Almond-shaped palpebral fissure
Page most recently updated 7 September 2026
This page focuses on almond-shaped palpebral fissure as a morphologic feature of conditions that may also be associated with psychiatric manifestations, such as psychosis, mania, autism spectrum disorder, ADHD, OCD, and self-injurious behaviours. The page begins with a clinical definition of almond-shaped palpebral fissure based on the standardized Elements of Morphology terminology, together with visual examples from the same source. This is followed by a list of conditions in which almond-shaped palpebral fissure has been described in association with psychiatric manifestations.
Of note, to optimize clinical utility, the list does not include conditions associated with intellectual disability in the absence of other psychiatric features.
Each condition listed below is linked to a dedicated page within this resource. These pages describe the psychiatric manifestations associated with each condition, as well as other morphologic and broader clinical features, allowing the differential diagnosis to be considered from multiple perspectives.
Almond-shaped palpebral fissure of the left eye
In this image, the palpebral fissure of the left eye is almond-shaped, while that of the right eye is not.
Image credit: National Human Genome Research Institute (NHGRI), Elements of Morphology.
Definition
Subjective: A shape created by an acute downward arching of the upper eyelid and upward arching of the lower eyelid, toward the medial canthus, which gives the outline of the palpebral fissures the configuration of an almond; thus, the maximum distance between the fissures is offset from, and medial to, the center point.
Note: The almond configuration tends to dissipate with time as the surrounding tissues (e.g., eyelid, nasal bridge) grow.
Conditions with potential psychiatric associations
Selected references and further reading — Morphologic lens
Allanson JE, Biesecker LG, Carey JC, Hennekam RCM. Elements of morphology: introduction. Am J Med Genet A. 2009;149A(1):2-5.
Hennekam RCM, Biesecker LG, Allanson JE, Hall JG, Opitz JM, Temple IK, Carey JC; Elements of Morphology Consortium. Elements of morphology: general terms for congenital anomalies. Am J Med Genet A. 2013;161A(11):2726-2733.
Jones KL, Jones MC, del Campo M. Smith's recognizable patterns of human malformation. 8th ed. Philadelphia: Elsevier; 2021.
Reardon W. The bedside dysmorphologist: a guide to identifying and assessing congenital malformations. 2nd ed. Oxford: Oxford University Press; 2016.