Phacolytic Glaucoma

ByAndrew Hendrick, MD

Phacolytic glaucoma is a secondary open-angle glaucoma that occurs with advanced cataract formation. Typically unilateral, the intact lens capsule of a hypermature cataract leaks high molecular-weight lens proteins. It is believed that these proteins are derived from cortical cataract and aggregate thereby inciting a vigorous immune response. Macrophages engulf the protein and together with free-floating protein, plug the trabecular meshwork leading to an acute increase in IOP.^1,2

Clinical Findings

Because phacolytic glaucoma is associated with advanced cataract formation, it is more common among the elderly and individuals who have limited access to medical care (eg, developing countries).³ It is often a unilateral process typified by a painful acute worsening of vision, and a rise in IOP with associated aqueous humor cell and flare. The inflammation does not typically form synechiae and rarely demonstrates keratic precipitates. Additionally, the aqueous humor may contain refractile bodies that are larger than normal white blood cells and believed to represent burdened macrophages. Importantly, the angle is open on gonioscopy.⁴

Diagnostic Features

Clinical history
Many patients with phacolytic glaucoma have had decreased vision due to the hypermature cataract and present with pain, redness, and watering in one eye. Although low socioeconomic status may be a risk factor, no known genetic or familial component exists.³

Slit lamp examination
Cornea
Corneal decompensation is possible with an acute rise in IOP and may manifest as cystic edema. Keratic precipitates are rare, but the endothelium can demonstrate hyperrefringent cholesterol granules.⁵

Anterior chamber
Marked anterior chamber inflammation is present with cell and flare.

Gonioscopy
Individuals with phacolytic glaucoma have a normal to deep angle in both eyes.

Iris
Posterior synechiae are uncommon.

Lens
The lens is mature or hypermature and may have white spots on the anterior lens capsule. As a rule, the lens capsule is intact but may be wrinkled due to volume loss and release of cortical lens material.

Optic nerve head
Although it may not initially be visible, glaucomatous optic nerve damage can occur with long-term elevated IOP associated with phacolytic glaucoma.

Differential Diagnosis

Following is the differential diagnosis for phacolytic glaucoma:

Phacomorphic glaucoma: Also associated with hypermature cataract formation, the key differentiating feature is gonioscopically closed angle and a shallow anterior chamber in phacomorphic glaucoma. Phacolytic glaucoma has a pronounced anterior chamber inflammatory component.
Phacoanaphylactic glaucoma: Traumatic disruption of the anterior capsule with spillage of lens proteins into the anterior chamber typifies phacoanaphylactic glaucoma. Prototypically has keratic precipitates with synechiae formation and also has an open anterior chamber.
Uveitic glaucoma: IOP can rise with acute and chronic uveitis and form extensive anterior or posterior synechiae with secondary angle closure glaucoma. These patients do not necessarily have hypermature cataract.

Treatment

Although initial management of phacolytic glaucoma includes management of IOP and inflammation, definitive treatment is surgical removal of the cataractous lens. Stabilization involves aggressive topical steroids such as prednisolone acetate 1% every 1 to 2 hours and IOP reduction. Topical or oral carbonic anhydrase inhibitors, alpha adrenergic agonists, beta antagonists should initially be attempted but additional control with osmotics such as mannitol may be required. Due to their possible pro-inflammatory side effects, cholinergics such as pilocarpine and prostaglandin analogues should be avoided.⁶

Outcome

Phacolytic glaucoma carries a favorable long-term prognosis if treated early.³ However, sequelae of the event can include permanent vision loss due to glaucomatous optic neuropathy or persistent corneal edema. Primary placement of posterior chamber IOL appears safe and effective.⁷ Some authors advocate trabeculectomy for IOP control if patients have delayed presentation for more than 7 days,⁴ while others believe it to be unnecessary within 2 to 3 weeks.⁷

Summary

Phacolytic glaucoma is an inflammatory open-angle glaucoma secondary to hypermature cataract formation with protein leakage through an intact lens capsule.
Gonioscopy with an open angle is crucial to proper diagnosis and management.
Treatment involves stabilization with topical steroids and IOP reducing medications until cataract extraction can be safely achieved.
Good visual prognosis if recognized and treated promptly.

References

Epstein DL, Jedziniak JA, Grant WM. Identification of heavy-molecular-weight soluble protein in aqueous humor in human phacolytic glaucoma. Invest Ophthalmol Vis Sci. 1978; 17:398-402.
Ueno H, Tamai A, Iyota K, Moriki T. Electron microscopic observation of the cells floating in the anterior chamber in a case of phacolytic glaucoma. Jpn J Ophthalmol. 1989; 33:103-113.
Prajna NV, Ramakrishnan R, Krishnadas R, Manoharan N. Lens induced glaucomas - visual results and risk factors for final visual acuity. Indian J Ophthalmol. 1996; 44:149-155.
Braganza A, Thomas R, George T, Mermoud A. Management of phacolytic glaucoma: Experience of 135 cases. Indian J Ophthalmol. 1998; 46:139-143.
Brooks AM, Grant G, Gillies WE. Comparison of specular microscopy and examination of aspirate in phacolytic glaucoma. Ophthalmology. 1990; 97:85-89.
American Academy of Ophthalmology. Noninfectious (autoimmune) uveitis. In: BCSC Intraocular Inflammation and Uveitis. San Francisco, Calif: American Academy of Ophthalmology; 2007-2008:156-157.
Mandal AK, Gothwal VK. Intraocular pressure control and visual outcome in patients with phacolytic glaucoma managed by extracapsular cataract extraction with or without posterior chamber intraocular lens implantation. Ophthalmic Surg Lasers. 1998; 29:880-889.