Department of Engineering, Computing and Design, University of Chichester, Chichester, UK.
Sapphire Eyecare, Southampton, UK.
Bioelectromagnetics. 2022 Feb;43(2):90-105. doi: 10.1002/bem.22386. Epub 2021 Dec 30.
Vitreous "floaters" are a common entoptic phenomenon that can result in significant reduction in quality of life in a proportion of sufferers. The authors use a computational mathematical model based on Fourier optics and reflection and transmission coefficients calculated for a planar type II collagen opacity suspended in aqueous to show that floaters are perceived by the patient through interference effects that result in significant variations in intensity on the retina when viewing a constant brightness surface. The model also predicts that backscattered intensity from floaters is ten thousand to one million times lower than the variations in intensity produced on the retina, which demonstrates that the visible effects of floaters for the patient can be highly significant, whereas clinical observation of the vitreous may be entirely unremarkable. Importantly, the results also demonstrate that floaters do not need to be opaque to cause symptoms, with only small differences in refractive index between the floater material and the surrounding vitreous needed to produce significant optical effects. The model predicts that pupil size is an important factor in determining the severity of symptoms from floaters, with constricted pupils giving much greater effect than dilated pupils. Finally, the authors' model predicts that floaters degrade contrast sensitivity function, with greatest degradation occurring in the 5-40 cycles per degree spatial frequency range and that the effects of shadowing caused by floaters are very strongly correlated to the predicted degradation of contrast sensitivity function. Bioelectromagnetics. 43:90-105, 2022. © 2021 The Authors. Bioelectromagnetics published by Wiley Periodicals LLC on behalf of Bioelectromagnetics Society.
玻璃体“飞蚊症”是一种常见的内视现象，可导致一部分患者的生活质量显著下降。作者使用基于傅里叶光学的计算数学模型和计算得到的平面 II 型胶原蛋白不透明度的反射和透射系数，表明飞蚊症是通过患者观察恒定亮度表面时视网膜上的强度出现显著变化的干涉效应而被感知的。该模型还预测，从飞蚊症散射回的强度比视网膜上产生的强度变化低一万到一百万倍，这表明飞蚊症对患者的可见效果可能非常显著，而玻璃体的临床观察可能完全没有明显变化。重要的是，结果还表明，飞蚊症不需要不透明才能引起症状，只要飞蚊症材料和周围玻璃体之间的折射率略有差异，就足以产生显著的光学效果。该模型预测，瞳孔大小是决定飞蚊症症状严重程度的重要因素，瞳孔收缩比瞳孔扩张产生的影响大得多。最后，作者的模型预测飞蚊症会降低对比敏感度函数，最大的降低发生在 5-40 周/度空间频率范围内，并且飞蚊症造成的阴影效果与预测的对比敏感度函数降低非常相关。生物电磁学。43:90-105,2022. 生物电磁学由 Wiley Periodicals LLC 代表生物电磁学学会出版。
