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Pseudoexfoliation Syndrome
In Pseudoexfoliation Syndrome, a protein-like material is deposited in the front and back segments of the eye. It is
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| believed to be comprised of particles from the lens of the eye along with pigment from the back surface of the iris, which mechanically block the aqueous from leaving the anterior chamber thus causing a rise in IOP. However, there are some who have this type of pseudoexfoliative debris in the eye's drainage system, but experience no decrease in aqueous flow and have normal IOPs. |
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| Neovascular glaucoma
Neovascular glaucoma is caused by rise in IOP due to new blood vessels growing at the pupil margin and then extending over the iris toward the angle. This new vessel growth is known as rubeosis irides.
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| Once the vessels reach the anterior chamber angle, they can block aqueous flow and may even close the angle by causing an peripheral anterior synechiae.
Some of the more common diseases that may cause this to occur are central retinal vein and artery occlusions, branch retinal artery and vein occlusions, diabetic retinopathy, chronic retinal detachment, carotid occlusive disease, and iridocyclitis. The picture above is the blood vessels in the pupil margin of the iris.
The treatment for neovascular glaucoma is to reduce the oxygen demand being made by the retina. This can be done by treating the retina with a laser. If the peripheral anterior synechiae has closed off a great portion of the angle, then filtering surgery may be required to lower the IOP.
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| Pigmentary Dispersion Syndrome
Pigmentary Dispersion Syndrome (PDS) is the release of pigment cells caused by the lens zonules rubbing the back of the iris and liberating the cells into the aqueous humor. With PDS, the
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| intraocular pressures, visual fields, and optic nerve head all appear to be within normal limits. However, many patients with PDS will go on to develop pigmentary glaucoma with time.
The top picture shows a Krukenberg's spindle, which is literally a spindle of iris pigment on the back surface of the cornea.
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| Pigmentary glaucoma is caused by the mechanical blocking of the trabecular meshwork by the iris pigment cells. The pigment then travels and is deposited on the trabecular meshwork, corneal endothelium, anterior lens capsule, and other areas on the lens. |
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This blocks the flow of aqueous out of the anterior chamber and leads to increased intraocular pressure.
Pigmentary glaucoma is usually found bilaterally with an onset occurring usually between the ages of 20 to 40. This type of glaucoma has been found to have an association with the presence of myopia (nearsightedness) and occurs more frequently in males than females.
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Uveitis
Uveitis is a term used to describe an inflammation of the ciliary body, iris, or choroid of the eye. Uveitis can cause either an open or closed angle glaucoma depending on the severity of the inflammation.
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During a severe uveitis there may be significant damage to the drainage system in the eye. This in turn will cause an elevated IOP which may become a chronic problem.
The goal of treating glaucoma secondary to uveitis is to decrease the inflammation. This will minimize vision loss and scarring of the trabeculum. If the use of drugs does not adequately manage the problem, a laser iridotomy should most like be performed
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| Steroid induced glaucoma
The use of all steroids (eye drops, by mouth, injections and creams) has been associated with causing glaucoma in certain individuals. It is thought that about 5% of people using topical steroids will have a large increase in intraocular pressures. The glaucomatous damage produced is usually stopped by discontinuing the use of the steroid and the intraocular pressures return to normal in about 2 to 4 weeks. However for those who were on corticosteroids for more than 4 years, developed a chronic glaucoma that requires treatment.
This type of glaucoma is asymptomatic similar to primary or low tension open angle glaucoma. Steroids use very rarely causes a closed angle attack. It is very important to obtain a good history of steroid use both topically and systemically on all glaucoma patients.
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