Role of waveform signal parameters in the classification of children as relatively slow and fast myopia progressors

ABSTRACT

Clinical Relevance

Identification of the baseline chracteristics for children undergoing orthokeratology with relatively fast myopia progression can allow a more accurate determination of the risk/benefit ratio.

Background

This study aimed to investigate if baseline corneal biomechanics can classify relatively slow and fast myopia progression in children.

Methods

Children aged six to 12 years with low myopia (0.50 to 4.00 D) and astigmatism (less than or equal to 1.25 D), were recruited. Participants were randomised to be fitted with orthokeratology contact lenses with a conventional compression factor (0.75 D, n = 29) or an increased compression factor (1.75 D, n = 33). Relatively fast progressors were defined as participants who had axial elongation of 0.34 mm or above per 2 years. A binomial logistic regression analysis and a classification and regression tree model were used in the data analysis. The corneal biomechanics were measured with a bidirectional applanation device. The axial length was measured by a masked examiner.

Results

As there were no significant between-group differences in the baseline data (all p > 0.05), data were combined for analysis. The mean ± SD axial elongation for relatively slow (n = 27) and fast (n = 35) progressors were 0.18 ± 0.14 mm and 0.64 ± 0.23 mm per 2 years, respectively. The area under the curve (p2area1) was significantly higher in relatively fast progressors (p = 0.018). The binomial logistic regression and classification and regression tree model analysis showed that baseline age and p2area1 could differentiate between slow and fast progressors over 2 years.

Conclusions

Corneal biomechanics could be a potential predictor of axial elongation in orthokeratology contact lens-wearing children.

KEYWORDS:

• Corneal biomechanics
• myopia
• orthokeratology

Acknowledgment

The authors thank Jason Lau for the assistance with Ocular Response Analyzer measurement. The authors also thank Dr Maureen Boost for her advice in the preparation of the manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The work was supported by the The Hong Kong Polytechnic University [Research Residency Scheme]; Menicon Co. Ltd., Japan [Collaborative Research Agreement (ZG3Z)].