Surgery For Intermittent Exotropia Research Articles

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 (BLR) 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 PD 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% (187/242), with a recurrence rate of 19.83% (48/242) and an overcorrection rate of 2.89% (7/242). 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 BLR in intermittent exotropia surgery resulted in successful surgical outcomes with small overcorrection, reducing the risk of consecutive esotropia due to excessive overcorrection.

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

<i>Background or purpose</i>: 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. <i>Methods</i>: 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 <0,05 was considered significant. <i>Results</i>: 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<0,001) and distance (p<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). <i>Conclusions</i>: 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.

The impact of simultaneous correction of the V pattern on the results of surgical treatment in children with intermittent exotropia.

This study is to investigate the impact of the coexistence of basic intermittent exotropia and vertical incomitance in the form of the V and sub-V pattern on the results of surgical correction of intermittent exotropia. The records of 81 pediatric patients who had surgery for intermittent exotropia and a follow-up of more than 1year were reviewed retrospectively. They were divided into groups: a concomitant group which underwent only horizontal muscle surgery of bilateral lateral rectus recession and a V pattern group which had additional inferior oblique recession, further separated into two subgroups: ≥ 15 prism diopters (classic V pattern group) and ≥ 10 < 15 prism diopters (sub-V pattern group). The surgical outcome, deviation control, stereoacuity, and postoperative drift were assessed after 3months and 1year postoperatively. Patients with sub-V and classic V pattern intermittent exotropia showed significantly better surgical success rate (p = 0.025) and less postoperative drift (p = 0.042) than patients without vertical incomitance. One year after surgery, successful surgical outcome was achieved in 83.72% of the vertically incomitant group: 80.76% for the classic V pattern and 88.24% for the sub-V pattern group, while only in 60.53% of nonpattern patients. Patients operated for intermittent exotropia with a coexistent V pattern have consistently better surgical long-term results than those with only horizontal deviation. Additional inferior oblique recessions in the sub V pattern group provided excellent outcomes with no overcorrections; therefore, surgeons should consider addressing vertical incomitance even when the typical criteria for the V pattern are not met.

Six-month binocular stereopsis recovery and its influencing factors in children with intermittent exotropia

ObjectiveTo investigate the recovery of binocular stereopsis recovery and its influencing factors in children with intermittent exotropia after successful correction of eye position.MethodsProspective clinical study. A total of 178 patients, aged 9 ∼ 14 (10.8 ± 1.7) years, who were successfully corrected after intermittent exotropia surgery at the Beijing Tongren Hospital Affiliated to Capital Medical University from October 2023 to September 2023 were collected, the follow-up duration was six-month or longer. Paired t test, Pearson correlation analysis and multivariable linear regression analysis were used to probe preoperative clinical features that may predict the stereopsis six months after surgery.ResultsSix months after surgery, the angle of deviation of the patients met the orthotopic standard, and there was significant difference compared with that before surgery (distant: -2.7△±3.2△ vs. -30.5△±8.4△, t=-25.3, P < 0.001. Near:-3.7△±4.1△ vs. -33.7△±8.0△, t=-26.1, P < 0.001). Distant stereopsis (3.0 ± 0.6 vs. 3.9 ± 0.4, t = 4.9, P < 0.05) and near stereopsis (2.3 ± 0.5 vs. 2.6 ± 0.4, t = 3.8, P < 0.05) were both significantly improved compared with that of before surgery. 17% and 22% patients rebuilt normal distant stereopsis and normal near stereopsis, respectively. Preoperative distant stereopsis (r=-0.26, P = 0.004) and near stereopsis (r=-0.23, P = 0.011) was significantly negatively correlated with convergence reserve. Multivariable analysis showed that patients’ age (β = 0.003, p = 0.037), anisometropia (β = 0.015, p = 0.043), and preoperative distant stereopsis (β = 0.456, p < 0.001) were significantly associated with postoperative distant stereopsis. Patients’ age (β = 0.005, p = 0.044), anisometropia (β = 0.127, p = 0.034), angle of deviation (β=-0.230, p = 0.020), and preoperative near stereopsis (β = 0.136, p < 0.001) were significantly associated with postoperative near stereopsis.ConclusionIXT patients could get eye position fixed after surgery, about 20% patients benefited from stereopsis improvement. Patient’s age, binocular anisometropia, angle of deviation and preoperative stereopsis were independent factors influencing postoperative stereopsis.

Effect of Low-dose Atropine on Myopia Control in Children Operated for Intermittent Exotropia

Purpose: To evaluate the effect of low-dose atropine on myopia control in children with a history of surgery for intermittent exotropia (IXT).Methods: We retrospectively reviewed the medical records of children who used 0.05% atropine for ≥ 1 year to control myopia progression. This group included 45 patients with a history of IXT surgery and 57 patients with no such history. The annual changes in spherical equivalent and axial length were compared 6 months before, 6 months after, and 1 year after atropine instillation between the IXT surgery group and myopia controls. In this comparison, the dominant eye was paired with the right eye and the non-dominant eye with the left eye. We also analyzed the difference between IXT surgery cases corrected within versus not within 10 prism diopters (PD) at the start of low-dose atropine treatment.Results: A total of 102 patients had an average of -3.81 ± 1.53 diopters (D) and used low-dose atropine for an average of 16.8 months from a mean age of 8.2 years. On average, the IXT surgery group underwent muscle surgery for 28.1 PD of IXT at 7.8 years. A year after instillation, the myopia progression rate was -0.52 ± 0.89 D/year and 0.27 ± 0.40 mm/year in the IXT surgery group compared to -0.47 ± 0.83 D/year and 0.31 ± 0.24 mm/year in the myopia control group with no significant differences. However, after 6 months of instillation, the dominant eye in the IXT surgery group exhibited a significantly faster myopia progression rate than the right eye in the myopia control group (-0.84 ± 1.61 D/year vs. -0.56 ± 0.80 D/year, &lt;i&gt;p&lt;/i&gt; = 0.04; 0.27 ± 0.33 mm/year vs. 0.22 ± 0.21 mm/year, &lt;i&gt;p&lt;/i&gt; = 0.02). No difference was found in the myopia control effect between corrected and uncorrected cases in the IXT surgery group.Conclusions: The effect of low-dose atropine on myopia control in children after IXT surgery was similar to that in myopia controls. However, it was less effective in the dominant eye during the early treatment period.

Parental perspectives and concerns regarding exotropia surgery and comparison with clinicians’ predictions

To evaluate parental perspectives and concerns regarding exotropia surgery and compare them with clinicians' predictions of parental responses in Korean pediatric patients with intermittent exotropia. This survey study included the parents of pediatric patients with intermittent exotropia who underwent surgery and clinicians at five hospitals from June 2022 to February 2023, who participated in the Survey of Parental Attitude and Concerns of Exotropia surgery (SPACE) study 1. Parental attitudes and concern about exotropia surgery were assessed using a questionnaire. Clinicians' estimation of each item corresponding to the parental questionnaire was also assessed and compared with parental responses. A total of 266 parents and 41 clinicians were included. More parents responded that information about surgery was most helpful or most commonly received from clinicians than clinicians estimated (P = 0.001). More parents reported actively communicating with the child about surgery than clinicians estimated (P < 0.001). Parents showed a higher level of concern for general anesthesia and the hospital environment than clinicians thought they would (P = 0.002 and P < 0.001, resp.). In the postoperative follow-up items, parents showed high levels of concern regarding postoperative infection (P < 0.001), conjunctival redness (P = 0.040), persistent overcorrection (P < 0.001), and glasses wearing (P = 0.019). Parental perspectives and concerns regarding pediatric intermittent exotropia surgery differed from clinicians' estimations thereof. More parents obtain information on exotropia surgery from clinicians and actively talk about surgery with their child than estimated by clinicians. Parents had a higher level of concern regarding general anesthesia, hospital environment, postoperative infection, conjunctival redness, persistent overcorrection, and glasses wearing compared with clinician estimations.

Effectiveness of Strabismus Surgery in Intermittent Exotropia and Factors Influencing Outcome.

Intermittent exotropia (IXT) is known to relapse after surgery. No factors to predict or prevent recurrence are known with certainty. This study investigated surgical outcome, potential influencing factors, and reoperation rate in patients with IXT. Medical records of 537 patients who underwent surgery for IXT from 2000 to 2022 with preoperative angles of exodeviation of 6 to 50 prism diopters (PD) were retrospectively studied. Multivariate regression analyses of factors influencing surgical outcome on postoperative day 1 (POD1) and reoperation rate were performed. A Kaplan-Meier analysis was performed to illustrate the reoperation rate. After the first surgery, 83.8% of patients had a successful surgical outcome on POD1 (esodeviation ≤ 5 PD or exodeviation ≤ 10 PD). Logistic regression analysis revealed that small preoperative angles of exodeviation increased the probability for surgical success. Follow-up data at different times (4 days-20 years) after surgery were available for 176 patients: 40 patients were still in the range of surgical success, 133 patients had exotropia > 10 PD. Of the follow-up patients, 65 (12.1%) underwent reoperation. A total of 8.5% had their reoperation within one year after the first surgery, 52.9% within five years. Cox regression analysis revealed that large preoperative angles of exodeviation, far/near incomitance and alphabet pattern strabismus increased the risk of reoperation. Most patients achieved surgical success on POD1, yet the squint angles often increased after surgery, resulting in reoperation in some patients. Prospective studies are needed for a better assessment of pre-, peri- and postoperative factors for surgical success in IXT.

Surgical Outcomes in Patients with Intermittent Exotropia with Siblings Who Underwent Surgery by the Same Surgeon

Purpose: We evaluated surgical outcomes in pediatric patients with intermittent exotropia with and without a family history of exotropia surgery performed by the same surgeon.Methods: We conducted a retrospective review of the medical records of pediatric patients aged ≤ 18 years who underwent surgery for intermittent exotropia between September 2015 and December 2021. We compared surgical outcomes between patients with and without a family history of exotropia surgery performed using 1:1 propensity score matching. A successful surgical outcome was defined as achieving alignment between an exodeviation of 10 prism diopters (PD) and an esodeviation of 4 PD.Results: This study included 60 patients with a family history of exotropia surgery and 60 matched controls with no such history. Notably, the log-rank test revealed no significant differences in surgical outcomes between the two groups (&lt;i&gt;p&lt;/i&gt; = 0.622). Furthermore, clinical characteristics, including the onset of exotropia, degree of ocular deviation, and age at surgery, were similar between first- and second-born siblings. Furthermore, no significant differences were observed in surgical outcomes between the two groups (&lt;i&gt;p&lt;/i&gt;= 0.540).Conclusions: Patients with a family history of exotropia surgery do not exhibit significantly different surgical outcomes compared to those with no such history. In addition, no significant differences were observed in surgical outcomes between the first- and second-born siblings.

Clinical Outcomes and Nutritional Status of Children with Intermittent Exotropia Treated with Surgery During the Preschool and Post-School Age

In this study, we compared the clinical outcomes and differences in nutritional status between preschool and post-surgical treatment of intermittent exotropia. We selected 100 children with intermittent exotropia between August 2019 and August 2022 for the study. Among them, 42 children received surgical treatment before school age (4–6 years) and were considered to be in group A, whereas 58 children received surgical treatment after school age (7–12 years) and were considered to be in group B. We found no difference in orthokeratology, overcorrection, or undercorrection rates between the two groups of children before and after surgery (P &gt; 0.05), and the strabismus was lower at 6 and 12 months after surgery than before surgery and lowest at 12 months after surgery (P &lt; 0.05). In addition, the normal rates of visual function, fusion function, and binocular stereopsis were higher in group A than in the control group at 6 and 12 months postoperatively (P &lt; 0.05). The Child Intermittent Exotropia Questionnaire scores were higher in both groups at 12 months postoperatively than at 6 months and were higher in group A than in group B (P &lt; 0.05). Family members of children in group A were more satisfied with the treatment than in group B (P &lt; 0.05), but the difference in albumin, transferrin, and proalbumin before and after surgery was lower in group B than in group A (P &lt; 0.05). It follows that performing intermittent exotropia surgery before school age can more effectively improve the prognosis of children’s binocular visual function, whereas performing intermittent exotropia after school age has less impact on nutritional status.

Myopic progression in school-aged children with moderate intermittent exotropia.

It is still controversial whether intermittent exotropia (IXT) affects myopic progression during the critical period of visual development. This study retrospectively analyzed the long-term myopic changes and the impact of IXT surgery on myopic progression in school-aged children with moderate IXT. The medical records of 65 children from 5 to 13 years old with or without IXT between 2015 and 2021 were retrospectively reviewed. Patients whose spherical equivalent refraction (SER) were less than -3.00 diopter (D) were included and divided into three groups: IXT surgery group (Group A), which comprised 22 IXT patients who received IXT surgery, IXT observation group (Group B), which comprises 19 IXT patients who only received long-term observational follow-up; and normal control group (Group C), which comprised 24 normal controls without IXT. The main outcome measurement was the rate of myopic progression, which was defined as the mean myopic shift in SER per year. The 3- and 5-years long-term follow-up rates of myopic progression were -0.47 ± 0.28 D per year and -0.48 ± 0.23 D per year respectively in Group B, and those were significantly slower than that in Group C (-0.73 ± 0.32 D per year and -0.76 ± 0.19 D per year respectively). However, there was no significant difference in the rate of myopic progression between Group A and B or between Group A and C. Moderate IXT may have lower rate of myopic progression in school-aged children. Whether IXT surgery influence the rate of myopic progression still needs further study.

Initial postoperative plasticity as a predictor of mid-term stereoacuity outcome after surgery for intermittent exotropia

BackgroundIntermittent exotropia (IXT) would cause different degrees of damage to stereopsis. We aimed to introduce a visual perception plasticity score (VPPS) that reflects initial postoperative plasticity and evaluate its effectiveness in predicting the mid-term surgical outcome in IXT patients.MethodsA total of 149 patients with intermittent exotropia who underwent surgery in November 2018 and October 2019 were recruited. All subjects underwent detailed ocular examinations before and after surgery. VPPS were calculated based on visual perception examination system at one week postoperatively. Demographic, angle of deviation and stereopsis were collected and analyzed with regard to the VPPSs preoperatively and at one week, one month, three months, six months postoperatively. Predictive performances of VPPS were assessed using receiver operating characteristic (ROC) curves, the area under the curve (AUC) and cut-offs were obtained.ResultsOf the 149 patients, the average deviation was 43Δ at distance and 46Δ at near. The average rate of normal stereopsis before surgery was 22.81% at distance and 29.53% at near. Higher VPPS was associated with preoperative better near stereoacuity (r = 0.362, p = 0.000), less angle of deviation at distance (r=-0.164, p = 0.046), and better near (r = 0.400, p = 0.000) and distant stereoacuity (r = 0.321, p = 0.000) during the early postoperative period (1 week). The areas under the curves suggested that VPPS could be an effective predictor of sensory outcome(AUC>0.6). Cut-off values of 50 and 80 were calculated for VPPS using ROC curve analysis.ConclusionHigher VPPSs were associated with a greater possibility of stereopsis improvement in patients with IXT. VPPS is a potentially promising indicator to predict the mid-term surgical outcome of intermittent exotropia.

Early post-operative angle as a predictor of surgical success in adult patients with intermittent exotropia

ABSTRACT Purpose: Intermittent exotropia is a condition where divergent strabismus is present at certain times or fixation distances and is surgically treated with bilateral lateral rectus recession or unilateral lateral rectus recession with medial rectus resection. The main purpose of our study is to assess the relationship between the initial post-operative deviation and surgical outcomes in adult exotropes undergoing recess-resect surgery. Methods: A retrospective chart review was performed on adult patients who underwent unilateral recess-resect surgery for intermittent exotropia between March 2010 and February 2022 at a single institution with at least 3 months of follow-up. Based on their motor alignment at 2 weeks following surgery, they were categorized as having exodeviation, esodeviation within 10 PD and esodeviation exceeding 10 PD. Surgical success was defined as motor alignment within 10 PD of exotropia and 5 PD of esotropia at distance and near at final follow-up. Results: 93 patients were included, 55% female and average age was 37 years. At postoperative week 2, 26 patients demonstrated residual exodeviation (Group A), 53 patients demonstrated an esodeviation of within 10 PD (Group B) and 14 patients demonstrated an esodeviation greater than 10 PD (Group C). There were no significant differences in pre-operative and demographic factors between the group. At the final follow-up, surgical success was observed in 57 patients: 12 in Group A, 41 in Group B and 4 in Group C (P < .01). Conclusion: Overcorrection of within 10 PD at 2 weeks following surgery showed a more favorable surgical outcome compared to exodeviation or esodeviation exceeding 10 PD.

Risk of consecutive esotropia after surgery for intermittent exotropia according to passive duction force.

To determine the relationship between consecutive esotropia (ET) and passive duction force (PDF) in patients with intermittent exotropia (XT). The study enrolled 70 patients in whom PDF was measured under general anesthesia prior to XT surgery. The preferred eye for fixation (PE) and the nonpreferred eye for fixation (NPE) were determined using a cover-uncover test. The patients were subdivided into two groups according to the angle of deviation at 1 month postoperation: (1) consecutive ET (CET group), >10 prism diopters (PD) of ET; and (2) non-CET (NCET group), ≤10 ET or residual exodeviation. The relative PDF of the medial rectus muscle (MRM) was obtained by subtracting the ipsilateral PDF of the lateral rectus muscle (LRM) from the PDF of the MRM. The PDFs for the LRM in the PE in the CET and NCET groups were 47.28 g and 58.59 g, respectively (p = 0.147), and 56.18 g and 46.59 g for the MRM (p = 0.11), and in the NPE were 59.84 g and 55.25 g, respectively, for the LRM (p = 0.993), and 49.12 g and 50.53 g, respectively, for the MRM (p = 0.81). However, in the PE, the PDF in the MRM was larger in the CET group than in the NCET group (p = 0.045), which was positively associated with the postoperatively overcorrected angle of deviation (p = 0.017). An increased relative PDF in the MRM in the PE was a risk factor for consecutive ET after XT surgery. Quantitative evaluation of the PDF could be considered when planning strabismus surgery to achieve the desired surgical outcome.

Timely Surgery in Intermittent Exotropia

ABSTRACT Introduction Surgical treatment of intermittent exotropia is indicated when periods of monocular deviation become longer or control over deviation deteriorates. However, there is no consensus on the ideal age to perform surgery in patients with intermittent exotropia. Purpose To evaluate ocular alignment and sensory results at 12 months of follow-up, in patients who received surgical treatment for intermittent exotropia at ≤4 years or >4 years. Methods A retrospective, observational, analytical, and comparative cohort study was carried out, which included 97 patients treated surgically for X(T), divided into two groups, ≤4 years and >4 years. The motor and sensory results of the patients were evaluated on the first day, 1 month and 12 months of postoperative follow-up. Results In this study, no statistically significant differences were observed in ocular alignment and postoperative sensory results at 1 year of follow-up between both groups. Conclusion Age is not a variable that influences surgical results in patients with intermittent exotropia. Instead of early or delayed surgery, we propose to use the term “timely surgery.”

Botulinum toxin augmented bilateral lateral rectus recession versus three muscles surgery in large-angle intermittent exotropia.

To report the surgical outcomes of correcting large angle intermittent exotropia in adult patients by bilateral lateral rectus muscle recession with intraoperative use of botulinum toxin and to compare the results with those of bilateral lateral rectus muscle recession and unilateral medial rectus resection. The medical records of patients who underwent surgical correction of large angle intermittent exotropia [exotropia >50 prism dioptre (PD)] were retrospectively reviewed. Two groups of patients were identified; Group I (21 patients) had bilateral lateral recti recession augmented with intraoperative botulinum toxin A (BTA) injection into the recessed muscles and group II (30 patients) were treated by bilateral lateral recti recession with unilateral medial rectus muscle resection. Preoperative data were extracted for age, gender, refraction, type of exotropia, angle of stereopsis and angle of deviation. The main outcome measures were the postoperative angle of deviation and stereoacuity angle by Titmus test measured at the end of one year of postoperative follow up. By the end of the first postoperative year, 10 patients in group I (47.6%) and 20 patients in group II (66.7%) achieved esotropia/esophoria <5 PD or exotropia/exophoria <10 PD. The difference in surgical success rate was not statistically significant (P=0.1) but there was a statistically significant higher rate of undercorrection in group I (P=0.03). On the other hand, 3 patients in group I (14.3%) and 5 patients in group II (16.7%) had improved stereopsis; this difference in the sensory outcome was not statistically significant (P=0.8). In the BTA augmented surgery group, good stereoacuity and smaller preoperative angle of deviation were associated with significantly higher surgical success rate (P=0.004, 0.01 respectively). BTA augmented bilateral lateral recti recession is associated with higher rate of undercorrection as compared to bilateral lateral recti recession with unilateral medial rectus resection in the correction of large angle intermittent exotropia. The surgical success rate in BTA augmented surgery group is observed to be higher in patients with preoperative smaller angle of deviation and in patients with good stereoacuity.

Effect of Mild to Moderate Myopic Refractive Error on Surgical Outcomes of Intermittent Exotropia in Children

Purpose: We evaluated the effect of myopia on lateral rectus recession in children with intermittent exotropia.Methods: Medical records of patients with mild to moderate myopia who underwent lateral rectus recession for intermittent exotropia surgery were retrospectively reviewed. Patients were grouped into three groups according to their spherical equivalents (SEs) (group 1: SE &gt; -1.0 diopter [D]; group 2: -3.0 D &gt; SE ≥ -1.0 D; group 3: SE ≤ -3.0 D). The success rate of surgery after 1 month, 3 months, and 12 months, and the degree of correction were reviewed. Surgeries were considered successful if the amount of exo/eso-tropia or phoria was within +10/-10 prism diopters (PD) after 12 months.Results: There were no significant differences in mean exodeviation at any time point among the three groups. The degree of correction per lateral muscle recession (PD/mm) was 2.05 ± 0.40, 2.33 ± 0.57, and 2.00 ± 0.30; 2.13 ± 0.46, 2.06 ± 0.26, and 2.14 ± 0.13; and 1.93 ± 0.47, 2.11 ± 0.32, and 1.92 ± 0.25 at 1, 3, and 12 month(s) after surgery in the three groups; however, the results were statistically significant at 3 months only. The surgical success rate was 81.82%, 100%, and 100% in the groups, respectively, with no significant differences among groups.Conclusions: There was no difference in the surgical success rate or degree of correction among groups with mild to moderate myopia. No additional surgical correction is needed in myopic patients with intermittent exotropia.

Comparison of sensory outcomes in patients with successful motor outcome versus recurrent exotropia after surgery for intermittent exotropia

Here, we compared sensory outcomes between patients with successful motor outcomes and recurrent exotropia after intermittent exotropia surgery. We retrospectively analyzed 303 patients who underwent surgery for intermittent exotropia, divided into two groups: successful motor outcome defined as an alignment between 10 prism diopters (PD) exodeviation and 5PD esodeviation at the final follow-up (Group A, n = 177) and residual or recurrent exotropia defined as exodeviation > 10 PD (Group B, n = 126). Preoperative and postoperative (at final visit) sensory outcomes were compared using the Titmus stereotest and distance Worth 4-dot test. Stereoacuity significantly improved postoperatively in both successful motor outcome group (Group A) and residual or recurrent exotropia group (Group B). However, stereoacuity did not differ between groups preoperatively and postoperatively. On the other hand, fusion rates for the Worth 4-dot test were significantly higher in group A than in group B, preoperatively and postoperatively, and significantly increased postoperatively only in group A. Therefore, the distance Worth 4-dot test may be useful for evaluating postoperative prognosis and preoperative sensory status.

Results of fusional vergence therapy in managing consecutive esotropia: A case series.

To analyze the efficacy of fusional vergence therapy (FVT) in management of consecutive esotropia with diplopia after intermittent exotropia (IXT) surgery. The current study is carried on how FVT affects the duration of treatment, sensory fusion, and exotropic drift. This was a retrospective study for the medical record of 11 patients with consecutive esotropia after IXT surgery of 543 patients over the period of 5 year, with mean surgery age of 9.5 (range: 4-33 y). FVT was planned after minimum 6 weeks of surgery and was considered for maximum 24 weeks. Patients underwent a combination of office-based and home-based FVT. Successful outcome of therapy was considered where diplopia resolves in free space and achieves sensory fusion, stereopsis with no manifest deviation. Record of 543 patients who had horizontal muscle surgery for IXT were identified and reviewed. Records of 11 patients who showed consecutive esotropia of 10 prism diopter (PD) or more with normal retinal correspondence, with or without diplopia complaint, after 6 week of surgery and had undergone vision therapy management were reviewed. A successful outcome of binocular single vision with good sensory and motor fusion with no manifest deviation or prism requirement was achieved with in the mean duration of 4.8 month of therapy. With a mean duration of 4 weeks of therapy, the mean angle of deviation reduced by 53% for distance (17 PD to 8 PD) and 27% for near (11 PD to 8 PD) and mean stereopsis improvement by 80% with 94% patients demonstrating sensory fusion on Bagolini test and 94% of patients having no symptoms of diplopia or squint. With nonsurgical management involving refractive error correction, FVT, and prism, consecutive esotropia was resolved in 74% cases. Management of consecutive esotropia with FVT can result in satisfactory sensory fusion and successful motor alignment.

Accommodative responses under various viewing conditions in surgical patients with intermittent exotropia: an institutional, retrospective study

PurposeTo investigate the difference of spherical equivalent (SE) and pupil diameter in adult patients with intermittent exotropia (IXT) under various viewing conditions before and after surgery.MethodsWe retrospectively analyzed the medical records of 23 adult patients who underwent a surgery for IXT. The angle of deviation was measured by the prism and alternative cover test. Refractive error and pupil diameter were measured using the Grand Seiko WAM-5500 open-field autorefractor under binocular and monocular viewing conditions when patients stared at distance (6 m) and near (33 cm). Regression analyses were performed between accommodative load and the angle of deviation.ResultsTwenty-three patients (10 males, 13 females) with a mean age of 31.17±8.95 years, of whom 13 (56.5%) had the right eye as the dominant eye. The mean angle of deviation at near and at distance was 69.57±26.37 and 65.43±28.92 prism diopters respectively. There were no significant differences in accommodative response and pupil diameter between the dominant and non-dominant eyes. SE decreased when patients changed from monocular to binocular viewing, and from distant to near viewing (all P< 0.05), so as the pupil diameter (all P< 0.001). During binocular, not monocular viewing, SE was significantly greater after operation than it was before operation (P< 0.001). Accommodative load and pupillary constriction narrowed (p< 0.001) after the operation. Linear regression analysis showed a correlation between the angle of deviation at distance and accommodative load at distance (r2=0.278, p=0.010) and at near (r2=0.332, p=0.005).ConclusionIn order to maintain ocular alignment, patients with IXT suffer a large accommodative load, which is related to the angle of deviation. Surgery helps eliminating extra accommodation.