In vivo fundus imaging and computational refocusing with a diffuser-based fundus camera

Area of Science:

• Ophthalmology
• Biomedical Imaging
• Computational Optics

Background:

• Diagnostic eye care can be enhanced with high-throughput, user-friendly tools.
• Phase mask-based imaging offers computational refocusing without moving parts, potentially reducing fundus camera complexity and cost.
• Previous demonstrations of phase mask imaging were limited to model eyes, not in vivo applications.

Purpose of the Study:

• To design, construct, and evaluate a computational fundus camera for in vivo imaging.
• To assess the feasibility and performance of phase mask-based computational imaging of the human fundus.

Main Methods:

• A holographic diffuser was integrated into a modified commercial fundus camera.
• The diffuser was placed conjugate to the ocular pupil, creating a shift-invariant point spread function dependent on refractive error.
• Digital refocusing was performed across a range of +/- 10 diopters of defocus.

Main Results:

• The system achieved digital refocusing of in vivo human fundus images.
• The field of view was >= 35 degrees, with a resolution of 7.7 to 9.6 line pairs per millimeter.
• The device underwent ocular safety testing and a pilot human imaging study.

Conclusions:

• This research presents the first in vivo diffuser-based fundus images.
• The findings demonstrate the feasibility of computational imaging for ocular diagnostics.
• Phase mask-based imaging holds promise for advancing fundus camera technology.