There were 1,652 boys and 1,518 girls aged 3-6 years included in the analysis and 551 children were excluded owing to incompletion of the study (n=548), true entropion (n=1) and external hordeolum (n=2). There was no significant difference in age between boys (4.10 ± 0.75 yrs) and girls (4.08 ± 0.76 yrs) of all included subjects (independent samples t-test; p = 0.46). Overall, 26.2% (830 out of 3,170) children had lower eyelid epiblepharon, which could be further grouped into mild (54.3%), moderate (29.6%) and severe (16.1%) classes based on the severity of skin-fold height and cilia-corneal touch (Table 1).
Table 1. Classification of lower eyelid epiblepharon
Class of cilia-cornea touching
|
Class of skin fold height
|
Total
|
I
|
II
|
III
|
IV
|
|
|
I
|
451 (54.3%)*
|
84 (10.1%)†
|
1 (0.1%)‡
|
0 (0%)‡
|
536 (64.5%)
|
|
II
|
2 (0.2%)†
|
160 (19.3%)†
|
66 (8.0%)‡
|
1 (0.1%)‡
|
229 (27.6%)
|
|
III
|
0 (0%)‡
|
3 (0.5%)‡
|
36 (4.3%)‡
|
26 (3.1%)‡
|
65 (7.9%)
|
|
Total
|
453 (54.5%)
|
247 (29.9%)
|
103 (12.4%)
|
27 (3.2%)
|
830 (100%)
|
|
|
|
|
|
|
|
|
|
|
|
|
Table 2 summarizes the general profile of all included children. Statistically significant differences were detected in sex, age, SE, CYL, astigmatism type (chi-square tests; p = < 0.001, < 0.001, < 0.001, < 0.001, and 0.022, respectively) and BMI (independent samples t-test; p = 0.018) between epiblepharon and nonepiblepharon children (Table 2); no significant differences were identified in either height or weight between these two groups (independent samples t-test; p = 0.303 and 0.413, respectively) (Table 2).
Table 2. Characteristics of children with and without lower eyelid epiblepharon
|
Epiblepharon
(n=830)
|
No epiblepharon
(n=2340)
|
P value
|
Gender, n (%)
|
|
|
<0.001*
|
boys
|
487 (29.5)
|
1165 (70.5)
|
|
girls
|
343 (22.6)
|
1175 (77.4)
|
|
Age (yrs), n (%)
|
|
|
<0.001*
|
3
|
152 (30.6)
|
344 (69.4)
|
|
4
|
601 (28.0)
|
1547 (72.0)
|
|
5
|
39 (15.0)
|
221 (85.0)
|
|
6
|
38 (14.3)
|
228 (85.7)
|
|
SE (D), n (%)
|
|
|
<0.001*
|
≤ - 0.5
|
22 (56.4)
|
17 (43.6)
|
|
- 0.5 to 2
|
713 (25.0)
|
2141 (75.0)
|
|
≥ 2
|
95 (34.3)
|
182 (65.7)
|
|
CYL (D), n (%)
|
|
|
<0.001*
|
0 to ˂1
|
541 (22.3)
|
1890 (77.7)
|
|
1 to ˂1.5
|
132 (30.6)
|
300 (69.4)
|
|
1.5 to ˂2
|
68 (43.0)
|
90 (57.0)
|
|
2 to <2.5
|
44 (57.1)
|
33 (42.9)
|
|
2.5 to <3
|
32 (65.3)
|
17 (34.7)
|
|
>3.0
|
13 (56.5)
|
10 (43.5)
|
|
Astigmatism type, n (%)
|
|
|
0.022*
|
WTR
|
127 (52.3)
|
112 (47.4)
|
|
ATR
|
7 (35.5)
|
20 (64.5)
|
|
OBL
|
23 (56.1)
|
18 (43.9)
|
|
Height (ms), mean (SD)
|
1.01 (0.07)
|
1.01 (0.07)
|
0.303
|
Weight (kgs), mean (SD)
|
15.72 (2.92)
|
15.63 (2.73)
|
0.413
|
BMI, mean (SD)
|
15.43 (1.83)
|
15.26 (1.69)
|
0.018*
|
*p is statistically significant at 5%. BMI: body mass index, SD: standard deviation, CI: confidence interval, SE: spherical equivalent refractive error, CYL: cylindrical refractive error, D: diopters, WTR: with-the-rule, ATR: against-the-rule, OBL: oblique.
The prevalence of lower eyelid epiblepharon based on age was 30.6%, 28.0%, 15.0%, and 14.3% for 3-, 4-, 5-, and 6-year-old children, respectively (Table 2). Figure 2 further illustrates the age-specific prevalence of lower eyelid epiblepharon by its severity according to criteria based on skin-fold height only (Figure 2A), cilia-cornea touching area only (Figure 2B), and criteria established by both (Figure 2C). At different degrees of severity, younger patients roughly demonstrated a higher prevalence of epiblepharon than older patients (Figure 2).
Lower Eyelid Epiblepharon Associated Risk Factors
As statistically significant differences in age, sex and BMI were detected between children with and without lower eyelid epiblepharon (Table 2), multivariable logistic regression analysis was performed to further evaluate the association between lower eyelid epiblepharon and these three variables to screen for the risk factors for this eyelid disorder (Table 3). After adjustment for potential confounders including age, sex and BMI, epiblepharon was significantly associated with sex and age. Specifically, boys were more likely to have epiblepharon than girls (OR = 1.41 with p < 0.001); younger children at 3, 4, and 5 years old demonstrated higher possibilities of having epiblepharon than older children (6 years old), although no statistically significant difference was identified between 5- and 6-year-old children (OR = 3.68, 2.95, and 1.24 with p = < 0.001, < 0.001 and 0.402, respectively). However, after adjusting for sex and age, the association between BMI and epiblepharon was no longer statistically significant (p = 0.062).
Table 3. Association between lower eyelid epiblepharon and age, gender, and BMI
Risk factors
|
OR
|
95%CI
|
p value
|
Gender
|
|
|
|
Boys vs girls
|
1.41
|
(1.20, 1.66)
|
P< 0.001
|
Age(yrs)
|
|
|
|
3 vs 6
|
3.68
|
(2.38, 5.68)
|
p < 0.001
|
4 vs 6
|
2.95
|
(2.01, 4.32)
|
p < 0.001
|
5 vs 6
|
1.24
|
(0.75, 2.03)
|
p = 0.402
|
BMI
|
1.07
|
(0.95, 1.15)
|
p = 0.062
|
OR = odds ratio, CI = confidential interval.
Relation between Lower Eyelid Epiblepharon and Refractive Errors
Astigmatism (CYL ≥ 1.5 D) was identified in 307 children (9.68%) and 157 of them had epiblepharon. A statistically significantly higher prevalence of astigmatism was detected in epiblepharon children than in nonepiblepharon children (18.9% vs 6.4%) (chi-square test; p < 0.001). Meanwhile, in both populations, the astigmatism type was largely WTR (80.9% for epiblepharon vs 74.7% for nonepiblepharon).
Myopia (SE ≤ -0.5 D) was recognized in 39 children (1.23%) with 22 of them having epiblepharon; hyperopia (SE ≥ 2 D) was found in 277 children (8.74%) with 95 of them being epiblepharon-positive. Higher prevalences of myopia (2.7% vs 0.7%) and hyperopia (11.4% vs 7.8%) were identified in epiblepharon children than in nonepiblepharon children (chi-square tests; p = < 0.01 and 0.002, respectively). To further evaluate the association between lower eyelid epiblepharon and refractive errors, multivariable logistic regression analysis was performed where age and sex were adjusted for (Table 4). Overall, epiblepharon children presented an increased risk of astigmatism relative to nonepiblepharon children (OR = 3.41; 95% CI, (2.68, 4.33)), and epiblepharon preschoolers had a higher risk of myopia (OR = 3.55; 95% CI, (1.86, 6.76)) and hyperopia (OR = 1.53 95% CI, (1.18, 1.99)) than nonepiblepharon children.
Table 4. Association between lower eyelid epiblepharon and refractive errors
|
Astigmatism(≥1.5D)
|
Myopia(≤-0.5D)
|
Hyperopia(≥2.0D)
|
|
OR (95%CI)
|
P value
|
OR (95%CI)
|
P value
|
OR (95%CI)
|
P value
|
No Epiblepharon
|
1.00 (ref)
|
1.00 (ref)
|
1.00 (ref)
|
Epiblepharon
|
|
Mild
|
3.15
(2.35, 4.22)
|
<0.001
|
4.38
(2.14, 8.95)
|
<0.001
|
1.51
(1.09, 2.10)
|
0.014
|
Moderate
|
3.82
(2.69, 5.42)
|
<0.001
|
4.00
(1.64, 9.75)
|
0.002
|
1.52
(1.00, 2.32)
|
0.050
|
Severe
|
3.55
(2.24, 5.62)
|
<0.001
|
-
|
-
|
1.62
(0.94, 2.79)
|
0.082
|
ALL
|
3.41
(2.68, 4.33)
|
<0.001
|
3.55
(1.86, 6.76)
|
<0.001
|
1.53
(1.18, 1.99)
|
0.001
|
OR: odd ratio, WTR: with the rule, OBL: oblique.