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Fetal Alcohol Syndrome, Fetal Alcohol Spectrum Disorder, dysmorphology, palpebral fissure length, facial measurement tools, photographic analysis
The assessment of individuals at risk of Fetal Alcohol Spectrum Disorders (FASD) includes the assessment of the craniofacial features that can result from prenatal alcohol exposure. The characteristic facial features of Fetal Alcohol Syndrome (FAS) consist of short palpebral fissures, smooth or flattened philtrum, and thin vermilion border of the upper lip. There are various methods for measuring palpebral fissure lengths (PFLs) and it can be challenging for clinicians to obtain reproducibly accurate measurements. The development of the FAS Facial Photographic Analysis Software by the University of Washington FAS Diagnostic and Prevention Network (DPN) is one such means of improving the accuracy and reproducibility in these measurements.
To assess concordance across three methods of PFL measurement: 1) a clear plastic handheld ruler, 2) blunt precision slide calipers, and 3) digital photometric photography (FAS Facial Photographic Analysis Software).
The PFLs of 50 children (referred to the Clinic for Alcohol and Drug Exposed Children, CADEC) at Children’s Hospital in Winnipeg and 50 adults from the University of Manitoba Medical Class of 2008 were measured once by a single clinician, using each of the three methods. The frequency and magnitude of discordance was tabulated. No method served as a gold-standard.
The PFLs ranged from 20 to 32 mm. The ruler and photometric measures were concordant in 42% of the subjects. When measures were discordant, half the ruler measures were larger and half were smaller. The caliper measure was concordant with the photometric and ruler measures on 18% and 24% of the subjects, respectively. When measures were discordant, the caliper measures were almost always larger than the photometric and ruler method (0.5 to 2.5 mm larger, 83% and 95% of the time, respectively). The presence of epicanthal folds did not appear to be a factor that contributed to discordance.
This study demonstrates the challenge in measuring the PFL, even when a single trained clinician is involved. Factors that can contribute to error include the subject’s willingness to cooperate, ability to tolerate placement of the tool close enough to the eye to obtain an accurate measure, and precision of the tool. When controlling for the clinician performing the measurements and the quality of the photographs, the ruler and photometric measures were most concordant. The caliper measures tended to measure larger than the ruler and photometric measures.
2. Clarren SK, Smith DW. The fetal alcohol syndrome. New Eng J Med 1978;298(19):1063-7.
3. Sampson PD, Streissguth AP, Bookstein FL, Little RE, Clarren SK, Dehaene P, et al. Incidence of fetal alcohol syndrome and prevalence of alcoholrelated neurodevelopmental disorder. Teratology 1997;56(5):317-26.
4. Chudley AE, Conry J, Cook JL, Loock C, Rosales T, LeBlanc N, and the Public Health Agency of Canada’s National Advisory Committee on Fetal Alcohol Spectrum Disorder. Fetal alcohol spectrum disorder: guidelines for diagnosis. CMAJ 2005;172(5suppl):S1-S21.
5. Astley SJ. Diagnostic Guide for Fetal Alcohol Spectrum Disorders: the 4-Digit Diagnostic Code, 3rd edn. Seattle, WA: University of Washington Publication Services, 2004.
6. Astley SJ, Clarren SK. Measuring the facial phenotype of individuals with prenatal alcohol exposure: correlations with brain dysfunction. Alcohol Alcohol 2001;36(2):147-59.
7. Astley SJ. Fetal Alcohol Syndrome Facial Photographic Analysis Software, Version 1.0.0, University of Washington, Seattle WA, 2003.
8. Astley SJ, Clarren SK. A case definition and photographic screening tool for the facial phenotype of fetal alcohol syndrome. J Pediatr 1996;129(1):33-41.
9. Hall JG, Froster-Iskenius UG, Allanson JE, editors. Handbook of normal physical measurements. Oxford: Oxford University Press; 1989. pp. 149-50.
10. Iosub S, Fuchs M, Bingol N, Stone R, Gromisch D, Wasserman E. Palpebral fissure length in black and hispanic children: Correlation with head circumference. Pediatr 1985;75(2):318-20.
11. Jones KL, Hanson JW, Smith DW. Palpebral fissure size in newborn infants. J Pediatr 1978;92(5):787.
12. Farkas LG. Anthropometry of the head and face. 2nd ed. New York: Raven Press; 1994.
13. Thomas IT, Gaitantzis YA, Frias JL. Palpebral fissure length from 29 weeks gestation to 14 years. J Pediatr 1987;111:267-8.
14. Avner M, Henning P, Koren G, Nulman I. Validation of the facial photographic method in fetal alcohol spectrum disorder screening and diagnosis. JFAS Int 2008; 4:e20.