Field trial of the Otago photoscreener.
OBJECTIVE
To assess the effectiveness of the Otago photoscreener in detecting amblyogenic factors in the general population.


METHODS
Prospective clinical trial.


METHODS
Suburban school district in Delta, BC.


METHODS
A total of 1245 kindergarten children.


METHODS
Screening for visual defects was done with the Otago photoscreener (by a technician) and the regular manual method (by a health care aide). A standard ophthalmologic examination was performed by a pediatric ophthalmologist and an orthoptist in a random sample of 20% of all children with normal results of screening (n = 241) plus all those with abnormal results (n = 29).


METHODS
Sensitivity, specificity, positive predictive value, rates of false-negative and false-positive results.


RESULTS
The Otago screener had higher sensitivity than the manual technique (81% vs. 33%), especially for strabismus and cataracts. The specificity values of the two techniques were 98% and 97% respectively, and the positive predictive values were 77% and 54% respectively. The manual technique failed to identify 5.8% of children with visual defects, compared with 1.6% for the Otago screener.


CONCLUSIONS
The Otago photoscreener is a superior instrument for identifying amblyogenic eye disease. However, given the relatively low yield, the value of any screening method should be assessed with regard to both costs and benefits.
Kennedy
R
R
Department of Ophthalmology, University of British Columbia, Vancouver.
Sheps
S B
SB
Bagaric
D
D
D000550:Amblyopia / Q000175:diagnosis*; D001955:British Columbia; D002675:Child, Preschool; D004311:Double-Blind Method; D005188:False Negative Reactions; D006801:Humans; D010781:Photography / Q000295:instrumentation*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012030:Refractive Errors / Q000175:diagnosis*; D012680:Sensitivity and Specificity; D013285:Strabismus / Q000175:diagnosis*; D014786:Vision Disorders; D014787:Vision Tests / Q000379:methods*