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

Clinical Relevance: Identification of the baseline characteristics 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 ortho-k lenses of different compression factors [0.75 D (OK-CCF) n=29 or 1.75 D (OK-ICF) n=33]. Relatively fast progressors were defined as participants who had axial elongation (AE) of 0.34 mm or above per two years. A binomial logistic regression analysis and a classification and regression tree (CART) model were used in the data analysis. The corneal biomechanics were measured with a bidirectional applanation device. Axial length was measured by a masked examiner. Results: As there were no significant between-group differences in baseline data (all p > 0.05), data were combined for analysis. The mean ± SD AE for relatively slow (n=27) and fast (n=35) progressors were 0.18 ± 0.14 mm and 0.64 ± 0.23 mm per two years, respectively. p2area1 was significantly higher in relatively fast progressors (p = 0.018). The binomial logistic regression and CART analysis showed baseline age and p2area1 could differentiate slow and fast progressors over two years. Conclusions: Corneal biomechanics could be a potential predictor of AE in ortho-k lens wearing children. A further investigation with a larger sample size is warranted to confirm the applicability of the finding