9C41

ICD-11 MMS 2026-01

Disorder of optic chiasm

Description

This is a group of conditions associated with the optic chiasm, the part of the brain where the optic nerves (CN II) partially cross.

Coding note

Use additional code, if desired, to identify underlying condition.

Index terms

  • Disorder of optic chiasm
  • chiasma syndrome
  • chiasmal lesion
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  • chiasmal optic disorder
  • disease of optic chiasm
  • intrachiasmal lesion
  • prechiasmal lesion

Exclusions from above levels

  • 01 – Certain infectious or parasitic diseases
  • 05 – Endocrine, nutritional or metabolic diseases
  • 18 – Complications of pregnancy, childbirth and the puerperium
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  • 19 – Certain conditions originating in the perinatal period
  • 22 – Injury, poisoning or certain other consequences of external causes
  • 8A21.0 – Posterior cortical atrophy

Sibling codes

  • 9C40 – Disorder of the optic nerve
  • 9C42 – Disorder of post chiasmal visual pathways
  • 9C43 – Disorder of visual cortex
  • 9C44 – Disorder of higher visual centres
  • 9C4Y – Other specified disorders of the visual pathways or centres
  • 9C4Z – Disorders of the visual pathways or centres, unspecified

Foundation entity

Disorder of optic chiasm – http://id.who.int/icd/entity/927459952

Allowed postcoordination axes

Part of: 09: Diseases of the visual system