Sleep Quality is Associated with Axial Length Elongation in Myopic Children Receiving Orthokeratology: A Retrospective Study

Figures & data

Figure 1 Schematic plot showing the possible factors contributing to the progression of myopia with ortho-k treatment.

Table 1 Comparisons of the Baseline Demographics Characteristics and Ocular Biometric Parameters Between Slow and Fast Progressions

Characteristics	Slow Progression (n = 62)	Fast Progression (n = 72)	P
Age (year)	10.55 ±1.70	9.90 ±1.18	0.009
Gender
Female (n, %)	34 (54.84%)	34 (47.22%)	0.392
Male (n, %)	28 (45.16%)	38 (52.78%)
SE (D)	−3.05±0.89	−2.52±0.63	<0.001
AL (mm)	25.21±0.60	24.82±0.62	0.039
CCT (µm)	557.31±29.56	550.71±23.48	0.078
Pupil size (µm)	3.85±0.47	3.75±0.48	0.130
IOP (mmHg)	15.10±2.66	15.42±2.43	0.733
Eccentricity value (µm)	0.71±0.26	0.70±0.30	0.664
Kf	42.75±1.09	42.43±1.31	0.126
Ks	43.97±1.19	43.68±1.29	0.123
ΔK	1.22±0.43	1.25±0.42	0.603
Anterior chamber depth (mm)	3.83±0.19	3.90±0.21	0.649
Average near-work distance
<33 cm (n, %)	2 (3.23%)	12 (16.67%)	0.010
33~40 cm (n, %)	55 (88.71%)	59 (81.94%)
>40 cm (n, %)	5 (8.06%)	1 (1.39%)
Average near-work duration (hour/day)
>5 h (n, %)	12 (19.35%)	18 (25.00%)	0.723
2–5 h (n, %)	40 (64.52%)	44 (61.11%)
<2 h (n, %)	10 (16.13%)	10 (13.89%)
Average outdoor time (hour/day)
<30 min	5 (8.06%)	5 (6.94%)	0.146
30–60 min	46 (74.19%)	63 (87.50%)
61–120 min	7 (11.29%)	2 (2.78%)
>120 min	4 (6.45%)	2 (2.78%)
Total PSQI	3.81±1.38	4.79±1.29	<0.001

Note: The results of statistical significance were presented in bold.

Figure 2 Simple linear regression analysis between AL change and (A) baseline age, (B) baseline SE, (C) average near-work distance per day and (D) total PSQI. Trend lines are fitted using binary linear regression (yellow–green lines).

Abbreviations: D, diopter; PSQI, Pittsburgh Sleep Quality Index; AL, axial length; SE, spherical equivalent.

Table 2 Multivariable Regression Analysis Showing the Strength of the Factors Related with Axial Length Growth

Variable	B Value	95% CI	P Value
Age (year)	−0.020	−0.037 ~ −0.003	0.020
Baseline SE (D)	0.057	0.024 ~ 0.090	0.001
Total PSQI	0.026	0.009 ~ 0.043	0.001
Near-work distance/day (cm)	−0.053	−0.110 ~ 0.004	0.673

Note: The results of statistical significance were presented in bold.

Table 3 Multivariable Regression Analysis Showing the Strength of the Factors Related with Fast Axial Elongation Incidence

Variable	B Value	95% CI	Odds Ratio	95% CI	P Value
Age (year)	−0.020	−0.332~0.291	0.981	0.717~1.338	0.902
Baseline SE (D)	0.741	0.120~1.406	2.097	1.128~4.081	0.023
Near-work distance/day (cm)	−1.405	−2.913~ −0.226	0.245	0.054~0.798	0.034
Total PSQI	0.472	0.171~0.8016	1.603	1.187~2.229	0.003

Note: The results of statistical significance were presented in bold.

Table 4 Subscales of PSQI in Slow and Fast Progression Groups of the Myopia Cases

Characteristics	Slow Progression (n = 62)	Fast Progression (n = 72)	P
Subjective sleep	0.95±0.76	0.93±0.76	0.807
Sleep latency	0.73±0.66	1.04±0.78	0.031
Sleep duration	0.06±0.25	0.13±0.37	0.200
Sleep efficacy	0.18±0.43	0.31±0.46	0.083
Sleep difficulty	0.92±0.58	0.97±0.63	0.511
Daytime dysfunction	0.97±0.79	1.42±0.82	0.002
Total PSQI	3.81±1.38	4.79±1.29	<0.001
Sleep quality
Good (< 6)	53 (85.48%)	49 (68.06%)	0.025
Poor (≥ 6)	9 (14.52%)	23 (31.94%)

Note: The results of statistical significance were presented in bold.