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

Effects of basic type of intermittent exotropia on myopic shift in children: a 12-month observational study

Background

To investigate the effect of basic intermittent exotropia (IXT) on myopic shift in children during 12-month follow-up.

Methods

165 children aged 4-15 years were recruited prospectively in this study and divided into 3 groups: Group A, consisted of 64 patients with basic IXT without surgery; Group B, consisted of 51 patients 1-month after IXT-corrected surgery; and Group C, consisted of 50 patients without any form of strabismus. All patients underwent assessments of spherical equivalent (SE), axial length (AL), exodeviation, and binocular function relating to accommodation and convergence. Examinations were conducted at baseline and 12-month. SE and AL changes were compared among groups. Univariate and multivariate linear analyses were employed to investigate the association between myopic shift and IXT, as well as other clinical parameters.

Results

Three groups showed comparable ages, genders and SEs at baseline (all P > .05). During 12-month follow-up, the rate of myopic shift varied among groups. Significant differences in SE progression (P = .006) and AL elongation (P = .014) between Group A and Group C were observed. Although SE progression and AL elongation in Group B were less than Group A, no significant differences were found (P = .125; P = .038). In the multivariate analysis, increases in exodeviation angle were significantly associated with both SE progression (β = 0.010, P = .041) and AL elongation (β = -0.005, P = .026). Each one prism diopter increase in the exodeviation angle was correlated with a 0.01D SE progression and a 0.005 mm AL elongation.

Conclusions

Children with basic IXT exhibited faster myopia shift compared to those without strabismus. Although surgical correction of strabismus appeared to slow this process, the effect was not statistically significant. Furthermore, greater increase in exodeviation angle was associated with higher rate of SE progression and AL elongation.

Trial registration

The study was approved by the Ethics Committee of Beijing TongRen Hospital (approved number: TRECKY2020-142, approved date: 2020.10.30).

Non-surgical therapy for intermittent exotropia: a systematic review and network analysis

OBJECTIVE

This study aimed to conduct a network meta-analysis to evaluate the efficacy of various non-surgical treatments for intermittent exotropia(IXT).

METHODS

A comprehensive search of the PubMed, EMbase, and Cochrane Library databases was performed to identify relevant randomized controlled trials (RCTs) up to June 2024. Following independent screening, data extraction, and bias assessment by two researchers, network meta-analysis was conducted using R 4.2.2 software.

RESULTS

A total of 11 RCTs involving 1411 patients were included. Treatment options included overminus lenses (OML), conventional prisms(base-in prism) (CP), part time occlusion (PTO), and binocular vision training (BVT). OML demonstrated superior efficacy in improving distance and near control(1.1, 95% confidence interval (CI), 0.22 ∼ 1.8); 0.67, 95% CI :0.027 ∼ 1.2), as well as reducing near exodeviation compared to observation(4.5, 95% CI, 1.9 ∼ 6.9), but failed to reduce distance angle of deviation(3.2, 95%CI, -1.1 ∼ 6.4). No significant effect in improving control and reducing exodeviation angle at both distance and near was observed in PTO, BVT, and CP. Probability ranking indicated that the top-ranking three non-surgical interventions were OML, BVT and PTO for improving distance control and reducing near exodeviation; the top three non-surgical interventions for reducing distance exodevition were OML, PTO and BVT; the best non-surgical intervention for improving near control was OML, BVT、 PTO and CP have similar effects. The four non-surgical treatments had no significant impact on near stereoacuity.

CONCLUSION

Overall, OML ranks first among the four conservative treatment methods. These four commonly used non-surgical interventions did not significantly impact near stereoacuity. Clinicians should tailor personalized treatment strategies for patients with intermittent exotropia based on disease severity, characteristics, efficacy, and cost considerations.

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.

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.