|LENS INDUCED GLAUCOMAS
||SIGNS AND SYMPTOMS
The lens induced glaucoma patient is typically elderly, with a
history of cataracts. There are four types of glaucomas associated with lens complications
(excluding cases of lens displacement in ectopia lentis):
- phacolytic glaucoma
- lens particle glaucoma
- phacoanaphylactic uveitis
- phacomorphic glaucoma
In all of these cases, the glaucoma is typically very symptomatic
with pain and redness in the involved eye, and cells and flare in the anterior chamber.
Frequently, an advanced cataract in the involved eye severely reduces vision.
Phacolytic glaucoma This condition involves a hypermature cataract
with severe visual reduction (typically light perception). It's characterized by acute
onset of pain and redness and IOPs often of 35mm Hg or greater. There is liquefaction of
the lens nucleus and cortex, and attenuation of the capsule with the release of lens
proteins into the anterior chamber. Macrophages engulf the lens proteins, become bloated,
and block trabecular outflow. The angle remains open, though in some cases peripheral
anterior synechiae may develop.
Lens particle glaucoma The mechanism of lens particle glaucoma
resembles that of phacolytic glaucoma, except that there is a history of surgery or trauma
that releases the lens proteins into the anterior chamber and initiates a
macrophage-driven inflammatory reaction. The angle remains open.
Phacoanaphylactic uveitis This is a chronic uveitis that occurs
one to 14 days following cataract extraction or lens trauma. This mechanism is similar to
the previous two types of glaucoma, except that inflammatory cells are not limited to
macrophages. Also, there is considerable flare and mutton-fat keratic precipitates, and a
propensity for synechiae formation. The angle may be open or closed.
Phacomorphic glaucoma In this case, an increase of lens thickness
from an advancing cataract leads to a relative pupil block, posterior bombé and angle
closure. The intumescence often develops quickly. Typically, the cataract reduces vision
severely. The angle in this glaucoma is closed.
Employ topical beta blockers, carbonic anhydrase inhibitors and
alpha adrenergic agonists to temporize the IOP. Avoid miotics and prostaglandin analogs in
cases where inflammation is present. In cases where there is significant anterior segment
inflammation, use topical steroids to quell the inflammation. In cases where the lens
precipitates a secondary glaucoma, the best management is surgical lens removal.
- In cases of severe granulomatous uveitis with IOP rise following cataract
extraction, consider phacoanaphylactic uveitis.
- In patients with hypermature cataracts and shallow anterior chambers with
angle closure, consider phacomorphic glaucoma, especially if the fellow lens has less
intumescence and there is a deeper chamber.
- Phacomorphic and phacolytic glaucoma develop only in eyes with
hypermature cataracts. Vision typically ranges from 20/400 to light perception. If vision
is better than 20/400, consider another cause for the glaucoma.
- In cases where there is phacomorphic glaucoma in a nanophthalmic eye,
surgical excision of the cataract is associated with severe complications of choroidal
detachment and hemorrhage. In these cases, you may prefer medical therapy and laser
iridotomy rather than surgical management.
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