Glaucoma refers to the optic nerve damage that is caused by a significant rise in intraocular pressure. The raised intraocular pressure is caused by a blockage in aqueous humour trying to escape the eye.

Pathophysiology:

Acute angle closure glaucoma = An urgent (uncommon) condition where there is reversible or adheisional closure of the anterior chamber angle (sealing off trabecular meshwork), preventing drainage of aqueous humour - resulting in elavation of the intra-ocular pressure (IOP)

Types

• Primary ACG: Occurs due to obstruction of the trabecular meshwork by the iris = raised ICP
• Secondary ACG: Occurs due to an underlying condition or medication that causes obstruction of the anterior chamber angle = raised ICP
  • Causes of SACG: Uveitis, neovascularisation, certain medications e.g. anticholinergics

Risk Factors:

• Females are affected around 4 times more often than males
• Hyperopia (smaller anterior chamber)
• Shallow anterior chamber
• Second eye having the condition
• Inuit and asian ethnicity. Unlike open-angle glaucoma, it is rare in people of black ethnic origin.
• Increasing age
• Family history
• Certain medications - adrenalin, anticholinergics, tricyclic antidepressants
• Mydriatic drops are a known precipitant of acute angle closure glaucoma

PC