title: Digital imaging in differential diagnosis of small choroidal melanoma.
abstract: BACKGROUND
  To assess the role of digital imaging and a new subtraction method for differential diagnosis of choroidal nevus and small choroidal melanoma.
  
  
  METHODS
  Of 241 consecutive patients referred to a tertiary referral center for suspected choroidal melanoma, 110 who underwent digital imaging of the ocular fundus were eligible for this study. Digital color, red-free and red light retinal images were evaluated in a randomized and masked manner and by the subtraction method for diagnosis of the fundus lesion. The reference standard was based on the combined results of ophthalmological examination, including mydriatic ophthalmoscopy, B scan ultrasonography, digital imaging and fluorescein angiography of the ocular fundus.
  
  
  RESULTS
  Comparative use of digital color, red-free and red light imaging had 85.7% (95%CI 42.1-99.6) sensitivity, 99.0% (95%CI 94.7-99.9) specificity and 98.2% (95%CI 93.6-99.8) exact agreement versus reference standard in differentiation of small choroidal melanoma from pseudomelanoma. Direct comparison between use of digital images and the reference standard showed excellent agreement in detecting small choroidal melanoma from suspected choroidal lesions (K 0.847; 95%CI 0.639-1.0). The subtraction method was useful to show growth in four of 94 melanocytic choroidal tumors. The mean annual incidence of choroidal melanoma in Southwest Finland was 0.80 per 100.000 population. The most frequent choroidal pseudomelanomas were choroidal melanotic and amelanotic nevi, disciform lesions, congenital hypertrophy of the retinal pigment epithelium, and circumscribed choroidal hemangioma.
  
  
  CONCLUSIONS
  Combined use of digital color, red-free and red light imaging was a suitable adjunct in differentiation of small choroidal melanoma from different pseudomelanomas. The subtraction method may reveal early growth of the melanotic choroidal tumors.
authors.affiliation: Department of Ophthalmology, Helsinki University Central Hospital, Finland. jzsaari@medscape.com
authors.forename: Jukka M
authors.initials: JM
authors.lastname: Saari
authors.forename: Tero
authors.initials: T
authors.lastname: Kivelä
authors.forename: Paula
authors.initials: P
authors.lastname: Summanen
authors.forename: Kari
authors.initials: K
authors.lastname: Nummelin
authors.forename: K Matti
authors.initials: KM
authors.lastname: Saari
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002830:Choroid Neoplasms / Q000175:diagnosis* / Q000453:epidemiology; D003937:Diagnosis, Differential; D004311:Double-Blind Method; D005260:Female; D005387:Finland / Q000453:epidemiology; D005451:Fluorescein Angiography; D005654:Fundus Oculi; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008545:Melanoma / Q000175:diagnosis* / Q000453:epidemiology; D018328:Melanoma, Amelanotic / Q000175:diagnosis* / Q000453:epidemiology; D008875:Middle Aged; D009508:Nevus, Pigmented / Q000175:diagnosis* / Q000453:epidemiology; D009887:Ophthalmoscopy; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013382:Subtraction Technique