TELE-OPHTHALMIC SCREENING USING DIGITAL IMAGING DEVICES

Background: Digital imaging systems provide immediate, magnified image s that can easily be analysed, enhanced, archived, printed on near pho tographic-quality paper and transferred electronically to remote compu ters. We have assembled a digital ophthalmic system and tested it on p atients with some common causes of blindness: corneal scarring and cat aract, diabetic retinopathy, macular degeneration and glaucoma. Method s: Digital images were obtained using a variety of ophthalmic imaging devices ranging from slit-lamp, fundus camera, indirect ophthalmoscope and scanning laser ophthalmoscope.These images were compressed in ord er to concentrate image information (image size reduced by 90-95%) and minimize transmission time (reduced by 97-98%). Standard or mobile te lephone lines were used to transmit images to remote terminals. Result s/Discussion: Transmission time was reduced from 15-20 min to 20-30 s and the image size was reduced from 1.3 MB to 20-30 kB by compressing the images before transmission. Image quality is still excellent.