The lens can play a role in the development of open-angle and angle-closure glaucoma. Lens-induced OAGs are divided into 3 clinical entities:
lens particle glaucoma
Lens-induced angle-closure glaucomas include phacomorphic glaucoma and ectopia lentis and are discussed in Chapter 10. See also BCSC Section 9, Uveitis and Ocular Inflammation, and Section 11, Lens and Cataract.
Phacolytic glaucoma is an inflammatory glaucoma caused by the leakage of high-molecular-weight lens protein through microscopic openings in the lens capsule of a mature or hypermature cataract (Fig 9-8) that subsequently obstructs the trabecular meshwork. As the lens ages, its protein composition changes, with an increased concentration of high-molecular-weight lens proteins. Elevated IOP occurs as a result of obstruction of the trabecular meshwork by these high-molecular-weight proteins, lens-laden macrophages, and other inflammatory debris.
Individuals with phacolytic glaucoma are usually older patients with a history of poor vision. They have a sudden onset of pain, conjunctival hyperemia, and worsening vision. Examination reveals markedly elevated IOP, microcystic corneal edema, prominent cell and flare reaction without keratic precipitates (KPs), an open anterior chamber angle, and a mature or hypermature cataract (Fig 10-8). The lack of KPs helps distinguish phacolytic glaucoma from phacoantigenic glaucoma. Cellular debris may be seen layered in the anterior chamber angle, and a pseudohypopyon may be present. Large white particles (clumps of lens protein) may also be present in the anterior chamber. The anterior lens capsule of the mature or hypermature (morgagnian) cataract may exhibit wrinkling, which represents loss of volume and the release of lens material (see Fig 9-8). Ocular hypotensive medications may be necessary to reduce the IOP; however, definitive therapy requires cataract extraction.
Figure 8-9 Characteristic appearance of hypermature cataract with wrinkling of the anterior lens capsule, which results from loss of cortical volume. Extensive posterior synechiae are present, which suggests previous inflammation.
(Courtesy of Steven T. Simmons, MD.)
Figure 8-10 Phacolytic glaucoma. The typical presentation of phacolytic glaucoma is conjunctival hyperemia, microcystic corneal edema, mature cataract, and prominent anterior chamber reaction, as shown in this photograph. Note the lens protein deposits on the endothelium and layering in the angle, creating a pseudohypopyon.
(Courtesy of George A. Cioffi, MD.)
Lens particle glaucoma
In lens particle glaucoma, retention of lens material in the eye after cataract extraction, capsulotomy, or ocular trauma results in obstruction of the trabecular meshwork. The severity of IOP elevation depends on the quantity of lens material released, the degree of inflammation, the ability of the trabecular meshwork to clear the lens material, and the functional status of the ciliary body, which is often altered after surgery or trauma.
Lens particle glaucoma usually occurs within weeks of the initial surgery or trauma, but it may occur months or years later. Clinical findings include cortical material in the anterior chamber, elevated IOP, moderate anterior chamber reaction, microcystic corneal edema, and, with time, posterior synechiae and peripheral anterior synechiae (PAS).
Medical therapy may be needed to reduce the IOP while the residual lens material resorbs. Appropriate therapy includes medications to decrease aqueous formation, mydriatics to inhibit posterior synechiae formation, and topical corticosteroids to reduce inflammation. If the IOP cannot be controlled, surgical removal of the lens material may be necessary.
Phacoantigenic glaucoma (previously known as phacoanaphylaxis) is a rare condition in which patients become sensitized to their own lens protein after surgery or penetrating trauma, resulting in a granulomatous inflammation. The clinical picture is quite varied, but most patients present with a moderate anterior chamber reaction with KPs on both the corneal endothelium and the anterior lens surface. In addition, a low-grade vitritis, posterior synechiae, PAS, and residual lens material in the anterior chamber may be present. Glaucomatous optic neuropathy may occur, but it is not common in eyes with phacoantigenic glaucoma. Initiation of topical corticosteroids and aqueous suppressants are recommended to reduce the inflammation and IOP. The residual lens material will likely need to be removed once the inflammation is controlled.
Excerpted from BCSC 2020-2021 series: Section 10 - Glaucoma. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.