II. Definition
- Palpebral Fissure
- Eliptical opening between the eye lids
- Normally 1 cm high by 3 cm wide in adults
- Downslanting Palpebral Fissure
- http://elementsofmorphology.nih.gov/index.cgi?tid=1c4dc8688933b9ef
- Downsloping lie of the eye opening with the medial canthus appearing higher than the lateral canthus
- With both eyes affected, a line drawn from each lateral canthus to medial canthus meeting at the Nasal Bridge, will form a "^" appearance
- Upslanting Palpebral Fissure
- http://elementsofmorphology.nih.gov/index.cgi?tid=f103f00fcb26b7c4
- Upsloping lie of the eye opening with the medial canthus appearing lower than the lateral canthus
- With both eyes affected, a line drawn from each lateral canthus to medial canthus meeting at the Nasal Bridge, will form a "V" appearance
- Short Palpebral Fissure
- http://elementsofmorphology.nih.gov/index.cgi?tid=8ea165ff88fe04c3
- Narrow eye openings with a decreased distance between the medial and lateral canthus
III. Causes: Upslanting Palpebral Fissure (V-shaped eye orientation) examples
- Trisomy 21 (Down Syndrome)
- Trisomy 9
- Microcephaly
- Prader-Willi Syndrome
IV. Causes: Downslanting Palpebral Fissure (^-shaped eye orientation) examples
- Marfan Syndrome
- Sotos Syndrome
- Lennox-Gastaut Syndrome
- Ehlers-Danlos Syndrome
V. Causes: Short Palpebral Fissure (narrow eye opening) examples
- Fetal Alcohol Syndrome
- Williams Syndrome
- DiGeorge Syndrome