Phacolytic glaucoma

Phacolytic Glaucoma is a secondary glaucoma that occurs due to the leakage of lens proteins through an intact but hypermature cataract, leading to an inflammatory response in the anterior chamber of the eye. This condition is characterized by a sudden increase in intraocular pressure (IOP), severe pain, and vision loss. It is a rare but serious complication that requires prompt diagnosis and treatment to prevent permanent damage to the optic nerve and loss of vision.

Etiology

Phacolytic glaucoma is caused by the leakage of lens proteins from a hypermature cataract, which is a cataract that has over-ripened to the point where the lens proteins become liquid. The lens capsule remains intact, but becomes permeable to the high-molecular-weight proteins. These proteins then enter the anterior chamber, where they are too large to be effectively cleared by the trabecular meshwork. The accumulation of proteins leads to blockage of the aqueous humor outflow, resulting in increased intraocular pressure.

Pathophysiology

The pathophysiology of phacolytic glaucoma involves an immune response to the leaked lens proteins. The presence of these proteins in the anterior chamber triggers an inflammatory reaction, attracting macrophages and other inflammatory cells to the area. These cells attempt to phagocytose the proteins, leading to further inflammation and blockage of the trabecular meshwork. The resultant increase in intraocular pressure can cause damage to the optic nerve and loss of vision if not promptly treated.

Clinical Presentation

Patients with phacolytic glaucoma typically present with symptoms of acute glaucoma, which include:

• Severe pain in the affected eye
• Redness of the eye
• Blurred vision or decreased visual acuity
• Seeing halos around lights
• Headache
• Nausea and vomiting

On examination, the eye may show signs of increased intraocular pressure, corneal edema, and an inflamed anterior chamber with cells and flare. The lens may appear white or 'overripe', indicating a hypermature cataract.

Diagnosis

Diagnosis of phacolytic glaucoma is primarily clinical, based on the patient's history and symptoms, along with the findings on eye examination. Additional tests may include:

• Measurement of intraocular pressure (IOP) with tonometry
• Slit-lamp examination to assess the anterior chamber and lens
• Gonioscopy to evaluate the angle of the anterior chamber
• Ultrasound biomicroscopy or anterior segment OCT to examine the lens and anterior chamber more closely

Treatment

The treatment of phacolytic glaucoma aims to reduce the intraocular pressure and remove the source of the inflammatory response. Initial management may include medical therapy with topical and systemic IOP-lowering medications, such as beta-blockers, alpha agonists, carbonic anhydrase inhibitors, and prostaglandin analogs. Anti-inflammatory medications, such as topical steroids, may also be used to reduce the inflammation in the anterior chamber.

The definitive treatment for phacolytic glaucoma is surgical removal of the cataract. Cataract surgery, typically performed using phacoemulsification, can effectively remove the hypermature lens and eliminate the source of the lens proteins that are causing the inflammation and increased IOP. In some cases, a combined procedure that includes both cataract surgery and glaucoma surgery (e.g., trabeculectomy) may be necessary to adequately control the intraocular pressure.

Prognosis

With prompt diagnosis and treatment, the prognosis for patients with phacolytic glaucoma is generally good. Surgical removal of the cataract can lead to a significant reduction in intraocular pressure and resolution of the inflammatory response. However, the outcome may be less favorable in patients who experience delays in treatment, leading to prolonged high IOP and optic nerve damage.