Phacomorphic glaucoma

A type of secondary angle-closure glaucoma

Phacomorphic glaucoma is a form of secondary glaucoma that occurs due to the swelling of the crystalline lens in the eye, leading to angle closure and increased intraocular pressure (IOP). This condition is often associated with cataract formation, where the lens becomes increasingly opaque and enlarged, causing mechanical obstruction of the anterior chamber angle.

Pathophysiology

Schematic diagram of the human eye

Phacomorphic glaucoma arises when the lens of the eye becomes swollen due to advanced cataract formation. The swollen lens pushes the iris forward, narrowing or closing the anterior chamber angle, which is the drainage pathway for the aqueous humor. This obstruction prevents the normal outflow of aqueous humor, leading to an increase in intraocular pressure. The elevated IOP can cause damage to the optic nerve, resulting in vision loss if not treated promptly.

Clinical Presentation

Patients with phacomorphic glaucoma typically present with symptoms of acute angle-closure glaucoma, including:

• Severe eye pain
• Headache
• Nausea and vomiting
• Blurred vision
• Halos around lights
• Red eye

On examination, the affected eye may show a shallow anterior chamber, a mid-dilated and non-reactive pupil, and corneal edema. The intraocular pressure is usually significantly elevated.

Diagnosis

The diagnosis of phacomorphic glaucoma is primarily clinical, based on the history and examination findings. Gonioscopy can be used to assess the angle closure, and ultrasound biomicroscopy may help in evaluating the lens size and position. Optical coherence tomography (OCT) can also be useful in assessing the anterior segment structures.

Management

The management of phacomorphic glaucoma involves both medical and surgical interventions:

Medical Management

Initial treatment focuses on lowering the intraocular pressure and relieving symptoms. This may include:

• Topical beta-blockers (e.g., timolol)
• Alpha agonists (e.g., apraclonidine)
• Carbonic anhydrase inhibitors (e.g., acetazolamide)
• Hyperosmotic agents (e.g., mannitol)

Surgical Management

Definitive treatment requires surgical intervention to remove the cataractous lens. The most common procedure is phacoemulsification, which involves emulsifying and aspirating the lens material, followed by the implantation of an intraocular lens. In some cases, a trabeculectomy or other glaucoma surgery may be necessary to manage the intraocular pressure.

Prognosis

The prognosis for phacomorphic glaucoma depends on the duration and severity of the angle closure and the extent of optic nerve damage. Early diagnosis and prompt surgical intervention can lead to a good visual outcome. However, delayed treatment may result in permanent vision loss due to optic nerve damage.

Prevention

Preventive measures include regular eye examinations, especially in older adults at risk for cataract formation. Early detection and management of cataracts can prevent the development of phacomorphic glaucoma.

Related pages

• Glaucoma
• Cataract
• Angle-closure glaucoma
• Intraocular pressure