optic chiasm


Summary: The X-shaped structure formed by the meeting of the two optic nerves. At the optic chiasm the fibers from the medial part of each retina cross to project to the other side of the brain while the lateral retinal fibers continue on the same side. As a result each half of the brain receives information about the contralateral visual field from both eyes.

Top Publications

  1. Erskine L, Herrera E. The retinal ganglion cell axon's journey: insights into molecular mechanisms of axon guidance. Dev Biol. 2007;308:1-14 pubmed
  2. Dehghan S, Javan M, Pourabdolhossein F, Mirnajafi Zadeh J, Baharvand H. Basic fibroblast growth factor potentiates myelin repair following induction of experimental demyelination in adult mouse optic chiasm and nerves. J Mol Neurosci. 2012;48:77-85 pubmed publisher
    ..current study, the effect of bFGF on lysolecithin-induced demyelination and remyelination processes in mouse optic chiasm and nerves was investigated. Lysolecithin was injected into the optic chiasm of Balb/C mice...
  3. Mozafari S, Sherafat M, Javan M, Mirnajafi Zadeh J, Tiraihi T. Visual evoked potentials and MBP gene expression imply endogenous myelin repair in adult rat optic nerve and chiasm following local lysolecithin induced demyelination. Brain Res. 2010;1351:50-6 pubmed publisher
    ..It also seems to be useful for studying the protective or remyelinating effects of different therapies in e.g. optic apparatus which is more affected by MS. ..
  4. Neveu M, Holder G, Ragge N, Sloper J, Collin J, Jeffery G. Early midline interactions are important in mouse optic chiasm formation but are not critical in man: a significant distinction between man and mouse. Eur J Neurosci. 2006;23:3034-42 pubmed
    The optic chiasm is one of the most popular models for studying axon guidance. Here axons make a key binary decision either to cross the midline to innervate the contralateral hemisphere or to remain uncrossed...
  5. Anupriya A, Sunithi M, Maya T, Goel M, Alexander M, Aaron S, et al. Tuberculous optochiasmatic arachnoiditis. Neurol India. 2010;58:732-5 pubmed publisher
    Arachnoiditis involving optic nerve and the optic chiasm can occur as a complication of tuberculous meningitis (TBM)...
  6. Liu G, Brodsky M, Phillips P, Belasco J, Janss A, Golden J, et al. Optic radiation involvement in optic pathway gliomas in neurofibromatosis. Am J Ophthalmol. 2004;137:407-14 pubmed
    ..Optic pathway gliomas (pilocytic astrocytomas) in neurofibromatosis type 1 (NF-1) typically involve some combination of the optic nerves, chiasm, or optic tracts. Involvement of the optic radiations is rare...
  7. Williams S, Grumet M, Colman D, Henkemeyer M, Mason C, Sakurai T. A role for Nr-CAM in the patterning of binocular visual pathways. Neuron. 2006;50:535-47 pubmed
    Retinal ganglion cell (RGC) axons diverge within the optic chiasm to project to opposite sides of the brain...
  8. Arai A, Morishita A, Hanada Y, Aihara H. Solitary metastatic tumor within the optic chiasm--case report. Neurol Med Chir (Tokyo). 2010;50:158-61 pubmed
    ..female, previously treated for lung cancer, presented with a rare case of metastasis directly to the optic chiasm manifesting as visual deficits...
  9. Jeffery G, Levitt J, Cooper H. Segregated hemispheric pathways through the optic chiasm distinguish primates from rodents. Neuroscience. 2008;157:637-43 pubmed publisher
    At the optic chiasm retinal fibers either cross the midline, or remain uncrossed...

More Information


  1. Tahir M, Shaikh F, Siddiqui A. Primary chiasmal sarcoid granuloma masquerading as glioma of the optic chiasm. J Coll Physicians Surg Pak. 2010;20:695-6 pubmed publisher
    ..Examination showed no neurological deficit with normal vision. MRI scans showed an enlarged optic chiasm. There was no dural or leptomeningeal enhancement or hydrocephalus...
  2. Pouya A, Satarian L, Kiani S, Javan M, Baharvand H. Human induced pluripotent stem cells differentiation into oligodendrocyte progenitors and transplantation in a rat model of optic chiasm demyelination. PLoS ONE. 2011;6:e27925 pubmed publisher
    ..stem cells (hiPSCs) into oligodendrocyte precursors and assess their recovery potential in a demyelinated optic chiasm model in rats...
  3. Gangwani V, Walker M, El Defrawy H, Nicoll J, Reck A, Pathmanathan T. Langerhans cell histiocytosis of the optic chiasm. Clin Exp Ophthalmol. 2007;35:66-8 pubmed
    ..Herein an unusual case of LCH involving the optic chiasm is presented...
  4. Sánchez Camacho C, Bovolenta P. Autonomous and non-autonomous Shh signalling mediate the in vivo growth and guidance of mouse retinal ganglion cell axons. Development. 2008;135:3531-41 pubmed publisher
  5. Conway C, Price D, Pratt T, Mason J. Analysis of axon guidance defects at the optic chiasm in heparan sulphate sulphotransferase compound mutant mice. J Anat. 2011;219:734-42 pubmed publisher
    ..of the visual system, retinal ganglion cells (RGCs) project their axons towards the brain, passing through the optic chiasm. Axons are guided on this journey by molecular cues in the environment...
  6. Chenaux G, Henkemeyer M. Forward signaling by EphB1/EphB2 interacting with ephrin-B ligands at the optic chiasm is required to form the ipsilateral projection. Eur J Neurosci. 2011;34:1620-33 pubmed publisher
    ..through the extracellular domain of EphB1 is not required for proper axon pathfinding of retinal axons at the optic chiasm. Further analysis of other EphB and ephrin-B mutant mice shows that EphB1 is the preferred receptor of ephrin-..
  7. Inatani M, Irie F, Plump A, Tessier Lavigne M, Yamaguchi Y. Mammalian brain morphogenesis and midline axon guidance require heparan sulfate. Science. 2003;302:1044-6 pubmed
    ..Furthermore, the EXT1-null brain displayed severe guidance errors in major commissural tracts, revealing a pivotal role of HS in midline axon guidance. These findings demonstrate that HS is essential for mammalian brain development. ..
  8. Thanos S, Püttmann S, Naskar R, Rose K, Langkamp Flock M, Paulus W. Potential role of Pax-2 in retinal axon navigation through the chick optic nerve stalk and optic chiasm. J Neurobiol. 2004;59:8-23 pubmed
    The degree of fiber decussation at the optic chiasm differs between species, ranging from complete crossing in lower vertebrates to highly complex patterns of intermingling of the fibers from the two eyes seen in mammals and birds...
  9. Hempelmann R, Mater E, Schroder F, Schon R. Complete resection of a cavernous haemangioma of the optic nerve, the chiasm, and the optic tract. Acta Neurochir (Wien). 2007;149:699-703; discussion 703 pubmed
    ..The vascular malformation of the optic pathways was completely removed via a pterional approach. This is the first reported instance of complete resection of a cavernoma involving the optic nerve, the chiasm, and the optic tract...
  10. Fabre P, Shimogori T, Charron F. Segregation of ipsilateral retinal ganglion cell axons at the optic chiasm requires the Shh receptor Boc. J Neurosci. 2010;30:266-75 pubmed publisher
    The pattern of contralaterally and ipsilaterally projecting retinal ganglion cell (RGC) axons at the optic chiasm is essential for the establishment of binocular vision...
  11. Hofmeyer K, Kretzschmar D, Pflugfelder G. Optomotor-blind expression in glial cells is required for correct axonal projection across the Drosophila inner optic chiasm. Dev Biol. 2008;315:28-41 pubmed publisher
    ..Lamina and medulla are joined by the first or outer optic chiasm (OOC). Medulla, lobula and lobula plate are connected by the second or inner optic chiasm (IOC)...
  12. Muta D, Nishi T, Koga K, Yamashiro S, Fujioka S, Kuratsu J. Cavernous malformation of the optic chiasm: case report. Br J Neurosurg. 2006;20:312-5 pubmed
    We report a 14-year-old boy with cavernous malformation of the optic chiasm. He had a 2-year history of gradually worsening visual disturbance...
  13. Gall C, Lucklum J, Sabel B, Franke G. Vision- and health-related quality of life in patients with visual field loss after postchiasmatic lesions. Invest Ophthalmol Vis Sci. 2009;50:2765-76 pubmed publisher
    ..Diminished health-related QoL was not associated with VFL and VA. Both VFL and VA should be considered when trying to explain variance of NEI-VFQ results in patients with postchiasmatic lesions of the visual pathway. ..
  14. Pratt T, Tian N, Simpson T, Mason J, Price D. The winged helix transcription factor Foxg1 facilitates retinal ganglion cell axon crossing of the ventral midline in the mouse. Development. 2004;131:3773-84 pubmed
    During normal development, retinal ganglion cells (RGCs) project axons along the optic nerve to the optic chiasm on the ventral surface of the hypothalamus...
  15. Foroozan R. Chiasmal syndromes. Curr Opin Ophthalmol. 2003;14:325-31 pubmed
    ..Visual loss is often the initial manifestation of disorders involving the optic chiasm. Hemianopic defects and preferential involvement of the temporal visual field are the earliest and most common ..
  16. Pinter R, Hindges R. Perturbations of microRNA function in mouse dicer mutants produce retinal defects and lead to aberrant axon pathfinding at the optic chiasm. PLoS ONE. 2010;5:e10021 pubmed publisher
    ..The optic chiasm is a major decision point for retinal ganglion cell (RGC) axons en route to their target in order to ensure the ..
  17. Conway C, Howe K, Nettleton N, Price D, Mason J, Pratt T. Heparan sulfate sugar modifications mediate the functions of slits and other factors needed for mouse forebrain commissure development. J Neurosci. 2011;31:1955-70 pubmed publisher
    ..the heparan sulfotransferases (Hsts) Hs2st or Hs6st1 display major axon guidance defects at the developing optic chiasm. Here we further explore the role of these Hsts at the optic chiasm and investigate their function in corpus ..
  18. Yamamoto H, Agata K. Optic chiasm formation in planarian I: Cooperative netrin- and robo-mediated signals are required for the early stage of optic chiasm formation. Dev Growth Differ. 2011;53:300-11 pubmed publisher
    ..planarians can regenerate a brain, including eyes, from the anterior blastema, and coordinately form an optic chiasm during eye and brain regeneration...
  19. Kuwajima T, Yoshida Y, Takegahara N, Petros T, Kumanogoh A, Jessell T, et al. Optic chiasm presentation of Semaphorin6D in the context of Plexin-A1 and Nr-CAM promotes retinal axon midline crossing. Neuron. 2012;74:676-90 pubmed publisher
    At the optic chiasm, retinal ganglion cells (RGCs) project ipsi- or contralaterally to establish the circuitry for binocular vision...
  20. Sinha M, Garg R, Anuradha Hk -, Agarwal A, Singh M, Verma R, et al. Vision impairment in tuberculous meningitis: predictors and prognosis. J Neurol Sci. 2010;290:27-32 pubmed publisher
    ..Vision impairment occurred in one-fourth of patients with tuberculous meningitis. Principal causes of vision loss were optochiasmatic arachnoiditis and optochiasmal tuberculoma. Impaired vision predicted death or severe disability. ..
  21. Erskine L, Reijntjes S, Pratt T, Denti L, Schwarz Q, Vieira J, et al. VEGF signaling through neuropilin 1 guides commissural axon crossing at the optic chiasm. Neuron. 2011;70:951-65 pubmed publisher
    ..the axons of retinal ganglion cell (RGC) neurons must decide whether to cross or avoid the midline at the optic chiasm to project to targets on both sides of the brain...
  22. Zakaria N, Kallakuri S, Bandaru S, Cavanaugh J. Temporal assessment of traumatic axonal injury in the rat corpus callosum and optic chiasm. Brain Res. 2012;1467:81-90 pubmed publisher
    ..is found clinically and in animal models in brainstem white matter (WM) tracts and in the corpus callosum (CC), optic chiasm (Och), and internal capsule...
  23. Yahyavi M, Abouzeid H, Gawdat G, de Preux A, Xiao T, Bardakjian T, et al. ALDH1A3 loss of function causes bilateral anophthalmia/microphthalmia and hypoplasia of the optic nerve and optic chiasm. Hum Mol Genet. 2013;22:3250-8 pubmed publisher
    ..with bilateral A/M and a simplex case with bilateral anophthalmia and hypoplasia of the optic nerve and optic chiasm. Analysis of novel sequence variants revealed homozygosity for two nonsense mutations in ALDH1A3, c...
  24. Dell A, Fried Cassorla E, Xu H, Raper J. cAMP-induced expression of neuropilin1 promotes retinal axon crossing in the zebrafish optic chiasm. J Neurosci. 2013;33:11076-88 pubmed publisher
  25. van Genderen M, Riemslag F, Schuil J, Hoeben F, Stilma J, Meire F. Chiasmal misrouting and foveal hypoplasia without albinism. Br J Ophthalmol. 2006;90:1098-102 pubmed
    ..The findings suggest that misrouting may exert a retrograde influence on foveal development. ..
  26. Monteiro M, Leal B, Rosa A, Bronstein M. Optical coherence tomography analysis of axonal loss in band atrophy of the optic nerve. Br J Ophthalmol. 2004;88:896-9 pubmed
    To measure axonal loss in patients with band atrophy of the optic nerve caused by optic chiasm compression using optical coherence tomography and to evaluate its ability in identifying this pattern of retinal nerve fibre layer (RNFL) loss...
  27. Herrera E, Marcus R, Li S, Williams S, Erskine L, Lai E, et al. Foxd1 is required for proper formation of the optic chiasm. Development. 2004;131:5727-39 pubmed
    ..sort in the developing ventral diencephalon to project to ipsi- or contralateral targets, thereby forming the optic chiasm. Ipsilaterally projecting axons arise from the ventrotemporal (VT) retina and contralaterally projecting axons ..
  28. Manuel M, Pratt T, Liu M, Jeffery G, Price D. Overexpression of Pax6 results in microphthalmia, retinal dysplasia and defective retinal ganglion cell axon guidance. BMC Dev Biol. 2008;8:59 pubmed publisher
    ..Here, we examined the consequences of over-expression for the eye and its axonal connections...
  29. Borgers A, Romeijn N, van Someren E, Fliers E, Alkemade A, Bisschop P. Compression of the optic chiasm is associated with permanent shorter sleep duration in patients with pituitary insufficiency. Clin Endocrinol (Oxf). 2011;75:347-53 pubmed publisher
    ..Because the SCN is located just superior to the optic chiasm, we hypothesized that a history of compression of the optic chiasm (CC) due to a tumour with suprasellar ..
  30. Mozafari S, Javan M, Sherafat M, Mirnajafi Zadeh J, Heibatollahi M, Pour Beiranvand S, et al. Analysis of structural and molecular events associated with adult rat optic chiasm and nerves demyelination and remyelination: possible role for 3rd ventricle proliferating cells. Neuromolecular Med. 2011;13:138-50 pubmed publisher
    Multiple sclerosis frequently affects the optic apparatus, particularly optic chiasm and nerves. Here, we have reported the structural and molecular characteristics of remyelination in the adult rat optic chiasm and nerves...
  31. Bommakanti K, Panigrahi M, Yarlagadda R, Sundaram C, Uppin M, Purohit A. Optic chiasmatic-hypothalamic gliomas: is tissue diagnosis essential?. Neurol India. 2010;58:833-40 pubmed publisher
    ..Hence primary radiotherapy without histological confirmation may have deleterious consequences...
  32. Tian N, Pratt T, Price D. Foxg1 regulates retinal axon pathfinding by repressing an ipsilateral program in nasal retina and by causing optic chiasm cells to exert a net axonal growth-promoting activity. Development. 2008;135:4081-9 pubmed publisher
    Mammalian binocular vision relies on the divergence of retinal ganglion cell axons at the optic chiasm, with strictly controlled numbers projecting contralaterally and ipsilaterally...
  33. Neveu M, Holder G, Sloper J, Jeffery G. Optic chiasm formation in humans is independent of foveal development. Eur J Neurosci. 2005;22:1825-9 pubmed
    ..This strongly suggests that separate mechanisms regulate the development of the central retina and decussation patterns at the optic chiasm.
  34. Petros T, Rebsam A, Mason C. Retinal axon growth at the optic chiasm: to cross or not to cross. Annu Rev Neurosci. 2008;31:295-315 pubmed publisher
    At the optic chiasm, retinal ganglion cell axons from each eye converge and segregate into crossed and uncrossed projections, a pattern critical for binocular vision...
  35. Pratt T, Conway C, Tian N, Price D, Mason J. Heparan sulphation patterns generated by specific heparan sulfotransferase enzymes direct distinct aspects of retinal axon guidance at the optic chiasm. J Neurosci. 2006;26:6911-23 pubmed
    ..axons from each eye execute a series of maneuvers as they converge on the ventral surface of the brain at the optic chiasm for sorting into the optic tracts...
  36. Garcia Frigola C, Carreres M, Vegar C, Mason C, Herrera E. Zic2 promotes axonal divergence at the optic chiasm midline by EphB1-dependent and -independent mechanisms. Development. 2008;135:1833-41 pubmed publisher
    Axons of retinal ganglion cells (RGCs) make a divergent choice at the optic chiasm to cross or avoid the midline in order to project to ipsilateral and contralateral targets, thereby establishing the binocular visual pathway...
  37. Garg R, Paliwal V, Malhotra H. Tuberculous optochiasmatic arachnoiditis: a devastating form of tuberculous meningitis. Expert Rev Anti Infect Ther. 2011;9:719-29 pubmed publisher
    ..In conclusion, presence of optochiasmatic arachnoiditis or tuberculoma has important therapeutic and prognostic implications for patients of tuberculous meningitis. ..
  38. Jeffery G. Architecture of the optic chiasm and the mechanisms that sculpt its development. Physiol Rev. 2001;81:1393-414 pubmed
    At the optic chiasm the two optic nerves fuse, and fibers from each eye cross the midline or turn back and remain uncrossed. Having adopted their pathways the fibers separate to form the two optic tracts...
  39. Kollias S, Landau K, Khan N, Golay X, Bernays R, Yonekawa Y, et al. Functional evaluation using magnetic resonance imaging of the visual cortex in patients with retrochiasmatic lesions. J Neurosurg. 1998;89:780-90 pubmed
  40. Waheed K, Jan W, Calver D. Aplasia of the optic chiasm and tracts with unifocal polymicrogyria in an otherwise healthy infant. J Pediatr Ophthalmol Strabismus. 2002;39:187-9 pubmed
  41. Runko E, Kaprielian Z. Expression of Vema in the developing mouse spinal cord and optic chiasm. J Comp Neurol. 2002;451:289-99 pubmed
    ..The distribution of Vema in the developing spinal cord and optic chiasm resembles the expression patterns of a variety of molecules known to play important roles in axon guidance, ..
  42. Monteiro M, Medeiros F, Ostroscki M. Quantitative analysis of axonal loss in band atrophy of the optic nerve using scanning laser polarimetry. Br J Ophthalmol. 2003;87:32-7 pubmed
    To measure axonal loss in patients with band atrophy from optic chiasm compression using scanning laser polarimetry (GDx, Laser Diagnostic Technologies, Inc, San Diego, CA, USA) and to evaluate the ability of this instrument to identify ..
  43. Schmitz B, Schaefer T, Krick C, Reith W, Backens M, Käsmann Kellner B. Configuration of the optic chiasm in humans with albinism as revealed by magnetic resonance imaging. Invest Ophthalmol Vis Sci. 2003;44:16-21 pubmed
    To determine whether the size and configuration of the optic chiasm in humans with albinism is different from that in normal control subjects...
  44. Nakagawa S, Brennan C, Johnson K, Shewan D, Harris W, Holt C. Ephrin-B regulates the Ipsilateral routing of retinal axons at the optic chiasm. Neuron. 2000;25:599-610 pubmed
    In Xenopus tadpoles, all retinal ganglion cells (RGCs) send axons contralaterally across the optic chiasm. At metamorphosis, a subpopulation of EphB-expressing RGCs in the ventrotemporal retina begin to project ipsilaterally...
  45. Deiner M, Sretavan D. Altered midline axon pathways and ectopic neurons in the developing hypothalamus of netrin-1- and DCC-deficient mice. J Neurosci. 1999;19:9900-12 pubmed
    ..Netrin protein localization also indicates that unlike in more caudal CNS, guidance about the hypothalamic ventral midline does not require midline expression of netrin. ..
  46. Paladino J, Rotim K, Pirker N, Gluncic V, Juric G, Kalauz M. Minimally invasive treatment of cavernous angioma of the optic chiasm: case report. Minim Invasive Neurosurg. 2001;44:114-6 pubmed
    Cavernous angioma of the optic chiasm or optic nerve is extremely rare. We report the case of a 58-year-old woman with cavernous angioma of the optic chiasm...
  47. Balcer L, Liu G, Heller G, Bilaniuk L, Volpe N, Galetta S, et al. Visual loss in children with neurofibromatosis type 1 and optic pathway gliomas: relation to tumor location by magnetic resonance imaging. Am J Ophthalmol. 2001;131:442-5 pubmed
    ..To examine the potential for visual acuity loss, and its relation to extent and location of optic pathway gliomas in a cohort of children with neurofibromatosis type 1 studied with magnetic resonance imaging...
  48. Rachel R, Murdoch J, Beermann F, Copp A, Mason C. Retinal axon misrouting at the optic chiasm in mice with neural tube closure defects. Genesis. 2000;27:32-47 pubmed
    ..of neural tube closure (embryonic day [E] 8-9) is associated with errors in retinal axon projection at the optic chiasm (E12-18), such that many axons normally projecting contralaterally instead grow to ipsilateral targets...
  49. Sretavan D, Kruger K. Randomized retinal ganglion cell axon routing at the optic chiasm of GAP-43-deficient mice: association with midline recrossing and lack of normal ipsilateral axon turning. J Neurosci. 1998;18:10502-13 pubmed
    During mammalian development, retinal ganglion cell (RGC) axons from nasal retina cross the optic chiasm midline, whereas temporal retina axons do not and grow ipsilaterally, resulting in a projection of part of the visual world onto one ..
  50. Boschert U, Ramos R, Tix S, Technau G, Fischbach K. Genetic and developmental analysis of irreC, a genetic function required for optic chiasm formation in Drosophila. J Neurogenet. 1990;6:153-71 pubmed
    ..In addition to a severe disorganization of the inner optic chiasm irreC mutants display a subtle phenotype in the outer optic chiasm, in which some bundles of axons that leave ..
  51. Pakzaban P, Westmark K, Westmark R. Chiasmal apoplexy due to hemorrhage from a pituitary adenoma into the optic chiasm: case report. Neurosurgery. 2000;46:1511-3; discussion 1513-4 pubmed
    Chiasmal apoplexy, defined as hemorrhage into the optic chiasm, generally is caused by an intrachiasmal vascular malformation...
  52. Marcus R, Blazeski R, Godement P, Mason C. Retinal axon divergence in the optic chiasm: uncrossed axons diverge from crossed axons within a midline glial specialization. J Neurosci. 1995;15:3716-29 pubmed
    ..crossed and uncrossed axons from each eye diverge in a zone 100-200 microns proximal to the midline of the optic chiasm. In this study, we identify cellular specializations in this zone that might serve as cues for retinal axon ..
  53. Sretavan D, Feng L, Pure E, Reichardt L. Embryonic neurons of the developing optic chiasm express L1 and CD44, cell surface molecules with opposing effects on retinal axon growth. Neuron. 1994;12:957-75 pubmed
    ..encounter an inverted V-shaped neuronal array defining the midline and posterior boundaries of the future optic chiasm. These neurons express L1, an immunoglobulin superfamily molecule known to promote retinal axon outgrowth, and ..