Applied Vision Research Centre, City, University of London, Northampton Square, London, UK.
Department of Twin Research and Genetic Epidemiology, King's College London, St Thomas' Hospital Campus, London, UK.
Acta Ophthalmol. 2018 Nov;96(7):e797-e803. doi: 10.1111/aos.13725. Epub 2018 Aug 29.
Classification of macular pigment (MP) spatial profile phenotypes varies and is often based on subjective visualisation. We investigated repeatability of MP optical density (MPOD) comparing an objective versus subjective profiling system.
The coefficient of repeatability (CoR) was calculated for point MPOD values (0-3.8°) obtained by dual-wavelength fundus autofluorescence (FAF) from two scans obtained in a single visit of 40 healthy individuals (39 ± 9 years). For each individual's dataset, the MP profile was classified as exponential, ring-like or central dip using an objective method (based on deviations away from an exponential fit), as well as by subjective visual profiling. Existing FAF images of 88 monozygotic (MZ) and 69 dizygotic (DZ) twin pairs were reanalysed using the objective profiling method and concordance and heritability of ring-like profiles determined.
The CoR was 0.23 at 0° and 0.06 at 0.8°. Agreement of objective profiling between scans was excellent (κ = 0.85, 95% CI 0.69 to 1.00; p < 0.0005). Subjective profiling showed moderate agreement between scans (κ = 0.48, 95% CI 0.23 to 0.73; p < 0.0005). Agreement between objective and subjective classification was low (κ = 0.23, 95% CI 0.04 to 0.42; p = 0.02). Concordance for the ring-like profile using objective profiling was 0.74 for MZ compared to 0.36 for DZ twins. Heritability was calculated as 81.5% (95% confidence interval 61.1-93.1%).
Compared to visual assessment, objective MP profiling is a more reliable method and should be considered in future observational and interventional studies. In addition, MP profile phenotypes showed high heritability.
黄斑色素（MP）空间分布表型的分类方法多种多样，且通常基于主观视觉化。我们通过比较客观与主观分析系统，探究了 MP 光密度（MPOD）的可重复性。
在 40 名健康个体（39±9 岁）的单次就诊中，对两次眼底自发荧光（FAF）扫描获得的 0-3.8°的点 MPOD 值进行重复性计算（CoR）。对于每个个体的数据，使用客观方法（基于与指数拟合的偏差）和主观视觉分析将 MP 分布分类为指数型、环状或中央凹陷型。使用客观分析方法对 88 对同卵（MZ）和 69 对异卵（DZ）双胞胎的现有 FAF 图像进行了重新分析，并确定了环状表型的一致性和遗传性。
0°处的 CoR 为 0.23，0.8°处的 CoR 为 0.06。两次扫描的客观分析结果一致性非常好（κ=0.85，95%CI 0.69-1.00；p<0.0005）。两次扫描的主观分析结果一致性中等（κ=0.48，95%CI 0.23-0.73；p<0.0005）。客观和主观分类的一致性较低（κ=0.23，95%CI 0.04-0.42；p=0.02）。使用客观分析方法对环状表型的一致性，MZ 双胞胎为 0.74，而 DZ 双胞胎为 0.36。遗传性计算为 81.5%（95%置信区间为 61.1%-93.1%）。
与视觉评估相比，客观的 MP 分析是一种更可靠的方法，应在未来的观察性和干预性研究中考虑。此外，MP 分布表型显示出较高的遗传性。
