EAGER: Ultra Low Light Level Imaging for Ophthalmological Applications

目前在眼科检查中使用的化学瞳孔扩张（瞳孔化学扩张）需要大量的时间来进行瞳孔扩张和瞳孔扩张后的恢复，在检查和恢复过程中经常使患者的眼睛处于高水平的光照下。仅时间方面的要求就限制了世界范围内全面眼科检查的可得性和频率，特别是在没有眼科诊所的地区。这项研究计划的目的是探索是否有可能在足够低的光照条件下进行眼科检查，以允许瞳孔自然扩张，而不需要化学扩张。该研究项目将探索超低光水平成像系统的开发，该系统可以在昏暗的诊所中提供包括视网膜在内的眼睛内部区域的高质量图像。减少每次眼科检查所需的时间将增加眼科检查的可用性，从而能够在世界范围内更早地诊断和治疗疾病。所开发的超低光成像系统的其他应用可以使眼科手术在视网膜上的光照强度低得多的情况下进行，从而最大限度地减少术后并发症并增强慢性耐受性，并可在其他光学成像应用中实施，例如，产生非常低强度散射的细胞内成像。本研究计划的目标是研究在低光照条件下进行眼科检查的可能性，这种检查将允许自然瞳孔扩张而不需要化学瞳孔散瞳。为此，该研究项目将侧重于确定影响眼科检查超低光成像系统发展的基础和技术限制，并分析先进技术以规避当前的技术限制。以直接检眼镜、大视场直接检眼镜和裂隙灯形式实现的超低光成像设备将使眼科检查仅在瞳孔自然扩张的情况下进行。该研究项目将涉及三个关键方面：(1)建立影响超低光水平眼科检查的基本限制，从量子水平开始，因为它影响每帧每像素低光子计数时可实现的信噪比，并包括前段和后段正常和异常区域（特别是包括视网膜）反射率的波长依赖性；(2)设计和评估超低光成像系统的技术实现，包括理论分析和实验原型，以确定当前影响性能的技术限制；(3)研究新的技术方法，使超低光成像系统的技术水平朝着基本限制所确立的界限前进；从而促进下一代眼科设备和手术的发展。超低光成像系统的成功开发反过来又将使实地条件下全面眼科检查的可用性和频率显著增加，从而为大大扩大的人口提供对不良眼病的早期发现和治疗。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The current use of chemical mydriasis (chemical dilation of the pupil) in eye/ophthalmological examinations requires significant time for both pupil dilation and recovery following pupil dilation, often subjecting the patient's eye to high levels of illumination during both the examination and recovery. The time requirement alone limits the availability and frequency of full ophthalmological examinations worldwide, particularly in regions without access to ophthalmological clinics. The goal of this research program is to explore whether it is possible to perform eye examinations under low enough light conditions to allow for natural dilation of the pupil without the need for chemical dilation. The research program will explore the development of ultra low light level imaging systems that can provide high quality images of the inner regions of the eye, including the retina, in a clinic with the lights dimmed. Reducing the time required for each ophthalmological examination would increase their availability and therefore enable both earlier diagnoses and treatment of diseases worldwide. Other applications of the ultra low light level imaging system developed could allow for eye surgeries to proceed with much lower intensity illumination incident on the retina, thereby minimizing post-surgical complications and enhancing chronic toleration, and be implemented in other optical imaging applications, e.g., intracellular imaging, that produce very low intensity scattering. The goal of this research program is to investigate the possibility of performing ophthalmological examinations under low light level conditions that would allow for natural pupil dilation without the need for chemical mydriasis. To this end, the research program will be focused on establishing the fundamental and technological limitations that impact the development of ultra low light level imaging systems for ophthalmological examinations and analyzing advanced techniques to circumvent current technological limits. Ultra low light level imaging devices implemented in the form of a direct ophthalmoscope, a wide field direct ophthalmoscope, and a slit lamp would enable ophthalmological examinations to be performed with only natural dilation of the pupil. This research program will involve three key aspects: (1) establishment of the fundamental limitations that affect ultra low light level ophthalmological examinations, starting at the quantum level as it impacts the signal to noise ratio achievable at low photon counts per pixel per frame, and including the wavelength dependence of the reflectivity of both normal and abnormal regions of the anterior and posterior segments, especially including the retina, (2) design and assessment of technological implementations of ultra low light level imaging systems, including both theoretical analysis and experimental prototypes, with the goal of establishing current technological limitations that impact performance, and (3) investigation of novel technical approaches that can advance the state of the art of ultra low light level imaging systems toward the boundaries established by fundamental limitations, thereby enabling the development of next generation ophthalmological devices and procedures. Successful development of ultra low light level imaging systems will in turn enable a significant increase in the availability and frequency of full ophthalmological examinations under field conditions, thereby providing earlier detection and treatment of adverse eye conditions to a greatly expanded population.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.