Abstract
Purpose :
Diabetic retinopathy (DR) is a complication from diabetes that causes damage to the retinal vasculature. It is the leading cause of blindness in working age adults, affecting approximately 100 million people worldwide. Despite this, DR remains highly treatable if detected early, with studies showing that early detection and treatment can reduce the risk of blindness by 95%. Here, we report on the development of a low-cost, portable color confocal scanning laser ophthalmoscope (cSLO) for remote screening and telemedicine applications. This non-mydriatic cSLO device is intended to be used handheld or mounted on a portable chin rest for use in non-clinical environments.
Methods :
Light from a laser diode and superluminescent diode, operating at 520 and 850nm respectively, is directed to a custom-designed, portable patient interface. The light is collimated, scanned by galvanometers and relayed into the patient’s pupil using off-the-shelf optics and custom 3D-printed opto-mechanics. Light returning from the patient eye is relayed back through the systems optics, coupled into a multimode fiber and detected on a photomultiplier tube. The optical design achieves a 40 degree FOV at a working distance of 16mm. Performance modeled in Zemax demonstrated diffraction-limited performance across the entire FOV with Airy disc radii < 20 µm for both sources. The system acquired data at 1800 lines/second, delivering 500 line/frame images at 3.6Hz. To ensure patient safety, the optical power of the illumination beam is kept well below the limits specified in ANSI Z80.36-2016. Specifically, the power incident on the subject eye is < 400µW during NIR imaging and <100µW during green imaging.
Results :
Feasibility of the prototype cSLO device for use in screening applications was demonstrated by imaging a healthy human volunteer. Imaging was performed under a protocol approved by the Duke University IRB.
Conclusions :
We have reported on the development of a low-cost, portable confocal scanning laser ophthalmoscope for remote screening and telemedicine applications. Performance and feasibility of the system were demonstrated by acquiring images on a healthy human volunteer. Future efforts will be directed towards further cost reduction and clinical validation.
This is a 2020 ARVO Annual Meeting abstract.