Design of optical system for binocular fundus camera

Area of Science:

• Ophthalmic optics
• Biomedical imaging
• Optical engineering

Background:

• Accurate 3D reconstruction of the human fundus requires advanced imaging systems.
• Existing systems often necessitate pupil dilation (mydriasis), limiting patient comfort and accessibility.
• Minimizing stray light and correcting optical aberrations are crucial for high-resolution fundus imaging.

Purpose of the Study:

• To design and simulate a non-mydriatic optical system for a binocular fundus camera.
• To enable simultaneous capture of fundus images from different angles for 3D reconstruction.
• To evaluate the system's imaging quality and performance across various refractive conditions.

Main Methods:

• Designed a binocular fundus camera optical system comprising imaging and illumination subsystems.
• Utilized the Gullstrand Le Grand eye model for normal eye simulation and a Schematic eye model for ametropia simulation.
• Incorporated an annular aperture and black dot board in the illumination system to mitigate stray light.
• Performed optical simulations to assess imaging performance metrics.

Main Results:

• Simulated Modulation Transfer Function (MTF) exceeded 0.2 at 90 lp/mm across visual fields.
• System distortion was measured at -2.7%, and field curvature was below 0.1 mm.
• Demonstrated strong chromatic aberration correction and focusing capabilities.
• Achieved clear imaging for human fundus with refractive errors ranging from -10 D to +6 D.

Conclusions:

• The designed non-mydriatic optical system effectively captures fundus images for 3D reconstruction.
• The system exhibits excellent imaging quality, robust aberration correction, and wide refractive error tolerance.
• This technology offers a promising advancement for non-invasive, high-resolution retinal imaging and analysis.