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