PALPEBRAL FISSURE LENGTH MEASUREMENT: ACCURACY OF THE FAS FACIAL PHOTOGRAPHIC ANALYSIS SOFTWARE AND INACCURACY OF THE RULER
Main Article Content
Keywords
Fetal alcohol spectrum disorders, palpebral fissure length, FASD 4- Digit Diagnostic Code, WA State Fetal Alcohol Syndrome Diagnostic & Prevention Network
Abstract
Background
Accurate fetal alcohol spectrum disorder diagnoses require accurate facial measurement. The Fetal Alcohol Syndrome (FAS) Facial Photographic Analysis Software was developed to overcome measurement error known to occur with ruler measurement of the PFL. Recent publications have queried the Software’s accuracy.
Objectives
1) Demonstrate the Software’s ability to accurately measure a PFL from a 2 -dimensional digital facial photograph. 2) Demonstrate the frequency and magnitude of error when the PFL is measured directly by clinicians using a ruler.
Methods
Objective 1: PFLs of mannequins were measured using the Software and a sliding digital caliper, with the latter serving as the gold -standard accurate measure. Mannequins allowed the caliper prongs to be placed directly on the landmarks that define the PFL. Objective 2: PFLs of 1,027 patients evaluated at the University of Washington FAS Diagnostic & Prevention Network were measured with the Software and directly by one or two clinicians using a ruler.
Results
Objective 1: The Software derived PFLs that were identical to or within 0.2 mm of the caliper measures. Objective 2: There was tremendous inter-rater variability in PFLs measured by clinicians using a hand held ruler. Seventy -seven percent of patients had their PFLs measured incorrectly (greater than 1 mm error) by at least one of the two clinicians using a ruler.
Conclusion
The FAS Facial Photographic Analysis Software measures the PFL with the same accuracy as a sliding digital caliper, as it was programmed to do. Direct measurement of the PFL with a ruler is very prone to error.
References
2. Astley SJ. Diagnostic Guide for Fetal Alcohol Spectrum Disorders: The 4 -Digit Diagnostic Code. 3rd ed. Seattle: University of Washington Publication Services; 2004.
3. Astley SJ, Clarren SK. 1997 Diagnostic Guide for Fetal Alcohol Syndrome and Related Conditions: The 4 -Digit Diagnostic Code, 1 st edition. University of Washington Publication Services, Seattle, WA.
4. Astley SJ, Clarren SK. Diagnosing the full spectrum of fetal alcohol exposed individuals: Introducing the 4 -Digit Diagnostic Code. Alcohol Alcohol 2000;35:400 -410.
5. Stromland K, Chen Y, Norberg T, Wennerstrom K, Michael G. Reference values of facial features in Scandinavian children measured with a range -camera technique. Scand. J Plast Reconstr Surg. Hand Surg 1999;33:59- 65.
6. Astley SJ. FAS Facial Photographic Analysis Software [computer program]. Version 1.0. Seattle: University of Washington; 2004.
7. Astley SJ. FAS Facial Photographic Analysis Software [computer program]. Version 2 .0. Seattle: University of Washington; 2012.
8. Astley S, Clarren S. A fetal alcohol syndrome screening tool. Alcohol Clin Exp Res 1995;19(6):1565- 1571.
9. Astley SJ, Clarren SK. A case definition and photographic screening tool for the facial phenotype of fetal alcohol syndrome. Journal of Pediatrics 1996;129:33- 41.
10. Avner M, Henning P, Koren G, Nulman I. Validation of the facial photographic method in fetal alcohol spectrum disorder screening and diagnosis. JFAS Int 2006;4:e20- October 10, 2006.
11. Avner M, Henning P, Koren G, Nulman I. Validation of the facial photographic method in fetal alcohol spectrum disorder screening and diagnosis. J Popul Ther Clin Pharmacol Vol 21(1):e106- e113; March 6, 2014.
12. Cranston M, Mhanni A, Marles S, Chudley A. Concordance of three methods for palpebral fissure length measurement in the assessment of fetal alcohol spectrum disorders. Can J Clin Pharmacol Vol 16 (1) Winter 2009:e234- e241; April 16, 2009.
13. SPSS 14.0 for Windows. SPSS Inc, 2006.