A prospective study to validate the computer-assisted method of measuring palpebral fissure length and philtrum smoothness using digital patient photographs. These are key diagnostic facial features of Fetal Alcohol Syndrome.
Motherisk Program (including Breaking the Cycle), Hospital for Sick Children, Toronto - a clinical, research and teaching program dedicated to antenatal drug, chemical, and disease risk counseling. 40 children referred for FASD assessment, 21 under 4 years old, 19 were 4 years or older.
Facial measurements were obtained directly from the patient by physicians and compared to those obtained by computer software measurement of photographs of the same patient.
Palpebral fissure length and philtrum smoothness.
The photographic measurements showed shorter palpebral fissure length than the direct measurements when analyzing all children (25.4±2.3 vs .23.2±2.4mm; p<0.0001), and children under four (n=21, 24.7±2.4 vs. 21.6±1.6mm; p<0.0001). The difference for older children (n=19) did not reach statistical significance. The computer found four false positive cases and no false negative cases of clinically short palpebral fissure (sensitivity=100%, specificity=64%). Direct measurement scores for philtrum smoothness were different from the computer’s measurements using the frontal view (p=0.0012) but not using the ¾ view.
The method of computer-assisted measurement tends to underestimate the true length and, hence, over- diagnose short palpebral fissure, especially in children under four years old. This method may serve as a useful fetal alcohol syndrome screening tool.
Key Words: Fetal alcohol syndrome, palpebral fissure length, philtrum smoothness, screening tools