• 7 SECTIONGlaucoma Angle Closed

Plateau Iris

Key Facts

•Plateau iris configuration represents a narrow angle on gonioscopy with flat iris plane

•Plateau iris syndrome present when narrow angle (and possible acute closure) seen despite patent iridectomy

•Increased prevalence in young myopes

•Patients tend to be younger than population that has primary angle closure attacks

Mechanism

•Anterior position of ciliary processes pushes peripheral iris forward, occluding trabecular meshwork (Fig. 7.6)

•Anterior insertion of iris root

Clinical Findings

•Asymptomatic unless acute closure develops

•Pain

•Redness

•Decreased vision

•Closed angle with flat iris plane (no iris bombe as with pupillary block)

•Narrowing at drainage angle with sharp drop-off at peripheral iris

•Double-hump sign (Fig. 7.7) represents elevation of iris due to the lens, with more peripheral elevation caused by ciliary process indentation

Ancillary Testing

•Gonioscopy

•Ultrasound biomicroscopy

Differential Diagnosis

•Pupillary block

•Chronic angle closure

•Phacomorphic glaucoma

•Inflammatory glaucoma

•Malignant glaucoma

•Pseudoplateau iris configuration due to ciliary body tumor or cyst

Treatment

•Topical hypotensive agents

•Peripheral iridotomy if not done already

•Laser iridoplasty for plateau iris syndrome

Prognosis

• Good

Fig. 7.6 Ultrasound biomicroscopy showing flat iris with loss of ciliary sulcus due to anterior position of ciliary process.

Fig. 7.7 Double-hump sign (arrows).

Iris Plateau

• 7 SECTIONGlaucoma Angle Closed

Phacomorphic Glaucoma

Key Facts

•The lens pushes the iris forward, causing pupillary block and closing the drainage angle

•Occurs with or without pupillary block

•Linked to advanced cataract (Fig. 7.8), traumatic cataract, and microspherophakia

•No sex predilection

•More common in hyperopic eyes with shallow anterior chamber

Clinical Findings

•Pain

•Redness

•Anterior chamber cell reaction

•Corneal edema

•Decreased vision

•Haloes in vision

Ancillary Testing

•Ultrasound biomicroscopy

•B-scan ultrasonography

Differential Diagnosis

•Primary angle closure glaucoma

•Plateau iris syndrome

•Inflammatory glaucoma

•Neovascular glaucoma

•Phacolytic glaucoma

•Lens particle glaucoma

•Presence of a phakic IOL

Treatment

•Topical hypotensive agents, possible need for oral agents in acute presentation

•Topical steroid drops

•Laser peripheral iridectomy

•Avoid miotics, which can cause anterior migration of lens–iris diaphragm

•Cataract extraction for definitive treatment

Prognosis

•Patients sometimes require continued treatment for IOP increases despite cataract extraction