Shabani Hasan, De Ridder Job, Asaad Mohammad Ali, Bramer Wichor M, Meester-Smoor Magda A, Geerards Annette A J M, Klaver Caroline C W, Ramdas Wishal D, van Dooren Bart T H
Department of Ophthalmology, Erasmus University Medical Center, Rotterdam, the Netherlands.
Department of Epidemiology, Erasmus University Medical Center, Rotterdam, the Netherlands.
Invest Ophthalmol Vis Sci. 2025 Feb 3;66(2):30. doi: 10.1167/iovs.66.2.30.
The reported prevalence of keratoconus varies widely worldwide, but the causes of this variation are not well understood. We therefore aimed to explore the potential impact of local climate variables on keratoconus prevalence.
The worldwide prevalence of clinical keratoconus in the general population was systematically reviewed. In each eligible prevalence area, four climate variables deemed possibly relevant to keratoconus were assessed: daily maximum temperature, relative humidity, ultraviolet radiation, and wind speed. Climate variables were calculated using worldwide gridded climate datasets from the European Center of Medium-Range Weather Forecasts. Population density weighting was applied to enhance exposure accuracy. The average of each climate variable was calculated over the 10 years preceding data collection of each study. The potential impact of those climate variables was investigated using multiple linear regression adjusted for the gross domestic product per capita (based on purchasing power parity) with the natural logarithm of prevalence as the outcome variable.
Sixteen eligible studies were identified. After filtering to retain one prevalence estimate per region, 11 studies including datapoints from 61 areas were analyzed. The median (interquartile range) prevalence of keratoconus was 0.10% (0.07%-0.19%). Multiple regression revealed a significant negative association between humidity and keratoconus prevalence (β = -0.03; 95% confidence interval, -0.06 to -0.01; P = 0.004). In contrast, the other analyzed climate variables were not significantly associated with keratoconus prevalence.
Using global gridded climate maps, we observed a significant and biologically plausible link between low humidity and keratoconus. This suggests that humidification could benefit patients and at-risk groups.
圆锥角膜在全球的报告患病率差异很大，但这种差异的原因尚不清楚。因此，我们旨在探讨当地气候变量对圆锥角膜患病率的潜在影响。
系统回顾了普通人群中临床圆锥角膜的全球患病率。在每个符合条件的患病率地区，评估了四个被认为可能与圆锥角膜相关的气候变量：每日最高温度、相对湿度、紫外线辐射和风速。使用欧洲中期天气预报中心的全球网格化气候数据集计算气候变量。应用人口密度加权以提高暴露准确性。在每项研究的数据收集前10年计算每个气候变量的平均值。使用以患病率的自然对数为结果变量、对人均国内生产总值（基于购买力平价）进行调整的多元线性回归，研究这些气候变量的潜在影响。
确定了16项符合条件的研究。在筛选后每个地区保留一个患病率估计值，分析了包括来自61个地区数据点的11项研究。圆锥角膜的患病率中位数（四分位间距）为0.10%（0.07%-0.19%）。多元回归显示湿度与圆锥角膜患病率之间存在显著负相关（β = -0.03；95%置信区间，-0.06至-0.01；P = 0.004）。相比之下，其他分析的气候变量与圆锥角膜患病率无显著关联。
使用全球网格化气候图，我们观察到低湿度与圆锥角膜之间存在显著且生物学上合理的联系。这表明加湿可能对患者和高危人群有益。
