Field evaluation of the Welch Allyn SureSight™ Vision Screener: Incorporating the Vision in Preschoolers study recommendations
Received 10 April 2006; received in revised form 6 September 2006 published online 12 December 2006.
Introduction
The prospective Vision in Preschoolers (VIP) study evaluated 11 methods of screening and proposed referral criteria for the Welch Allyn SureSight™ Vision Screener with 90% and 94% specificity. The SureSight had a higher sensitivity than most other screening techniques when these criteria were applied. We evaluated the usefulness of these criteria in a field study of healthy preschool children.
Methods
The SureSight software was altered to recommend referral using the VIP referral criteria with 90% specificity. Lions Club volunteers screened preschool children throughout Tennessee. Referred children underwent comprehensive eye examinations with cycloplegic refraction. Examination failure criteria were based upon published standards. Reanalysis using the 94% specificity criteria was then performed. Outcomes included referral rate and positive predictive value.
Results
The SureSight was used to screen 4,733 children, and screening was successful in 99.7% of children. The referral rate using the 90% specificity criteria was 12.2%. Most children (73%) were referred for suspected astigmatism. The positive predictive value was 30%. Using the 94% specificity criteria from the VIP study decreased the referral rate to 7.9% and substantially decreased over referral for suspected astigmatism; however, several anisometropes went undetected. Higher specificity was achieved by raising astigmatism referral criteria to 2.2 diopters while leaving the anisometropia criteria unchanged.
Conclusions
The SureSight can be used successfully for preschool screening in the field provided that criteria with high specificity are incorporated into the instrument’s software program. Higher rates of positive predictive value can be achieved without jeopardizing sensitivity by raising astigmatism referral criteria to 2.2 diopters.
Departments of Ophthalmology and Visual Sciences, Vanderbilt University School of Medicine, Nashville, Tennessee
Address reprint requests to Sean P. Donahue MD, PhD, Ophthalmology and Visual Sciences, 8000 Medical Center East, Nashville, TN 37232-8808
Supported by the TN Lions Charities Research to Prevent Blindness; Lions Clubs International Foundation.
Financial conflict of interest: No authors have any financial interest in the Welch Allyn SureSight™ Vision Screener or any competing product. Dr. Donahue has served as a paid (hourly) consultant for several vision screening companies during the past 5 years.
Institution at which the study was conducted: Vanderbilt University Medical Center.
ABSTRACT