What Is Pseudoexfoliation (PXF) Glaucoma?

Intraocular pressure testing for glaucoma. Westend61

Pseudoexfoliation (PXF) glaucoma (also known as exfoliative glaucoma or exfoliation syndrome) is a type of open-angle glaucoma. Open angle glaucoma is an eye disease in which the pressure in the eye is higher than normal causing damage to the optic nerve, the nerve cable that connects the eye to the brain. Over time, nerve fibers may die causing loss of vision. Eye pressure increases inside the eye for a variety of reasons but usually does so because there is too much fluid for the eye or the eye’s filter, called the trabecular meshwork, becomes plugged up.

What causes pseudoexfoliation glaucoma?

In pseudoexfoliation glaucoma, there is an abnormal accumulation of protein in the drainage system and fluid builds up, increasing eye pressure. Eventually, this pressure causes optic nerve damage. Some people develop pseudoexfoliative syndrome in which an abnormal amount of protein is released, but there seems to be no increase in eye pressure. Fifty percent of people with pseudoexfoliative syndrome develop exfoliative glaucoma. All people that have pseudoexfoliative syndrome are considered suspicious for developing glaucoma. Pseudoexfoliation syndrome is actually a systemic condition, meaning that this abnormal protein is present throughout the body as well. There is a link between pseudoexfoliation and cardiovascular disease, strokes and hearing loss.

Who is at risk for pseudoexfoliation glaucoma?

Pseudoexfoliative glaucoma is more common in older individuals and in people of northern european descent such as the Scandinavian countries.

How is pseudoexfoliation glaucoma diagnosed?

In general, a comprehensive eye examination must be performed. During the eye examination your pupils will be dilated. Often, if a person has pseudoexfoliation, white, flakey, flecks of protein material can be seen on the crystalline lens of the eye right behind the iris.

This flakey material can also be found on the border of the pupil and in the angle of the eye (the angle that the cornea makes with the iris.) If an eye doctor sees this, he or she will perform gonioscopy. Gonioscopy is a test in which a special hand held mirror is placed directly onto the eye. Gonioscopy is used to examine the angle of eye where the trabecular meshwork filters the fluid out of the eye. Next, the doctor will examine the internal structures of the eye with special emphasis on inspecting the size, color and shape of the optic nerve. Next, a computerized visual field test will be performed to analyze the entire field of vision, looking in certain spots where glaucoma tends to develop early. People with pseudoexfoliation tend to have cataracts earlier than normal. Cataracts are a clouding of the lens of the eye that occurs in humans as they get older.

Why is it called "pseudo" exfoliation glaucoma?

The condition is called pseudoexfoliative glaucoma because true exfoliative glaucoma appears very similar but the flakes on the lens are from an old occupational hazard of glass blowers.

 The heat causes the front part of the capsule that holds the lens of the eye to peel off and create white flakey material similar to that found in pseudoexfoliation syndrome.

How does pseudoexfoliation glaucoma differ from open-angle glaucoma?

Open angle glaucoma usually develops very slowly, usually over many years. Because it is such a slow process, it may go undiagnosed for a while, as it does not usually present any symptoms.  Unless regular glaucoma screenings occur on a regular basis, it may go untreated for years. Pseudoxfoliative glaucoma is much different as eye pressure rises much quicker, potentially creating loss of vision must faster. Eye pressure tends to rise much more quickly and the condition progressives faster. Normal glaucoma treatment tends to fail with pseudoexfoliative glaucoma. There is usually a need for surgical intervention earlier in the disease process.  

How is pseudoexfoliation glaucoma treated?

Pseudoexoliation glaucoma is treated in much the same way as open-angle glaucoma. First, most eye doctors prescribe topical medicational eye drops that are instilled into the eye to lower the eye pressure to safe level. If medications are not enough, then laser and surgical procedures are tried.  


Source:

Desai, Manishi A. MD and Richard K Lee. The Medical and Surgical Management of Pseudoexfoliation Glaucoma. Int Ophthalmology Clinic, 2008, pp 95-113.

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