EAGER: Ultra Low Light Level Imaging for Ophthalmological Applications

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.