Carbonaro F, Andrew T, Mackey D A, Spector T D, Hammond C J
Twin Research and Genetic Epidemiology Unit, King's College London School of Medicine, London, UK.
Br J Ophthalmol. 2008 Aug;92(8):1125-8. doi: 10.1136/bjo.2007.133272.
To estimate the heritability of intraocular pressure (IOP) by performing a classical twin study and to determine whether the use of different instruments influences calculation of eye IOP heritability.
Twin pairs were recruited to participate from the TwinsUK Adult Twin Registry at St. Thomas' Hospital London. IOP was measured using Goldmann applanation tonometry (GAT). A subset of twins also had their IOP measured using the Ocular Response Analyser (ORA; Reichert, Buffalo, NY) and the Dynamic Contour Tonometer (DCT, Pascal; Swiss Microtechnology AG, Port, Switzerland). We compared the covariance of IOP within monozygotic (MZ) and dizygotic (DZ) pairs using genetic modelling techniques to determine the relative contribution of genes and environment to the variation in IOP seen in this population.
Data for 422 twin pairs (211 MZ; 211 DZ) were analysed. The mean IOP for GAT was 15.4 (SD 2.7) mm Hg (range: 8.7-26.2 mm Hg). The MZ correlations were significantly higher than DZ for IOP measured by GAT, DCT and ORA (correlation coefficients: GAT: 0.57:0.39, DCT: 0.62:0.36, Goldmann-correlated ORA (IOPg) 0.73:0.47, for MZ:DZ twins, respectively). Modelling suggested heritability for GAT IOP of 0.62, with individual environmental factors accounting for 0.38 of the variation.
This study demonstrated that genetic effects are important in determining IOP in this twin population. IOP readings differed depending upon the instrument used, and this resulted in different heritability values; genetic factors explained 62%, 63% and 74% of the variation in IOP using GAT, DCT and ORA IOPg, respectively. Environmental factors determined the remainder of the variation.
通过开展经典双生子研究评估眼压（IOP）的遗传度，并确定使用不同仪器是否会影响眼内压遗传度的计算。
从伦敦圣托马斯医院的英国双生子成人双生子登记处招募双生子对参与研究。使用Goldmann压平眼压计（GAT）测量眼压。一部分双生子还使用眼反应分析仪（ORA；Reichert，布法罗，纽约）和动态轮廓眼压计（DCT，Pascal；瑞士微技术公司，波特，瑞士）测量了眼压。我们使用遗传建模技术比较了同卵双生子（MZ）和异卵双生子（DZ）对内眼压的协方差，以确定基因和环境对该人群中观察到的眼压变化的相对贡献。
分析了422对双生子（211对MZ；211对DZ）的数据。GAT测量的平均眼压为15.4（标准差2.7）mmHg（范围：8.7 - 26.2 mmHg）。通过GAT、DCT和ORA测量的眼压，MZ的相关性显著高于DZ（相关系数：GAT：0.57:0.39，DCT：0.62:0.36，与Goldmann相关的ORA（IOPg）0.73:0.47，分别为MZ:DZ双生子）。建模表明GAT眼压的遗传度为0.62，个体环境因素占变异的0.38。
本研究表明，遗传效应在决定该双生子人群的眼压方面很重要。眼压读数因使用的仪器而异，这导致了不同的遗传度值；使用GAT、DCT和ORA IOPg时，遗传因素分别解释了眼压变异的62%、63%和74%。环境因素决定了其余的变异。
