Detection of age-related macular degeneration using a nonmydriatic digital camera and a standard film fundus camera.
OBJECTIVE
To compare gradings of lesions associated with age-related macular degeneration (AMD) from digital and stereoscopic film images.


METHODS
Instrument validation study.


METHODS
Sixty-two subjects (124 eyes) with varying degrees of AMD, including no AMD.


METHODS
Images of the optic disc and macula were taken using a 45 degrees digital camera (6.3 megapixels) through dark-adapted pupils and pharmacologically dilated pupils. In addition, 30 degrees stereoscopic retinal film images were taken through pharmacologically dilated pupils of the same eyes. All images were graded for drusen size, type, and area; pigmentary abnormalities; geographic atrophy; and neovascular lesions using the modified Wisconsin Age-Related Maculopathy Grading System. Exact agreement and unweighted kappa scores were calculated for paired gradings resulting from digital and film images.


METHODS
Agreement between gradings obtained from stereoscopic slide transparencies and digital nonstereoscopic images.


RESULTS
Exact agreement between gradings of digital and stereoscopic film images taken through pharmacologically dilated pupils was 91% (kappa = 0.85) for the categories of none, early AMD, and late AMD. Exact agreement for gradings of digital images taken through dark-adapted pupils compared with gradings of film images was 80% (kappa = 0.69). Exact agreement for gradings of digital images captured through dark-adapted and pharmacologically dilated pupils was 86% (kappa = 0.78). In addition, kappa scores for agreement between different approaches for individual lesions were moderate to almost perfect.


CONCLUSIONS
Gradings resulting from high-resolution digital images, especially when the pupil is pharmacologically dilated, are comparable with those resulting from film-based images. We conclude that digital imaging of the retina is useful for epidemiological studies of AMD.
Klein
Ronald
R
Department of Ophthalmology and Visual Sciences, University of Wisconsin, Madison 53726, USA. klienr@epi.ophth.wisc.edu
Meuer
Stacy M
SM
Moss
Scot E
SE
Klein
Barbara E K
BE
Neider
Michael W
MW
Reinke
Jennifer
J
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003623:Dark Adaptation; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation; D008266:Macula Lutea / Q000473:pathology*; D008268:Macular Degeneration / Q000145:classification / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D009184:Mydriatics / Q000008:administration & dosage; D010656:Phenylephrine / Q000008:administration & dosage; D010781:Photography / Q000295:instrumentation* / Q000379:methods*; D011680:Pupil / Q000187:drug effects; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014331:Tropicamide / Q000008:administration & dosage
D009184:Mydriatics; D010656:Phenylephrine; D014331:Tropicamide