye. Five (63%) with poor control closed their nondominant eyes, and in all of them, outward eye deviation was observed before TEC. The angle of deviation at far and near and the degree of near stereopsis were not related to presence of TEC (P = 0.70, P = 0.06, and P = 0.34, resp.). ConclusionsIn patients with intermittent exotropia who exhibit TEC under bright light, those with good control tend to close the dominant eye, whereas in the majority of patients with poor control, spontaneous deviation occurs and is then followed by TEC of the nondominant eye.

Binocular Visual Deficits at Low to High Spatial Frequency in Intermittent Exotropia After Surgery.

To investigate binocular visual deficits at low to high spatial frequencies in patients with intermittent exotropia (IXT) after surgical correction, using the binocular orientation combination task. Thirteen patients whose IXT has been aligned surgically (17 ± 4.8 years old; 7 females) and 13 normal individuals (21.8 ± 2.5 years old; 6 females) were recruited. All participants had normal or corrected-to-normal visual acuity. The IXT patients had undergone surgery at least one month prior to the study and achieved successful eye alignment post-surgery. We measured participants' balance points (BPs), defined as the interocular contrast ratio (nondominant eye/dominant eye) when both eyes contributed equally to binocular combination, using the binocular orientation combination task at three spatial frequencies (0.5, 4.0, and 8.0 cycles/degree). The absolute values of log10(BP) (i.e., |logBP|) and the area under of the |logBP| versus spatial frequency curve were used to quantify the extent of binocular imbalance. Surgery aligned the eye position of patients with IXT, with a postoperative exodeviation of -4.92 ± 4.29 prism diopters at distance. Participants' |logBP| values showed significant differences between groups, F(1,24) = 9.175, P = 0.006, and across spatial frequencies, F(2,48) = 7.127, P = 0.002. However, the interaction between group and spatial frequency was not significant, F(2,48) = 0.379, P = 0.687. Patients whose IXT has been alighted surgically experience binocular imbalance across a wide range of spatial frequencies, with greater binocular imbalance occurring at high spatial frequencies than low spatial frequencies.

Stability of the angle of deviation in basic intermittent exotropia (IXT) following surgical correction: a retrospective observational study from southern India

ABSTRACT Introduction: Intermittent exotropia (IXT) is commonly seen in areas with more sunlight, females and Asians. Surgical alignment is recommended to improve binocular function, but a high recurrence rate has been reported. This study aimed to assess the stability of ocular alignment and factors contributing to exodrift post-surgery for IXT over 6-month follow-up. Methods: We retrospectively reviewed the medical records of patients with IXT who underwent unilateral recess resect procedures and attended follow-up examinations for at least six months post-surgery. A significant exodrift was defined as exodrift of more than 10PD at distance and near. Ocular deviation, binocularity, and stereopsis at one and six-month post-operative visits were studied to assess the incidence of exodrift post-surgery and the probable factors causing such drift. Results: Of the 50 patients studied, 26 (52%) were males, 42 (84%) were <20 years. The median age at surgery was 10 years (range 6–14), and the median preoperative angle of deviation was 37 PD. Majority of patients (62%) had exodrift within six months of surgery, and about a quarter of the study population had significant exodrift >10 PD. No clinical factors were found to contribute significantly to exodrift in this study.16 (61.5%) patients attained near and distance BSV post-surgery (p-value: <0.001). Six (12%) and 10 (20%) patients with subnormal near and distance stereopsis, respectively, attained normal stereopsis post-surgery. Conclusion: Over half of the patients operated for IXT had some Exodrift, and one-fourth had significant exodrift within six months post-surgery. Despite improved BSV, many patients failed to attain normal stereopsis with just motor alignment.

Association of Accommodation and Convergence with Axial Length Elongation in Children with Basic Intermittent Exotropia: A 12-Month Observational Study.

The aim of the study was to investigate the association of parameters related to accommodation and convergence and axial elongation in basic intermittent exotropia (IXT) patients and the potential clinical predictors of axial length (AL) growth. A total of 140 basic IXT patients were recruited in this study. The medians of AL growth in different age brackets were chosen to divide the subjects into group A (slower axial elongation group, n = 69) and group B (faster axial elongation group, n = 71). Parameters of dominant and nondominant eyes were compared and analyzed during the 12-month follow-up period. The parameters, including baseline refraction, angle of deviation, Newcastle control score (NCS), accommodative amplitude (AMP), accommodative facility (AMF), accommodative response, positive or negative relative accommodation (PRA/NRA), and near point of convergence (NPC), were analyzed via univariate and multivariate regression. Subjects in the faster axial elongation group tended to have more myopic spherical equivalents (t = 3.956, p &lt; 0.001), greater AMPs of dominant eyes (t = -2.238, p = 0.027), and fewer near points of convergence (t = 2.347, p = 0.020) than in the slower axial elongation group. For dominant eyes, logistic and linear regression analysis revealed that more negative spherical equivalents (OR = 0.603, p &lt; 0.001; β = -0.045, p &lt; 0.001), greater AMPs (OR = 1.201, p = 0.027; β = 0.023, p = 0.010), and less near points of convergence (OR = 0.883, p = 0.021; β = -0.012, p = 0.019) were correlated with the faster axial elongation. For nondominant eyes, a more myopic spherical equivalent (OR = 0.682; p = 0.001; β = -0.029, p = 0.005) was the only parameter correlated with faster axial elongation through regression analysis. In children with basic IXT, faster axial elongation in the dominant eyes was associated with more myopic spherical equivalents, greater AMPs, and lower NPCs. These accommodative parameters can serve as potential clinical indicators for monitoring myopia progression in addition to AL.

Surgical Planning for Pattern Strabismus in Patients with Intermittent Exotropia: Evaluating Techniques and Outcomes

&amp;lt;i&amp;gt;Background or purpose&amp;lt;/i&amp;gt;: Intermittent exotropia is the most common cause of divergent deviation. Pattern strabismus may coexist with horizontal deviations in up 35% of cases. Managing pattern strabismus concomitantly with the correction of horizontal strabismus poses a challenge due to imbalances in force vectors. This study aims to evaluate the effects of planning an intermittent exotropia surgery considering the presence of pattern strabismus and its surgical resolution. &amp;lt;i&amp;gt;Methods&amp;lt;/i&amp;gt;: Observational retrospective study of patients with intermittent exotropia who underwent surgical correction at center between 2017 and 2022. Patients were categorized by the presence of pattern strabismus and furthermore by surgical technique for the correction of said incomitance (weakening of inferior oblique muscles or vertical transposition of lateral rectus muscles). Outcomes of post-surgical horizontal deviation and presence of postoperative pattern strabismus were statistical analyzed between groups using SPSS software v28.0. A p-value &amp;lt;0,05 was considered significant. &amp;lt;i&amp;gt;Results&amp;lt;/i&amp;gt;: A total of 169 patients had surgical correction for intermittent exotropia. Pattern strabismus was observed in 35,5% of patients, primarily V-pattern (88,3%). Most were male (58, 35%) with mean age of 15,13±16,38 years. 41,7% patients with pattern strabismus underwent correction of the incomitance. All techniques showed significant reduction of horizontal near (p&amp;lt;0,001) and distance (p&amp;lt;0,001) deviation. However, incomitance correction favored strongly not only the collapsing of pattern strabismus (p=0,027) but also achieved better results in postoperative distance (p=0,002) and near (p=0,031) horizontal deviation. The two techniques for resolution of pattern strabismus showed comparable results in postoperative horizontal near deviation values and resolution of pattern strabismus, favoring vertical transposition in horizontal distance deviation values (p=0,015). &amp;lt;i&amp;gt;Conclusions&amp;lt;/i&amp;gt;: The presence of pattern deviations should be actively persecuted in pre-operatively appointments to plan the surgery appropriately, as benefits in correcting the vertical incomitance are supported by this study findings. Both vertical transposition of lateral rectus muscles and weakening of inferior oblique muscles are effective techniques to correct vertical incomitances.

Pencil push-up training compared with binocular vision training in the management of slight post-operative under-correction of intermittent exotropia: A prospective study.

This study aims to compare the effectiveness of pencil push-up training and binocular vision training in treating post-operative mild under-correction in patients with intermittent exotropia. A prospective cohort study was conducted, including patients who underwent surgery for intermittent exotropia at Children's Hospital of Nanjing Medical University between June 2022 and January 2023 and experienced post-operative mild under-correction (-8∆ to -15∆). Patients were divided into two groups: pencil push-up training group and binocular vision training group. All patients underwent measurements of exodeviation and stereoacuity at distance and near, sensory fusion, and fusion convergence amplitude. The data were analyzed using independent sample t-tests, repeated measures analysis of variance, and Chi-square tests. There were no statistically significant differences in exodeviation at distance and near between the two training groups before the training. After 6 months of training, the exodeviation at distance and near achieved a significant decrease in both groups (P < 0.05), and the pencil push-up training group showed a similar distance and near exodeviation compared to the binocular vision training group (t = 1.58, P ＞ 0.05; t = 0.43, P ＞ 0.05). After 6 months of training, the binocular vision training group exhibited significantly superior stereoacuity and fusion convergence amplitude compared to the pencil push-up training group (P < 0.001). Both pencil push-up training and binocular vision training are effective in reducing exodeviation in patients with post-operative mild under-correction of intermittent exotropia. However, binocular vision training demonstrates superior efficacy in restoring stereopsis and fusion convergence amplitude compared to pencil push-up training.

Symmetric versus asymmetric surgery for the treatment of intermittent exotropia with equal dominance.

Long-term surgical outcomes were compared between bilateral lateral rectus recession (BLR) and unilateral lateral rectus recession combined with medial rectus resection in the same eye (R&R) for therapy of basic type intermittent exotropia (IXT) with equal dominance. Two hundred and sixty-eight subjects (3-11 years old) with basic IXT with equal dominance who underwent BLR or R&R surgery were enrolled to this study, and with a minimum follow-up period of 18 months. One hundred and fourteen patients underwent BLR surgery and 144 underwent R&R surgery at a single centre. Surgical outcomes between groups were compared. Surgery results were divided into 3 categories: undercorrection/recurrence (exotropia/phoriaå 10PD), success(esotropia/phoria ≤5PD to exotropia/phoria≤10PD), and overcorrection (esotropia/phoriaå 5 PD) according to postoperative deviation angle. No statistical difference was detected between BLR group and R&R group at all intervals with the exception of the last examination, demonstrating a higher success rate and a lower recurrence rate in the BLR group than R&R group at last visit (P = 0.04). Additionally, the BLR group demonstrated a smaller exodrift than the R&R group at distance and near fixation (P = 0.01; P = 0.03). Stereoacuity and exotropia control showed overall improvement following both surgeries, and this improvement had no statistical difference between groups(P > 0.05). BLR showed better long-term results than R&R in the treatment of basic type intermittent exotropia with equal dominance given its low recurrence rate. Both BLR and R&R surgeries could improve stereoacuity function and exotropia control, and to same extents.

Comparison of clinical characteristics in intermittent exotropia patients with different visual perception and oculomotor control

Objective: To explore the clinical characteristics of intermittent exotropia (IXT) patients with different visual perception and oculomotor control. Methods: A cross-sectional study was conducted. Minor IXT patients between March 2021 and May 2023 at Beijing Tongren Hospital were enrolled. Demographic characteristics were recorded, and visual perception and oculomotor control were evaluated. The patients were divided into simultaneous vision disappearing and existing groups, fusion disappearing and existing groups, distant stereoscopic vision disappearing and normal groups, and near stereoscopic vision injury and normal groups. Statistical description was performed by using M (Q1, Q3). Rank sum test was used to compare the Revised Newcastle Control Score (RNCS), near and far strabismus degree, duration of disease, and age of onset among different groups. The correlation between visual perception and oculomotor control and the correlation of duration of disease and age of onset with visual perception and oculomotor control were analyzed by Pearson correlation analysis. Results: A total of 381 patients were enrolled, including 189 males and 192 females, with a median age of 7 (6, 9) years. The incidence of normal visual perception was 19.4% (74/381). Compared with simultaneous vision and fusion existing groups and distant and near stereoscopic vision normal groups, the RNCS [7 (5, 9) vs 4 (3, 6), 6 (5, 8) vs 4 (3, 6), 5 (4, 7) vs 3 (3, 5), and 5 (3, 6) vs 4 (3, 6)], near strabismus degree [65Δ (60Δ, 80Δ) vs 40Δ (30Δ, 50Δ), 60Δ (45Δ, 65Δ) vs 40Δ (30Δ, 50Δ), 50Δ (40Δ, 60Δ) vs 35Δ (30Δ, 45Δ), and 45Δ (30Δ, 60Δ) vs 40Δ (30Δ, 50Δ)] and far strabismus degree [60Δ (50Δ, 75Δ) vs 35Δ (25Δ, 50Δ), 55Δ (41Δ, 65Δ) vs 35Δ (25Δ, 45Δ), 45Δ (30Δ, 60Δ) vs 35Δ (25Δ, 45Δ), and 40Δ (30Δ, 60Δ) vs 35Δ (25Δ, 45Δ)] increased significantly in disappearing simultaneous vision, fusion, and distant stereoscopic vision groups and injury near stereoscopic vision group (all P<0.05). Compared with simultaneous vision and fusion existing groups and distant stereoscopic vision normal group, duration of disease was significant longer in disappearing simultaneous vision, fusion, and distant stereoscopic vision groups [3 (1, 5) years vs 2 (1, 3) years, 2 (1, 4) years vs 1 (1, 3) years, 2 (1, 4) years vs 1 (1, 3) years, all P<0.05]. The age of onset in disappearing distant stereoscopic vision group was significantly lower than normal distant stereoscopic vision group [5 (3, 7) years vs 6 (4, 8) years, P=0.005]. Pearson correlation analysis showed that subjective angle and random dot stereogram (RDS) stereoacuity were positive correlation with RNCS, and the near and far strabismus degree (r=0.414, 0.516, and 0.559, all P<0.001; r=0.153, 0.142, and 0.173, all P<0.05). Subjective angle, RNCS, and the near and far strabismus degree were positive correlation with duration of disease (r=0.238, 0.195, 0.236, 0.239, all P<0.001) and negative correlation with age of onset (r=-0.184, -0.279, -0.112, -0.147, all P<0.05). Conclusions: Nearly 20% of IXT patients have normal visual perception. With the longer duration of disease or lower age of onset, the incidence of abnormal visual perception is higher and injury of visual perception and oculomotor control is more serious.

Maternal Hypertensive Disorder in Pregnancy and Childhood Strabismus in Offspring

Maternal hypertensive disorder in pregnancy (HDP) might affect ocular health in offspring; however, its association with strabismus remains unclear. To examine the association of maternal HDP with overall and type-specific strabismus in offspring. In the Jiangsu Birth Cohort study, a population-based study in China, pregnant women were recruited from April 24, 2014, to November 30, 2018. A total of 6195 offspring had maternal HDP diagnosis information, of whom 3078 were excluded due to having no information on ocular alignment or due to having ocular diseases other than strabismus or refractive error. Offspring underwent ocular examinations at 3 years of age, completed May 21, 2022. Data were analyzed from May 28, 2022, through December 15, 2023. Maternal HDP, categorized into hypertension and preeclampsia or with blood pressure (BP) well controlled (systolic BP, <130; diastolic BP, <80 mm Hg) and poorly controlled (systolic BP, ≥130; diastolic BP, ≥80 mm Hg). The primary outcome was the incidence of strabismus in offspring. Poisson generalized linear mixed models were used to estimate the association between maternal HDP and strabismus. Among the included 3117 children (mean [SD] age, 36.30 [0.74] months; 1629 boys [52.3%]), 143 (4.6%) were exposed to maternal HDP and 368 (11.8%) had strabismus. Offspring exposed to maternal HDP had an 82% increased risk of overall strabismus (relative risk [RR], 1.82 [95% CI, 1.21-2.74]), an 82% increased risk of exophoria (RR, 1.82 [95% CI, 1.11-3.00]), and a 136% increased risk of intermittent exotropia (RR, 2.36 [95% CI, 1.13-4.93]) compared with unexposed offspring. When considering the type of maternal HDP, the risk for all strabismus was high for offspring exposed to preeclampsia (RR, 2.38 [95% CI, 1.39-4.09]) compared with unexposed offspring. When considering the BP control level of maternal HDP, the risk for all strabismus was high for offspring born to mothers with HDP and poorly controlled BP (RR, 2.07 [95% CI, 1.32-3.24]) compared with unexposed offspring. These findings suggest that maternal HDP is associated with an increased risk of offspring strabismus. Early screening of strabismus might be recommended for offspring with maternal HDP. Further exploration of the underlying mechanism of the association between HDP and strabismus is warranted.