Palpebral fissure
{{Short description|The fissure separating the eyelids, defining the opening between them when the eyes are open}}
{{Infobox anatomy
| Name = Palpebral fissure
| Synonyms = Interpalpebral fissure
| Latin = rima palpebrarum
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| Image = Gray892.png
| Caption = Front of left eye with eyelids separated to show medial canthus. (Palpebral fissure, visible but not labeled, is artificially widened.)
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The palpebral fissure is the elliptic space between the medial and lateral canthi of the two open eyelids. In simple terms, it is the opening between the eyelids. In adult humans, this measures about 10 mm vertically and 30 mm horizontally.
Variations
= Congenital dysmorphisms =
It can be reduced (short, "narrow") in horizontal size by fetal alcohol syndrome{{cite web |url=http://embryology.med.unsw.edu.au/Defect/page5a.htm |title=UNSW Embryo- Abnormal Development - Fetal Alcohol Syndrome |access-date=2007-12-23 }} and in Williams syndrome. The chromosomal conditions trisomy 9 and trisomy 21 (Down syndrome) can cause the palpebral fissures to be upslanted,{{cite journal |last1=Kannan |first1=TP |last2=Hemlatha |first2=S |last3=Ankathil |first3=R |last4=Zilfalil |first4=BA |title=Clinical manifestations in trisomy 9 |journal=Indian Journal of Pediatrics |volume=76 |issue=7 |pages=745–6 |year=2009 |pmid=19475342 |name-list-style=vanc |doi=10.1007/s12098-009-0158-2 }} whereas Marfan syndrome can cause a downslant.{{cite journal |last1=Loeys |first1=BL |last2=Dietz |first2=HC| year=2010 |last3=Braverman |first3=AC |last4=Callewaert |first4=BL |last5=De Backer |first5=J |last6=Devereux |first6=RB |last7=Hilhorst-Hofstee |first7=Y |last8=Jondeau |first8=G |last9=Faivre |first9=L| last10=Milewicz |first10=D. M. |last11=Pyeritz |first11=R. E. |last12=Sponseller |first12=P. D. |last13=Wordsworth |first13=P. |last14=De Paepe |first14=A. M. |title=The revised Ghent nosology for the Marfan syndrome |url=https://biblio.ugent.be/publication/1013955| journal=Journal of Medical Genetics |volume=47 |issue=7| pages=476–85 |pmid=20591885 |doi=10.1136/jmg.2009.072785 |name-list-style=vanc |display-authors=8 |hdl=1854/LU-1013955 |hdl-access=free }} An increase in vertical height can be seen in genetic disorders such as cri-du-chat syndrome.
= Acquired =
The fissure may be increased in vertical height in Graves' disease, which is manifested as Dalrymple's sign. It is seen in disorders such as cri-du-chat syndrome.
In animal studies using four times the therapeutic concentration of the ophthalmic solution latanoprost, the size of the palpebral fissure can be increased. The condition is reversible. Latanoprost is a prostaglandin F receptor agonist.United States Food and Drug Administration (Nov. 2006). [http://www.accessdata.fda.gov/drugsatfda_docs/label/2010/020597s035s036lbl.pdf Xalatan (latanoprost ophthalmic solution) 0.005% (50 μg/mL)]. Accessed 5 Feb 2011.
See also
References
{{Reflist}}
External links
- [https://www.utoronto.ca/neuronotes/NeuroExam/cranial_7b.htm Facial Neurological Examination] from University of Toronto
{{Accessory organs of the eye}}
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