Fred Hollows lecture: digital screening for eye disease

Area of Science:

• Ophthalmology
• Medical Imaging
• Public Health

Background:

• Digital imaging technology is advancing for eye disease screening.
• Portable devices are crucial for widespread community screening.
• Evaluating new technologies against gold standards is essential.

Purpose of the Study:

• To assess the progress of digital imaging devices for community screening of blinding eye diseases.
• To compare the sensitivity and specificity of available imaging systems with clinical photography.
• To evaluate portable fundus cameras and a prototype digital indirect ophthalmoscope for glaucoma and diabetic retinopathy screening.

Main Methods:

• Compared a portable Nidek fundus camera and a prototype digital indirect ophthalmoscope against a Zeiss retinal camera.
• Assessed diagnostic accuracy (sensitivity, specificity) for optic disc cupping and diabetic retinopathy.
• Conducted field trials for image compression, storage, and transmission (mobile, satellite) in remote locations.

Main Results:

• Digital imaging demonstrated good to excellent agreement (Kappa 0.87, 0.45, 0.84) for glaucoma screening (VCDR measurement), with high sensitivity (70-95%) and specificity (79-97%).
• The Nidek camera showed lower image quality (56%) and agreement (Kappa 0.30) for diabetic retinopathy screening compared to standard photographs (93%).
• Image compression significantly reduced transmission times via mobile and satellite, with satellite offering more stable but expensive connections.

Conclusions:

• Digital imaging is a powerful tool for ophthalmology, with significant potential for community screening of blinding eye diseases.
• Development and validation of inexpensive, portable, user-friendly imaging devices are needed for effective community-based screening.
• Rapid advancements in digital imaging technology, compression, and transmission are making remote eye care more accessible and affordable.