Objective To establish an optical model of the emmetropic eye based on the ocular parameters of emmetropic children. Methods Based on the data of ″the Anyang Childhood Eye Study″ that included corneal curvature radius, corneal thickness, anterior chamber depth, crystalline lens thickness, refraction and axial length, we used ZEMAX software and the data of the right eyes to establish an optical model of the emmetropic eye that conformed to the features of emmetropic eyes in Chinese children. Results A total of 332 emmetropic children were included in the study. Their mean age was 7.1±0.4 years and mean spherical equivalent was 0.11±0.24 D. The optical parameters for the model of the emmetropic eye in children were: Cornea: 7.78 mm anterior corneal curvature radius, -0.18 asphericity coefficient, 6.4 mm posterior corneal curvature radius, -0.60 asphericity coefficient, 0.54 mm corneal thickness, and 1.376 refractive index; Anterior chamber: 3.00 mm for depth and 1.336 for the refractive index; Crystalline lens: 12.4 mm anterior corneal curvature radius, -0.94 asphericity coefficient, -8.1 mm posterior corneal curvature radius, 0.96 asphericity coefficient, and 3.55 mm thickness and gradient refractive index; Vitreous: 15.94 mm depth, 1.336 refractive index, and -12.3 mm retinal curvature radius; Axial length: 23.03 mm; Total refractive power: 62.55 D. Conclusion We have established an optical model that conforms to the features of emmetropic eyes in children. The optical model has a total refractive power of 62.55 D and axial length of 23.03 mm, and can be used as a reference for studying emmetropization and myopia in children.
李仕明,杨宙,李偲圆,康梦田,李翯,刘洛如,朱苾丹,王宁利. 基于儿童正视眼的眼光学模型构建[J]. 中华眼视光学与视觉科学杂志, 2016, 18(1): 29-32.
Li Shiming*,Yang Zhou,Li Siyuan,Kang Mengtian,Li He,Liu Luoru,Zhu Bidan,Wang Ningli. Establishment of an optical model based on the eyes of emmetropic children. Chinese Journal of Optometry Ophthalmology and Visual science, 2016, 18(1): 29-32. DOI: DOI:10.3760/cma.j.issn.1674-845X.2016.01.007
Li SM, Liu LR, Li SY, et al. Design, methodology and baseline data of a school-based cohort study in Central China: the Anyang Childhood Eye Study[J]. Ophthalmic Epidemiol, 2013,20(6):348-359. DOI:10.3109/09286586.2013.842596.
Liou HL, Brennan NA. Anatomically accurate, finite model eye for optical modeling[J]. J Opt Soc Am A Opt Image Sci Vis,1997,14(8):1684-1695. DOI:10.1364/JOSAA.14.001684.
[5]
Gullstrand J. Appendices II and IV[M]//Helmholtz HV. Handbuch der physiologischen Optik. Hamburg: Leopld,1909.
[6]
Le Grand. Physiological optics[M]. Berlin: Springer-Verlag,1980.
[7]
Navarro R, Santamaría J, Bescós J. Accommodation-dependent model of the human eye with aspherics[J]. J Opt Soc Am A,1985,2(8):1273-1281.
[8]
Lotmar. Theoritical Eye Model with Aspherics[J]. J Opt Soc Am,1971,61:1522-1528.
[9]
Kooijman AC. Light distribution on the retina of a wide-angle theoretical eye[J]. J Opt Soc Am,1983,73(11):1544-1550.
[10]
Escudero-Sanz I, Navarro R. Off-axis aberrations of a wide-angle schematic eye model[J]. J Opt Soc Am A Opt Image Sci Vis,1999,16(8):1881-1891. DOI:10.1364/JOSAA.16.001881.
[11]
Atchison DA. Optical models for human myopic eyes[J]. Vision Res,2006,46(14):2236-2250. DOI:10.1016/j.visres.2006.01.004.
[12]
Atchison DA, Markwell EL, Kasthurirangan S, et al. Age-related changes in optical and biometric characteristics of emmetropic eyes[J]. J Vis,2008,8(4):29.1-20. DOI:10.1167/8.4.29.
[13]
Jansson F. Measurements of intraocular distances by ultrasound[J]. Acta Ophthalmol Suppl,1963,Suppl 74:1-51.
[14]
Zadnik K, Manny RE, Yu JA, et al. Ocular component data in schoolchildren as a function of age and gender[J]. Optom Vis Sci,2003,80(3):226-236.
[15]
Brown N. The change in lens curvature with age[J]. Exp Eye Res,1974,19(2):175-183.