| Palpebral fissure | |
|---|---|
 Front of left eye with eyelids separated to show medial canthus. (Palpebral fissure, visible but not labeled, is artificially widened.) | |
| Details | |
| Synonyms | Interpalpebral fissure |
| Identifiers | |
| Latin | rima palpebrarum |
| TA98 | A15.2.07.030 |
| TA2 | 205 |
| FMA | 59110 |
| Anatomical terminology | |
Thepalpebral fissure is the elliptic space between the medial and lateralcanthi of the two openeyelids. In simple terms, it is the opening between the eyelids. In adult humans, this measures about 10 mm vertically and 30 mm horizontally.
It can be reduced (short, "narrow") in horizontal size byfetal alcohol syndrome[1] and inWilliams syndrome. The chromosomal conditionstrisomy 9 andtrisomy 21 (Down syndrome) can cause the palpebral fissures to be upslanted,[2] whereasMarfan syndrome can cause a downslant.[3] An increase in vertical height can be seen in genetic disorders such ascri-du-chat syndrome.
The fissure may be increased in vertical height inGraves' disease, which is manifested asDalrymple'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 solutionlatanoprost, the size of the palpebral fissure can be increased. The condition is reversible. Latanoprost is aprostaglandin F receptoragonist.[4]
