Although only population-based studies with reasonable response rates were included, we did not think that the final sample in some individual studies could be representative of the target population. The response rates were a bit low and there were significant differences in age distribution between responders and nonresponders in some individual studies. For this meta-analysis, the response rate bias is small as we are estimating the pooled age-specific prevalence rather than the overall prevalence. Therefore, we included these studies in the analysis. In addition, the data were not all primarily from a prevalence study designed for that purpose in all studies. Especially in adult studies, the study was usually designed to estimate the prevalence of other age-related eye diseases such as glaucoma, cataract, or age-related macular degeneration. The mode of data collection (e.g., refraction method, machine used for refraction) was the same for all subjects in all studies. The refraction data in each individual study have been collected directly from the patient by standardized approaches such as objective or subjective refraction. All studies described the target population and the source of participant recruitment, albeit in various extents.
A meta-regression model was constructed on study subjects younger than 70 years with refraction methods (subjective vs. objective), year of birth, and age group as independent variables. In this model, neither per decade increase in year of birth nor age group (per decade increase) showed a significant linear effect (both p > 0.05) on the prevalence of myopia. There was a significant U-shaped relationship between both age and year of birth and the prevalence of myopia in a regression model with age2 or year of birth2 as an independent variable (both p < 0.05). We found no significant difference in myopia prevalence measured by subjective and objective refraction (p = 0.32).
Omission of individual studies revealed that no single study had a particular influence on the pooled estimate. No publication bias was detected by the Egger test (p > 0.05).
Received May 17, 2014; accepted October 7, 2014.
1. Pan CW, Ramamurthy D, Saw SM. Worldwide prevalence
and risk factors for myopia
. Ophthalmic Physiol Opt 2012; 32: 3–16.
2. Vitale S, Cotch MF, Sperduto R, Ellwein L. Costs of refractive correction of distance vision impairment in the United States, 1999-2002. Ophthalmology 2006; 113: 2163–70.
3. Rein DB, Zhang P, Wirth KE, Lee PP, Hoerger TJ, McCall N, Klein R, Tielsch JM, Vijan S, Saaddine J. The economic burden of major adult visual disorders in the United States. Arch Ophthalmol 2006; 124: 1754–60.
4. Zheng YF, Pan CW, Chay J, Wong TY, Finkelstein E, Saw SM. The economic cost of myopia
in adults aged over 40 years in Singapore. Invest Ophthalmol Vis Sci 2013; 54: 7532–7.
5. Pararajasegaram R. VISION 2020—the right to sight: from strategies to action. Am J Ophthalmol 1999; 128: 359–60.
6. Saw SM, Gazzard G, Shih-Yen EC, Chua WH. Myopia
and associated pathological complications. Ophthalmic Physiol Opt 2005; 25: 381–91.
7. Pan CW, Cheung CY, Aung T, Cheung CM, Zheng YF, Wu RY, Mitchell P, Lavanya R, Baskaran M, Wang JJ, Wong TY, Saw SM. Differential associations of myopia
with major age-related eye diseases: the Singapore Indian Eye Study. Ophthalmology 2013; 120: 284–91.
8. Marcus MW, de Vries MM, Junoy Montolio FG, Jansonius NM. Myopia
as a risk factor for open-angle glaucoma: a systematic review and meta-analysis
. Ophthalmology 2011; 118: 1989–94.
9. Pan CW, Cheng CY, Saw SM, Wang JJ, Wong TY. Myopia
and age-related cataract: a systematic review and meta-analysis
. Am J Ophthalmol 2013; 156: 1021–33.
10. Pan CW, Boey PY, Cheng CY, Saw SM, Tay WT, Wang JJ, Tan AG, Mitchell P, Wong TY. Myopia
, axial length, and age-related cataract: the Singapore Malay eye study. Invest Ophthalmol Vis Sci 2013; 54: 4498–502.
11. Resnikoff S, Pascolini D, Mariotti SP, Pokharel GP. Global magnitude of visual impairment caused by uncorrected refractive errors in 2004. Bull World Health Organ 2008; 86: 63–70.
12. Smith TS, Frick KD, Holden BA, Fricke TR, Naidoo KS. Potential lost productivity resulting from the global burden of uncorrected refractive error. Bull World Health Organ 2009; 87: 431–7.
13. Fricke TR, Holden BA, Wilson DA, Schlenther G, Naidoo KS, Resnikoff S, Frick KD. Global cost of correcting vision impairment from uncorrected refractive error. Bull World Health Organ 2012; 90: 728–38.
14. Bowden R. Asia
. Milwaukee, WI: World Almanac Library; 2005.
15. Park DJ, Congdon NG. Evidence for an “epidemic” of myopia
. Ann Acad Med Singapore 2004; 33: 21–6.
16. Sawada A, Tomidokoro A, Araie M, Iwase A, Yamamoto T. Refractive errors in an elderly Japanese population: the Tajimi study. Ophthalmology 2008; 115: 363–70.
17. Lin LL, Shih YF, Hsiao CK, Chen CJ. Prevalence
in Taiwanese schoolchildren: 1983 to 2000. Ann Acad Med Singapore 2004; 33: 27–33.
18. 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: 234–9.
19. Stroup DF, Berlin JA, Morton SC, Olkin I, Williamson GD, Rennie D, Moher D, Becker BJ, Sipe TA, Thacker SB. Meta-analysis
of observational studies in epidemiology: a proposal for reporting. Meta-analysis
Of Observational Studies in Epidemiology (MOOSE) group. JAMA 2000; 283: 2008–12.
20. Porta MS (Ed). A Dictionary of Epidemiology. 5th ed. New York, NY: Oxford University Press; 2008.
21. National Geographic Maps. Atlas of the World. Washington, D.C.: National Geographic Society; 2005.
22. Leboeuf-Yde C, Lauritsen JM. The prevalence
of low back pain in the literature. A structured review of 26 Nordic studies from 1954 to 1993. Spine (Phila Pa 1976) 1995; 20: 2112–8.
23. Walker BF. The prevalence
of low back pain: a systematic review of the literature from 1966 to 1998. J Spinal Disord 2000; 13: 205–17.
24. Kawasaki R, Yasuda M, Song SJ, Chen SJ, Jonas JB, Wang JJ, Mitchell P, Wong TY. The prevalence
of age-related macular degeneration in Asians: a systematic review and meta-analysis
. Ophthalmology 2010; 117: 921–7.
25. Egger M, Davey Smith G, Schneider M, Minder C. Bias in meta-analysis
detected by a simple, graphical test. BMJ 1997; 315: 629–34.
26. He M, Huang W, Li Y, Zheng Y, Yin Q, Foster PJ. Refractive error and biometry in older Chinese adults: the Liwan eye study. Invest Ophthalmol Vis Sci 2009; 50: 5130–6.
27. Li Z, Sun D, Cuj H, Zhang L, Lju P, Yang H, Baj J. Refractive error among the elderly in rural Southern Harbin, China. Ophthalmic Epidemiol 2009; 16: 388–94.
28. Xu L, Li J, Cui T, Hu A, Fan G, Zhang R, Yang H, Sun B, Jonas JB. Refractive error in urban and rural adult Chinese in Beijing. Ophthalmology 2005; 112: 1676–83.
29. Liang YB, Wong TY, Sun LP, Tao QS, Wang JJ, Yang XH, Xiong Y, Wang NL, Friedman DS. Refractive errors in a rural Chinese adult population the Handan eye study. Ophthalmology 2009; 116: 2119–27.
30. 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: 427–35.
31. He M, Huang W, Zheng Y, Huang L, Ellwein LB. Refractive error and visual impairment in school children in rural southern China. Ophthalmology 2007; 114: 374–82.
32. He M, Zeng J, Liu Y, Xu J, Pokharel GP, Ellwein LB. Refractive error and visual impairment in urban children in southern China. Invest Ophthalmol Vis Sci 2004; 45: 793–9.
33. Pi LH, Chen L, Liu Q, Ke N, Fang J, Zhang S, Xiao J, Ye WJ, Xiong Y, Shi H, Zhou XY, Yin ZQ. Prevalence
of eye diseases and causes of visual impairment in school-aged children in Western China. J Epidemiol 2012; 22: 37–44.
34. Li ZJ, Xu KK, Wu SB, Lv J, Jin D, Song Z, Wang ZL, Liu P. Population-based survey of refractive error among school-aged children in rural northern China: the Heilongjiang eye study. Clin Experiment Ophthalmol 2014; 42: 379–84.
35. Fan DS, Lam DS, Lam RF, Lau JT, Chong KS, Cheung EY, Lai RY, Chew SJ. Prevalence
, incidence, and progression of myopia
of school children in Hong Kong. Invest Ophthalmol Vis Sci 2004; 45: 1071–5.
36. Lam CS, Lam CH, Cheng SC, Chan LY. Prevalence
among Hong Kong Chinese schoolchildren: changes over two decades. Ophthalmic Physiol Opt 2012; 32: 17–24.
37. Li SM, Liu LR, Li SY, Ji YZ, Fu J, Wang Y, Li H, Zhu BD, Yang Z, Li L, Chen W, Kang MT, Zhang FJ, Zhan SY, Wang NL, Mitchell P. Design, methodology and baseline data of a school-based cohort study in Central China: the Anyang Childhood Eye Study. Ophthalmic Epidemiol 2013; 20: 348–59.
38. Hashemi H, Khabazkhoob M, Jafarzadehpur E, Yekta AA, Emamian MH, Shariati M, Fotouhi A. High prevalence
in an adult population, Shahroud, Iran. Optom Vis Sci 2012; 89: 993–9.
39. Yekta AA, Fotouhi A, Khabazkhoob M, Hashemi H, Ostadimoghaddam H, Heravian J, Mehravaran S. The prevalence
of refractive errors and its determinants in the elderly population of Mashhad, Iran. Ophthalmic Epidemiol 2009; 16: 198–203.
40. Hashemi H, Rezvan F, Ostadimoghaddam H, Abdollahi M, Hashemi M, Khabazkhoob M. High prevalence
of refractive errors in a rural population: ‘Nooravaran Salamat’ Mobile Eye Clinic experience. Clin Experiment Ophthalmol 2013; 41: 635–43.
41. Hashemi H, Fotouhi A, Mohammad K. The age- and gender-specific prevalences of refractive errors in Tehran: the Tehran Eye Study. Ophthalmic Epidemiol 2004; 11: 213–25.
42. Fotouhi A, Hashemi H, Khabazkhoob M, Mohammad K. The prevalence
of refractive errors among schoolchildren in Dezful, Iran. Br J Ophthalmol 2007; 91: 287–92.
43. Yekta A, Fotouhi A, Hashemi H, Dehghani C, Ostadimoghaddam H, Heravian J, Derakhshan A, Yekta R, Behnia M, Khabazkhoob M. Prevalence
of refractive errors among schoolchildren in Shiraz, Iran. Clin Experiment Ophthalmol 2010; 38: 242–8.
44. Ostadimoghaddam H, Fotouhi A, Hashemi H, Yekta A, Heravian J, Rezvan F, Ghadimi H, Rezvan B, Khabazkhoob M. Prevalence
of the refractive errors by age and gender: the Mashhad eye study of Iran. Clin Experiment Ophthalmol 2011; 39: 743–51.
45. Rezvan F, Khabazkhoob M, Fotouhi A, Hashemi H, Ostadimoghaddam H, Heravian J, Azizi E, Khorasani AA, Yekta AA. Prevalence
of refractive errors among school children in Northeastern Iran. Ophthalmic Physiol Opt 2012; 32: 25–30.
46. Wong TY, Foster PJ, Hee J, Ng TP, Tielsch JM, Chew SJ, Johnson GJ, Seah SK. Prevalence
and risk factors for refractive errors in adult Chinese in Singapore. Invest Ophthalmol Vis Sci 2000; 41: 2486–94.
47. Saw SM, Chan YH, Wong WL, Shankar A, Sandar M, Aung T, Tan DT, Mitchell P, Wong TY. Prevalence
and risk factors for refractive errors in the Singapore Malay Eye Survey. Ophthalmology 2008; 115: 1713–9.
48. Pan CW, Wong TY, Lavanya R, Wu RY, Zheng YF, Lin XY, Mitchell P, Aung T, Saw SM. Prevalence
and risk factors for refractive errors in Indians: the Singapore Indian Eye Study (SINDI). Invest Ophthalmol Vis Sci 2011; 52: 3166–73.
49. Pan CW, Zheng YF, Anuar AR, Chew M, Gazzard G, Aung T, Cheng CY, Wong TY, Saw SM. Prevalence
of refractive errors in a multiethnic Asian population: the Singapore epidemiology of eye disease study. Invest Ophthalmol Vis Sci 2013; 54: 2590–8.
50. Tan CS, Chan YH, Wong TY, Gazzard G, Niti M, Ng TP, Saw SM. Prevalence
and risk factors for refractive errors and ocular biometry parameters in an elderly Asian population: the Singapore Longitudinal Aging Study (SLAS). Eye (Lond) 2011; 25: 1294–301.
51. Dirani M, Chan YH, Gazzard G, Hornbeak DM, Leo SW, Selvaraj P, Zhou B, Young TL, Mitchell P, Varma R, Wong TY, Saw SM. Prevalence
of refractive error in Singaporean Chinese children: the strabismus, amblyopia, and refractive error in young Singaporean Children (STARS) study. Invest Ophthalmol Vis Sci 2010; 51: 1348–55.
52. Dandona R, Dandona L, Srinivas M, Giridhar P, McCarty CA, Rao GN. Population-based assessment of refractive error in India: the Andhra Pradesh eye disease study. Clin Experiment Ophthalmol 2002; 30: 84–93.
53. Raju P, Ramesh SV, Arvind H, George R, Baskaran M, Paul PG, Kumaramanickavel G, McCarty C, Vijaya L. Prevalence
of refractive errors in a rural South Indian population. Invest Ophthalmol Vis Sci 2004; 45: 4268–72.
54. Nangia V, Jonas JB, Sinha A, Matin A, Kulkarni M. Refractive error in central India: the Central India Eye and Medical Study. Ophthalmology 2010; 117: 693–9.
55. Murthy GV, Gupta SK, Ellwein LB, Munoz SR, Pokharel GP, Sanga L, Bachani D. Refractive error in children in an urban population in New Delhi. Invest Ophthalmol Vis Sci 2002; 43: 623–31.
56. Dandona R, Dandona L, Srinivas M, Sahare P, Narsaiah S, Munoz SR, Pokharel GP, Ellwein LB. Refractive error in children in a rural population in India. Invest Ophthalmol Vis Sci 2002; 43: 615–22.
57. Yoo YC, Kim JM, Park KH, Kim CY, Kim TW. Refractive errors in a rural Korean adult population: the Namil Study. Eye (Lond) 2013; 27: 1368–75.
58. Jung SK, Lee JH, Kakizaki H, Jee D. Prevalence
and its association with body stature and educational level in 19-year-old male conscripts in Seoul, South Korea. Invest Ophthalmol Vis Sci 2012; 53: 5579–83.
59. Lee JH, Jee D, Kwon JW, Lee WK. Prevalence
and risk factors for myopia
in a rural Korean population. Invest Ophthalmol Vis Sci 2013; 54: 5466–71.
60. Cheng CY, Hsu WM, Liu JH, Tsai SY, Chou P. Refractive errors in an elderly Chinese population in Taiwan: the Shihpai Eye Study. Invest Ophthalmol Vis Sci 2003; 44: 4630–8.
61. Lee YY, Lo CT, Sheu SJ, Lin JL. What factors are associated with myopia
in young adults? A survey study in Taiwan military conscripts. Invest Ophthalmol Vis Sci 2013; 54: 1026–33.
62. Shimizu N, Nomura H, Ando F, Niino N, Miyake Y, Shimokata H. Refractive errors and factors associated with myopia
in an adult Japanese population. Jpn J Ophthalmol 2003; 47: 6–12.
63. Pokharel GP, Negrel AD, Munoz SR, Ellwein LB. Refractive Error Study in Children: results from Mechi Zone, Nepal. Am J Ophthalmol 2000; 129: 436–44.
64. Sapkota YD, Adhikari BN, Pokharel GP, Poudyal BK, Ellwein LB. The prevalence
of visual impairment in school children of upper-middle socioeconomic status in Kathmandu. Ophthalmic Epidemiol 2008; 15: 17–23.
65. Goh PP, Abqariyah Y, Pokharel GP, Ellwein LB. Refractive error and visual impairment in school-age children in Gombak District, Malaysia. Ophthalmology 2005; 112: 678–85.
66. Hashim SE, Tan HK, Wan-Hazabbah WH, Ibrahim M. Prevalence
of refractive error in Malay primary school children in suburban area of Kota Bharu, Kelantan, Malaysia. Ann Acad Med Singapore 2008; 37: 940–6.
67. Bourne RR, Dineen BP, Ali SM, Noorul Huq DM, Johnson GJ. Prevalence
of refractive error in Bangladeshi adults: results of the National Blindness and Low Vision Survey of Bangladesh. Ophthalmology 2004; 111: 1150–60.
68. Shah SP, Jadoon MZ, Dineen B, Bourne RR, Johnson GJ, Gilbert CE, Khan MD. Refractive errors in the adult Pakistani population: the National Blindness and Visual Impairment Survey. Ophthalmic Epidemiol 2008; 15: 183–90.
69. Saw SM, Gazzard G, Koh D, Farook M, Widjaja D, Lee J, Tan DT. Prevalence
rates of refractive errors in Sumatra, Indonesia. Invest Ophthalmol Vis Sci 2002; 43: 3174–80.
70. Gupta A, Casson RJ, Newland HS, Muecke J, Landers J, Selva D, Aung T. Prevalence
of refractive error in rural Myanmar: the Meiktila Eye Study. Ophthalmology 2008; 115: 26–32.
71. Casson RJ, Kahawita S, Kong A, Muecke J, Sisaleumsak S, Visonnavong V. Exceptionally low prevalence
of refractive error and visual impairment in schoolchildren from Lao People’s Democratic Republic. Ophthalmology 2012; 119: 2021–7.
72. Gao Z, Meng N, Muecke J, Chan WO, Piseth H, Kong A, Jnguyenphamhh T, Dehghan Y, Selva D, Casson R, Ang K. Refractive error in school children in an urban and rural setting in Cambodia. Ophthalmic Epidemiol 2012; 19: 16–22.
73. Wickremasinghe S, Foster PJ, Uranchimeg D, Lee PS, Devereux JG, Alsbirk PH, Machin D, Johnson GJ, Baasanhu J. Ocular biometry and refraction in Mongolian adults. Invest Ophthalmol Vis Sci 2004; 45: 776–83.
74. Hyman L. Myopic and hyperopic refractive error in adults: an overview. Ophthalmic Epidemiol 2007; 14: 192–7.
75. Saw SM. A synopsis of the prevalence
rates and environmental risk factors for myopia
. Clin Exper Optom 2003; 86: 289–94.
76. Saw SM, Katz J, Schein OD, Chew SJ, Chan TK. Epidemiology of myopia
. Epidemiol Rev 1996; 18: 175–87.
77. Kempen JH, Mitchell P, Lee KE, Tielsch JM, Broman AT, Taylor HR, Ikram MK, Congdon NG, O’Colmain BJ. The prevalence
of refractive errors among adults in the United States, Western Europe, and Australia. Arch Ophthalmol 2004; 122: 495–505.
78. Pan CW, Zheng YF, Wong TY, Lavanya R, Wu RY, Gazzard G, Saw SM. Variation in prevalence
between generations of migrant Indians living in Singapore. Am J Ophthalmol 2012; 154: 376–81.
79. Saw SM, Chua WH, Hong CY, Wu HM, Chan WY, Chia KS, Stone RA, Tan D. Nearwork in early-onset myopia
. Invest Ophthalmol Vis Sci 2002; 43: 332–9.
80. Vera-Diaz FA, Strang NC, Winn B. Nearwork induced transient myopia
progression. Curr Eye Res 2002; 24: 289–95.
81. 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. Ophthalmology 2013; 120: 1482–91.
82. Zadnik K. The Glenn A. Fry Award Lecture (1995). Myopia
development in childhood. Optom Vis Sci 1997; 74: 603–8.
83. O’Donoghue L, McClelland JF, Logan NS, Rudnicka AR, Owen CG, Saunders KJ. Refractive error and visual impairment in school children in Northern Ireland. Br J Ophthalmol 2010; 94: 1155–9.
84. Morgan IG, Ohno-Matsui K, Saw SM. Myopia
. Lancet 2012; 379: 1739–48.
85. Mutti DO, Zadnik K. Age-related decreases in the prevalence
: longitudinal change or cohort effect? Invest Ophthalmol Vis Sci 2000; 41: 2103–7.
86. Quek TP, Chua CG, Chong CS, Chong JH, Hey HW, Lee J, Lim YF, Saw SM. Prevalence
of refractive errors in teenage high school students in Singapore. Ophthalmic Physiol Opt 2004; 24: 47–55.
87. Lin LLK, Shih YF, Hsiao CK, Chen CJ, Lee LA, Hung PT. Epidemiologic study of the prevalence
and severity of myopia
among school children in Taiwan in 2000. J Formos Med Assoc 2001; 100: 684–91.
88. Lin LL, Shih YF, Tsai CB, Chen CJ, Lee LA, Hung PT, Hou PK. Epidemiologic study of ocular refraction among schoolchildren in Taiwan in 1995. Optom Vis Sci 1999; 76: 275–81.