Combined orthokeratology with atropine for children with myopia: a meta-Analysis

Authors: Wang S, Wang J, Wang N.

Geographical coverage: Asia

Sector: Biomedical

Sub-sector: Treatment

Equity focus: Children aged 16 and under.

Study population: Children with low to moderate myopia aged 6 to 16 years.

Review type: Effectiveness review

Quantitative synthesis method: Meta-analysis

Qualitative synthesis method: Not applicable

Background: Myopia, increasingly prevalent globally and manifesting at younger ages, poses a significant public health concern. High myopia can result in irreversible vision loss due to associated ocular complications. Therefore, it is of utmost importance and urgency to identify effective treatments that can halt or even reverse the progression of myopia in children.

Objectives:

To evaluate the additive effects of orthokeratology (OK) and 0.01% atropine ophthalmic solution for myopia in children.

Main findings:

According to the analysis in this study, the authors affirm that the combined use of Orthokeratology (OK) and 0.01% atropine is more successful in decelerating axial elongation compared to using OK alone in children with myopia, without adversely affecting clinical requirements.

A total of four studies were included in this review, involving 267 subjects, with an age range from 6 to 16 years old. The time to intervention ranged from one to 12 months. All studies concentrated on children with low to moderate myopia.

The mean axial length of the subjects in the experimental group was 0.09 mm less than that of subjects in the control group (WMD = -0.09, 95% CI [-0.15, -0.03], p = 0.003). Authors found no significant difference in UCVA, CECD, and IOP between the two groups (WMD was -0.01 [95% CI: -0.03, 0.01], 11.75 [95% CI: -4.09, 27.58], 0.12 [95% CI: -0.40, 0.63], respectively). None of the studies reported severe adverse events.

Authors note that the long-term efficacy and safety of the combination therapy of OK and 0.01% atropine in children with myopia will need to be further confirmed by more studies. These would need to address some of the weaknesses in the current evidence included in this review, for example, examine longer-treatment times, take account of external factors.

Methodology:

Studies were selected by the authors according to the following criteria: (1) the type of study included were RCTs; (2) the participants were younger than 18 years and definitely diagnosed as myopia; (3) the experimental group was treated with OK and 0.01% atropine, while the control group was treated with OK or 0.01% atropine alone; and (4) at least one outcome of interested reported, including the changes in AL, uncorrected distant visual acuity (UCVA), corneal endothelial cell density (CECD), and intraocular pressure (IOP). The following studies were excluded: conference abstracts, case reports, duplicate publications, letters and reviews, and studies without complete data or with inconsistent or erroneous data, incorrect random methods, or intervention methods.

Authors searched PubMed, Cochrane Library, EMBASE, Medline, Web of Science, Ovid, EBSCO host, CNKI and CBM to obtain relevant studies from their inception to March 2020 in all languages, using Medical Subject Headings and free words combined with “myopia”, “refractive errors”, “OK” and “atropine”. Authors screened reference lists of published reviews to identify applicable studies.

Two researchers independently screened titles, abstracts, and full-text to determine study eligibility. Disagreements were resolved by discussion. Two researchers independently extracted the required data from each eligible study, including first author, publication year, country or area, sample size, age, intervention and control, duration of treatment and outcomes. Quality of the included literature was assessed for the following seven aspects according to the Cochrane Collaboration tool.

The Review Manager (version 5.3) was used for data analysis. The weighted mean difference (WMD) with 95% confidence intervals (CIs) in AL, UCVA, CECD and IOP were used to assess myopia progression as well as adverse effects. Heterogeneity was assessed by means of I² statistics. If I² ≥50%, the random-effect model was used for meta-analysis, otherwise the fixed-effect model was chosen. A sensitivity analysis was performed to investigate the sources of heterogeneity (removing one study at a time).

Applicability/external validity: The authors point out several limitations, such as the consideration of only short-term treatment effects and the disregard of external factors like near-work activities, which limits the applicability and external validity of findings.

Geographic focus: The four studies included in the analysis were all carried out in Asia, and authors emphasize the necessity for these treatments to undergo testing in a more diverse array of geographical locations.

Summary of quality assessment:

The methods employed for the identification, inclusion, and critical evaluation of the studies were solid, despite the absence of efforts to incorporate unpublished works or consult with subject matter experts. The data analysis methods were particularly robust, although it’s understood that the authors faced limitations due to the limited number of studies and sample sizes. Consequently, we assigned a medium level of confidence to the review’s findings.