Intermittent Exotropia: The Effect of Alternating Occlusion Therapy on Control of Strabismus.

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.

Effects of vision therapy on near exodeviation in children with convergence insufficiency treated during the convergence insufficiency treatment trials.

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.

Refractive Error Change and Overminus Lens Therapy for Childhood Intermittent Exotropia.

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.

Nonsurgical Consecutive Exotropia Following Childhood Esotropia: A Multicentered Study.

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.

The Influence of Overminus Lens Therapy on Control of Intermittent Exotropia: A Meta-Analysis of Randomized Clinical Trials.

BACKGROUND: Intermittent exotropia (IXT) is the most common type of strabismus, overminus lens (OML) therapy is frequently prescribed to treat IXT. OBJECTIVES: The purpose of this study was to compare the effectiveness of OML and observation in the treatment of IXT. METHOD: An exhaustive search of the literature in PubMed, Embase, Web of Science, and Cochrane Library databases was performed until July 2022. No language restrictions were used. The literature was rigorously screened according to eligibility criteria. Weighted mean differences and 95% confidence intervals (CIs) were calculated. RESULTS: A total of 4 articles with 561 participants were included in this meta-analysis. Our pooled results showed that OML demonstrated superior outcomes compared with observation, with greater decreases in distance and near exodeviation control (MD = -1.08, 95% CI: -1.96 to -0.20, p = 0.02; MD, -0.64, 95% CI: -1.15 to -0.13, p < 0.001). Patients who received OML therapy had a greater decrease in the deviation at both distance and near (MD = -4.00, 95% CI: -7.03 to -0.98, p < 0.001; MD = -4.79, 95% CI: -6.29 to -3.30, p < 0.001). There was no statistical difference between the two groups in terms of post-treatment proximal stereopsis (MD, 0.00, 95% CI: -0.08 to 0.08, p = 1.00). CONCLUSIONS: The present meta-analysis indicated that OML therapy was effective in improving the control and decreasing exodeviation angle of IXT. However, it seemed not to be effective in improving the level of near stereopsis.

A Pilot Randomized Clinical Trial of Base-in Relieving Prism Spectacle Treatment of Intermittent Exotropia.

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.

Improved control of intermittent exotropia with part-time patching.

We evaluated the effect of part-time patching versus observation on distance exodeviation control in post hoc analyses of 3- to <11-year-olds with intermittent exotropia who were assigned to either patching 3 hours/day or observation in a previously reported randomized clinical trial. The present analysis was limited to a subgroup of 306 participants who at distance fixation spontaneously manifested either a constant or intermittent exotropia or had prolonged recovery after monocular occlusion (a distance control score of 2 or worse using the 0-5 Office Control Score scale) at baseline. We assessed change in control at distance and near fixation, from baseline to 3 months and baseline to 6 months (1 month after discontinuing patching). We found greater improvement in the distance control score with patching than with observation at 3 months (mean difference, 0.4 points; 95% CI, 0.1-0.7) and 6 months (mean difference, 0.3 points; 95% CI, 0.02-0.6). These analyses suggest that part-time patching may improve distance control in children with intermittent exotropia and a control score ≥ 2; however, because this conclusion is based on post hoc subgroup analyses, further studies are needed.

Comparison of biometric and refractive changes in intermittent exotropia with and without overminus lens therapy.

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.

Comparison of alternate part-time patching and pencil push-up training for patients with intermittent exotropia.

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.

Rasch-calibrated Intermittent Exotropia Symptom Questionnaire for Children.

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.

Optimised minus lens overcorrection for paediatric intermittent exotropia: A randomised clinical trial.

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.

Factors associated with the effectiveness of part-time patching for intermittent exotropia in children.

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.

Effect of the Control Ability on Stereopsis Recovery of Intermittent Exotropia in Children.

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.].

A Survey of Clinical Opinions and Preferences on the Non-surgical Management of Intermittent Exotropia in China.

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 25th to August 3rd, 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.

Overminus Lens Therapy for Children 3 to 10 Years of Age With Intermittent Exotropia: A Randomized Clinical Trial.

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.

A randomized trial evaluating efficacy of overminus lenses combined with prism in the children with intermittent exotropia.

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.

Spectacle Decentration to Augment Over-minus Therapy in Cases with Intermittent Exotropia.

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.

The influence of alternate part-time patching on control of intermittent exotropia: a randomized clinical trial.

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).