Limbal ring
A limbal ring is a dark ring around the iris of the eye, where the sclera meets the cornea.[1] It is a dark-colored manifestation of the corneal limbus resulting from optical properties of the region.[2] The appearance and visibility of the limbal ring can be negatively affected by a variety of medical conditions concerning the peripheral cornea.[3] It has been suggested that limbal ring thickness may correlate with health or youthfulness and may contribute to facial attractiveness.[3][4] The thickness of the limbal ring varies by pupil dilation: When the pupil is larger, the limbal ring narrows.[5] Some contact lenses are colored to simulate limbal rings.[1]
Youth, health, and attractiveness
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Both health and youth are positively correlated with a prominent limbal ring.[6] For instance, a darker limbal ring tends to be found more attractive than the absence of a limbal ring, suggesting that both sexes "use the limbal ring as a probabilistic indicator of reproductive fitness".[6] Furthermore, limbal rings appear to be most noticeable "for individuals relatively free from chronic health issues".[4]
The limbal ring is thought to contain corneal epithelium stem cells.[7] Diseases involving a limbal stem cell deficiency are associated with blindness, as those with such deficiencies are "unable to maintain a stable corneal surface".[8] Transplantation of limbal stem cells is a promising therapy for limbal stem cell deficiency.[9]
See also
[edit]References
[edit]- ^ a b United States US7246903B2, "Tinted contact lenses with combined limbal ring and iris patterns", published 24 July 2007, assigned to Johnson and Johnson Vision Care Inc.
- ^ Shyu, Betsy P.; Wyatt, Harry J. (2009). "Appearance of the human eye: Optical contributions to the 'limbal ring'". Optometry and Vision Science. 86 (9): E1069 – E1077. doi:10.1097/OPX.0b013e3181b4f010. PMID 19648842. S2CID 39174174.
- ^ a b Peshek D, Semmaknejad N, Hoffman D, Foley P (2011). "Preliminary evidence that the limbal ring influences facial attractiveness" (PDF). Evolutionary Psychology. 9 (2): 137–146. doi:10.1177/147470491100900201. PMID 22947961.
- ^ a b Brown M, Sacco DF (2018). "Put a (limbal) ring on it: Women perceive men's limbal rings as a health cue in short-term mating domains". Personality and Social Psychology Bulletin. 44 (1): 80–91. doi:10.1177/0146167217733072. PMID 28978250.
- ^ Shyu, Betsy P.; Wyatt, Harry J. (September 2009). "Appearance of the human eye: Optical contributions to the "limbal ring"". Optometry and Vision Science. 86 (9): E1069 – E1077. doi:10.1097/OPX.0b013e3181b4f010. ISSN 1040-5488.
- ^ a b Peshek D, Semmaknejad N, Hoffman D, Foley P (2011). "Preliminary evidence that the limbal ring influences facial attractiveness" (PDF). Evolutionary Psychology. 9 (2): 137–146. doi:10.1177/147470491100900201. PMID 22947961.
- ^ Li, De-Quan; Chen, Zhuo; Song, Xiu Jun; de Paiva, Cintia S.; Kim, Hyun-Seung; Pflugfelder, Stephen C. (April 2005). "Partial enrichment of a population of human limbal epithelial cells with putative stem cell properties based on collagen type IV adhesiveness". Experimental Eye Research. 80 (4): 581–590. doi:10.1016/j.exer.2004.11.011. ISSN 0014-4835. PMC 2906384. PMID 15781286.
- ^ James, S. Elizabeth; Rowe, Andrea; Ilari, Luca; Daya, Sheraz; Martin, Robin (July 2001). "The potential for eye bank limbal rings to generate cultured corneal epithelial allografts". Cornea. 20 (5): 488–494. doi:10.1097/00003226-200107000-00010. ISSN 0277-3740. PMID 11413404. S2CID 21296292.
- ^ Utheim, O.A.; Pasovic, L.; Raeder, S.; Eidet, J.R.; Fostad, I.–G.; Sehic, A.; Roald, B.; de la Paz, M.F.; Lyberg, T.; Dartt, D. A.; Utheim, T.P. (2019-03-12). "Effects of explant size on epithelial outgrowth, thickness, stratification, ultrastructure, and phenotype of cultured limbal epithelial cells". PLoS One. 14 (3): e0212524. Bibcode:2019PLoSO..1412524U. doi:10.1371/journal.pone.0212524. ISSN 1932-6203. PMC 6413940. PMID 30861002.
External links
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Media related to Limbal rings at Wikimedia Commons
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