State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.
Invest Ophthalmol Vis Sci. 2013 Feb 5;54(2):1048-53. doi: 10.1167/iovs.12-10066.
Peripheral eye length (PEL) provides a measure of overall eye shape, which may play a role in the development of myopia. The current study explores the distribution and heritability of PEL, relative PEL (RPEL, defined as PEL minus axial eye length) and relative ratio PEL (RRPEL, defined as PEL divided by axial eye length) in Chinese children and adolescents.
Subjects included both male and female youths participating in the Guangzhou Twin Eye Study. Eye length was measured by partial coherence laser interferometry axially, 40° temporally (PEL-T(40)) and 40° nasally (PEL-N(40)). Structural equation modeling (SEM) was used to estimate the relative contribution of genetic and environmental factors on PEL, RPEL, and RRPEL, adjusting for age and sex.
We examined 104 monozygotic (MZ) and 54 dizygotic (DZ) twins aged 8 to 20 years old. The intraclass correlation coefficients were 0.89 for PEL-T(40), 0.92 for PEL-N(40), 0.80 for RPEL-T(40), 0.73 for RPEL-N(40), 0.77 for RRPEL-T(40), and 0.73 for RRPEL-N(40) in MZ pairs, and 0.52, 0.50, 0.39, 0.58, 0.37, and 0.58 in DZ pairs, respectively. The best fit adjusted models estimated that additive genetic effects accounted for approximately 86.2%, 89.8%, 79.9%, 75.5%, 77.1%, and 74.5% of the variance for the above mentioned traits, respectively, while dominant genetic effects and shared environmental factors were negligible.
Additive genetic effects had a substantial influence on phenotypic variation in PEL and RPEL, suggesting genetic rather than environmental factors play a major role in determining eye shape.
外周眼长（PEL）提供了一种整体眼形的测量方法，可能在近视的发展中起作用。本研究探讨了中国儿童和青少年外周眼长（PEL）、相对眼长（RPEL，定义为 PEL 减去眼轴长度）和相对比眼长（RRPEL，定义为 PEL 除以眼轴长度）的分布和遗传性。
研究对象包括参与广州双胞胎眼研究的男性和女性青少年。眼长通过部分相干激光干涉法轴向测量，40°颞向（PEL-T(40)）和 40°鼻向（PEL-N(40)）。结构方程模型（SEM）用于估计遗传和环境因素对 PEL、RPEL 和 RRPEL 的相对贡献，同时调整年龄和性别。
我们检查了 104 对同卵（MZ）和 54 对异卵（DZ）双胞胎，年龄 8 至 20 岁。MZ 双胞胎的内类相关系数为 0.89 用于 PEL-T(40)，0.92 用于 PEL-N(40)，0.80 用于 RPEL-T(40)，0.73 用于 RPEL-N(40)，0.77 用于 RRPEL-T(40)，0.73 用于 RRPEL-N(40)；DZ 双胞胎的内类相关系数分别为 0.52、0.50、0.39、0.58、0.37 和 0.58。最佳拟合调整模型估计，加性遗传效应分别约占上述性状变异的 86.2%、89.8%、79.9%、75.5%、77.1%和 74.5%，而显性遗传效应和共享环境因素可忽略不计。
加性遗传效应对外周眼长和 RPEL 的表型变异有很大影响，这表明遗传因素而不是环境因素在决定眼形方面起主要作用。
