FAS Facial Photography and Measurement Instruction    

 

The FAS facial phenotype is defined by three facial features:

  1. small eyes
  2. smooth philtrum
  3. thin upper lip

An accurate FASD diagnosis requires accurate measurement of these facial features.

These three features can be measured:

  1. Directly with a ruler and Lip-Philtrum Guide or from
  2. Digital facial photographs with the aid of the FAS Facial Photographic Analysis Software. The software produces the most consistently accurate facial measures.

 

Instruction: Below are a series of images and animations that provide instruction on how to take properly aligned facial photographs for accurate measurement of the FAS facial features. Also included are instructions for direct measurement of facial features.

Quick Reference Page: First click here to view a 1-page brief instruction form for taking facial photographs. Then review the instructions below.

To View Animations Below: Click your left mouse key on the animation. If you do not see the animations playing in the windows below, that means you do not have Quicktime installed on your computer. You can download it for free from Apple.

Copyright: Please do not copy or distribute the material presented below without written permission from Susan Astley, Ph.D., University of Washington, Seattle WA.
INSTRUCTIONS
Foreword: Obtaining properly aligned photographs does not require a professional photographer or fancy equipment. They can be obtained using a hand-held digital camera. The ideal photographer has two qualities: 1) attention to detail, and 2) patience. The trick to obtaining good photos (especially on those young moving toddlers) is to take many photos. Digitial photos are free, thus take as many photos as you need to obtain the quality you are looking for.
1. The goal is to obtain 3 photos of good quality (frontal, 3/4, and lateral).
2. Fill the camera frame with the face
d

Stand 3 feet from patient. Zoom camera lens until head fills the frame.

Photo resolution should be 1200 x 1200 bytes or greater.

Photo is typically 1 megabyte or greater in size.

3. Animation demonstrating proper alignment of the camera to the patient's face.

Accurate measures of the frontal photo require standardized alignment of the patient's head relative to the clinician's eyes or the camera lens.

Left-to-Right Rotation

You should be able to see the patient's ears equally on both sides. Improper rotation will result in erroneous right and left palpebral fissure length measures.

Up and Down Rotation

When viewing the patient from the front, the clinician's eyes, or the center of the camera lens, should be in line with the patient's frankfort horizontal (FH) plane (green line). The FH plane extends from the tragion (a landmark next to the ear canal) through the orbitale (a landmark under the eye). These landmarks are marked with BLUE DOTS .

Proper alignment can be judged when viewing the patient from the front by imagining a line drawn between the left and right ear canals. Rotate the head up or down until the orbitale landmarks fall directly on the green line (bottom image).

Improper rotation will result in erroneous measures of upper lip thiness. For example, if the patient's head is rotated down toward their chest, the lip will appear thinner than it truly is.


Top Animation
Orientation of Camera to Patient

Bottom Animation
View of Patient through Camera

The camera is properly aligned when the line turns GREEN.

4. The 3/4 inch dot (ruler) must be placed between the eyebrows.

A ruler (3/4 inch dot) must be placed in the photo to measure the real size of the palpebral fissure length in a photo.

Correct Dot Placement
The dot must be placed between the eyebrows (top left photo).

The dot must be firmly afixed, not curled up at the edges. Obtain adhesive paper dots at an Office supply store.

Incorrect Dot Placement
Images with red line drawn through them.

 

5. The eyes must be wide open to see the inner (A) and outer (B) corners of the eye.

The palpebral fissure length is the distance from the endocanthion (A) to the exocanthion (B).

Correct Top Photo
The eyes are fully open. Points A and B are clearly visable.

 

Incorrect Bottom Photo
The eyes are NOT fully open. The outer corner (B) is blocked from view by the upper eyelid and lashes.

 

6. Animation demonstrating the importance of the eye being fully open to obtain an accurate measure of the palpebral fissure length.
The eye must be fully open to obtain an accurate measure of palpebral fissure length.

Incorrect Method (RED)

Note how the palpebral fissure length is incorrectly being recorded as 2.6 cm (red arrow) when the upper eyelid is in a relaxed position. A length of 2.6 cm is 1 standard deviation below the mean for a "normal" 7-year-old child. (red dot)

Correct Method (GREEN)

When the eye is opened fully, by having the patient look up at the ceiling without tilting their head back, the palpebral fissure length is correctly recorded as 2.7 cm (green arrow). A length of 2.7 cm is just slightly less than the mean palpebral fissure length for a "normal" 7-year-old child (green dot).

Failure to have the eye fully opened resulted in a clinically significant error of approximately 1 standard deviation in magnitude.


Normal 7-Year Old.
Effect of Eye Positioning.

.

7. Estimating the position of the inner corner of the eye (endocanthion) under an epicanthal fold.
The palpebral fissure length is measured from the endocanthino (en) (inner corner of the eye) to the exocanthion (ex) (outer corner of the eye).
 

An epicanthal fold (a fold of skin covering the inner corner of the eye) can block the view of the endocanthion (en).

The location of the endocanthion (en) under the epicanthal fold can be estimated in a photograph by extending the curvature of the upper and lower eyelids (yellow lines) until they cross.

8. Lips must be gently closed with no smile.

Correct
Photo

 

 

Incorrect
Photo

 

A smile will distort the soft tissues of the philtrum and upper lip.

The photos to the left are the same child
with and without a smile.

The smile incorrectly makes the philtrum appear smoother and the upper lip thinner than they truly are.

 
9. Up or down rotation of the head will cause incorrect measurement of lip thickness.
 

Correct Rotation (Green)

When the boy is aligned properly in the frankfort horizontal plane, the correct rank for his lip thickness is Rank 3. His head is rotated properly when the line drawn between his ear canals falls just below his eyes (The line in the animation turns GREEN).

Incorrect Rotation (Red)

As the boy's head rotates down toward his chest, his upper lip appears thinner than it truly is (Rank 3). When the boy's head rotates up, his upper lip appears thicker than it truly is (Rank 1). Ranks 1 and 3 are incorrect.

 
10. Illustration of correct use of the Lip-Philtrum Guide.

The physician's eyes must be aligned in the patient's frankfort horizontal plane (green line).

This typically requires the physician to kneel down to the level of the patient.

If the physician stood above the patient, the patient's upper lip would appear thinner than it truly is.

See animation #9 above.

11. Illustration of how the FAS Facial Software is used to measure lip thinness.
 

To measure lip thinness using the FAS Facial Software, the User outlines the upper lip with the mouse (see blue lines in animation).

The software uses this outline to compute a measure of lip thinness called 'circularity' (perimeter squared / area).

The thinner the lip, the bigger the circularity.

The Lip Table on the backside of the Lip-Philtrum Guide defines the range of circularity for each of the five Ranks.

When the User finishes outlining the upper lip, the software automatically computes the correct Rank for lip thinness.

 
12. It is difficult to measure the palpebral fissure length accurately with a ruler.

Physician measuring the
left eye, right eye, and
distance between the eyes. 

If a ruler is used to measure the palpebral fissure length (PFL), here are tips to improve accuracy.

  1. Align yourself directly in front of the patient's eye.
  2. If the patient wears glasses, remove the glasses.
  3. Place the ruler as close to the eye without touching the lashes.
  4. Have the patient open their eyes wide by looking up at the ceiling.

IMPORTANT: Do not assume your measures with a ruler are accurate. Confirm the accuracy of your technique by measuring a PFL that has been measured with a sliding digital caliper (the gold standard).

The FAS Facial Photograhic Analysis Software provides a consistently more accurate measure of the PFL than a ruler.

 
13. The ruler must be placed close to the eye to obtain an accurate measure.
 

The ruler must be placed sufficiently close to the eye to measure the palpebral fissure length (PFL) accurately.

Incorrect Method (RED)

If the ruler is held beyond the nasal bridge (bottom image, red arrow) the PFL is incorrectly measured as 2.6 cm (top image, red arrow). A measure of 2.6 cm is 1 standard deviation below the mean for a normal 7-year-old child (red dot).

Correct Method (GREEN)

When the ruler is placed closer to the eye (without touching the eyelashes) (bottom image, green arrow), the PFL is correctly measured as 2.7 cm (top image, green arrow). A measure of 2.7 cm is near the mean for a 'normal' 7-year-old child (green dot).

This 1 mm error from incorrect ruler placement resulted in a normal-sized palpebral fissure being incorrectly recorded as 1 S.D. below the mean.

 
14. Click here to view instructional photos to correctly identify Rank 4 and 5 philtrums.

  1. Rank 5 Philtrum on Left: Completely smooth. There is no hint of a philtrum depression, no matter what angle you view it from.

  2. Rank 4 Philtrum on Right: Just the bare semblance of a philtrum depression exists. You typically have to view the philtrum from an angle to detect the depression. A Rank 4 philtrum is so close to being smooth, it is often difficult to detect in a frontal photo.

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