Angle-Closure glaucoma
Prof K N Jha,MS.
Learning Aim
• Definition of Angle-closure glaucoma
• Primary angle-closure glaucoma (PACG)
• Clinical features and treatment of PACG
Angle Closure glaucoma
• Angle closure glaucoma are a large and diverse group
of diseases characterized by peripheral anterior
synechia and/ or iridotrabecular apposition.
• Angle closure: apposition of peripheral iris to the
trabecular meshwork and the resulting reduced
drainage of the aqueous humor through anterior
chamber angle.
Angle closure: Schematic
Angle Closure glaucoma
• Primary angle closure glaucoma: there is no
underlying pathologic cause , there is only
anatomic predisposition.
• Secondary angle closure glaucoma: underlying
pathologic cause e.g. intumescent lens, iris
neovascularisation initiates the angle closure.
Primary Angle Closure glaucoma( PACG)
• Primary angle closure Suspect( PAC-Suspect)
• Primary angle Closure (PAC)
• Primary Angle-Closure Glaucoma(PACG)
Mechanism of angle closure
• Mechanism that push the iris forward
• Mechanism that pull the iris forward
PRIMARY ANGLE CLOSURE GLAUCOMA (PACG)
Primary angle closure glaucoma ( PACG)
• Primary angle closure is the leading cause of
glaucoma worldwide.
• Cause: relative pupillary block, plateau iris,
anterior lens movement.
PACG : Risk Factors• Race: prevalence variable across races
• Ocular biometrics: crowded anterior segment of the eye, short axial length, shallow anterior chamber ( < 2.5 mm)
• Age above 40 years
• Gender: M:F
• Family history
• Refraction
Anatomical predispositions
Convex iris-lens diaphragm
• Shallow anterior chamber
• Narrow entrance to chamber angle
Acute PAC:Pathophysiology
IOP rises rapidly due to sudden blockage of TM by iris.• Pupillary block: flow of aqueous through pupil is
impeded ( relative pupillary block)• Pupillary block causes pressure gradient between
posterior and the anterior chamber.• Due to pressure gradient the peripheral iris bows
forward ( iris bombé )against the trabecular meshwork leading to obstruction of aqueous outflow and rise of IOP.
Pathogenesis : Pupillary block
• Increase in physiological pupil block
• Dilatation of pupil renders peripheral iris more flaccid• Increased pressure in posterior chamber causes iris bombe
• Angle obstructed by peripheral iris and rise in IOP
Relative Pupillary Block
Angle closure
Relative Pupillary Block
ACUTE ANGLE CLOSURE
Acute angle closure
Symptoms: Ocular pain, headache, blurred vision, halos , nausea , vomiting.SignsConjunctival and circumcorneal congestionCornea: hazy Anterior chamber: shallowPupil: mid dilated, sluggish and irregularMild aqueous flare and ant chamber cellsOptic nerve head may be swollenIOP: high
DiagnosisHistoryIOP
ocular examination:
CCC, corneal edema , shallow ant chamber, pupillary signs
Gonioscopy : Peripheral anterior synechia
Sector atrophy of iris
Pigment dusting on iris surface and corneal endothelium
Glaukomflecken: small ant subcapsular lens opacities
Treatment
• Preventive: Screening for people at greatest
risk for angle closure.
• Definitive treatment: Iridectomy/ / laser
iridoplasty/ pupilloplasty
• Treatment of the acute angle closure
PACG : Treatment of the acute attack
• Pilocarpine eye drop 1-2% in the affected and the
fellow eye
• Topical beta-adrenergic blocker
• Carbonic anhydrase inhibitor
• Hyperosmotic agent: Mannitol 20% I.V., Oral glycerol
• Globe compression
Globe Compression
Peripheral Iridectomy
PACG:Treatment of the fellow eye
• PAC is a bilateral disease
• There is 50-80 % chance of the fellow eye
developing acute attack over next 5-10 years.
• Peripheral Iridectomy
Follow up
• Repeat gonioscopy to look for chronic angle closure.
PACG : Points to remember
• Predisposing factors
• Pathophysiology
• Clinical features
• Treatment
• Prevention
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