Tele-ophthalmic screening using digital imaging devices.
BACKGROUND
Digital imaging systems provide immediate, magnified images that can easily be analysed, enhanced, archived, printed on near photographic-quality paper and transferred electronically to remote computers. We have assembled a digital ophthalmic system and tested it on patients with some common causes of blindness: corneal scarring and cataract, diabetic retinopathy, macular degeneration and glaucoma.


METHODS
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 order to concentrate image information (image size reduced by 90-95%) and minimize transmission time (reduced by 97-98%). Standard or mobile telephone lines were used to transmit images to remote terminals.


CONCLUSIONS
Transmission time was reduced from 15-20min to 20-30s 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.
Lions Eye Institute, Centre for Ophthalmology and Visual Science, University of Western Australia, Nedlands, Australia. yogesan@cyllene.uwa.edu.au
K
K
Yogesan
I J
IJ
Constable
R H
RH
Eikelboom
P P
PP
van Saarloos
D002386:Cataract / Q000175:diagnosis; D003316:Corneal Diseases / Q000175:diagnosis; D003930:Diabetic Retinopathy / Q000175:diagnosis; D003952:Diagnostic Imaging; D005128:Eye Diseases / Q000175:diagnosis*; D005901:Glaucoma / Q000175:diagnosis; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation / Q000379:methods*; D008268:Macular Degeneration / Q000175:diagnosis; D019113:Telepathology / Q000295:instrumentation / Q000379:methods*