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Background: Intermittent exotropia (IXT) is one of the most common forms of strabismus usually seen in the pediatric age group, the prevalence of IXT is higher in Africa and the Middle East. IXT treatment strategies include both surgical and non-surgical methods, non-surgical management is preferred in general as it is less invasive and avoids the risks associated with surgery and anesthesia., Aims: This study aims to determine the effectiveness of patching therapy for the treatment of IXT in different age groups and to compare the success of patching therapy in preventing surgery in IXT patients in different age groups., Methodology: A retrospective chart review was conducted from September 2022 until February 2023 at King Abdulaziz University Hospital in Riyadh. The data was collected retrospectively from electronic medical records from 2016 to 2021 of all patients diagnosed with IXT and were managed by patching therapy fitting the inclusion criteria., Results: A total of 76 patients with IXT enrolled in the study with 56.5% of the participants were older than 7 years old. Overall, there was no improvement in the angle of deviation but 34% of patients had improved control over the follow-up period. 55.3% of the participants didn't require surgery. Younger age, longer duration of patching per month, and good compliance were significantly associated with treatment success., Conclusion: Younger age groups were more likely to benefit from patching therapy than older age groups, and good compliance to patching therapy is an important factor in preventing the need for surgery., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Purpose: To report the change in the magnitude of near exodeviation in children with symptomatic convergence insufficiency successfully treated with office-based vergence/accommodative therapy in the Convergence Insufficiency Treatment Trial-Attention and Reading Trial., Methods: A total of 131 children 9-14 years of age with symptomatic convergence insufficiency classified as successfully treated with office-based vergence/accommodative therapy at the 16-week outcome visit were included. Masked examiners measured the near ocular deviation by the prism and alternate cover test at baseline, primary outcome and 1-year post-treatment. The mean change in near deviation was calculated from baseline to primary outcome, from primary outcome to 1-year post-treatment and from baseline to 1-year post-treatment., Results: Of the 131 participants successfully treated with vergence/accommodative therapy, 120 completed the 1-year post-treatment visit. A significant change in near exodeviation was observed at baseline to primary outcome (2.6Δ less exo, p < 0.001, moderate effect size d = 0.61) and at baseline to 1-year post-treatment (2.0Δ less exo; p < 0.001, small effect size d = 0.45). The change from primary outcome to 1-year post-treatment (0.6Δ more exo; p = 0.06, small effect size d = 0.11) was not significant. Forty per cent (48/120) of participants had a decrease in near exodeviation >3.5∆ (expected test/retest variability) between baseline and the primary outcome examination. Of the 120 participants, one (1.0%) was esophoric at the primary outcome and was subsequently exophoric at 1-year post-treatment. Four participants (3.3%) who were orthophoric or exophoric at the primary outcome were esophoric (all ≤3∆) at the 1-year post-treatment visit., Conclusion: On average, the near exodeviation was smaller in size immediately after the discontinuation of vergence/accommodative therapy (2.6∆, moderate effect size) and 1 year post vergence/accommodative therapy (2.0∆, small effect size) in children with convergence insufficiency who were successfully treated; 40% had a clinically meaningful decrease in exophoria. The development of near esophoria was rare., (© 2024 The Authors. Ophthalmic and Physiological Optics published by John Wiley & Sons Ltd on behalf of College of Optometrists.)

Importance: Increased myopic shift was found to be associated with 1 year of overminus spectacle treatment for children with intermittent exotropia (IXT). Persistence of myopic shift after discontinuing overminus spectacles is unknown., Objective: To compare refractive error change over 3 years in children with IXT originally treated with overminus vs nonoverminus spectacles., Design, Setting, and Participants: This study was an 18-month extension of the Trial of Overminus Spectacle Therapy for Intermittent Exotropia cohort, which previously randomized children aged 3 to 10 years with IXT and baseline spherical equivalent refractive error (SER) between -6.00 diopters (D) and 1.00 D to overminus spectacles (-2.50 D for 12 months, -1.25 D for 3 months, and nonoverminus for 3 months) or nonoverminus spectacles. Children were recruited from 56 sites from July 2010 to February 2022. Data were analyzed from February 2022 to January 2024., Interventions: After trial completion at 18 months, participants were followed up at 24 and 36 months. Treatment was at investigator discretion from 18 to 36 months., Main Outcomes and Measures: Change in SER (cycloplegic retinoscopy) from baseline to 36 months., Results: Of 386 children in the Trial of Overminus Spectacle Therapy for Intermittent Exotropia, 223 (57.8%) consented to 18 months of additional follow-up, including 124 of 196 (63.3%) in the overminus treatment group and 99 of 190 (52.1%) in the nonoverminus treatment group. Of 205 children who completed 36-month follow-up, 116 (56.6%) were female, and the mean (SD) age at randomization was 6.2 (2.1) years. Mean (SD) SER change from baseline to 36 months was greater in the overminus group (-0.74 [1.00] D) compared with the nonoverminus group (-0.44 [0.85] D; adjusted difference, -0.36 D; 95% CI, -0.59 to -0.12; P = .003), with 30 of 112 (26.8%) in the overminus group having more than 1 D of myopic shift compared with 14 of 91 (15%) in the nonoverminus group (risk ratio, 1.8; 95% CI, 1.0-3.0). From 12 to 36 months, mean (SD) myopic shift was -0.34 (0.67) D and -0.36 (0.66) D in the overminus and nonoverminus groups, respectively (adjusted difference, -0.001 D; 95% CI, -0.18 to 0.18; P = .99)., Conclusions and Relevance: The greater myopic shift observed after 1 year of -2.50-D overminus lens treatment remained at 3 years. Both groups had similar myopic shift during the 2-year period after treatment weaning and cessation. The risk of myopic shift should be discussed with parents when considering overminus lens treatment., Trial Registration: ClinicalTrials.gov Identifier: NCT02807350.

Background: Intermittent exotropia is a common form of pediatric strabismus characterized by intermittent misalignment of the eyes. This study investigated the clinical effectiveness of alternating occlusion therapy as a non-surgical alternative for children aged 3-10 with intermittent exotropia., Methods: A comprehensive review of recent research, including randomized controlled trials and case series, was conducted. These studies utilized standardized control scores to assess the impact of alternating occlusion therapy on both distance and near control of alignment., Results: The findings indicated a significant improvement in exotropia control, particularly at distance fixation, among children undergoing alternating occlusion therapy. While some variability in outcomes exists, all articles demonstrate positive responses to this noninvasive approach. Notably, the patients with poor initial control tended to benefit the most., Discussion: The potential advantages of alternating occlusion therapy are its cost-effectiveness and noninvasive nature. However, it is essential to manage patient and parental expectations and address potential drawbacks, including social stress, irritation associated with occlusion therapy and the possibility that strabismus surgery may still be needed in the future because of decompensation., Conclusion: Alternating occlusion therapy is a promising option to improve exotropia control in children with intermittent exotropia. It offers a viable non-surgical strategy to delay or potentially avoid strabismus surgery, although approximately 45% of the patients might eventually still require strabismus surgery. Healthcare providers should carefully weigh the benefits and limitations of this intervention to make informed decisions through shared decision-making with the patients and their families. This review offers diverse insights into the clinical management of intermittent exotropia and provides an evidence-based alternative to surgical interventions.

Purpose: Nonsurgical consecutive exotropia (NCX) occurs when an esotropia (ET) spontaneously converts to exotropia (XT) without surgical intervention. Although NCX is considered to occur in early-onset accommodative ET with high hyperopia, consensus on causation is lacking. We report the clinical characteristics of NCX and assess the response to conservative management., Design: Retrospective, multicenter, observational case series., Methods: Patients aged 6 months and older with an initial diagnosis of ET who converted to XT without surgical intervention. Sensory strabismus was excluded. Age, visual acuity, cycloplegic refraction, glasses prescriptions, deviation, and binocular vision were collected., Results: Forty-nine children were included with a mean age of 3.5 ± 1.6 years and 8.4 ± 3.6 years at the time of ET and NCX, respectively. Mean refractive error was +4.40 ± 2.13 diopters (D) and +4.05 ± 2.74 D at the time of ET and NCX, respectively. Accommodative ET occurred in 60% of cases, and only 35.7% were high hyperopes. All but 1 patient presented with XT at distance. In response to the XT, a mean decrease in hyperopic prescription of 1.55 ± 0.48 D was given (N = 17); only 1 case reverted to ET. Eventually, 43% underwent XT surgery, with similar rates between those who had refractive management and those who did not., Conclusions: NCX occurs in both accommodative and nonaccommodative ET; high hyperopia is present in only one-third of cases. On average, drift to XT occurs within 5 years. Refractive management has a modest result. No predictive risk factors were identified. Our findings challenge hyperopia-linked theories of causation. Nonrefractive explanations, such as the role of the vergence system, deserve further study., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: Overminus lens is an effective non-surgical treatment of intermittent exotropia (IXT). Whether this treatment causes development of myopia is recently debated. This study evaluated ocular biometric changes in IXT children treated with and without overminus lens., Methods: Children with IXT were randomly assigned to control and overminus groups. Cycloplegic refraction, axial length and other parameters (keratometry, anterior chamber depth and lens thickness) were evaluated for up to 30 months and compared between the groups. Axial length to corneal curvature (AL/CR) ratio was examined as an indicator of myopia progression. Changes prior to and after overminus were also assessed in a subgroup., Results: Mean age of the total 84 subjects (58% women) was 7.2 years (range 4-15 years). Baseline refractive and biometric parameters of 39 control and 45 overminus subjects were not significantly different. Mean±SD change in refraction was -0.34±0.45D in controls and -0.41±0.66D in overminus group (p=0.527). AL increased by 0.29±0.20 millimetre (mm) in controls and 0.28±0.23 mm in overminus group (p=0.766). In the subgroup, the changes before and after overminus therapy was not significantly different (p>0.05). AL/CR ratio was maintained from baseline to follow-up visit (p=0.298) in both groups., Conclusion: No significant differences in biometry or refraction were found between the two groups and before and after the therapy. We conclude that the overminus therapy in children, not accounting for other myopia risk factors, does not affect normal refractive growths., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. No commercial re-use. See rights and permissions. Published by BMJ.)

Significance: This pilot randomized trial, the first to evaluate a specific base-in relieving prism treatment strategy for childhood intermittent exotropia, did not support proceeding to a full-scale clinical trial. Defining and measuring prism adaptation in children with intermittent exotropia are challenging and need further study., Purpose: This study aimed to determine whether to proceed to a full-scale trial of relieving base-in prism spectacles versus refractive correction alone for children with intermittent exotropia., Methods: Children 3 years old to those younger than 13 years with distance intermittent exotropia control score of ≥2 points on the Intermittent Exotropia Office Control Scale (Strabismus 2006;14:147-150; 0 [phoria] to 5 [constant]), ≥1 episode of spontaneous exotropia, and 16 to 35∆ by prism-and-alternate-cover test, who did not fully prism adapt on a 30-minute in-office prism-adaptation test were randomized to base-in relieving prism (40% of the larger of distance and near exodeviations) or nonprism spectacles for 8 weeks. A priori criteria to conduct a full-scale trial were defined for the adjusted treatment group difference in mean distance control: "proceed" (≥0.75 points favoring prism), "uncertain" (>0 to <0.75 points favoring prism), or "do not proceed" (≥0 points favoring nonprism)., Results: Fifty-seven children (mean age, 6.6 ± 2.2 years; mean baseline distance control, 3.5 points) received prism (n = 28) or nonprism (n = 29) spectacles. At 8 weeks, mean control values were 3.6 and 3.3 points in prism (n = 25) and nonprism (n = 25) groups, respectively, with an adjusted difference of 0.3 points (95% confidence interval, -0.5 to 1.1 points) favoring nonprism (meeting our a priori "do not proceed" criterion)., Conclusions: Base-in prism spectacles, equal to 40% of the larger of the exodeviations at distance or near, worn for 8 weeks by 3- to 12-year-old children with intermittent exotropia did not yield better distance control than refractive correction alone, with the confidence interval indicating that a favorable effect of 0.75 points or larger is unlikely. There was insufficient evidence to warrant a full-scale randomized trial., Competing Interests: Conflict of Interest Disclosure: None of the authors have reported a financial conflict of interest., (Copyright © 2023 American Academy of Optometry.)

Background: To compare the effect of alternate part-time patching and pencil push-up training on control ability in patients with intermittent exotropia., Methods: Patients (3-7 years old) with previously untreated intermittent exotropia were randomly assigned to receive alternate part-time patching, pencil push-up training, or observation. Control ability was assessed using the Office Control Score. Stereoacuity at 40 cm was evaluated with Titmus. Results were compared after a 12-week follow-up., Results: Ninety-two patients (28 in patching, 30 in pencil push-ups, and 34 in observation group) completed 12-week follow-up assessments. Based on 6-point scale, the mean deviation control was significantly better in patching and pencil push-up group after 12 weeks at distance (P = 0.002 and 0.026, respectively). Furthermore, there were greater control changes in patching and pencil push-up groups in comparison with observation group from baseline to 12 weeks (P<0.001; P = 0.003, respectively). After 12 weeks of treatment, stereoacuity and stereoacuity changes were not significantly different between either the intervention group or control group (P = 0.140 and 0.393, respectively)., Conclusions: Based on the common office control scale, alternate part-time patching and pencil push-up training were effective treatment strategies for intermittent exotropia., (© 2022. The Author(s).)

Purpose: To evaluate the factors associated with the efficacy of low-dose part-time patching in children with intermittent exotropia (IXT)., Methods: In this prospective observational study, we enrolled 186 patients diagnosed with IXT. Outcome measures included office based control scales, magnitude of exo-deviation, and stereoacuity at near and distance after daily patching for 2 h. We analyzed the clinical data and demographic factors association with improvement of IXT., Results: The study was completed by 152 subjects of total enrolled patients on a consecutive basis followed up for 1 year. Decrease in the magnitude of exo-deviation, improvement of control, and or gain of stereoacuity were observed in 31.6% patients of the recruited subjects after part-time patching. Multivariate analyses showed that prognostic factors determining improvement to part-time patching included convergence insufficiency (CI) type IXT ( p  = 0.016), poor distance stereopsis ( p  = 0.044), and large exotropic deviation at distance ( p  = 0.025)., Conclusions: CI-type exotropia, large distance magnitude of exo-deviation, or poor distance stereopsis appear to be associated with a better response to part-time patching. Therefore low dose part-time patching may be a useful non-surgical treatment alternative to delay surgery in these cases.

Significance: A rigorously designed and calibrated symptom questionnaire for childhood intermittent exotropia would be useful for clinical care and for research., Purpose: The aim of this study was to Rasch-calibrate and evaluate the previously developed Child Intermittent Exotropia Symptom Questionnaire using data gathered as part of a randomized clinical trial., Methods: The questionnaire was administered to 386 children aged 3 to 10 years with intermittent exotropia who were enrolled in a randomized clinical trial comparing overminus with nonoverminus spectacles. Participants were followed at 6 and 12 months while on treatment and at 18 months off treatment. Factor analysis determined dimensionality, and Rasch analysis evaluated questionnaire performance. Logit values were converted to 0 (best) to 100 (worst). We evaluated differences in questionnaire scores between treatment groups and time points, and correlations with control scores., Results: The Child Intermittent Exotropia Symptom Questionnaire was unidimensional. Rasch analysis indicated that there was no notable local dependence and no significant differential item functioning for sex or age. There was suboptimal targeting (mean logit, -1.62), and person separation was somewhat poor (0.95). There were no significant differences in the Child Intermittent Exotropia Symptom score between overminus spectacles and nonoverminus spectacles at 6, 12, and 18 months. Combining data from both treatment groups, there was significant improvement from baseline at all follow-up visits (e.g., mean change from baseline to 12 months, -6.6 points; 95% confidence interval, -8.6 to -4.6). Child Intermittent Exotropia Symptom scores were not correlated with distance or near control scores at 12 months., Conclusions: The seven-item Rasch-scored Child Intermittent Exotropia Symptom Questionnaire is limited by suboptimal performance. Future study is needed to determine whether it may be useful for clinical practice and for research., Competing Interests: Conflict of Interest Disclosure: None of the authors have reported a financial conflict of interest., (Copyright © 2022 American Academy of Optometry.)

Background: Aim of this study was to evaluate the efficacy of a novel algorithm to customise overminus lens therapy in intermittent exotropia (IXT) based on clinical factors associated with control of the deviation., Methods: Clinical parameters in IXT vary among individuals. Based on individual's physiological factors, an algorithm was developed. Children aged between 4 and 15 years with IXT were randomised into OML and observation groups. Participants in the observation group were corrected for any significant refractive error. IXT control score, angle of deviation, refraction, axial length and stereopsis were examined at baseline and follow up ranging between 6 and 15 months and compared. Compliance and tolerance to OML was determined by a symptom survey., Results: The OML power ranged between -1.00D and - 6.25D. Of the total 141 participants (mean age 6.8 ± 2.5 year), 77 were in the OML and 66 were in observation group. IXT control score improved (mean difference - 2.5 ± 1.1; p < 0.001) and angle of deviation reduced (6.9 ± 7.2pd; p < 0.001) significantly in the OML group only. Compliance rate to OML wear was 80%; 90% never or rarely experienced asthenopia symptoms. Slightly greater myopic shift (-0.36 ± 0.53D vs. -0.18 ± 0.55D) and change in axial length (0.17 vs. 0.14 mm) were observed in the OML group, but these differences were not statistically significant., Conclusions: A customised OML, calculated using this novel algorithm was effective in improving distance control, angle of deviation and stereopsis. Glasses wear was highly tolerable., (© 2022 Royal Australian and New Zealand College of Ophthalmologists.)

Purpose: To explore the relationship between ocular position control ability and stereopsis recovery in children with intermittent exotropia, and to analyze the influencing factors of distance stereopsis recovery., Methods: In this retrospective study, 78 children with small angle intermittent exotropia received vision training for 3 months. All patients were examined for distance stereopsis with the synoptophore and for near stereopsis with the Titmus stereogram before and after the training. The patients were divided into low and high Newcastle Control Score (NCS) groups. The stereopsis of the two groups was compared. Logistic regression analysis was used to analyze the influencing factors of distance stereopsis recovery., Results: Among 78 children with intermittent exotropia, 33 had near stereopsis (42.3%) and 22 had distance stereopsis (28.2%); the difference was significant ( P < .05). After 3 months of training, there were statistically significant differences between distance and near stereopsis in the low NCS group and the high NCS group (chi-square = 7.127, P = .008; chi-square = 13.005, P < .001). The number of children with distance and near stereopsis in the low NCS group increased significantly compared with before training (chi-square = 13.471, P < .001; chi-square = 22.244, P < .001). Multivariate logistic regression analysis showed that age of onset (odds ratio [OR] = 3.768, P = .001), near point of convergence (OR = 0.347, P = .002), and NCS (OR = 0.142, P = .002) were risk factors that affected stereopsis recovery in children with small angle intermittent exotropia., Conclusions: Control ability is one of the important indicators to assess the severity of intermittent exotropia. The worse the control ability, the more difficult the recovery of stereopsis. Age of onset, near point of convergence, and NCS are risk factors that affect the recovery of distance stereopsis. [ J Pediatr Ophthalmol Strabismus . 2021;58(6):350-354.] .

Purpose: This study reports clinical opinions and preferences on the non-surgical management of intermittent exotropia (IXT) among practitioners in China., Methods: An online survey was developed and distributed through professional bodies. The study was conducted from July 25 th to August 3 rd , 2019. A total of 300 ophthalmologists and 188 optometrists responded., Results: Of 488 participants, 257 (53%) considered fusion defects as the main cause of IXT, and 299 (61%) took IXT as a progressive disorder. Two hundred and seventy-one (56%) participants considered orthoptic exercises as the most effective non-surgical intervention for IXT. Likewise, 245 (50%) participants reported that orthoptic exercises were their most frequent non-surgical option, followed by observation (178, 37%). There are discrepancies between ophthalmologists and optometrists. A greater proportion of ophthalmologists (201, 67%) shared the view that IXT worsens over time (98, 52%) ( p = .001). Additionally, ophthalmologists (121, 40%) tended to prefer observation compared with optometrists (57, 30%) ( p = .021)., Conclusions: This study shows that there is no general consensus on the non-surgical management of IXT in China. Given the lack of robust evidence, the findings from this study highlight the need for future randomized clinical trials to validate the effectiveness of non-surgical interventions, orthoptic exercises in particular, and to establish treatment guidelines accordingly.

Purpose: To evaluate the effect of alternate part-time patching on deviation control in patients with intermittent exotropia in comparison to observation., Methods: In a randomized clinical trial, untreated 3-8-year-old children with intermittent exotropia were randomly divided into patching group who treated with alternate part-time patching and observation group. Deviation control was assessed with 3-point and 6-point scales. Stereoacuity and suppression were evaluated with Titmus and Worth-4-dot tests respectively. All exams were repeated 3 and 6 months after beginning of treatment., Results: Seventy-six patients (35 in patching and 41 in observation group) with a mean age of 4.99 ± 1.33 years completed the 6-month course of study. Based on 3-point scale, deviation control was significantly better in patching group after 3 and 6 months at near and after 3 months at far (p = 0.011, 0.011, and 0.03, respectively) but non-significant after 6 months at far (p = 0.16). According to 6-point scale, deviation control was also significantly better in patching group after 3 months (p = 0.03 at far, 0.003 at near) and 6 months (p = 0.03 at far, 0.003 at near). Three and 6 months stereoacuity was not significantly different between groups (p = 0.86 for both). However, there was greater stereoacuity changes among patching group in comparison with observation group from baseline to 3 and 6 months (p = 0.006 for both)., Conclusion: Patching seems effective in improving deviation control of 3-8-year-old children with intermittent exotropia in comparison with observation based on two common office control scales., Trial Registration Number and Date: NCT03700632 (10/9/2018).

Importance: This is the first large-scale randomized clinical trial evaluating the effectiveness and safety of overminus spectacle therapy for treatment of intermittent exotropia (IXT)., Objective: To evaluate the effectiveness of overminus spectacles to improve distance IXT control., Design, Setting, and Participants: This randomized clinical trial conducted at 56 clinical sites between January 2017 and January 2019 associated with the Pediatric Eye Disease Investigator Group enrolled 386 children aged 3 to 10 years with IXT, a mean distance control score of 2 or worse, and a refractive error between 1.00 and -6.00 diopters (D). Data analysis was performed from February to December 2020., Interventions: Participants were randomly assigned to overminus spectacle therapy (-2.50 D for 12 months, then -1.25 D for 3 months, followed by nonoverminus spectacles for 3 months) or to nonoverminus spectacle use., Main Outcomes and Measures: Primary and secondary outcomes were the mean distance IXT control scores of participants examined after 12 months of treatment (primary outcome) and at 18 months (3 months after treatment ended) assessed by an examiner masked to treatment group. Change in refractive error from baseline to 12 months was compared between groups. Analyses were performed using the intention-to-treat population., Results: The mean (SD) age of 196 participants randomized to overminus therapy and 190 participants randomized to nonoverminus treatment was 6.3 (2.1) years, and 226 (59%) were female. Mean distance control at 12 months was better in participants treated with overminus spectacles than with nonoverminus spectacles (1.8 vs 2.8 points; adjusted difference, -0.8; 95% CI, -1.0 to -0.5; P < .001). At 18 months, there was little or no difference in mean distance control between overminus and nonoverminus groups (2.4 vs 2.7 points; adjusted difference, -0.2; 95% CI, -0.5 to 0.04; P = .09). Myopic shift from baseline to 12 months was greater in the overminus than the nonoverminus group (-0.42 D vs -0.04 D; adjusted difference, -0.37 D; 95% CI, -0.49 to -0.26 D; P < .001), with 33 of 189 children (17%) in the overminus group vs 2 of 169 (1%) in the nonoverminus group having a shift higher than 1.00 D., Conclusions and Relevance: Children 3 to 10 years of age had improved distance exotropia control when assessed wearing overminus spectacles after 12 months of overminus treatment; however, this treatment was associated with increased myopic shift. The beneficial effect of overminus lens therapy on distance exotropia control was not maintained after treatment was tapered off for 3 months and children were examined 3 months later., Trial Registration: ClinicalTrials.gov Identifier: NCT02807350.

Purpose : To evaluate the adding effect of inward decentration of concave spectacle lenses (adding a prismatic effect) on angle control in cases with distance intermittent exotropia (IXT) receiving over-minus therapy. Methods : Patients with myopia with IXT angles ≤25 and a Newcastle score (NCS) ≥5 were included. Patients were randomised into two groups. Group 1 received over-minus therapy. Group 2 received over-minus therapy with inward decentration of spectacle glasses to add a base out prism effect equal to one-third of the distance angle of deviation. Success was measured as the percentage of orthotropic cases or those with orthophoria or IXT with improved NCS ≤ 3 and tolerant to treatment. Patients were evaluated 3 months after initial treatment, 3 months after partial weaning and 18 months after complete weaning. Results : Sixty-four patients were included, with 32 in each group. The success rates of group 1 were 65.6%, 37.5%, and 31.3%, in group 2, the rates were 75%, 65.6%, and 65.6% for orthotropic cases or those with orthophoria or IXT with improved NCS ≤ 3, respectively. Moreover, NCS significantly improved in group 2 till last visit. Conclusion : Adding decentration to over-minus therapy can result in better control of small angle IXT and could be considered as a non-invasive and reversible therapy.

Background: To evaluate the efficacy of overminus lenses combined with prism spectacles in children of 3 to 6 years of age with intermittent exotropia (IXT)., Methods: Sixty patients with IXT were randomly assigned to the treatment and observation groups. Each group included 30 IXT children aged 3 to 6 years. The treatment group was prescribed overminus lenses of - 2.50 D incorporated with the 2 PD base-in prisms on each side. Ocular alignment, the status of binocular vision, as well as the refraction changes were carried out and followed at 1, 3, 6, and 12 months. A revised form of the Newcastle Control Score (NCS) was used to evaluate the patients' ability to control their IXT., Results: After 12 months, the mean refractive error was 1.42 ± 1.25 D, and 1.43 ± 1.12 D for the observation and the treatment group, respectively (95% CI: - 0.61 to 0.62)); the mean exotropia control score was 5.72 ± 1.28 and 1.75 ± 1.18 in the observation and the treatment group, respectively (95% CI: - 4.63 to - 3.33); the mean near stereoacuity was 2.16 ± 0.42 log arcsec and 1.91 ± 0.26 log arcsec in the observation and the treatment group, respectively (95% CI: - 0.44 to - 0.06)., Conclusions: In our randomized clinical trial, overminus spectacles with prism significantly improved the control of IXT and stereopsis, by reducing the angle of strabismus in children with IXT. This treatment does not appear to cause myopia, at least in the manner used this series. A further randomized trial is warranted to assess the effect of overminus spectacles with prism after the treatment has been discontinued., Trial Registration: This study adheres to CONSORT 2010 guidelines. Chinese Clinical Trial Registry, ChiCTR1900025243 . Registered 17 August 2019.

Background: Convergence insufficiency is a common binocular vision disorder in which the eyes have a strong tendency to drift outward (exophoria) with difficulty turning the eyes inward when reading or doing close work., Objectives: To assess the comparative effectiveness and relative ranking of non-surgical interventions for convergence insufficiency through a systematic review and network meta-analysis (NMA)., Search Methods: We searched CENTRAL, MEDLINE, Embase, PubMed and three trials registers up to 20 September 2019., Selection Criteria: We included randomized controlled trials (RCTs) examining any form of non-surgical intervention versus placebo, no treatment, sham treatment, or other non-surgical interventions. Participants were children and adults with symptomatic convergence insufficiency., Data Collection and Analysis: We followed standard Cochrane methodology. We performed NMAs separately for children and adults., Main Results: We included 12 trials (six in children and six in adults) with a total of 1289 participants. Trials evaluated seven interventions: 1) office-based vergence/accommodative therapy with home reinforcement; 2) home-based pencil/target push-ups; 3) home-based computer vergence/accommodative therapy; 4) office-based vergence/accommodative therapy alone; 5) placebo vergence/accommodative therapy or other placebo intervention; 6) prism reading glasses; and 7) placebo reading glasses. Six RCTs in the pediatric population randomized 968 participants. Of these, the Convergence Insufficiency Treatment Trial (CITT) Investigator Group completed four RCTs with 737 participants. All four CITT RCTs were rated at low risk of bias. Diagnostic criteria and outcome measures were identical or similar among these trials. The four CITT RCTs contributed data to the pediatric NMA, incorporating interventions 1, 2, 3 and 5. When treatment success was defined by a composite outcome requiring both clinical measures of convergence to be normal, and also show a pre-specified magnitude of improvement, we found high-certainty evidence that office-based vergence/accommodative therapy with home reinforcement increases the chance of a successful outcome, compared with home-based computer vergence/accommodative therapy (risk ratio (RR) 1.96, 95% confidence interval (CI) 1.32 to 2.94), home-based pencil/target push-ups (RR 2.86, 95% CI 1.82 to 4.35); and placebo (RR 3.04, 95% CI 2.32 to 3.98). However, there may be no evidence of any treatment difference between home-based computer vergence/accommodative therapy and home-based pencil/target push-ups (RR 1.44, 95% CI 0.93 to 2.24; low-certainty evidence), or between either of the two home-based therapies and placebo therapy, for the outcome of treatment success. When treatment success was defined as the composite convergence and symptom success outcome, we found moderate-certainty evidence that participants who received office-based vergence/accommodative therapy with home reinforcement were 5.12 (95% CI 2.01 to 13.07) times more likely to achieve treatment success than those who received placebo therapy. We found low-certainty evidence that participants who received office-based vergence/accommodative therapy with home reinforcement might be 4.41 (95% CI 1.26 to 15.38) times more likely to achieve treatment success than those who received home-based pencil push-ups, and 4.65 (95% CI 1.23 to 17.54) times more likely than those who received home-based computer vergence/accommodative therapy. There was no evidence of any treatment difference between home-based pencil push-ups and home-based computer vergence/accommodative therapy, or between either of the two home-based therapies and placebo therapy. One RCT evaluated the effectiveness of base-in prism reading glasses in children. When base-in prism reading glasses were compared with placebo reading glasses, investigators found no evidence of a difference in the three outcome measures of near point convergence (NPC), positive fusional vergence (PFV), or symptom scores measured by the Convergence Insufficiency Symptom Survey (CISS). Six RCTs in the adult population randomized 321 participants. We rated only one RCT at low risk of bias. Because not all studies of adults included composite success data, we could not conduct NMAs for treatment success. We thus were limited to comparing the mean difference (MD) between interventions for improving NPC, PFV, and CISS scores individually using data from three RCTs (107 participants; interventions 1, 2, 4 and 5). Compared with placebo treatment, office-based vergence accommodative therapy was relatively more effective in improving PFV (MD 16.73, 95% CI 6.96 to 26.60), but there was no evidence of a difference for NPC or the CISS score. There was no evidence of difference for any other comparisons for any outcomes. One trial evaluated base-in prism glasses prescribed for near-work activities and found that the prism glasses group had fewer symptoms compared with the placebo glasses group at three months (MD -8.9, 95% CI -11.6 to -6.3). The trial found no evidence of a difference with this intervention in NPC or PFV. No adverse effects related to study treatments were reported for any of the included studies. Excellent adherence was reported for office-based vergence/accommodative therapy (96.6% or higher) in two trials. Reported adherence with home-based therapy was less consistent, with one study reporting decreasing adherence over time (weeks 7 to 12) and lower completion rates with home-based pencil/target push-ups., Authors' Conclusions: Current research suggests that office-based vergence/accommodative therapy with home reinforcement is more effective than home-based pencil/target push-ups or home-based computer vergence/accommodative therapy for children. In adults, evidence of the effectiveness of various non-surgical interventions is less clear., (Copyright © 2020 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.)

Purpose: To evaluate the prevalence of the prism adaptation response in patients with intermittent exotropia (IXT) using the short-term prism adaptation test (PAT) and to assess factors associated with prism adaptation response in IXT patients., Methods: A case-controlled retrospective analysis was performed on 113 patients with IXT without prior surgical treatment. Age, sex, visual acuity, refraction, stereoacuity, control scale, type of exotropia, history of occlusion, and presence of accompanying visual symptoms were recorded. Prism alternate cover test (PACT) was performed with fixation targets at 6 m and 1/3 m. All patients underwent short-term PAT wearing prism glasses that offset the exodeviation previously measured by PACT. After 30 minutes, angle deviation was measured, and patients were classified into either an increase group, which had an increase in deviation ≥5 prism diopters after short-term PAT, or a no-change group. Analysis was performed to investigate the clinical factors influencing the increase in exodeviation after short-term PAT., Results: Fifty patients (44.2%) showed an increase ≥5 prism diopters during distance or near fixation after short-term PAT compared to the previous PACT: 12 patients (10.6%) showed an increment at distance fixation, and 45 patients (39.8%) showed an increase at near fixation. At distance fixation, the increase-group had a significantly smaller maximum angle measured by PACT. At near distance, age at PAT, maximum distance angle, minimum distance angle, maximum near angle, minimum near angle, angle fluctuation at near, and IXT type showed significant associations with positive short-term PAT response. In the multivariate analysis, older age and smaller maximum near angle were significantly associated with positive short-term PAT response at near fixation., Conclusions: Short-term PAT could be helpful in older IXT patients with a small maximum angle of deviation at near fixation to mitigate the vergence aftereffect and show the maximum angle of deviation.

Introduction: In an environment where strabismus is poorly understood and management centers rare, we studied the epidemiological, clinical and therapeutic aspects of neglected childhood strabismus., Materials and Methods: This was a retrospective study carried out from March 1st, 2013 to September 30, 2018. Neglected childhood strabismus was defined as strabismus occurring in the first 5 years of life, for which the patient was over 7-years-old at the time of first consultation. The variables studied were age at first consultation, gender, age of onset, type of strabismus, etiology of strabismus, angle of deviation and rate of surgery., Results: We found 113 cases of neglected childhood strabismus among the 430 cases of strabismus seen during the study period. There were more females (n=64) than males. The mean age was 17.7±10.5 years. There were 73 exotropias (64.6 %). The mean angle of deviation was 41.2±12.2PD. Strabismus was early in 70.8 % of cases. Innervational strabismus accounted for 86.7 % of cases. The most frequent refractive error was hyperopic astigmatism (55.3 %). Of the 45 patients who were seen again after full-time wear of their full cycloplegic correction, 2 were orthotropic. Surgery was performed in 60.5 % of cases. The average postoperative angle of deviation was 6.6±9.4PD., Conclusion: Management of neglected childhood strabismus provides good results and should therefore be encouraged in order to improve the quality of life of affected patients., (Copyright © 2020 Elsevier Masson SAS. All rights reserved.)

In young children with small angle exotropia, making decisions for the individual patient whether to perform surgery or not, and choosing the optimal time for surgical intervention are quite difficult. We aimed to compare the long-term outcomes of small angle intermittent exotropia of 20 prism diopters (PD) or less after observation versus strabismus surgery. A retrospective study was performed on 164 patients aged 3 to 13 who underwent surgical intervention or observation with or without conservative management for intermittent exotropia of 14 to 20 PD. The minimum follow-up period was 2 years. The average follow-up period was 3.9 ± 2.2 years in the observation group and 4.5 ± 2.3 years in the surgery group. At the final examination, the mean angle of deviation at distance was 11.1 ± 8.9 PD in the observation group and 9.0 ± 7.5 PD in the surgery group, which was not significantly different (P = 0.121). Changes in sensory outcome and fusional control were not significantly different between both groups (P = 0.748 and P = 0.968). Subgroup analysis including patients with poor fusional control also showed similar results. By multivariate analysis, the type of surgery, unilateral recess-resect procedure, was the only predictive factor of good motor outcome in the surgery group. In conclusion, long-term surgical outcomes in small angle exotropia did not appear to be more satisfying than observation in terms of motor and sensory outcomes.

Purpose: The aim is to investigate the effect of alternate occlusion on control of intermittent exotropia in children 3 to 8 years old., Methods: The ability of 28 children to control of the deviation at far and near was evaluated based on 3-point and 6-point control scales. Stereopsis and fusion were assessed using the Titmus and Worth 4-dot tests, respectively. Two-hour alternate daily occlusion was prescribed for children with no dominancy. For children with a dominant eye, 2-h occlusion of the dominant eye for 5 days and the non-dominant eye for 2 days. All measurements were repeated at 3, 6, and 9 months after the treatment., Results: For all children with a mean age of 4.7 ± 1.56 years, deviation control at far improved significantly after 3, 6, and 9 months of treatment using both control scales when compared with baseline ( p  = 0.005 after 3 months and p  = 0.008 after 6 and 9 months for the 3-point scale, and p  < 0.001 after 3 and 6 months and p  = 0.010 after 9 months for the 6-point scale). Control at near showed a significant improvement after 3, 6, and 9 months of treatment based on the 6-point scale ( p  = 0.007 for 3 months, p  = 0.004 for 6 months, and p  = 0.014 for 9 months). Near stereopsis improved significantly after 9 months of treatment ( p  = 0.043)., Conclusion: Alternate occlusion is significantly effective on control of intermittent exotropia. As a result, it can be used as a useful method to postpone or even eliminate the need for surgery in intermittent exotropia.

Significance: This study will help to demonstrate the potential value of office-based vergence/accommodative therapy for the treatment of intermittent exotropia and provide data that can be used for planning future clinical trials., Purpose: This study was designed to evaluate changes in the office control score after office-based vergence/accommodative therapy for intermittent exotropia., Methods: This was a prospective, unmasked pilot study. Fourteen Chinese participants aged 6 to 18 years with intermittent exotropia (excluding the convergence insufficiency type) were enrolled. All participants received 60 minutes of office-based vergence/accommodative therapy with home reinforcement once per week for 12 weeks. Therapy included vergence, accommodation, saccades and pursuits, antisuppression, and monocular fixation in binocular field techniques. The primary outcome measure was the change in the office control score from the baseline visit to the 13-week outcome visit., Results: All participants completed the study. The office control score at distance changed by -1.0 (95% confidence interval [CI] = -1.6 to -0.4; P = .005; Cohen's d effect size, 0.93). The distant Look And Cover, then Ten seconds Observation Scale for Exotropia score and distant Newcastle control score total score changed by -0.7 (95% CI, -1.2 to -0.2; P = .02; Cohen's d effect size, 0.55) and -1.9 (95% CI, -2.8 to -1.0; P < .001; Cohen's d effect size, 1.37), respectively. Although there was no significant change in the angle of distance exodeviation (-1.8 prism diopter [Δ] less exodeviation; 95% CI, -3.74 to 0.14Δ; P = .11), a significant change was observed in the near angle (-4.4Δ less exodeviation; 95% CI, -7.3 to -1.5Δ; P = .01; Cohen's d effect size, 0.79). There was no significant change in stereopsis or the Chinese Intermittent Exotropia Questionnaire score., Conclusions: In this select group of children with intermittent exotropia, 12 weeks of office-based vergence/accommodative therapy with home reinforcement resulted in a statistically and clinically significant improvement in the distance control of exodeviation and the near exodeviation magnitude. These results suggest that there is a need for a randomized clinical trial designed to determine the effectiveness of vision therapy as a treatment modality for intermittent exotropia.

Intermittent exotropia (IXT) is the most common type of divergent strabismus. It is the consequence of passive mechanisms due to the anatomy of the globes and orbits or due to active innervational mechanisms, resulting in divergence of the visual axes, which is compensated by fusional convergence. Intermittent insufficiency in this compensation gives this form of exotropia its intermittent nature. The most common symptoms of IXT are closure of one eye, asthenopia and diplopia, but they are often absent. The clinical classification of IXT (according to Burian) is based on the difference between the distant and the near angles of deviation. It defines 4 types: true divergence excess (at distance), pseudo-divergence excess, the basic form (distance and near angles are equal) and convergence insufficiency (near angle greater than distance angle). One of the main difficulties in examination of IXT is neutralizing the fusional convergence in order to classify the strabismus. For this purpose, the monocular occlusion test, a near addition, or a prism adaptation test can be used. IXT is also characterised by the quality of control of the deviation by the patient, which is taken in account for therapeutic decision. Tools for measurement of this control have recently been developed and are not commonly used. The natural history of IXT is not well understood. Treatment relies mainly on optical correction, binocular visual training therapy and surgery, but their indications are not well defined, nor are outcomes analysis criteria. In the case of surgery, it aims to treat the maximum measured distance angle; the medium- and long-term angular results of surgery are often disappointing, although it probably improves control of the strabismus in most cases., (Copyright © 2019. Published by Elsevier Masson SAS.)

Background: Surgery for intermittent exotropia performed at a very young age has poorer sensory outcomes than surgery performed later; moreover, postoperative recurrence is common, regardless of age. Alternate occlusion decreases the size of the exotropia and improves control. The purpose of this study was to report the long-term effects of part-time alternate occlusion and overminus spectacles combined with prism on delaying or avoiding surgery in intermittent exotropia., Methods: The study included consecutive patients from 1979 to 2010 who had poorly controlled intermittent exotropia and were treated with alternate occlusion, followed in some cases by overminus spectacles with base-in prism. Outcome measures were initial improvement and subsequent time to surgery, if required., Results: A total of 279 patients had initial control poor enough to otherwise be considered candidates for surgery. After occlusion therapy, 219 (78%) improved their angle and control, and 62 (22%) converted to an exophoria. After 1 year, 9 cases deteriorated, and surgery was recommended. In 207 (74%), conservative treatment delayed surgery for at least 1 year. At 20 years, 42 of 279 patients were still being followed. Of these, 22 of 219 (7%) were known to have not undergone surgery, and 127 (45%) had undergone surgery; 130 (47%) were lost to follow-up., Conclusions: Part-time alternate occlusion and overminus spectacles with prism can defer the need for surgery in a large percentage of patients with intermittent exotropia; for a small number it may be curative., (Copyright © 2019 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.)

Purpose: To describe the course of intermittent exotropia (IXT) in children followed up without treatment for 3 years., Design: Observation arm from randomized trial of short-term occlusion versus observation., Participants: One hundred eighty-three children 3 to 10 years of age with previously untreated IXT and 400 seconds of arc (arcsec) or better near stereoacuity., Methods: Participants were to receive no treatment unless deterioration criteria were met at a follow-up visit occurring at 3 months, 6 months, or 6-month intervals thereafter for 3 years., Main Outcome Measures: The primary outcome was deterioration by 3 years, defined as meeting motor criterion (constant exotropia ≥10 prism diopters [Δ] at distance and near) or near stereoacuity criterion (≥2-octave decrease from best previous measure). For the primary analysis, participants also were considered to have deteriorated if treatment was prescribed without meeting either deterioration criterion., Results: The cumulative probability of protocol-specified deterioration by 3 years was 15% (95% confidence interval, 10%-22%), but that was likely an overestimate, partly because of misclassification. Among 25 deteriorations, 2 met motor deterioration, 11 met stereoacuity deterioration, and 12 started treatment without meeting either criteria (7 for social concern, 1 for diplopia, 4 for other reasons). Among the 132 participants who completed the 3-year visit and had not been treated during the study, only 1 (<1%) met motor or stereoacuity deterioration criteria at 3 years. Of the 4 participants completing the 3-year visit who met deterioration criteria previously and had not started treatment, none still met deterioration criteria. Between the baseline and 3-year examination for these 132 patients, improvement occurred in distance and near stereoacuity (mean improvement, 0.14 and 0.14 logarithm of arcsec; P ≤ 0.001 and P ≤ 0.001, respectively), distance exotropia control (mean improvement, 0.6 points; P ≤ 0.001), and distance exodeviation magnitude (mean improvement, 2.2 Δ; P = 0.002)., Conclusions: Among children 3 to 10 years of age with IXT for whom surgery was not considered to be the immediately necessary treatment, stereoacuity deterioration or progression to constant exotropia over 3 years was uncommon, and exotropia control, stereoacuity, and magnitude of deviation remained stable or improved slightly., (Copyright © 2019 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.)

In order to propose alternative treatments for strabismus, conventional visual therapies implemented in VR, which could be rendered in portable devices for pediatric strabismus treatment is proposed in this paper. In comparison with other virtual environments for visual correction proposes, the proposed system is based on conventional visual therapies for amblyopia and strabismus treatment. Three fundamental visual therapeutic exercises were considered in the present proposal: (1) Brock cord, (2) approach technique, and (3) convergence and divergence. The first exercise, Brock Cord, has the purpose of improving the binocular fixation for exotropia and esotropia. The second exercise pursues to normalize the Cerebral Perfusion Pressure by an approach technique. The third exercise known as fusion of eccentric circles, aims vision training by converging and diverging objects at specific distances. Before a clinical application, it was paramount important to guarantee system simplicity and versatility for both clinicians and infant patients. Therefore, the user experience evaluation of a sample of 45 students between 17 and 28 years old was undertaken. The system proposed in this paper achieved a pragmatic quality above average (1.73), a parameter that reflects simplicity and versatility. In addition, the present VR system displayed attractiveness (2.03) and hedonic (1.90) qualities above average. Then, it is expected that end-users will follow the visual exercise program.

Purpose : To determine the effect of prism orientation on the Newcastle Control Score (NCS) in patients with basic intermittent exotropia (IXT). Methods : Patients with IXT with a distant angle of deviation (DAD) ≤50∆ and NCS≥5 were recruited and randomly divided into two groups. The inverse prism (IP) group received a base-out Fresnel prism addition to achieving full refractive correction, and the conventional prism (CP) group received base-in Fresnel prism addition. The prism addition was equivalent to one-third of the mean DAD. Patients were evaluated 3 months after initial treatment, 3 months after partial weaning and 6 months after complete weaning. NCS and DAD values were compared. Tolerance was defined as the ability to wear the prescription 80% of waking hours. Results : Fifty patients were enrolled in each group. The IP group had 6 intolerant patients, and the CP group had 3 intolerant patients. NCS improved in both groups (from 6.2 ± 0.7 to 3.4 ± 2.5 in the IP group and from 6.4 ± 0.7 to 3.7 ± -2.2 in the CP group). However, the final NCS difference was nonsignificant (Mann-Whitney, p = .6). The DAD changes were not significantly different between the 2 groups (t-test = 0.04). The average DAD decreased from 31.9 ± 6.9∆ to 10.11 ± 11∆ in the IP group and from 30.7 ± 8.5∆ to 15.5 ± 13.5∆ in the CP group. Four patients in the CP group exhibited an increase in DAD. Conclusion : The two types of prism therapy showed comparable improvements in NCS.

We evaluated the effect of dichoptic visual training based on a unique virtual reality (VR) platform mounted display in patients with intermittent exotropia (IXT). A total of 25 IXT patients (8 men, 17 women) with a mean age of 12.3 years (range, 5-39 year) were recruited. The Hirschberg test, prism and alternate cover testing (with accommodative targets for fixation at 33 cm in all patients), perceptual eye position (PEP), and stereopsis were evaluated after 1, 3, and 6 months of dichoptic visual neuroplasticity training with a computer-controlled perceptual examination evaluation system. Data collected before and after training were evaluated using SPSS software. After 6 months of perceptual training, a new order stereopsis was established, and eye positions were improved in all 25 patients. After training for 1 and 6 months, the horizontal PEP pixels were much lower than those pretraining, respectively (Δ 1-0  = -0.53, p = 0.028; Δ 6-0  = -0.80, p = 0.018). There was no statistically significant difference between pretraining and 3 months after training in horizontal PEP (Δ 3-0  = -0.29, p = 0.370). There was no significant difference between pretraining and post-training in vertical PEP (p > 0.05). There were significant differences between pretraining and post-training in the cornea's optical reflection and prism diopters (p < 0.01). Dichoptic visual neuroplasticity training based on a VR platform is an effective nonsurgical treatment in patients with IXT. With the VR treatment, the degree of strabismus and stereopsis was improved in IXT patients. Perceptual training with VR can remove obstacles in the visual processing channel and repair defects in visual function. The clinical manifestations of improvement were the decrease in the degree of strabismus and the re-establishment of stereopsis.

Introduction Orbital meningoencephalocele formation is primarily a result of congenital defects in the pediatric population and trauma of the anterior cranial fossa in adults. We present a unique case of nontraumatic nasal and orbital meningoencephaloceles presenting as bilateral proptosis with exotropia secondary to chronic hydrocephalus. Clinical presentation A 20-year-old male with a history of tuberous sclerosis, X-linked intellectual disability, and epilepsy presented to the emergency department with two days of nausea, emesis, seizures, and two months of progressive proptosis. Initial radiographs of the skull showed a "copper beaten" appearance, indicating chronically elevated intracranial pressure. Computed tomography imaging of the head demonstrated bilateral defects in the cribriform plate and anterior cranial fossa. Magnetic resonance imaging of the brain revealed triventricular hydrocephalus with meningoencephalocele extension into the nasal cavity and frontal horn herniation into the extraconal space of the orbits. The hydrocephalus was managed with ventriculoperitoneal shunt placement with rapid and complete resolution of the proptosis. Conclusion No reports have described bilateral proptosis as the presenting finding of orbital and nasal meningoencephaloceles in the absence of trauma or congenital defect. This case study demonstrates the management of meningoencephalocele formation secondary to chronic hydrocephalus.

Purpose: To compare the characteristics of intermittent exotropia patients according to their response to the diagnostic monocular occlusion test., Study Design: Retrospective study., Methods: A retrospective review was performed of 141 patients with intermittent exotropia who had taken a monocular occlusion test before surgery. We classified the patients into 3 groups based on the response to monocular occlusion. The increase group was defined as those patients having an increase in deviation of ≥ 5 prism diopters (PD) after monocular occlusion as compared with the maximum measured angle. The decrease group was defined as those patients having a decrease in deviation of ≥ 5 PD. Otherwise, patients were classified as having no change. The patients' characteristics were compared among the groups., Results: At distance fixation, 9 patients (6.5%) were classified as increase, 92 patients (66.7%) as no change, and 37 patients (26.8%) as decrease after monocular occlusion. At near fixation, 50 patients (35.5%) were classified as increase, 65 patients (46.1%) as no change, and 26 patients (18.4%) as decrease. At distance fixation, no significant differences were found between the parameters of the patients in the increase group and those of the patients in the other 2 groups. In patients with a small maximum angle of exodeviation at near fixation and with few visits, the deviation at near fixation significantly increased after diagnostic occlusion., Conclusion: Fifty-two patients (36.8%) showed an increase of ≥ 5 PD during distance or near fixation after monocular occlusion. In patients with a small maximum angle at near fixation and with few visits, it would be beneficial to perform the monocular occlusion test before surgery to reveal the maximal deviation angle, regardless of exotropia type.

Purpose: To investigate the effect of preoperative part-time occlusion therapy on long-term surgical success in early-onset exotropia., Methods: The medical records of patients who underwent surgery for exotropia with onset before the first year of age and who were followed for ≥3 years were reviewed. Patients were divided into two groups according to the degree of compliance with part-time occlusion therapy: the good compliance group (>50% adherence rate) and the poor compliance group (≤50% adherence rate). Surgical success was defined as orthophoria to exodeviation less than 10 prism diopters both at distance and near. The level of postoperative stereopsis was compared between the two study groups among total enrolled patients and among those with constant exotropia., Results: Of the 51 patients, 26 were assigned to the good compliance group and the remaining 25 patients to the poor compliance group. The surgical success rate was significantly higher in the good compliance group than in the poor compliance group (80.8% vs. 52.0%, p = 0.040). Among 24 constant exotropia patients (12 patients for each group), the success rate was insignificantly higher in the good compliance group than in the poor compliance group (75.0% vs. 58.3%, p = 0.448). The good compliance group had a better level of stereopsis than the poor compliance group (p = 0.045 for all 44 patients, p = 0.020 for 19 patients with constant exotropia)., Conclusions: Preoperative part-time occlusion therapy was useful for improving the surgical outcome of early-onset exotropia and postoperative stereopsis., Competing Interests: No potential conflict of interest relevant to this article was reported., (© 2017 The Korean Ophthalmological Society)

To evaluate medium-term outcomes of overminus lens treatment in patients with intermittent exotropia [X(T)]. A retrospective analysis was performed of the outcomes of 19 children with X(T) who were prescribed overminus lens (-2.00 to -4.00 D) for a median period of 18 months (6-33). The success was evaluated using two assessment methods: 1. Newcastle Control System (NCS), and 2. Jampolsky's assessment. The mean age of the patients was 6.8 ± 3.3 years (range 3-14 years). After the therapy, the median NCS score significantly improved from 5 to 1 (p < 0.001). Sixteen children (84 %) showed a NCS score of 2 or less after overminus lens treatment. According to Jampolsky's assessment, 84 % of the patients showed marked improvement from the baseline (47 % had qualitative improvement, 37 % quantitative decrease in the angle of deviation in addition to a qualitative improvement). The median pre-treatment distant angle decreased from 25 prism diopters (PD) to 18 PD after the treatment (p = 0.002). Overcorrecting minus lens treatment has a reasonable rate of success in the medium term and may be advised as primary therapeutic alternative for X(T). Both NCS and Jampolsky's scoring system appear to be useful and comparable for follow-up of patients with X(T).

Purpose: To evaluate the short-term effectiveness of overminus spectacles in improving control of childhood intermittent exotropia (IXT)., Design: Randomized, clinical trial., Participants: A total of 58 children aged 3 to <7 years with IXT. Eligibility criteria included a distance control score of 2 or worse (mean of 3 measures during a single examination) on a scale of 0 (exophoria) to 5 (constant exotropia) and spherical equivalent refractive error between -6.00 diopters (D) and +1.00 D., Methods: Children were randomly assigned to overminus spectacles (-2.50 D over cycloplegic refraction) or observation (non-overminus spectacles if needed or no spectacles) for 8 weeks., Main Outcome Measures: The primary outcome was distance control score for each child (mean of 3 measures during a single examination) assessed by a masked examiner at 8 weeks. Outcome testing was conducted with children wearing their study spectacles or plano spectacles for the children in the observation group who did not need spectacles. The primary analysis compared mean 8-week distance control score between treatment groups using an analysis of covariance model that adjusted for baseline distance control, baseline near control, prestudy spectacle wear, and prior IXT treatment. Treatment side effects were evaluated using questionnaires completed by parents., Results: At 8 weeks, mean distance control was better in the 27 children treated with overminus spectacles than in the 31 children who were observed without treatment (2.0 vs. 2.8 points, adjusted difference = -0.75 points favoring the overminus group; 2-sided 95% confidence interval, -1.42 to -0.07 points). Side effects of headaches, eyestrain, avoidance of near activities, and blur appeared similar between treatment groups., Conclusions: In a pilot randomized clinical trial, overminus spectacles improved distance control at 8 weeks in children aged 3 to <7 years with IXT. A larger and longer randomized trial is warranted to assess the effectiveness of overminus spectacles in treating IXT, particularly the effect on control after overminus treatment has been discontinued., Competing Interests: No conflicting relationships exist for any author., (Copyright © 2016 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.)

Intermittent exotropia (IXT) is a congenital form of divergent strabismus. Its incidence is estimated to be 32 per 100 000. Most often, IXT is first noted in early childhood when intermittently manifest outward deviation of the eyes is seen. Patients with IXT can control the deviation and keep the eyes aligned; this ability can be measured with "control scores". Complications such as amblyopia and loss of binocular functions are rare but should be looked for and need to be avoided. IXT can have a negative impact on quality of life. Conservative treatment includes the correction of refractive errors, (alternating) occlusion, over-minus lenses and orthoptic exercises. By injecting an extraocular muscle with botulinum toxin (to weaken its function) or with bupivacaine (to strengthen its function), IXT can be treated pharmacologically. Diagnostic occlusion and prism adaptation are strategies to uncover the true (largest) angle. Eye muscle surgery aims at eliminating the condition, but recurrences are common. The literature on large, randomized prospective trials for IXT is scarce. However, there are trials underway in the United Kingdom and in North America to better understand the natural course of IXT and to determine the most appropriate therapeutic approach., (Georg Thieme Verlag KG Stuttgart · New York.)

Purpose: Vertical yoked prisms (VYPs) have been recommended for the remediation of vergence dysfunction, but the evidence base for their use is mostly low level. This study investigates the effect of VYP on horizontal subjective dissociated heterophoria., Methods: Phoria measurement was performed in primary gaze with the Modified Thorington technique at 3 m and at 40 cm on 40 nonpresbyopic young adults. Subjects were seated and head position was held constant. Baseline measures (without yoked prism) of distance and near phoria were measured. Phorias were measured again through the following range of VYP, randomly presented: 2 prism diopters (Δ) base up (BU), 2Δ base down (BD), 5Δ BU, and 5Δ BD. Twenty-six subjects also had their phorias measured with control lenses of +0.125 DS OU (because of unavailability of Plano trial lenses) randomly presented along the other conditions., Results: There was no significant difference overall between phoria measured in any of the yoked prism conditions, including the baseline measure, at distance or near. Neither was there evidence of a predictable esophoric or exophoric shift with either BU or BD prism., Conclusions: Vertical yoked prisms did not exert any immediate effect on horizontal phoria in young adults when posture was controlled. This suggests that, if VYPs do indeed improve horizontal vergence problems, they do not do so by a direct or immediate impact on horizontal phoria.

Venomous snakes with hematotoxin-Russell's viper (Daboia spp), Malayan pit viper (Calloselasma rhodostoma), and green pit viper (Cryptelytrops albolabris and C macrops, previously named Trimeresurus spp) are commonly found in Thailand. Coagulation factor activation, thrombocytopenia, hyperfibrinolysis, and disseminated intravascular coagulation are the main mechanisms of hemorrhaging from these snake bites. The neurological involvement and hepatocellular injury after Russell's viper bites were reported in Sri Lanka, but there is no report from Southeast Asia. This case was a 12-year-old hill tribe boy who had ptosis and exotropia of the left eye, respiratory distress, and prolonged venous clotting time, prothrombin time, and activated partial thromboplastin time; low fibrinogen and platelet count; and transaminitis after being bitten by a darkish-colored snake. He did not respond to antivenom for cobra, Malayan pit viper, or Russell's viper. However, his neurological abnormalities, respiratory failure, and hepatocellular injury improved, and coagulopathy was finally corrected after receiving antivenom for green pit viper. The unidentified snake with hematotoxin was alleged for all manifestations in this patient., (Copyright © 2015 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.)

Purpose: To determine the effectiveness of part-time patching for treating intermittent exotropia (IXT) in young children., Design: Multicenter, randomized clinical trial., Participants: Two hundred one children 12 to 35 months of age with untreated IXT meeting the following criteria: (1) IXT at distance OR constant exotropia at distance and either IXT or exophoria at near, and (2) 15-prism diopter (Δ) or more exodeviation at distance or near by prism and alternate cover test (PACT) but at least 10 Δ exodeviation at distance by PACT., Methods: Participants were assigned randomly to either observation (no treatment for 6 months) or patching prescribed for 3 hours daily for 5 months, followed by 1 month of no patching., Main Outcome Measures: The primary outcome was deterioration, defined as constant exotropia measuring at least 10 Δ at distance and near or receipt of nonprotocol treatment for IXT., Results: Of the 177 participants (88%) completing the 6-month primary outcome examination, deterioration occurred in 4.6% (4 of 87) of the participants in the observation group and in 2.2% (2 of 90) of the participants in the patching group (difference, 2.4%; P = 0.27; 95% confidence interval, -3.8% to +9.4%). Motor deterioration occurred in 2.3% (2 of 87) of the observation group and in 2.2% (2 of 90) of the patching group (difference, 0.08%; P = 0.55; 95% confidence interval, -5.8% to +6.1%). For the observation and patching groups, respectively, 6-month mean PACT measurements were 27.9 Δ versus 24.9 Δ at distance (P = 0.02) and 19.3 Δ versus 17.0 Δ at near (P = 0.10); 6-month mean exotropia control scores were 2.8 versus 2.3 points at distance (P = 0.02) and 1.4 versus 1.1 points at near (P = 0.26)., Conclusions: Among children 12 to 35 months of age with previously untreated IXT, deterioration over 6 months was uncommon, with or without patching treatment. There was insufficient evidence to recommend part-time patching for the treatment of IXT in children in this age group., (Copyright © 2015 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.)

Background: Intermittent exotropia is the most common form of divergent strabismus (squint) in children. Evidence regarding its optimum management is limited. A pilot randomised controlled trial has recently been completed (Surgery versus Active Monitoring in Intermittent Exotropia trial) to determine the feasibility of a full randomised controlled trial., Purpose: To identify drivers for and barriers against parents' participation in Surgery versus Active Monitoring in Intermittent Exotropia and to seek their views on information received, the need for randomisation, and enhancing acceptability., Methods: Multiple method qualitative study using semi-structured telephone interviews to explore parents' motivations and trial screening logs to provide an indication of common barriers. Exploratory thematic analysis identified key themes., Results: A total of 48 interviews were conducted (14 participants; 34 non-participants). Barriers included no desire for surgery/preference to 'wait and see', wanting surgery immediately, feeling uncomfortable about 'surrendering control' over decision-making/being managed 'at random', lack of confidence in the effectiveness of surgery, believing the risks outweighed the benefits, and lack of trust. Drivers included desiring surgery, 'nothing to lose', benefits offsetting the risks, and being in a trial would result in better care. Some also mentioned 'doing their bit' for research. Suggestions for enhancing acceptability included allowing choice of treatment group, giving more time for decision-making, expanding on information given, and improving communication. Many felt the necessity of randomisation was adequately explained, but there was some indication that it was misunderstood. Information extracted from the screening logs of 80/89 eligible non-participants indicated the most prevalent barrier was not wanting surgery/preferring to observe (56%), followed by desiring surgery straightaway (15%). Opposition to randomisation/wanting to retain control was recorded in 9% of cases as was the belief that the child's squint was not severe enough to warrant surgery., Limitations: Interviews were not audio-recorded. Not all who consented to interview could be contacted, although the response/contact rate was good (48/62). A few parents did not provide reasons for refusing the trial., Conclusion: Opposition to surgery and concerns about surrendering control were common obstacles to participation, whereas parents keen for their child to undergo the operation but happy to defer tended to embrace a 'nothing to lose' attitude. Many non-participants would have consented if allowed to choose group, although most of these would have chosen observation. While most parents felt happy with information given and that randomisation was adequately explained, it is of concern that there may be some misunderstanding, which should be addressed in any trial. These findings will inform future trials in childhood exotropia, for example, consideration of preference arms and improving communication. Lessons learnt from the Surgery versus Active Monitoring in Intermittent Exotropia trial could prove valuable to paediatric and surgical trials generally., (© The Author(s) 2015.)