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Exfoliation Syndrome: a Cause of Glaucoma
 Pseudoexfoliation
(PEX) syndrome, one of the most common causes of
glaucoma, represents a complex, multifactorial, late-onset
disease of worldwide significance.
Pseudoexfoliation syndrome (PEX) is an aging–related
(69-75 yrs) systemic disease (affecting the whole body) manifesting itself
primarily in the
eyes
which is characterized by the accumulation of microscopic granular amyloid-like
protein fibers. The build up of protein clumps can block normal drainage of the
eye fluid called the aqueous humor and can cause, in turn, a build up of
pressure leading to glaucoma and loss of
vision.
The clinical features include: white flake-like material on the
anterior lens surface, the pupillary border, trabecular
meshwork, zonula, ciliary body, and other anterior segment
structures. XFS is a major risk factor for the development of
glaucoma.
PEX is usually diagnosed by an eye doctor who examines the
eye using a microscope. The method is termed slit lamp
examination and it is done with an "85% sensitivity rate and a
100% specificity rate."
Possible Causes
There is speculation that PEX may be caused by oxidative damage and the presence of free radicals, although the exact nature of how this might happen is still under study.
Studies of PEX patients have found,
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A decrease in the concentrations of ascorbic acid,
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Increase in concentrations of malondialdehyde, and
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An increase in concentrations of 8-iso-prostaglandinF2a.
Both population-based and pedigree-based studies have suggested that PEX
syndrome is
inherited
as an autosomal dominant trait with late onset and incomplete penetrance.
According to studies worldwide, there is evidence showing that genetic factors
may play an important role in the pathogenesis of XFS. The gene is called LOXL1.
Maybe someday we will test individuals at risk for XFS/XFG for this gene.
XFS can not only lead to severe chronic open-angle glaucoma but also to
acceleration of
cataract formation, lens subluxation, angle-closure glaucoma, and severe
complications at the time of cataract extraction, such as zonular dialysis,
capsular rupture, and vitreous loss
Treatment Options:
 Patients
with pseudoexfoliation syndrome should have annual eye examinations for early
detection of glaucoma. Glaucoma in pseudoexfoliation is more resistant to
medical therapy and has a poorer prognosis than primary open-angle glaucoma.
Eye drops are suggested at initial stage in order to reduce the
intraocular pressure within the eye. The medications within the eye drops can
include beta blockers (such as levobunolol or timolol) which slow the production
of the aqueous humor. And other medications can increase its outflow, such as
prostaglandin analogues (e.g. latanoprost).
Eye Surgery: A type of laser therapy known as trabeculoplasty is a
treatment option in which a high-energy laser beam is pointed at the trabecular
meshwork to cause it to "remodel and open" and improve the outflows of the
aqueous humor. This can be done as an outpatient procedure and take less than
twenty minutes. Laser trabeculoplasty is less effective in people who have
inflammatory glaucoma, a type of glaucoma caused by an existing inflammation,
and in young people who have developmental defects. Laser trabeculoplasty is not
done for patients who have closed-angle glaucoma.
Selective
eye
exercises as well as eye relaxing methods can help prevent vision loss
in many cases. If performed regularly, these kinds of exercises can help
regulate the eye tension and thus encourage better vision and
healthier eyes. Visualization and meditation exercises are highly
recommended.
Glaucoma in pseudoexfoliation is more resistant to medical therapy and has a
poorer prognosis than primary open-angle glaucoma.
Content Support:
-
WF Team
Dated 04 January 2012
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