Skip to main content
PMC home page
PLOS ONE logoLink to PLOS ONE
. 2020 Aug 27;15(8):e0238122. doi: 10.1371/journal.pone.0238122

Prevalence of myopia among disadvantaged Australian schoolchildren: A 5-year cross-sectional study

Aicun Fu 1, Kathleen Watt 2, Barbara M Junghans 2, Androniki Delaveris 2, Fiona Stapleton 2,*
Editor: I-Jong Wang3
PMCID: PMC7451552  PMID: 32853278

Abstract

Purpose

Myopia prevalence is influenced by environmental factors including heritability and social disadvantage. The current prevalence of myopia among disadvantaged school children in Australia has not been reported. Therefore, this study analyses refractive data for children from rural and outer suburban areas.

Methods

The records of 4,365 children aged 6–15 visiting a city-based government-school respite care center during the years 2014/2016/2018 were analyzed for right eye non-cycloplegic spherical equivalent refraction (SER). The prevalence of myopia (SER≤-0.50D) was compared with historical data.

Results

The prevalence of myopia was 3.5%, 4.4% and 4.3% in 2014, 2016 and 2018, respectively. The prevalence of myopia increased with age (P<0.0001), but was not related to sex or year of testing (all P >0.05). The overall mean SER was 0.89±0.86D, 0.62±0.89D and 0.56±0.95 in 2014, 2016 and 2018, respectively. Mean SER was associated with year of testing, age (all P <0.0001) and sex (P = 0.03). Mean SER decreased slightly from 2014 to 2018 and demonstrated a significant shift towards less hyperopia with increasing age. Mean SER of females was higher than that of males and decreased faster than in males with age (P interaction = 0.03).

Conclusions

Myopia prevalence increased with age. The mean SER decreased slightly from 2014 to 2018. Sex differences in the rate of change with age was observed. Compared with 40 years ago, the prevalence of myopia has doubled, but it remains significantly lower than in school children of a similar age living in established urban areas that are regarded as having a higher socioeconomic status.

Introduction

There is evidence that myopia is reaching epidemic proportions at a speed that suggests strong environmental influences [1]. Myopia is not just an optical inconvenience, its detrimental impacts on the eyeball itself include a several fold increase in the risk of many sight-threatening ocular conditions, including cataracts, glaucoma, retinal detachments and myopic retinopathy [2].

There is clear evidence for a high and increasing prevalence of myopia in East Asia [3–8], apparently driven by increasing educational pressures and urbanization [9–13]. The absolute prevalence of myopia in Australia is much lower than in East Asian [14–16], United States [13] and Western Europe [17–20]. However, the evidence for an increasing prevalence of myopia in Australia is more questionable, due to the limited number of cross-sectional studies over time and the confounding effects of age-related emmetropization [21]. Therefore, studies at different time points are clearly required to quantify changes in the prevalence of myopia, for accurate assessment of the public health impacts and to assist with the development of preventive approaches.

There have been two cross-sectional studies at different time points evaluating the prevalence of myopia among schoolchildren in Sydney urban areas. French et al. [14] found that the prevalence of myopia in children aged 12 years living in Sydney over a 6-year period (from 2004–2005 to 2009–2011) increased from 4.4% to 8.4% in Caucasian and from 38.5% to 42.7% in East Asian children, respectively. Conversely, Junghans et al. [16] found little evidence of an epidemic of myopia in Australian primary school children aged 4–12 over a 30-year period, although they mention that only 8.8% of their cohort comprised Asian children.

Many studies have shown that the prevalence of myopia is influenced by environmental factors, such as living in urban as against rural areas [22–24], inner city-urban and outer suburban areas [25], population density and house size [26], and housing type [27]. Other external factors such as social disadvantage appear to impact myopia prevalence, such that children of parents having fewer years education and lower incomes are less likely to become myopic [28–30].

The Stewart House Children’s Charity is located on the northern beaches in Sydney and provides a unique service for children coming from disadvantaged populations by offering respite care with health screening and personal health and wellbeing education and support [31]. Children attend the service from predominantly rural or remote areas of New South Wales and the Australian Capital Territory. The School of Optometry and Vision Science at the University of New South Wales (UNSW) has provided a comprehensive vision care service to Stewart House since 1972. This retrospective cross-sectional study captured 3 time points to assess the prevalence of myopia and mean spherical equivalent refraction (SER) among this population of disadvantaged schoolchildren in Sydney, Australia in 2014, 2016 and 2018. In addition, the data from this study was compared with historical data from the same location.

Methods

This is a retrospective study of existing clinical records obtained during the Stewart House visits. The participants were from government schools in New South Wales and the Australian Capital Territory. Each school Principal chose children from disadvantaged families to attend a 2-week program at Stewart House. An information flyer describing the Stewart House program and age-appropriate eye examination was sent to parents or guardians prior to the children attending the service, which required signed consent. A short questionnaire asking parents of their children if they had visual symptoms was included. All children who were granted permission by their parents or guardians to visit the Stewart House in 2014, 2016 and 2018 were included, regardless of visual status. Each child attended Stewart House once. This study was approved by the Human Ethics Committee of UNSW Sydney (HC No:190255) and conformed to the tenets of the Declaration of Helsinki. The Research Ethics Committee specifically waived the requirement for parental or guardian consent.

Refractive error was determined by noncycloplegic retinoscopy while the child maintained fixation on a distant non-accommodative (6 m) target. All retinoscopy was performed by one examiner (AD). Other tests included in the eye examination were letter visual acuity at 6 m and 33 cm, cover test for strabismus, ocular motilities, saccades, pupil reactions, near point of convergence, heterophoria, stereopsis, accommodative facility, color vision and ophthalmoscopy.

For this study myopia was defined [1, 3, 15, 16] as SER equal to or more minus than -0.50D, and hyperopia as SER greater than +0.50D. Thus, emmetropia was defined as SER in the range -0.49 to +0.50D. Only refractive data from right eyes was used for the current refractive class analysis as the correlation between right and left eye refraction was extremely high (P < 0.0005).

Continuous baseline variables were expressed as mean ± standard deviation and evaluated with a one-way analysis of variance. Categorical variables, such as sex were expressed as a percentage (%) and evaluated with the Chi-square test. The factors related to the prevalence of myopia, mean SER and astigmatism were assessed with univariate and multivariate regression analyses. The interaction test was used to assess the changing trend in the mean SER and age between males and females. A P-value < 0.05 was considered statistically significant. All analyses were performed using Empower (R) (www.empowerstats.com, X & Y solutions Inc., Boston, MA) and R (http://www.R-project.org).

Results

Among the 4585 children who consented to participate in an eye examination, the data of 4365 (95.2%) children were used for analysis. Of the 220 children whose data were excluded (67, 67 and 86 cases in 2014, 2016 and 2018, respectively), 112 were excluded for strabismus (64 exotropia, 47 esotropia, 1 vertical strabismus), 89 were absent on the day of the eye examination or returned home early before the eye examination, 8 attended twice (but only data from the first attendance has been included), 11 were excluded due to pathology (2 cases of unilateral corneal opacity, 2 cases of bilateral severe keratoconus, 2 cases of pseudophakia following bilateral congenital cataract surgery, 2 cases of unilateral blindness due to congenital fundus abnormalities, 2 cases of congenital high myopia over -12D in both eyes, 1 case of nystagmus in conjunction with unilateral myopia of -20D). There were no significant differences in age and sex between the children whose data were analyzed and excluded (unpaired t-test, all P > 0.05). Table 1 shows a summary of the baseline data of the children included in the analysis. There were significant differences in sex and age between the three years of the study. Due to lower numbers of children in the younger (6 and 7 years) and older (14 and15 years) ends of the age range, data for the 6 and 7 years old were combined into one group and 14 and 15 were similarly combined for analysis. Two thirds of the children came from rural areas (socioeconomic status level 5), one third came from low-density housing in the outer suburbs of Sydney [32].

Table 1. Characteristics of the schoolchildren [mean ± SD or n (%)].

Group All 2014 2016 2018 P-value (3 years)
N 4365 1517 1394 1454
Sex 0.01
    Male 2054 (47.1%) 696 (45.9%) 629 (45.1%) 729 (50.1%)
    Female 2311 (52.9%) 821 (54.1%) 765 (54.9%) 725 (49.9%)
Age 11.12 ± 1.66 11.08 ± 1.81 11.04 ± 1.66 11.23 ± 1.49 0.008
Age groups (N, % of total) < 0.001
    6 and 7 158 (3.6%) 74 (4.9%) 57 (4.1%) 27 (1.9%)
    8 301 (6.9%) 126 (8.3%) 92 (6.6%) 83 (5.7%)
    9 552 (12.7%) 189 (12.5%) 202 (14.5%) 161 (11.1%)
    10 874 (20.0%) 285 (18.8%) 279 (20.0%) 310 (21.3%)
    11 1248(28.6%) 408 (26.9%) 390 (28.0%) 450 (30.9%)
    12 625 (14.4%) 210 (13.8%) 185 (13.3%) 230 (15.8%)
    13 408 (9.4%) 128 (8.4%) 134 (9.6%) 146 (10.0%)
    14 and 15 199 (4.6%) 97 (6.4%) 55 (3.9%) 47 (3.2%)
Prevalence Refractive errors
    Myopia 176 (4.0%) 53 (3.5%) 61 (4.4%) 62 (4.3%) 0.41
    Hyperopia 1935 (44.3%) 959 (63.2%) 528 (37.8%) 448 (30.9%) < 0.001
    Emmetropia 2254 (51.6%) 505 (33.3%) 805 (57.8%) 944 (64.9%) < 0.001
Overall SER (D) 0.69 ± 0.91 0.89 ± 0.86 0.62 ± 0.89 0.56 ± 0.95 < 0.001
    Male 0.66 ± 0.88 0.84 ± 0.85 0.58 ± 0.81 0.56 ± 0.96 < 0.001
    Female 0.72 ± 0.94 0.93 ± 0.88 0.65 ± 0.96 0.56 ± 0.99 < 0.001
Overall astigmatism (D) -0.16 ± 0.39 -0.16 ± 0.40 -0.17 ± 0.38 -0.15 ± 0.39 0.32
    Male -0.16 ± 0.40 -0.16 ± 0.40 -0.15 ± 0.39 -0.15 ± 0.41 0.51
    Female -0.16 ± 0.38 -0.16 ± 0.37 -0.17 ± 0.38 -0.15 ± 0.39 0.43
Astigmatism† direction
    WRT (30–0–1500) 474 (53.1%) 131 (37.9%) 146 (60.6%) 197 (64.4%) < 0.001
    ATR (60–120 0) 372 (41.7%) 193 (55.8%) 84 (34.9%) 95 (31.0%) < 0.001
    Oblique (31–59 0 and 121–149 0) 47 (5.3%) 22 (6.4%) 11(4.6%) 14 (4.6%) 0.51
Open in a new tab

SER = spherical equivalent refraction.

† astigmatism > 0.25D.

The overall prevalence of myopia, emmetropia and hyperopia were 4.0%, 51.6% and 44.3%, respectively. With respect to age groups, myopia prevalence increased gradually from 2.5% to 7.0%, at age 6 and 7, and 14 and 15, respectively, with a corresponding increase in the prevalence of emmetropia from 38.0% to 54.8% (all P < 0.0001). For the same age range a decrease in prevalence of hyperopia was observed with age from 59.5% to 38.2% (P < 0.0001) (Table 2). Across the three time points, the prevalence of emmetropia increased from 33.3% to 57.8% and 64.9% in 2014, 2016 and 2018, respectively (P < 0.001). In comparison, over the 3 years, hyperopia prevalence decreased from 63.2% to 37.8% and 30.9%, respectively (P < 0.001), myopia prevalence was 3.5%, 4.4% and 4.3%, respectively. There was no significant difference in the prevalence of myopia between three years (all P > 0.05). Multivariate regression analyses showed that the older the age, the higher the prevalence of myopia (OR = 1.20, 95% CI: 1.09~1.31, P = 0.0001), but the prevalence of myopia was not related to sex (OR = 1.10, 95% CI: 0.81~1.49, P = 0.53) or year of testing (P > 0.05, Table 3).

Table 2. Prevalence of refractive errors, mean Spherical Equivalent Refraction (SER) and astigmatism for all 4,365 schoolchildren according to sex and age.

Prevalence (%) Mean (D)
Myopia Emmetropia Hyperopia SER Astigmatism
All 176 (4.0%) 2254 (51.6%) 1935 (44.3%) 0.69 ± 0.91 -0.16 ± 0.39
Sex
    Male 78 (3.8%) 1109 (54.0%) 867 (42.2%) 0.66 ± 0.88 -0.16 ± 0.40
    Female 98 (4.2%) 1145 (49.5%) 1068 (46.2%) 0.72 ± 0.94 -0.16 ± 0.38
P value 0.46 0.003 0.008 < 0.001 0.54
Age groups
    6 and 7 4 (2.5%) 60 (38.0%) 94 (59.5%) 0.97 ± 1.04 -0.15 ± 0.32
    8 5 (1.7%) 144 (47.8%) 152 (50.5%) 0.80 ± 0.84 -0.14 ± 0.32
    9 14 (2.5%) 271 (49.1%) 267 (48.4%) 0.75 ± 0.86 -0.16 ± 0.40
    10 38 (4.3%) 459 (52.5%) 377 (43.1%) 0.70 ± 0.96 -0.15 ± 0.39
    11 50 (4.0%) 668 (53.5%) 530 (42.5%) 0.66 ± 0.83 -0.18 ± 0.44
    12 26 (4.2%) 323 (51.7%) 276 (44.2%) 0.70 ± 1.02 -0.17 ± 0.39
    13 25 (6.1%) 220 (53.9%) 163 (40.0%) 0.54 ± 0.82 -0.16 ± 0.41
    14 and 15 14 (7.0%) 109 (54.8%) 76 (38.2%) 0.59 ± 1.07 -0.17 ± 0.39
P value < 0.0001 < 0.0001 < 0.0001 < 0.001 0.48
Open in a new tab

Table 3. Multivariate regression analyses to estimate the changing trend of prevalence of myopia, mean Spherical Equivalent Refraction (SER) and astigmatism with years of test.

Exposure Year Non-adjusted, (95% CI) P value Model I, (95% CI) P value Model II, (95% CI) P value

Myopia prevalence 		2014 Reference Reference Reference
2016 1.26 (0.87, 1.84) 0.22 1.28 (0.88, 1.87) 0.19 1.28 (0.88, 1.87) 0.19
2018 1.23 (0.85, 1.79) 0.28 1.22 (0.84, 1.77) 0.30 1.22 (0.84, 1.78) 0.29

Mean SER 		2014 Reference Reference Reference
2016 -0.27 (-0.34, -0.20) < 0.0001 -0.27 (-0.34, -0.21) < 0.0001 -0.27 (-0.345, -0.21) < 0.0001
2018 -0.32 (-0.39, -0.26) < 0.0001 -0.32 (-0.38, -0.25) < 0.0001 -0.31 (-0.38, -0.25) < 0.0001

Mean astigmatism 		2014 Reference Reference Reference
2016 0.03 (0, 0.06) 0.11 0.03 (0, 0.06) 0.11 0.03 (0, 0.06) 0.12
2018 0 (-0.03, 0.03) 0.93 0 (-0.03,0.03) 0.92 0 (-0.03, 0.03) 0.93
Open in a new tab

Model I is adjusted for age; Model II is adjusted for age and sex.

The overall mean SER was 0.69 ± 0.91D (range 9.88D to -5.75D), of which male and female means were 0.66 ± 0.88D and 0.72 ± 0.94D, respectively (P < 0.0001). The mean SER decreased significantly with age, from 1.00 ± 1.03D in the 6 and 7 years-old female cohort to 0.62 ± 1.30D in the 14 and 15 years-old cohort and from 0.92 ± 1.06D to 0.57 ± 0.73D in the corresponding male cohort. The mean SER was 0.89 ± 0.86D, 0.62 ± 0.89D and 0.56 ± 0.95D in 2014, 2016 and 2018, respectively (P < 0.001). Multivariate regression analyses showed that the mean SER was related to sex, age and year of testing. The mean SER of females was higher than that of males (β = 0.06, 95% CI: 0 ~ 0.11, P = 0.04). The mean SER demonstrates a significant shift towards less hyperopia with increasing age (β = -0.05, 95% CI: -0.06~ -0.03, P < 0.0001). Moreover, the mean SER in females (β = -0.06, 95% CI: -0.09~ -0.04, P < 0.0001) decreased faster than in males (β = -0.02, 95% CI: -0.05~ 0, P = 0.04) with age (P interaction = 0.02, Fig 1). The mean SER decreased slightly from 2014 to 2018 (P < 0.0001, Table 3).

Fig 1. Smooth curve fitting between mean spherical equivalent refraction (SER) and age.

Fig 1

Open in a new tab

Mean SER decreased with age both in males (solid lines, β = -0.02, 95% CI: -0.05~0, P = 0.04) and females (dashed lines, β = -0.06, 95% CI: -0.09~ -0.04, P < 0.0001). There was a faster mean SER reduction in females compared to males (P = 0.02, interaction test).

The overall mean astigmatism was -0.16 ± 0.39D (range 0 to -5.00D). Seventy-nine percent of eyes exhibited negligible astigmatism (i.e. ≤0.25 D) and 18% showed astigmatism between -0.25 D and -1.0 D. Multivariate regression analyses showed that the mean astigmatism was not related to sex (β = 0.002, 95% CI: -0.024~ 0.028, P = 0.89), age (β = -0.01, 95% CI: -0.02~ 0, P = 0.27) and year of testing (all P > 0.05). Of the 893 (21%) eyes with astigmatism >0.25 D in the current study, approximately 53% exhibited with-the-rule astigmatism (WTR: negative axis within 30° of the horizontal), nearly 5% exhibited oblique astigmatism (axis 30–60° or 120–150°) and the remaining 42% exhibited against-the-rule astigmatism (ATR: axis 60–120°). Across the three time points, the prevalence of WTR increased from 37.9% to 60.6% and 64.4% in 2014, 2016 and 2018, respectively (P < 0.001). In comparison, over the 3 years, ATR prevalence decreased from 55.8% to 34.9% and 31.0%, respectively (P < 0.001), oblique astigmatism prevalence was 5.3%, 6.4% and 4.6%, respectively. (P = 0.51).

Compared with a similar population of children seen at Stewart House 40 years ago, and for data gathered using the same testing protocol (Table 4) [31], the age distribution was similar, although the proportion of females was higher in the current study (53.1% vs. 48.6%). Using the definition of myopia (in either eye data, SER < 0) as used in the earlier report, the prevalence of myopia has doubled in both males and females (male: 7.4% vs. 3.3%; female: 7.3% vs. 3.8%) and there is a higher prevalence hypermetropia greater than >1.25D (male: 14.0% vs. 7.1%; female: 19.8% vs. 13.1%) in the current study. The prevalence of astigmatism and sex differences were very similar across these two separate historic cohorts.

Table 4. Comparison between 1976 and the current study.

Study 1976 Current study (2014, 2016 and 2018)
N 1166 (1 year) 4365 (3 years)
Age: Min~Max (Mean) 5~16 6~15 (11.13)
Sex (%): male / female 51.4 / 48.6 46.9 / 53.1
Prevalence (%): male / female
    Hypermetropia † 7.1 / 13.1 14.0 / 19.8
    Myopia † 3.3 / 3.8 7.4 / 7.3
    Astigmatism †
        Right eye 7.9 / 11.6 7.1 / 7.4
        Left eye 6.6 / 7.8 6.6 / 7.5
Open in a new tab

Definition criteria (Study in 1976: in either eye data. myopia = spherical equivalent refraction (SER) < 0; hypermetropia SER greater than >1.25D; astigmatism: >0.75D.

† Prevalence of hypermetropia (myopia or astigmatism) in males means percentage of males with hypermetropia (myopia or astigmatism) in the total number of males.

Discussion

In this retrospective cross-sectional audit, we evaluated 4365 disadvantaged Australian schoolchildren and showed that myopia prevalence increased with age and mean SER decreased slightly from 2014 to 2018. Sex differences in the rate of change with age were observed. Compared with a similar population examined 40 years ago [31], the prevalence of myopia has doubled, but it remains significantly lower, and the refraction is slightly more hyperopic, than in other locations amongst schoolchildren of a similar age.

Other cross-sectional studies at different time points in different countries or areas also showed that the prevalence of myopia among schoolchildren increased over time (Table 5) [7,13,14,16, 33–36]. Differences in prevalence between studies may be related to race, age distribution, myopia definition and follow-up time in different studies. In these studies, the highest prevalence of myopia was in Asia (Mainland China, Hong Kong, Taiwan and Japan), second highest in United States and Israeli, third highest in Northern Ireland and Australian urban areas, and the lowest in disadvantaged Australian schoolchildren. The lower prevalence of myopia in Australia generally may be related to Australia's educational system and lifestyle [16]. This study has demonstrated for the first time, lower myopia prevalence and higher SER associated with socioeconomic disadvantage in Australia, particularly in a population of children from rural areas. Geographical remoteness is associated with children spending more physically active time outdoors than children living in urban areas and conceivably spending less free time on digital devices and near tasks. Educational expectations and learning outcomes are higher for children living in urban regions, particularly in high density housing [37–39].

Table 5. Change in myopia prevalence and mean Spherical Equivalent Refraction (SER) of schoolchildren over time in different countries.

Author Country Study commenced (number) Study completed (number) Study duration (year) Age (year) Refraction method Myopia definition Myopia prevalence (%) Mean SER (D)
From To From To
Chen et al [36] 2018 Eastern China 2001 2015 15 18.5 Non—cycloplegic autorefraction ≤ - 0.50 all 79.5 87.7 - 2.5 - 3.4
(2418) (2932)
Lam et al [5] 2011 Hong Kong 1991 2005–2010 20 6–12 Non—cycloplegic autorefraction < - 0.50 age 6 25 18.3 - 0.03 - 0.06
Chinese (383) (-) age12 64 61.5 - 1.45 - 1.67
Lin et al [7] 2004 Taiwanese 1983 2000 18 7–18 Cycloplegic autorefraction < - 0.25 age 7 5.8 20 0.52 0.17
(4125) (10878) age 12 36.7 61 - 0.48 - 1.45
age 15 64.2 81 - 1.49 - 2.89
Li et al [35] 2017 Beijing, China 2006 2015 10 15 Cycloplegic autorefraction < - 0.50 all 55.95 65.48 - 2.23 -3.13
(3657) (3676)
Matsumura et al [33] 1999
 Japan 1984 1996 13 3–17 Non—cycloplegic autorefraction ≤ - 0.50 age 7 5 15 0.50 0.50
(-) (-) age 12 35 60 - 0.75 - 1.75
age 17 49.3 65.6 - 1.75 - 2.25
Vitale et al [13] 2009 United States 1971–1972 1999–2004 30 12–17 Objective refraction or lensometry < 0 all 24 33.9 - -
(-) (-) black 12 31.2
white 25.8 34.5
Bar et al [34] 2005 Israeli 1990 2002 13 16–22 Non—cycloplegic autorefraction ≤ - 0.50 all 20.3 28.3 - -
(56639) (83966)
McCullough et al [17] 2016 Northern Ireland 2006–2008 2011–2014 6 12–13 Cycloplegic autorefraction ≤ - 0.50 all 16.4 14.6 - 1.25 - 1.25
(669) (212)
1960 2011–2014 50 Cycloplegic autorefraction ≤ - 0.50 all 7.2 14.6 1.8 1.13
(-) (212) (age 10–16) (age 12–13) (age 7) (age 7)
French et al [14] 2013 Sydney, urban 2004–2005 2009–2011 6 12 Cycloplegic autorefraction ≤ - 0.50 all 13 14.4 0.38 0.31
(2353) (1084) European
Caucasian 4.4 8.3
East Asian 38.5 42.7
Junghans et al [16] 2005 Sydney, urban 1990 1998–2004 10 4–12 Non—cycloplegic retinoscopy ≤ - 0.50 all 6.5 8.4 0.50 0.45
(2535) (1936) age 4 2 2.3
age 12 10.9 14.7
Current study Sydney, 2014 2018 5 6–15 Non—cycloplegic retinoscopy ≤ - 0.50 all 3.8 4.3 0.88 0.60
disadvantaged (1599) (1499) age 7 1.4 1.7 1.09 0.94
age 12 6.4 4.6 1.01 0.69
age 15 6.8 6.4 0.62 0.58
1976 (1166) 2014–2018 (4365) 40 6–15 Non—cycloplegic retinoscopy ≤ - 0.50 male 3.3 4.9 - 0.76
female 3.8 5.4 0.83
Open in a new tab

In a study of Chinese schoolchildren in Hong Kong in 2005–2010 [5,6], the prevalence of myopia in schoolchildren aged 6 and 12, was similar to 20 years prior. In a study comparing the prevalence of myopia in 6- and 7-year- old children of Chinese ethnicity in Sydney and Singapore [40], the prevalence of myopia was significantly lower in Sydney than in Singapore. Taken together, these studies suggest that environmental factors such as living areas, lifestyles and early educational pressures may have an impact on the prevalence of myopia [40]. Our participants are from rural and outer suburban areas of New South Wales and the Australian Capital Territory where Asian children are a minority and the ethnic mix of participants has not changed significantly over the period of the study [41].

In the current study, the mean SER showed a slight shift towards less hyperopia and the astigmatism remained stable from 2014 to 2018. This SER could be reasoned to be related to the significant reduction in the prevalence of hyperopia and increased prevalence of emmetropia, but stable prevalence of myopia over the three years. Several cross-sectional studies have also found at different time points that the refractions shifted in a myopic direction or became more severe myopic shift over time (Table 5) [7,14,17,33,35,36]. Compared with the studies above, the SER in this study showed a slightly higher degree of hyperopia for children of the same age. Moreover, the mean SER was hyperopic across all ages in the current study. The trend of changing refractive state with age was similar to a study of children from urban areas of Sydney [16], but the children in the latter study were younger (aged 4–12) and had a slightly lower hyperopic SER (0.60D vs. 0.45D). Compared with other studies, the schoolchildren with a slightly higher degree of hyperopia in this study may be partly responsible for the low and stable prevalence of myopia. Mean astigmatism was not related to age and sex. The trends of changing mean astigmatism with age [42,43] and sex [43] were similar to other studies.

There was no sex difference in the prevalence of myopia, although, females had a significantly higher mean hyperopic refraction than males in this study. These trends were consistent with that of children within a similar Australian population from 40 years ago [31]. In contrast, the later study of urban children in Sydney aged of 4-12-years-old found that there was no sex difference in myopia prevalence and mean refraction [16]. Studies in Beijing, China [44] and Taiwan [7] found that females had a higher prevalence of myopia and females had a higher mean refraction of myopia. In cross-sectional studies carried out in Beijing over a 10 year period [35] and in Western China over 15 years [36], the prevalence of myopia in females was higher than in males each year. However, a cross-sectional study of 6-12-year-olds in Hongkong [5] found that males and females had the same myopia prevalence, with older males having longer axial length and flatter corneal curvature. Contrasting findings in these prior studies may be related to different race and age distributions. Moreover, in the current study, we found that the mean SER of females decreased faster than males with age. Similar findings have been reported in both cross-sectional [44] and longitudinal studies [3]. This may be related to different visual experiences in daily life [35,44]. One possible explanation was that females tend to spend more time reading and performing near work and less time outdoors [39,45,46]. Children experiencing appropriate outdoor light intensity and those spending more time spent outdoors showed significantly less myopic shift and axial elongation [47,48].

The main strength of this study is that the cross-sectional data at 3 time points included 4365 disadvantaged Australian schoolchildren aged 6–15, and thus describes accurate and representative data on the changing trend of the related factors of myopia prevalence and mean SER. Potential limitations of non-cycloplegia in our analysis should be mentioned. Cycloplegic refraction is proposed as the gold standard for determining refractive error and yields better results than non-cycloplegic retinoscopy [49,50]. Non-cycloplegic retinoscopy can result in overestimation of myopia and underestimation of hyperopia in young children [50,51]. However, Yeotikar [52] found that mean difference in SER for 7 to 16 years children obtained by non-cycloplegic refraction with contralateral fogging and cycloplegic refraction was small (mean of 0.29D) and not clinically significant. Meanwhile, if we remove the 6–7 age group or 6–8 age group from the analysis, the overall trend of myopia prevalence with age does not change, indicating that this overestimation is unlikely to have occurred. In this study, the screening eye examination was part of a battery of other physical examinations, consequently cycloplegic refraction was not appropriate. In several previous Australian studies, non-cycloplegic refraction was performed in a similar age groups in a similar manner allowing a meaningful comparison over time [15,16,31]. In addition, there are less children enrolled in the low-grade groups in 2018, with more children enrolled in the middle to high grade groups, comparing with 2014 and 2016 (ex. Only 1.9% in age group 6 and 7 in 2018 vs. 4.7% and 4.1% in 2014 and 2016, respectively). However, the School Principal selects all eligible children from disadvantaged families, so there is some variation in the age and sex profile of children year to year. Meanwhile, multivariate regression analyses accommodate these variations in numbers by adjusting for age and sex to estimate the changing trend of refractive error over time.

In conclusion, this study showed that the prevalence of myopia among disadvantaged Australian schoolchildren aged 6–15 has doubled compared with 40 years ago amongst schoolchildren of a similar age, but it continues to be significantly lower and the refraction is slightly more hyperopic than in other locations including in Australian urban areas. This may suggest that reasons for the large increase in prevalence of myopia reported in other countries must include questions relating to environmental risk factors, in particular, socioeconomic status, education and outdoor activity in addition to genetic propensity.

Supporting information

S1 Data

(XLSX)

Click here for additional data file. (225.9KB, xlsx)

Acknowledgments

The authors wish to acknowledge Mr Graeme Philpotts, Chief Executive Officer of Stewart House and the staff of Stewart House for their support, and the families and children who participated in this study.

Data Availability

All relevant data are within the manuscript and its Supporting Information files.

Funding Statement

Aicun Fu: Henan overseas study project of health and family planning technology (2018038) NO-The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

References

  • 1.Holden BA, Fricke TR, Wilson DA, et al. Global prevalence of myopia and high myopia and temporal trends from 2000 through 2050. Ophthalmol. 2016; 123 (5):1036–42. [DOI] [PubMed] [Google Scholar]
  • 2.Flitcroft DI. The complex interactions of retinal, optical and environmental factors in myopia aetiology. Prog Retin Eye Res. 2012; 31(6): 622–60. 10.1016/j.preteyeres.2012.06.004 [DOI] [PubMed] [Google Scholar]
  • 3.Zhou WJ, Zhang YY, Li H, et al. Five-year progression of refractive errors and incidence of myopia in school-aged children in Western China. J Epidemiol. 2016; 26(7):386–95. 10.2188/jea.JE20140258 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 4.Pan CW, Dirani M, Cheng CY, Wong TY, Saw SM. The age-specific prevalence of myopia in Asia: a meta-analysis. Optom Vis Sci. 2015;92(3): 258–66. 10.1097/OPX.0000000000000516 [DOI] [PubMed] [Google Scholar]
  • 5.Lam CS, Lam CH, Cheng SC, Chan LY. Prevalence of myopia among Hong Kong Chinese schoolchildren: changes over two decades. Ophthalmic Physiol Opt. 2012; 32(1):17–24. 10.1111/j.1475-1313.2011.00886.x [DOI] [PubMed] [Google Scholar]
  • 6.Lam CSY, Goh WSH. The incidence of refractive errors among school children in Hong Kong and its relationship with the optical components. Clin Exp Optom. 1991; 74(3):97–103. [Google Scholar]
  • 7.Lin LL, Shih YF, Hsiao CK, Chen CJ. Prevalence of myopia in Taiwanese schoolchildren:1983 to 2000. Ann Acad Med Singapore. 2004; 33(1): 27–33. [PubMed] [Google Scholar]
  • 8.Sensaki S, Sabanayagam C, Verkicharla PK, et al. An ecologic study of trends in the prevalence of myopia in Chinese adults in Singapore born from the 1920s to 1980s. Ann Acad Med Singapore. 2017; 46(6):229–36. [PubMed] [Google Scholar]
  • 9.Wensor M, McCarty CA, Taylor HR. Prevalence and risk factors of myopia in Victoria, Australia. Arch Ophthalmol. 1999;117(5):658–63. 10.1001/archopht.117.5.658 [DOI] [PubMed] [Google Scholar]
  • 10.Wu HM, Seet B, Yap EP, Saw SM, Lim TH, Chia KS. Does education explain ethnic differences in myopia prevalence? A population-based study of young adult males in Singapore. Optom Vis Sci. 2001;78(4):234–9. 10.1097/00006324-200104000-00012 [DOI] [PubMed] [Google Scholar]
  • 11.Williams KM, Bertelsen G, Cumberland P, et al. Increasing Prevalence of Myopia in Europe and the Impact of Education. Ophthalmol. 2015; 122(7): 1489–97. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 12.Xu L, Li J, Cui T, et al. Refractive error in urban and rural adult Chinese in Beijing. Ophthalmol. 2005;112(10):1676–83. [DOI] [PubMed] [Google Scholar]
  • 13.Vitale S, Sperduto R, Ferris F. Increased prevalence of myopia in the United States between 1971–1972 and 1999–2004. Arch Ophthalmol. 2009;127 (12):1632–9. 10.1001/archophthalmol.2009.303 [DOI] [PubMed] [Google Scholar]
  • 14.French AN, Morgan IG, Burlutsky G, Mitchell P, Rose KA. Prevalence and 5- to 6-year incidence and progression of myopia and hyperopia in Australian schoolchildren. Ophthalmol. 2013;120(7):1482–91. [DOI] [PubMed] [Google Scholar]
  • 15.Junghans BM, Crewther SG. Prevalence of myopia among primary school children in eastern Sydney. Clin Exp Optom. 2003; 86(5):339–45. 10.1111/j.1444-0938.2003.tb03130.x [DOI] [PubMed] [Google Scholar]
  • 16.Junghans BM, Crewther SG. Little evidence for an epidemic of myopia in Australian primary school children over the last 30 years. BMC Ophthalmol. 2005; 5(1): 1. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 17.McCullough SJ, O'Donoghue L, Saunders KJ. Six-year refractive change among white children and young adults: evidence for significant increase in myopia among White UK children. PLoS One. 2016; 11(1): e0146332 10.1371/journal.pone.0146332 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 18.Wen G, Tarczy-Hornoch K, McKean-Cowdin R, et al. Prevalence of myopia, hyperopia, and astigmatism in non-Hispanic white and Asian children: multi-ethnic pediatric eye disease study. Ophthalmol. 2013;120(10):2109–16. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 19.Kempen JH, Mitchell P, Lee KE, et al. The prevalence of refractive errors among adults in the United States, Western Europe, and Australia. Arch Ophthalmol. 2004;122(4):495–505. 10.1001/archopht.122.4.495 [DOI] [PubMed] [Google Scholar]
  • 20.French AN, O'Donoghue L, Morgan IG, Saunders KJ, Mitchell P, Rose KA. Comparison of refraction and ocular biometry in European Caucasian children living in Northern Ireland and Sydney, Australia. Invest Ophthalmol Vis Sci. 2012; 53(7):4021–31. 10.1167/iovs.12-9556 [DOI] [PubMed] [Google Scholar]
  • 21.Rose K, Smith W, Morgan I, Mitchell P. The increasing prevalence of myopia: implications for Australia. Clin Exp Ophthalmol. 2001; 29(3):116–20. 10.1046/j.1442-9071.2001.00389.x [DOI] [PubMed] [Google Scholar]
  • 22.Guo Y, Liu LJ, Xu L, et al. Outdoor activity and myopia among primary students in rural and urban regions of Beijing. Ophthalmology. 2013; 120 (2):277–83. 10.1016/j.ophtha.2012.07.086 [DOI] [PubMed] [Google Scholar]
  • 23.He M, Zheng Y, Xiang F. Prevalence of myopia in urban and rural children in mainland China. Optom Vis Sci. 2009; 86(1): 40–4. 10.1097/OPX.0b013e3181940719 [DOI] [PubMed] [Google Scholar]
  • 24.Shih YF, Chiang TH, Hsiao CK, Chen CJ, Hung PT, Lin LL. Comparing myopic progression of urban and rural Taiwanese schoolchildren. Jpn J Ophthalmol. 2010; 54(5): 446–51. 10.1007/s10384-010-0860-7 [DOI] [PubMed] [Google Scholar]
  • 25.Ip JM, Rose KA, Morgan IG, Burlutsky G, Mitchell P. Myopia and the urban environment: findings in a sample of 12-year-old Australian school children. Invest Ophthalmol Vis Sci. 2008; 49(9):3858–63. 10.1167/iovs.07-1451 [DOI] [PubMed] [Google Scholar]
  • 26.Choi KY, Yu WY, Lam CHI, et al. Childhood exposure to constricted living space: a possible environmental threat for myopia development. Ophthalmic Physiol Opt. 2017;37(5):568–75. 10.1111/opo.12397 [DOI] [PubMed] [Google Scholar]
  • 27.Wu X, Gao G, Jin J, et al. Housing type and myopia: the mediating role of parental myopia. BMC Ophthalmol. 2016;16(1):151 10.1186/s12886-016-0324-z [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 28.Wong TY, Foster PJ, Johnson GJ, Seah SKL. Education, socioeconomic status, and ocular dimensions in Chinese adults: the Tanjong Pagar Survey. Br J Ophthalmol.2002; 86: 963–8. 10.1136/bjo.86.9.963 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 29.Rahi JS, Cumberland PM, Peckham CS. Myopia over the life course: prevalence and early life influences in the 1958British birth cohort. Ophthalmology. 2011; 118: 797–804. 10.1016/j.ophtha.2010.09.025 [DOI] [PubMed] [Google Scholar]
  • 30.Foster PJ, Jiang Y. Epidemiology of myopia. Eye. 2014; 28:202–8. 10.1038/eye.2013.280 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 31.Amigo G, McCarthy A, Pye D. Visual characteristics of an underprivileged group of Australian children. The Aust J Optom. 1976; 59(6):188–97. [Google Scholar]
  • 32.Australian Bureau of Statistics. 2033.0.55.001—census of population and housing: socio-economic indexes for areas (SEIFA), Australia. 2016. Available from: https:/www.abs.gov.au/ausstats/abs@.nsf/Lookup/by%20Subject/2033.0.55.001~2016~Main%20Features~Interactive%20Maps~7.
  • 33.Matsumura H, Hirai H. Prevalence of myopia and refractive changes in students from 3 to 17 years of age. Surv Ophthalmol. 1999; Suppl 1: S109–15. [DOI] [PubMed] [Google Scholar]
  • 34.Bar Dayan Y, Levin A, Morad Y, et al. The changing prevalence of myopia in young adults: a 13-year series of population-based prevalence surveys. Invest Ophthalmol Vis Sci. 2005; 46(8):2760–5. 10.1167/iovs.04-0260 [DOI] [PubMed] [Google Scholar]
  • 35.Li Y, Liu J, Qi P. The increasing prevalence of myopia in junior high school students in the Haidian District of Beijing, China: a 10-year population-based survey. BMC Ophthalmol. 2017;17(1):88 10.1186/s12886-017-0483-6 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 36.Chen M, Wu A, Zhang L, et al. The increasing prevalence of myopia and high myopia among high school students in Fenghua city, eastern China: a 15-year population-based survey. BMC Ophthalmol. 2018;18(1):159 10.1186/s12886-018-0829-8 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 37.Dollman J, Maher C, Olds TS, Ridley K. Physical activity and screen time behavior in metropolitan, regional and rural adolescents: a -sectional study of Australians aged 9–16 years. J Sci Med Sport. 2012;15(1):32–7. 10.1016/j.jsams.2011.05.011 [DOI] [PubMed] [Google Scholar]
  • 38.Baxter J, Gray M, Hayes A. Families in regional, rural and remote Australia. Melbourne: Australian Institute for Family Studies. 2011. [Google Scholar]
  • 39.Hardy LL, Dobbins TA, Denney-Wilson EA, Okely AD, Booth ML. Descriptive epidemiology of small screen recreation among Australian adolescents. J Paediatr Child Health. 2006; 42(11):709–14. 10.1111/j.1440-1754.2006.00956.x [DOI] [PubMed] [Google Scholar]
  • 40.Rose KA, Morgan IG, Smith W, Burlutsky G, Mitchell P, Saw SM. Myopia, lifestyle, and schooling in students of Chinese ethnicity in Singapore and Sydney. Arch Ophthalmol. 2008;126(4):527–30. 10.1001/archopht.126.4.527 [DOI] [PubMed] [Google Scholar]
  • 41.Wikipedia. Asian Australians. Available from: https://en.wikipedia.org/wiki/Asian_Australians.
  • 42.Junghans B, Kiely PM, Crewther DP, Crewther SG. Referral rates for a functional vision screening among a large cosmopolitan sample of Australian children. Ophthalmic Physiol Opt. 2002; 22(1):10–25. 10.1046/j.1475-1313.2002.00010.x [DOI] [PubMed] [Google Scholar]
  • 43.Fotouhi A, Hashemi H, Yekta AA, Mohammad K, Khoob MK. Characteristics of astigmatism in a population of schoolchildren, Dezful, Iran. Optom Vis Sci. 2011;88(9):1054–9. 10.1097/OPX.0b013e318221727d [DOI] [PubMed] [Google Scholar]
  • 44.Zhao J, Pan X, Sui R, Munoz SR, Sperduto RD, Ellwein LB. Refractive error study in children: results from Shunyi District, China. Am J Ophthalmol. 2000; 129(4):427–35. 10.1016/s0002-9394(99)00452-3 [DOI] [PubMed] [Google Scholar]
  • 45.You QS, Wu LJ, Duan JL, et al. Prevalence of myopia in school children in greater Beijing: the Beijing childhood eye study. Acta Ophthalmol. 2014; 92(5): e398–406. 10.1111/aos.12299 [DOI] [PubMed] [Google Scholar]
  • 46.Saw SM, Zhang MZ, Hong RZ, Fu ZF, Pang MH, Tan DT. Near-work activity, night-lights, and myopia in the Singapore-China study. Arch Ophthalmol. 2002; 120(5):620–7. 10.1001/archopht.120.5.620 [DOI] [PubMed] [Google Scholar]
  • 47.Sherwin JC, Reacher MH, Keogh RH, Khawaja AP, Mackey DA, Foster PJ. The association between time spent outdoors and myopia in children and adolescents: a systematic review and meta-analysis. Ophthalmol. 2012; 119 (10):2141–2151. [DOI] [PubMed] [Google Scholar]
  • 48.Wu PC, Chen CT, Lin KK, et al. Myopia prevention and outdoor light intensity in a school-based cluster randomized trial. Ophthalmol 2018; 125(8):1239–50. [DOI] [PubMed] [Google Scholar]
  • 49.Saw SM, Katz J, Schien OD, Chew SJ, Chan TK: Epidemiology of myopia. Epidem Rev 1996; 18(2):175–87. [DOI] [PubMed] [Google Scholar]
  • 50.Mutti DO, Zadnik K, Egashira S, Kish L, Twelker JD, Adams AJ. The effect of cycloplegia on measurement of ocular components. Invest Ophthalmol Vis Sci 1994; 35(2):515–527. [PubMed] [Google Scholar]
  • 51.Sanfilippo PG, Chu BS, Bigault O, et al. What is the appropriate age cut-off for cycloplegia in refraction? Acta Ophthalmol. 2014; 92(6):458–62. [DOI] [PubMed] [Google Scholar]
  • 52.Yeotikar Nisha S., Bakaraju Ravi Chandra, Reddy P.S. Roopa, Prasad Kalyani. Cycloplegic refraction and non-cycloplegic refraction using contralateral fogging: a comparative study. Journal of Modern Optics. 2007;54(9):1317–24. [Google Scholar]

Decision Letter 0

I-Jong Wang

27 Apr 2020

PONE-D-20-09893

Prevalence of myopia among disadvantaged Australian schoolchildren: a 5-year cross-sectional study

PLOS ONE

Dear Dr. Stapleton,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

We would appreciate receiving your revised manuscript by Jun 11 2020 11:59PM. When you are ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter.

To enhance the reproducibility of your results, we recommend that if applicable you deposit your laboratory protocols in protocols.io, where a protocol can be assigned its own identifier (DOI) such that it can be cited independently in the future. For instructions see: http://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols

Please include the following items when submitting your revised manuscript:

  • A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). This letter should be uploaded as separate file and labeled 'Response to Reviewers'.

  • A marked-up copy of your manuscript that highlights changes made to the original version. This file should be uploaded as separate file and labeled 'Revised Manuscript with Track Changes'.

  • An unmarked version of your revised paper without tracked changes. This file should be uploaded as separate file and labeled 'Manuscript'.

Please note while forming your response, if your article is accepted, you may have the opportunity to make the peer review history publicly available. The record will include editor decision letters (with reviews) and your responses to reviewer comments. If eligible, we will contact you to opt in or out.

We look forward to receiving your revised manuscript.

Kind regards,

I-Jong Wang

Academic Editor

PLOS ONE

Journal requirements:

When submitting your revision, we need you to address these additional requirements:

1.    Please ensure that your manuscript meets PLOS ONE's style requirements, including those for file naming. The PLOS ONE style templates can be found at http://www.plosone.org/attachments/PLOSOne_formatting_sample_main_body.pdf and http://www.plosone.org/attachments/PLOSOne_formatting_sample_title_authors_affiliations.pdf

2. You indicated that you had ethical approval for your study and that parents provided consent for their children to attend the Stewart House service described in the study. In your Methods section, please ensure you have also stated whether you obtained consent specifically for participation in research from the parents or guardians of the minors included in the study or whether the research ethics committee or IRB specifically waived the need for their consent.

3. Please include captions for your Supporting Information files at the end of your manuscript, and update any in-text citations to match accordingly. Please see our Supporting Information guidelines for more information: http://journals.plos.org/plosone/s/supporting-information.

[Note: HTML markup is below. Please do not edit.]

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

Reviewer #4: Yes

**********

2. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

Reviewer #4: Yes

**********

3. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

Reviewer #4: Yes

**********

4. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

Reviewer #4: Yes

**********

5. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: It's a known fact, nothing new. Study of myopia,astigmatism separately,not using SER may be more important in the future. Full cycloplegic refraction data will be needed. Different age groups will be also needed to be separated.

Reviewer #2: This is a detailed study, but as you've mentioned, this study didn't use cycloplegic refraction. Since the overall spherical equivalent refraction was less than 1 diopter, the amount of refraction changed might be significant.

Reviewer #3: 1. In this study, refractive error was determined by noncycloplegic retinoscopy, instead of cycloplegic autorefractometry. Noncycloplegic refraction could result in overestimation of myopia and underestimation of hyperopia, especially in young children. Therefore, there would be some impacts in the statistical results. For example, in table 2, the higher prevalence of myopia in age group 6-7 than that in age group 8 could be the result of pseudomyopia in younger kids. In table 1, higher proportions of younger children (age 6-8) in 2014 group might result in more overestimation of myopia.

2. Children with ocular pathology were excluded from the study, but strabismus cases were not excluded. Without cycloplegia, the real refractive status could be masked by accommodation in strabismic children (ex. accommodative esotropia, intermittent exotropia ...).

3. The author did not mention that the retinoscopy was performed by one or multiple examiners. There would be inter-observer variability of retinoscopy.

4. The author did not mention the composition of subjects. As we know, race is an important factor of myopia prevalence.

5. There is no discussion about the significantly increased proportions of both myopia and hyperopia in this study as compared to the similar study in 1976.

Reviewer #4: The authors of the paper “Prevalence of myopia among disadvantaged Australian schoolchildren: a 5-year cross-sectional study “presents a cross-sectional analysis of refractive data and myopia prevalence in Australian children during the years 2014/2016/2018. The authors found that, although the prevalent of myopia remained low comparing with other locations, the mean spherical equivalent refraction (SER) decreased from 2014 to 2018, accompany with shifting towards less hyperopia. They also found that females had higher mean SER, but with faster decrease than male with age. In general, this paper is well-written and easy to follow. However, there are few points to be considered.

1.This paper found the mean SER decreased from 2016 to 2018, with trends of less hyperopia and stable myopia. However, reviewing the numbers of included cases, there are less children enrolled in the low grade groups in 2018, with more children enrolled in the middle to high grade groups, comparing with 2014 and 2016 (ex. Only 1.9% in age group 6 and 7 in 2018 vs. 4.7% and 4% in 2014 and 2016, respectively). Could the authors make some explanations that this will not lead to selection bias?

2.The authors found females had higher mean SER, but with faster decrease with age comparing with male. Unlike other studies with higher prevalence of myopia in female, the higher prevalence of hyperopia in female in the present study is somewhat different. This could possibly be explained by different visual experiences in daily life. However, similar to question 1, there are more female children included in this study, especially in 2014 and 2016, could this also be a confounding factor?

**********

6. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: Yes: HON-LEUNG YUEN

Reviewer #2: No

Reviewer #3: No

Reviewer #4: No

[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files to be viewed.]

While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email us at figures@plos.org. Please note that Supporting Information files do not need this step.

PLoS One. 2020 Aug 27;15(8):e0238122. doi: 10.1371/journal.pone.0238122.r002

Author response to Decision Letter 0

29 May 2020

Thank you for the opportunity to revise this manuscript for consideration. The comments have been carefully considered and a revised submission has been uploaded, including both a marked up version and clean version. Changes to the manuscript are highlighted in yellow and detailed responses to the reviewers’ comments are presented in italics below.

Reviewer #1:

It's a known fact, nothing new. Study of myopia, astigmatism separately, not using SER may be more important in the future. Full cycloplegic refraction data will be needed. Different age groups will be also needed to be separated.

Answer: (1) Thank you for this comment. We have separated the astigmatic component as suggested and presented this by age (in Tables 1 and 2).

We have added this information to lines 187-201, page 8: “The overall mean astigmatism was -0.16 ± 0.39D (range 0 to -5.00D). Seventy-nine percent of eyes exhibited negligible astigmatism (i.e. ≤0.25 D) and 18% showed astigmatism between -0.25 D and -1.0 D. Multivariate regression analyses showed that the mean astigmatism was not related to sex (β=0.002, 95% CI: -0.024~ 0.028, P =0.89), age (β= -0.01, 95% CI: -0.02~ 0, P = 0.27) and year of testing (all P > 0.05). Of the 893 (21%) eyes with astigmatism >0.25 D in the current study, approximately 53% exhibited with-the-rule astigmatism (WTR: negative axis within 30° of the horizontal), nearly 5% exhibited oblique astigmatism (axis 30 - 60° or 120 - 150°) and the remaining 42% exhibited against-the-rule astigmatism (ATR: axis 60 - 120°). Across the three time points, the prevalence of WTR increased from 37.9% to 60.6% and 64.4% in 2014, 2016 and 2018, respectively (P < 0.001). In comparison, over the 3 years, ATR prevalence decreased from 55.8% to 34.9% and 31.0%, respectively (P < 0.001), oblique astigmatism prevalence was 5.3%, 6.4% and 4.6%, respectively. (P = 0.51).”

(2) This was a screening study and cycloplegic refraction was not determined. This limitation has been addressed in the discussion at lines 308-319, page12: “Cycloplegic refraction is proposed as the gold standard for determining refractive error and yields better results than non-cycloplegic retinoscopy. Non-cycloplegic retinoscopy can result in overestimation of myopia and underestimation of hyperopia in young children. However, if we remove the 6-7 age group or 6-8 age group from the analysis, the overall trend of myopia prevalence with age does not change, indicating that this overestimation is unlikely to have occurred. In this study, the screening eye examination was part of a battery of other physical examinations, consequently cycloplegic refraction was not appropriate. In several previous Australian studies, non-cycloplegic refraction was performed in a similar age groups in a similar manner allowing a meaningful comparison over time.”

Reviewer #2:

This is a detailed study, but as you've mentioned, this study didn't use cycloplegic refraction. Since the overall spherical equivalent refraction was less than 1 diopter, the amount of refraction changed might be significant.

Answer: Please see the response to question 2, reviewer #1.

Reviewer #3:

1. In this study, refractive error was determined by noncycloplegic retinoscopy, instead of cycloplegic autorefractometry. Noncycloplegic refraction could result in overestimation of myopia and underestimation of hyperopia, especially in young children. Therefore, there would be some impacts in the statistical results. For example, in table 2, the higher prevalence of myopia in age group 6-7 than that in age group 8 could be the result of pseudomyopia in younger kids. In table 1, higher proportions of younger children (age 6-8) in 2014 group might result in more overestimation of myopia.

Answer: (1) Noncycloplegic refraction may indeed result in overestimation of myopia and underestimation of hyperopia, especially in young children. We have further analysed the data based on age. In Table 2, there are 4(2.5%) and 5(1.7%) children with myopia in age 6-7 group and in age 8 group respectively. If we remove the 6-7 age group or 6-8 age group, the overall trend of myopia prevalence with age does not change.

A sentence has been added at lines 312-314 as follows: “However, if we remove the 6-7 age group or 6-8 age group from the analysis, the overall trend of myopia prevalence with age does not change, indicating that this overestimation is unlikely to have occurred.”

In Table 1, there are 2(1%), 3(2%) and 4(3.6%) children with myopia aged 6-8 in 2014, 2016 and 2018, respectively. Although there are more children aged 6-8 in 2014, the proportion of myopia is not statistically higher. Meanwhile, we found that the mean SER decreased slightly and the mean astigmatism was stable from 2014 to 2018.

2. Children with ocular pathology were excluded from the study, but strabismus cases were not excluded. Without cycloplegia, the real refractive status could be masked by accommodation in strabismic children (ex. accommodative esotropia, intermittent exotropia ...).

Answer: Thank you for this comment. We excluded the 112 strabismus cases (64 exotropia, 47 esotropia, 1 vertical strabismus) and reanalyzed the data. We added this content and changed all other relevant data throughout the manuscript. See lines 119-122, page 4: “the data of 4365 (95.2%) children were used for analysis. Of the 220 children whose data were excluded (67, 67 and 86 cases in 2014, 2016 and 2018, respectively), 112 were strabismus (64 exotropia, 47 esotropia, 1 vertical strabismus)”. Meanwhile, the conclusions of the article did not change after excluding the112 strabismus cases compared with including them.

3. The author did not mention that the retinoscopy was performed by one or multiple examiners. There would be inter-observer variability of retinoscopy.

Answer: Thank you for this comment. All the retinoscopy was performed by one examiner (AD). We added this content on lines 93-94, page 4.

4. The author did not mention the composition of subjects. As we know, race is an important factor of myopia prevalence.

Answer: Thank you for this comment. Please see the links (https://en.wikipedia.org/wiki/Asian_Australians) for specific data on Asians lived in Australia. The table "Metropolitan areas with significant Asian Australian populations (2016 Census)” seems to indicate that 97.7% of Asians live in the capital cities. Our participants are from rural and outer suburban areas and Asian children are a minority. This has been addressed in the discussion at lines 261-264(Our participants are from rural and outer suburban areas and Asian children are a minority and the ethnic mix of participants has not changed significantly over the period of the study).

5. There is no discussion about the significantly increased proportions of both myopia and hyperopia in this study as compared to the similar study in 1976.

Answer: The prevalence of myopia in Australia is increasing, consistent with reports from many other parts of the world. The main reason of the increased proportions of myopia may be the changing educational system and lifestyle. The slightly higher proportion of hyperopia compared to the earlier studies is consistent with another recent study in the Sydney urban population and is discussed at lines 272-279.

Reviewer #4:

The authors of the paper “Prevalence of myopia among disadvantaged Australian schoolchildren: a 5-year cross-sectional study “presents a cross-sectional analysis of refractive data and myopia prevalence in Australian children during the years 2014/2016/2018. The authors found that, although the prevalent of myopia remained low comparing with other locations, the mean spherical equivalent refraction (SER) decreased from 2014 to 2018, accompany with shifting towards less hyperopia. They also found that females had higher mean SER, but with faster decrease than male with age. In general, this paper is well-written and easy to follow. However, there are few points to be considered.

1. This paper found the mean SER decreased from 2016 to 2018, with trends of less hyperopia and stable myopia. However, reviewing the numbers of included cases, there are less children enrolled in the low grade groups in 2018, with more children enrolled in the middle to high grade groups, comparing with 2014 and 2016 (ex. Only 1.9% in age group 6 and 7 in 2018 vs. 4.7% and 4% in 2014 and 2016, respectively). Could the authors make some explanations that this will not lead to selection bias?

Answer: Thank you for this comment. The School Principal selects all eligible children from disadvantaged families, so there is some variation in the age and sex profile of children year to year. However, multivariate regression analyses accommodate these variations in numbers by adjusting for age and sex to estimate the changing trend of refractive error over time (Table 3). We have added this information to lines 319-327, page 12: “ In addition, there are less children enrolled in the low-grade groups in 2018, with more children enrolled in the middle to high grade groups, comparing with 2014 and 2016 (ex. Only 1.9% in age group 6 and 7 in 2018 vs. 4.7% and 4.1% in 2014 and 2016, respectively). However, the School Principal selects all eligible children from disadvantaged families, so there is some variation in the age and sex profile of children year to year. Meanwhile, multivariate regression analyses accommodate these variations in numbers by adjusting for age and sex to estimate the changing trend of refractive error over time.”

2.The authors found females had higher mean SER, but with faster decrease with age comparing with male. Unlike other studies with higher prevalence of myopia in female, the higher prevalence of hyperopia in female in the present study is somewhat different. This could possibly be explained by different visual experiences in daily life. However, similar to question 1, there are more female children included in this study, especially in 2014 and 2016, could this also be a confounding factor?

Answer: Thank you for this comment. As for the question regarding age, multivariate regression analyses accommodate these variations by adjusting for age and sex to estimate the changing trend of refractive error over time (Table 3).

Attachment

Submitted filename: PONE-D-20-09893 Response to Reviewer Comments.docx

Click here for additional data file. (28.1KB, docx)

Decision Letter 1

I-Jong Wang

10 Jun 2020

PONE-D-20-09893R1

Prevalence of myopia among disadvantaged Australian schoolchildren: a 5-year cross-sectional study

PLOS ONE

Dear Dr. Stapleton,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

Please submit your revised manuscript by Jul 25 2020 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

Please include the following items when submitting your revised manuscript:

  • A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'.

  • A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'.

  • An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'.

If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: http://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols

We look forward to receiving your revised manuscript.

Kind regards,

I-Jong Wang

Academic Editor

PLOS ONE

[Note: HTML markup is below. Please do not edit.]

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #2: All comments have been addressed

Reviewer #3: All comments have been addressed

Reviewer #4: All comments have been addressed

**********

2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #2: Partly

Reviewer #3: Yes

Reviewer #4: Yes

**********

3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #2: Yes

Reviewer #3: Yes

Reviewer #4: Yes

**********

4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #2: Yes

Reviewer #3: Yes

Reviewer #4: Yes

**********

5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #2: Yes

Reviewer #3: Yes

Reviewer #4: Yes

**********

6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #2: Thank you for our response. But I wonder that why did you choose to remove the 6-7 age group or 6-8 age

group from the analysis for supporting your opinion?

To my knowledge, previous study suggested that cycloplegia refraction should be performed before age 20, because the differences might up to 0.36±0.41D in the 13 year olds group (IOVS April 2010).

Reviewer #3: The analysis in this study is detailed. However, there are two weaknesses.

1. Noncycloplegic refractive examination was used.

2. There are a lot of similar studies in the literature, including quite a few studies of Australian children. This study did not provide anything new.

Reviewer #4: (No Response)

**********

7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #2: No

Reviewer #3: No

Reviewer #4: No

[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.]

While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step.

PLoS One. 2020 Aug 27;15(8):e0238122. doi: 10.1371/journal.pone.0238122.r004

Author response to Decision Letter 1

29 Jul 2020

“Prevalence of myopia among disadvantaged Australian schoolchildren: a 5-year cross-sectional study”

We thank the reviewers again for their helpful suggestions and offer this rejoinder in response to the comments.

Reviewer #2:

(1) I wonder that why did you choose to remove the 6-7 age group or 6-8 age group from the analysis for supporting your opinion?

Response:

During the first round of comments on the manuscript, the third reviewer raised a question as follows ‘Noncycloplegic refraction potentially resulting in overestimation of myopia and underestimation of hyperopia, especially in young children. Therefore, there would be some impacts in the statistical results. For example, in table 2, the higher prevalence of myopia in age group 6-7 than that in age group 8 could be the result of pseudomyopia in younger kids. In table 1, higher proportions of younger children (age 6-8) in 2014 group might result in more overestimation of myopia.” To address this question, we reanalyzed the data with either the 6-7 age group or 6-8 age group removed. The overall trend of myopia prevalence with age did not change. This has been described at line 315 and we have made no further changes to the manuscript in this revision.

(2) To my knowledge, previous study suggested that cycloplegia refraction should be performed before age 20, because the differences might up to 0.36±0.41D in the 13 year olds group (IOVS April 2010).

Response:

In the study referred to (IOVS April 2010),1 refractive error before and after cycloplegia was measured using a Humphrey 598 Autorefractor. They compared the difference between refractive error before and after cycloplegia resulting in the conclusion above. However, a different method was used in our study: refractive error was determined by non-cycloplegic retinoscopy using the fogging technique while the child maintained fixation on a distant (6 m) non-accommodative target. Yeotikar 2 found that mean difference in SER for 7 to 16 years children obtained by non-cycloplegic refraction with contralateral fogging and cycloplegic refraction was small (mean of 0.29D) and was not clinically significant. We have added this content to the section on limitations in the discussion (line 312-315).

We agree that with respect to physiological aspects, the absence of cycloplegia (thus allowing accommodation as an uncontrolled variable) does affect one’s power to understand the degree of refractive latency to a certain degree. However, the dogmatic use of cycloplegics in all studies as dictated by the RESC protocol is not warranted, particularly in a screening examination in a respite environment as described in this study. The percentage of children affected by this latency is quite small and will have a very small impact on the mean SER of a cohort of thousands of children.

Furthermore, the mandatory inclusion of cycloplegia avoids the issue arising from a number of reports alluding to the fact that cycloplegia can physiologically cause a significant minus shift in refractive error in a (albeit small) percentage of children (e.g. FA Young etal 1971, WM Ludlam et al 1972, HC Cheng & YT Hsieh 2014) and adults (TT Toh et al 2005). Other reports do not comment on this aspect, yet their data clearly indicate the same message when visually inspecting their scatter plots showing the difference in SER pre/post cycloplegic (e.g. R Fotedar etal 2007, where all dots below the x-axis represent children exhibiting a minus shift during cycloplegia). This minus-wards shift is due presumably to a forward shift of the crystalline lens during cycloplegia (L Gao etal 2002). Notably, the percentage of children shifting from one RESC-designated refractive group to another as a result of cycloplegia is very small, either plus-wards or minus-wards, indicating that net relative shift in numbers due to the physiological variable of accommodation does not necessarily mean that the any overall claims driven by the data will change substantially.

As other non-cycloplegic studies also exist in the literature, we believe there are sufficient data for direct comparison with the results presented in this study and have not made further changes in the manuscript.

Reviewer #3: The analysis in this study is detailed. However, there are two weaknesses.

1. Noncycloplegic refractive examination was used.

Response:

See above for Response to Reviewer 1, Q (2)

2. There are a lot of similar studies in the literature, including quite a few studies of Australian children. This study did not provide anything new.

Response：

The other Australian data either represents a complete cross section of society (Sydney Myopia study data),3-5 or, comes mainly from higher socioeconomic groups (VEC).6,7 Our new data focusses more on lower socioeconomic groups, and the lower prevalence of myopia in those children from predominantly rural regions corresponds with the lower prevalence found in these social groups in other countries .

References

1. Paul G Sanfilippo, Byoung-Sun Chu, Olivia Bigault, et al. Up to What Age is a Cyclopleged Refraction Required? Results from the Twins Eye Study Tasmania (TEST). Acta Ophthalmol. 2014; 92(6): e458-62.

2. Nisha S. Yeotikar, Ravi Chandra Bakaraju, P.S. Roopa Reddy, Kalyani Prasad. Cycloplegic refraction and non-cycloplegic refraction using contralateral fogging: a comparative study. Journal of Modern Optics. 2007;54(9):1317- 24.

3. French AN, Morgan IG, Burlutsky G, Mitchell P, Rose KA. Prevalence and 5- to 6-year incidence and progression of myopia and hyperopia in Australian schoolchildren. Ophthalmol. 2013;120(7):1482-91.

4. French AN, O'Donoghue L, Morgan IG, Saunders KJ, Mitchell P, Rose KA. Comparison of refraction and ocular biometry in European Caucasian children living in Northern Ireland and Sydney, Australia. Invest Ophthalmol Vis Sci. 2012; 53(7):4021-31.

5. Elvis Ojaimi, Kathryn A Rose, Ian G Morgan, et al. Distribution of Ocular Biometric Parameters and Refraction in a Population-Based Study of Australian Children. Invest Ophthalmol Vis Sci. 2005;46(8):2748-54.

6. Junghans BM, Crewther SG. Prevalence of myopia among primary school children in eastern Sydney. Clin Exp Optom. 2003; 86(5):339-45.

7. Junghans BM, Crewther SG. Little evidence for an epidemic of myopia in Australian primary school children over the last 30 years. BMC Ophthalmol. 2005; 5(1): 1.

Attachment

Submitted filename: PONE-D-20-09893 Response to Reviewer Comments.docx

Click here for additional data file. (23.6KB, docx)

Decision Letter 2

I-Jong Wang

11 Aug 2020

Prevalence of myopia among disadvantaged Australian schoolchildren: a 5-year cross-sectional study

PONE-D-20-09893R2

Dear Dr. Stapleton,

We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements.

Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication.

An invoice for payment will follow shortly after the formal acceptance. To ensure an efficient process, please log into Editorial Manager at http://www.editorialmanager.com/pone/, click the 'Update My Information' link at the top of the page, and double check that your user information is up-to-date. If you have any billing related questions, please contact our Author Billing department directly at authorbilling@plos.org.

If your institution or institutions have a press office, please notify them about your upcoming paper to help maximize its impact. If they’ll be preparing press materials, please inform our press team as soon as possible -- no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org.

Kind regards,

I-Jong Wang

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #2: All comments have been addressed

**********

2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #2: Yes

**********

3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #2: Yes

**********

4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #2: Yes

**********

5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #2: Yes

**********

6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #2: Thank you for the detailed replication with addressing corresponding references. There was no further question about this article.

**********

7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #2: No

Acceptance letter

I-Jong Wang

17 Aug 2020

PONE-D-20-09893R2

Prevalence of myopia among disadvantaged Australian schoolchildren: a 5-year cross-sectional study

Dear Dr. Stapleton:

I'm pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now with our production department.

If your institution or institutions have a press office, please let them know about your upcoming paper now to help maximize its impact. If they'll be preparing press materials, please inform our press team within the next 48 hours. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information please contact onepress@plos.org.

If we can help with anything else, please email us at plosone@plos.org.

Thank you for submitting your work to PLOS ONE and supporting open access.

Kind regards,

PLOS ONE Editorial Office Staff

on behalf of

Dr. I-Jong Wang

Academic Editor

PLOS ONE

Associated Data

    This section collects any data citations, data availability statements, or supplementary materials included in this article.

    Supplementary Materials

    S1 Data

    (XLSX)

    Click here for additional data file. (225.9KB, xlsx)
    Attachment

    Submitted filename: PONE-D-20-09893 Response to Reviewer Comments.docx

    Click here for additional data file. (28.1KB, docx)
    Attachment

    Submitted filename: PONE-D-20-09893 Response to Reviewer Comments.docx

    Click here for additional data file. (23.6KB, docx)

    Data Availability Statement

    All relevant data are within the manuscript and its Supporting Information files.

    Articles from PLoS ONE are provided here courtesy of PLOS

    RESOURCES