Abstract
Purpose :
With increasing use of axial length to monitor myopia progression, the ratio of refractive error (RE) change to axial elongation (AE) has important clinical implications. However, the true value of the ratio and how age and axial length affect it remain uncertain. We conducted a systematic review and meta-analysis to model the ratio.
Methods :
A systematic search was performed using Ovid Medline, EMBASE, and Cochrane Central Register of Controlled Trials. The following combined terms were used: “myopia” or “myopic” and “child” or “children” and “progression” or “longitudinal” or “follow-up” or “shift” and “axial”. Studies containing simultaneous RE change and AE in untreated eyes were identified. Other data collected were mean baseline age, standard deviation (SD) of AE, SD of RE change, sample size and proportion of Asian subjects in the study population. Due to desired statistical properties, the natural logarithm of the magnitude of mean refractive error change versus mean axial elongation was analyzed with a weighted multivariable linear mixed effects meta-analysis model, including three levels of random effects to account for all variability. The standard inverse variance method was used for weighting. Baseline values for mean RE and mean AE were included in the model as covariates.
Results :
A total of 67 studies with 86 different subpopulations and 167 evaluations contained complete data sets. The model is plotted in the Figure and covariates summarized in the Table. The overall weighted mean ratio was 2.04 [95%CI: 1.96, 2.12] D/mm. No covariates were statistically significant. Prediction intervals were relatively large, potentially reflecting variability in refractive error.
Conclusions :
This work sets a benchmark for clinical expectations with respect to the ratio between RE change and AE in myopic children. The lack of apparent impact of age on the ratio may reflect counterbalance between physiologic growth observed in younger children and a decreased ratio, anticipated from optical calculations, in longer eyes of older children. Interpretation should take into account limitations of using aggregated rather than individual subject data.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.