From 1996 through
April 2005, the Alaska Blind Child Discovery Project has screened over
The majority of ABCD screenings included MTI photoscreens, however recent
screens have also been performed using ADBC
(Amblyopia Detection by Camera) using JVC and Gateway DV-S20 digital cameras.
The ABCD Coordinating Center Interpretations
are as follows:
Refer (“positive”): 5.8%
Normal : 93.8%
Inconclusive / incomplete: 0.4%
Breakdown of referral interpretations: anisometropia (29%), hyperopia
(33%), astigmatism (18%), strabismus (7%), myopia (6%), cataract (1%),
The percent of referred screenings for whom the ABCD Coordinating Center
has direct or indirect follow-up confirmatory exam data are just over
The following are estimated Validation
Positive Predictive Value: 89%The first 4000 screenings included a steep
learning curve in photoscreen interpretation. For the years 1998-99,
PPV was greater than 90%. With highly experienced photographers and
directed interpretation, ABCD achieved a PPV of greater than 90% with
estimated specificity of 97%-100%.
1. Arnold RW, Gionet E, Jastrzebski A, Kovtoun T, Armitage
M, Coon L. The Alaska Blind Child Discovery project: Rationale, Methods
and Results of 4000 screenings. Alaska Med. 2000;42:58-72.
2. Arnold RW, Armitage MD, Gionet EG, et al. The cost and yield of photoscreening:
Impact of photoscreening on overall pediatric ophthalmic costs. JPOS.
3. Arnold RW. Highly specific photoscreening at the Alaska State Fair:
Valid Alaska Blind Child Discovery photoscreening and interpretation.
Alaska Med. April/May/June 2003 2003;45(2):34-40.