Ameln Julius, Witten Jenny L, Gutnikov Aleksandr, Lukyanova Veronika, Holz Frank G, Harmening Wolf M
Department of Ophthalmology, University of Bonn, Bonn, Germany.
Invest Ophthalmol Vis Sci. 2025 Aug 1;66(11):13. doi: 10.1167/iovs.66.11.13.
To study in vivo cone topography of the normal human foveola.
The fovea in both eyes of 30 healthy participants was imaged with adaptive optics scanning light ophthalmoscopy. High-resolution image montages spanning two degrees of visual angle were created and cone center locations annotated. Continuous cone density maps were computed by a Voronoi cell area approach to also yield the topographical center, the cone density centroid (CDC). Cone density profiles were extracted and fit with a four-parameter decay function, D = D0 / (1 + (E/a)b)c, with D as cone density (cones/mm2), D0 as cone density at the CDC, and E as eccentricity (µm).
Across eyes, D0 was 175,474 ± 20,543 cones/mm2, on average (range 136,001-216,209 cones/mm2). Density dropped anisotropically along the meridians, shallower horizontally, with average best fit parameters (a, b, c) of 61.95, 2.469, 0.268 for horizontal, and 59.11, 2.012, 0.357, for vertical profiles, respectively. In radially averaged profiles, cone density reached 50% of D0 at 151 ± 17 µm eccentricity (range 128-193 µm). Temporal cone density was slightly higher than nasal. Most topographical metrics were highly correlated between fellow eyes.
Despite a 1.6-fold range in absolute cone density, foveolar density profiles could be well described by a sigmoidal decay function across all eyes. This established a normative cone density profile of the healthy foveola. It allowed cone density estimation in cases of only partially available data, which alleviates resolution demands for future studies and renders possible retrospective analyses of foveolar cone topography in sub-optimal imagery.
研究正常人中心小凹的体内视锥细胞地形图。
使用自适应光学扫描激光检眼镜对30名健康受试者双眼的中央凹进行成像。创建跨越两个视角的高分辨率图像蒙太奇，并标注视锥细胞中心位置。通过Voronoi细胞面积法计算连续的视锥细胞密度图，以得出地形中心，即视锥细胞密度质心（CDC）。提取视锥细胞密度分布曲线，并用四参数衰减函数D = D0 / (1 + (E/a)b)c进行拟合，其中D为视锥细胞密度（个/mm2），D0为CDC处的视锥细胞密度，E为偏心率（μm）。
双眼的D0平均为175,474 ± 20,543个/mm2（范围为136,001 - 216,209个/mm2）。密度沿子午线各向异性下降，水平方向下降较浅，水平分布曲线的平均最佳拟合参数（a、b、c）分别为61.95、2.469、0.268，垂直分布曲线的平均最佳拟合参数分别为59.11、2.012、0.357。在径向平均分布曲线中，视锥细胞密度在偏心率为151 ± 17 µm（范围为128 - 193 µm）时达到D0的50%。颞侧视锥细胞密度略高于鼻侧。大多数地形学指标在双眼之间高度相关。
尽管视锥细胞绝对密度范围为1.6倍，但所有眼睛的中心小凹密度分布曲线都可以用S形衰减函数很好地描述。这建立了健康中心小凹的标准视锥细胞密度分布。它允许在仅有部分可用数据的情况下估计视锥细胞密度，这减轻了未来研究的分辨率要求，并使得对次优图像中的中心小凹视锥细胞地形图进行回顾性分析成为可能。
