In the present study, we described the characteristics of monochromatic aberrations at 5.0-mm pupil size in 404 rural Chinese adults and investigated the relation between refraction, age, and HOAs. To the best of our knowledge, this is the first population-based study on monochromatic aberrations in a large sample of rural Chinese adults. It was found that coma, trefoil, SA, and third- and fourth-order aberrations were dominant among HOAs. Root mean square values of total HOAs, coma, trefoil, and SA significantly increased with age. However, there were no significant differences in HOAs among emmetropic, hyperopic, and myopic eyes after adjusting for age.
The present results showed that monochromatic aberrations varied widely among rural Chinese adults (0.077 to 1.254 μm), which was in agreement with previous studies.4 Mean RMS values of total HOAs were 0.296 ± 0.147 μm for all participants and 0.300 ± 0.017 μm for myopic participants in our study, which was smaller than that of younger myopic Chinese adults in Singapore (0.49 ± 0.16 μm).17 One important reason for the difference is that we measured aberrations at a smaller pupil size (5.0 mm) than they did (6.0 mm).17 It is well known that pupil size decreases with increasing age, thus reducing aberration magnitudes.35 The magnitudes of HOAs in our study were slightly higher than that reported by Wang et al.36 (0.229 μm, third- to sixth-order aberration at 5.0-mm pupil) on young myopic adults in Tianjin. Considering that aberrations increased with age6,7 and that our sample is composed of much older adults (49.9 years) than those of Wang et al.36 (21.9 years), our values of HOAs are consistent with theirs.
We found that RMS of total HOAs, coma, trefoil, SA, and third- to seventh-order aberrations significantly increased with age (Table 4), which is consistent with most previous studies.6,35,37,39–41 Atchison et al.42 only found a moderate effect of age on RMS of HOAs, which might be caused by a small refractive error range. Atchison and Markwell42 found that only the coefficient of horizontal coma demonstrated a negative correlation with age. In the present study, the coefficient of vertical coma (C3 −1) and secondary astigmatism (C4 2) showed a significant negative correlation with age. However, only 2.7 and 3.7% of the variation are explained by vertical coma (C3 −1) and secondary astigmatism (C4 2). The coefficient of spherical aberration (C4 0) showed a borderline correlation with age, which was in agreement with previous studies.6,35,37,41 Wei et al.17 found that only SA and vertical coma slightly increased with age. This may be accounted for by the fact that all their subjects were myopic (−5.23 ± 1.79 D, −0.75 to approximately −9.75 D) and had a relatively small age range (21.5 to approximately 52.8 years).
Interestingly, we found no significant differences in RMS of total HOAs, SA, coma, and trefoil between hyperopic, emmetropic, and myopic eyes after adjusting for age. This was consistent with some previous studies.43–45 Li et al.44 reported that ocular HOAs were similar among Chinese schoolchildren with different refractive errors (∼0.19 μm). Although these two studies focused on different Chinese populations, it seems that HOAs may play a weak role in the development of refractive error. However, some studies8,46,47 have reported higher HOAs in myopes than in emmetropes or higher HOAs in hyperopes than in emmetropes.48 We found that coefficients of SA were higher in hyperopic eyes than in emmetropic and myopic eyes (0.076 μm vs. 0.056 μm and 0.028 μm), which was in agreement with the findings of Hartwig and Atchison.48 The discrepancies among these studies may be explained by different subject groups, measurement techniques, and data analysis. In addition, it is not clear whether higher HOAs in these studies were merely the consequence of refractive error development. Therefore, longitudinal prospective studies on the same populations are necessary to investigate the effect of HOAs on refractive error development.
Strengths of the present study include a population-based survey among a large sample of rural Chinese adults. In addition, all participants grew up in villages and did farm work during their lives, which form an ideal condition to evaluate the effect of rural environments on refractive error. However, there are some limitations for this study. First, it is a cross-sectional analysis from which it is hard to establish a causative relation between monochromatic aberrations and refractive development. Second, other confounding variables such as time spent in outdoor activities and near work were not available for adjustment.
In conclusion, the current results demonstrated that ocular refraction in rural Chinese adults significantly increased with age. Higher-order aberrations in rural Chinese adults showed considerable variability and significantly increased with age. However, there was no difference in HOAs among myopic, emmetropic, and hyperopic adults. These findings suggest that HOAs may play a weak role in the development of refractive error.
No. 1 Dongjiaominxiang, Dongcheng District
This work was supported by the Major State Basic Research Development Program of China (973 Program, 2011CB504601), the Major International (Regional) Joint Research Project of the National Natural Science Foundation of China (81120108807), and the Beijing Nova Program (Z121107002512055). We thank Dr. Michel Millodot (School of Optometry and Vision Sciences, Cardiff University, Cardiff, UK) for his help in revising this manuscript.
The authors declare that they have no competing financial interests.
Received November 2, 2012; accepted September 17, 2013.
1. Howland B, Howland HC. Subjective measurement of high-order aberrations of the eye. Science 1976; 193: 580–2.
2. Collins MJ, Wildsoet CF, Atchison DA. Monochromatic aberrations and myopia. Vision Res 1995; 35: 1157–63.
3. Charman WN. Aberrations and myopia. Ophthalmic Physiol Opt 2005; 25: 285–301.
4. Porter J, Guirao A, Cox IG, Williams DR. Monochromatic aberrations of the human eye in a large population. J Opt Soc Am (A) 2001; 18: 1793–803.
5. Cordain L, Eaton SB, Brand Miller J, Lindeberg S, Jensen C. An evolutionary analysis of the aetiology and pathogenesis of juvenile-onset myopia. Acta Ophthalmol Scand 2002; 80: 125–35.
6. McLellan JS, Marcos S, Burns SA. Age-related changes in monochromatic wave aberrations of the human eye. Invest Ophthalmol Vis Sci 2001; 42: 1390–5.
7. Calver RI, Cox MJ, Elliott DB. Effect of aging on the monochromatic aberrations of the human eye. J Opt Soc Am (A) 1999; 16: 2069–78.
8. He JC, Sun P, Held R, Thorn F, Sun X, Gwiazda JE. Wavefront aberrations in eyes of emmetropic and moderately myopic school children and young adults. Vision Res 2002; 42: 1063–70.
9. Cheng H, Barnett JK, Vilupuru AS, Marsack JD, Kasthurirangan S, Applegate RA, Roorda A. A population study on changes in wave aberrations with accommodation. J Vis 2004; 4: 272–80.
10. Pallikaris IG, Kalyvianaki MI, Kymionis GD, Panagopoulou SI. Phakic refractive lens implantation in high myopic patients: one-year results. J Cataract Refract Surg 2004; 30: 1190–7.
11. Prakash G, Sharma N, Choudhary V, Titiyal JS. Higher-order aberrations in young refractive surgery candidates in India: establishment of normal values and comparison with white and Chinese Asian populations. J Cataract Refract Surg 2008; 34: 1306–11.
12. Yoon G, Jeong TM, Cox IG, Williams DR. Vision improvement by correcting higher-order aberrations with phase plates in normal eyes. J Refract Surg 2004; 20: S523–7.
13. Li S, Xiong Y, Li J, Wang N, Dai Y, Xue L, Zhao H, Jiang W, Zhang Y, He JC. Effects of monochromatic aberration on visual acuity using adaptive optics. Optom Vis Sci 2009; 86: 868–74.
14. El Awady HE, Ghanem AA, Saleh SM. Wavefront-optimized ablation versus topography-guided customized ablation in myopic LASIK: comparative study of higher order aberrations. Ophthalmic Surg Lasers Imaging 2011; 42: 314–20.
15. Kim SW, Ahn H, Kim EK, Kim TI. Comparison of higher-order aberrations in eyes with aspherical or spherical intraocular lenses. Eye (Lond) 2008; 22: 1493–8.
16. Sabesan R, Jeong TM, Carvalho L, Cox IG, Williams DR, Yoon G. Vision improvement by correcting higher-order aberrations with customized soft contact lenses in keratoconic eyes. Opt Lett 2007; 32: 1000–2.
17. Wei RH, Lim L, Chan WK, Tan DT. Higher order ocular aberrations in eyes with myopia in a Chinese population. J Refract Surg 2006; 22: 695–702.
18. Carkeet A, Luo HD, Tong L, Saw SM, Tan DT. Refractive error and monochromatic aberrations in Singaporean children. Vision Res 2002; 42: 1809–24.
19. Hu JR, Yan ZH, Liu CF, Huang LN. [Higher-order aberrations in myopic and astigmatism eyes]. Zhonghua Yan Ke Za Zhi 2004; 40: 13–6.
20. Kong MM, Gao ZS, Li XH, Ding SH, Qu XM, Yu MQ. A generic eye model by reverse building based on Chinese population. Opt Express 2009; 17: 13283–97.
21. 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.
22. He M, Zheng Y, Xiang F. Prevalence of myopia in urban and rural children in mainland China. Optom Vis Sci 2009; 86: 40–4.
23. 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.
24. 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.
25. Congdon N, Wang Y, Song Y, Choi K, Zhang M, Zhou Z, Xie Z, Li L, Liu X, Sharma A, Wu B, Lam DS. Visual disability, visual function, and myopia among rural chinese secondary school children: the Xichang Pediatric Refractive Error Study (X-PRES)–report 1. Invest Ophthalmol Vis Sci 2008; 49: 2888–94.
26. 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.
27. Liang YB, Friedman DS, Wong TY, Wang FH, Duan XR, Yang XH, Zhou Q, Tao Q, Zhan SY, Sun LP, Wang NLHandan Eye Study Group. Rationale, design, methodology, and baseline data of a population-based study in rural China: the Handan Eye Study. Ophthalmic Epidemiol 2009; 16: 115–27.
28. Peng XY, Wang FH, Liang YB, Wang JJ, Sun LP, Peng Y, Friedman DS, Liew G, Wang NL, Wong TY. Retinopathy in persons without diabetes: the Handan Eye Study. Ophthalmology 2010; 117: 531–7.
29. Wang FH, Liang YB, Peng XY, Wang JJ, Zhang F, Wei WB, Sun LP, Friedman DS, Wang NL, Wong TY, Handan Eye Study G. Risk factors for diabetic retinopathy in a rural Chinese population with type 2 diabetes: the Handan Eye Study. Acta Ophthalmol 2011; 89: e336–43.
30. Wang FH, Liang YB, Zhang F, Wang JJ, Wei WB, Tao QS, Sun LP, Friedman DS, Wang NL, Wong TY. Prevalence of diabetic retinopathy in rural China: the Handan Eye Study. Ophthalmology 2009; 116: 461–7.
31. Yang K, Liang YB, Gao LQ, Peng Y, Shen R, Duan XR, Friedman DS, Sun LP, Mitchell P, Wang NL, Wong TY, Wang JJ. Prevalence of age-related macular degeneration in a rural Chinese population: the Handan Eye Study. Ophthalmology 2011; 118: 1395–401.
32. Wang Y, Liang YB, Sun LP, Duan XR, Yuan RZ, Wong TY, Yi P, Friedman DS, Wang NL, Wang JJ. Prevalence and causes of amblyopia in a rural adult population of Chinese the Handan Eye Study. Ophthalmology 2011; 118: 279–83.
33. Liang YB, Friedman DS, Zhou Q, Yang X, Sun LP, Guo LX, Tao QS, Chang DS, Wang NLHandan Eye Study Group. Prevalence of primary open angle glaucoma in a rural adult Chinese population: the Handan eye study. Invest Ophthalmol Vis Sci 2011; 52: 8250–7.
34. Carkeet A, Velaedan S, Tan YK, Lee DY, Tan DT. Higher order ocular aberrations after cycloplegic and noncycloplegic pupil dilation. J Refract Surg 2003; 19: 316–22.
35. Applegate RA, Donnelly WJ 3rd, Marsack JD, Koenig DE, Pesudovs K. Three-dimensional relationship between high-order root-mean-square wavefront error, pupil diameter, and aging. J Opt Soc Am (A) 2007; 24: 578–87.
36. Wang Y, Zhao K, Jin Y, Niu Y, Zuo T. Changes of higher order aberration with various pupil sizes in the myopic eye. J Refract Surg 2003; 19: S270–4.
37. Wang L, Koch DD. Ocular higher-order aberrations in individuals screened for refractive surgery. J Cataract Refract Surg 2003; 29: 1896–903.
38. Atchison DA. Recent advances in measurement of monochromatic aberrations of human eyes. Clin Exp Optom 2005; 88: 5–27.
39. Artal P, Berrio E, Guirao A, Piers P. Contribution of the cornea and internal surfaces to the change of ocular aberrations with age. J Opt Soc Am (A) 2002; 19: 137–43.
40. Fujikado T, Kuroda T, Ninomiya S, Maeda N, Tano Y, Oshika T, Hirohara Y, Mihashi T. Age-related changes in ocular and corneal aberrations. Am J Ophthalmol 2004; 138: 143–6.
41. Amano S, Amano Y, Yamagami S, Miyai T, Miyata K, Samejima T, Oshika T. Age-related changes in corneal and ocular higher-order wavefront aberrations. Am J Ophthalmol 2004; 137: 988–92.
42. Atchison DA, Markwell EL. Aberrations of emmetropic subjects at different ages. Vision Res 2008; 48: 2224–31.
43. Cheng X, Bradley A, Hong X, Thibos LN. Relationship between refractive error and monochromatic aberrations of the eye. Optom Vis Sci 2003; 80: 43–9.
44. Li T, Zhou X, Chen Z, Zhou X, Chu R, Hoffman MR. Relationship between ocular wavefront aberrations and refractive error in Chinese school children. Clin Exp Optom 2012; 95: 399–403.
45. Atchison DA, Schmid KL, Pritchard N. Neural and optical limits to visual performance in myopia. Vision Res 2006; 46: 3707–22.
46. Paquin MP, Hamam H, Simonet P. Objective measurement of optical aberrations in myopic eyes. Optom Vis Sci 2002; 79: 285–91.
47. Buehren T, Collins MJ, Carney LG. Near work induced wavefront aberrations in myopia. Vision Res 2005; 45: 1297–312.
48. Hartwig A, Atchison DA. Analysis of higher-order aberrations in a large clinical population. Invest Ophthalmol Vis Sci 2012; 53: 7862–70.