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Often abbreviated as PEX and sometimes as PES or PXS, is an aging-related systemic disease manifesting itself primarily in the eyes which is characterized by the accumulation of microscopic granular amyloid-like protein fibers.
There may be a genetic basis.
More prevalent in women than men, and in persons past the age of seventy.
Is prevalent in Scandinavia.
The buildup of protein clumps can block normal drainage of the aqueous humor and can cause, in turn, a buildup of pressure leading to glaucoma and loss of vision.
Patients may have no specific symptoms.
Patients may complain of lessened visual acuity or changes in their perceived visual field,
Visual changes may be secondary to or different from symptoms normally associated with cataracts or glaucoma.
Characterized by tiny microscopic white or grey granular flakes which are clumps of proteins within the eye.
The abnormal flakes are visible during an examination of the lens of an eye by an ophthalmologist or optometrist.
The white fluffy material is seen in many tissues both ocular and extraocular, such as in the anterior chamber structures, trabecular meshwork, central disc, zonular fibres, anterior hyaloid membrane, pupillary and anterior iris, trabecula, and occasionally the cornea.
Granular flakes are from abnormalities of the basement membrane in epithelial cells, and are distributed widely throughout the body and not just within structures of the eye.
PEX problematic when the flakes become enmeshed in the trabecular meshwork and block its normal functioning, and may interact with degenerative changes in the Schlemm’s canal and the juxtacanalicular area.
The blockage results in greater-than-normal elevated intraocular pressure which, in turn, can damage the optic nerve.
Glaucoma can result if this normal outflow of fluid is blocked.
PEX has been known to cause a weakening of structures within the eye which help hold the eye’s lens in place, called lens zonules.
Deposits of PEX material in various parts of the body, including in the skin, heart, lungs, liver, and kidneys.
Tends to occur in only one eye first, and , gradually afflicts the other eye.
Studies have found higher levels of plasma homocysteine in PEX patients, ] or elevated homocysteine concentrations in tear fluids produced by the eye.
A predisposition to develop PEX later in life may be an inherited characteristic, with polymorphisms in gene LOXL1.
PEX is usually diagnosed by slit lamp examination and it is done with an 85% sensitivity rate and a 100% specificity rate.
It is possible to minimize the damage to vision and to the optic nerves by the same medical techniques used to prevent glaucoma.
Eyedrops, the first treatment, can reduce intraocular pressure within the eye.
The medications include beta blockers, such as levobunolol or timolol, which slow the production of the aqueous humor, and medications that can increase its outflow, such as prostaglandin analogues, latanoprost.
In most cases of glaucoma, eye drops alone will suffice to solve the problem.
Laser therapy known as trabeculoplasty in which a high-energy laser beam is pointed at the trabecular meshwork to cause it to open and improve the outflows of the aqueous humor, is usually effective.
In glaucoma patients a trabeculectomy surgically removes the trabecular meshwork, and it is usually effective at preventing glaucoma.
Surgical treatment method is of last resort.
Surgical management can be complicated if the fibers which hold the lens have become weakened because of a buildup from the flakes.
There are cases of persons with PEX without glaucoma, and persons with glaucoma without PEX.
PEX is present in approximately 12% of glaucoma patients and is present in 6% of an open-angle glaucoma group, and is considered to be the most common of identifiable causes of glaucoma.
If PEX is diagnosed without glaucoma, there is a high risk of a patient subsequently developing glaucoma.
Prevalence of PEX varies by geography.
It is reportedly high in northern European countries such as Norway, Sweden and Finland,as well as high among Arabic populations,
It is relatively rare among African Americans and Eskimos.
It affects women more than men, about three times more likely than men to develop PEX.
Older persons are more likely to develop PEX.
Persons younger than 50 are highly unlikely to have PEX.
In Norway the prevalence of PEX of persons aged 50–59 was 0.4% while it was 7.9% for persons aged 80–89 years.
The average age of diagnosis is between 69 and 75 years.
Studies suggest links with Alzheimer’s disease, senile dementia, cerebral atrophy, chronic cerebral ischemia, stroke, transient ischemic attacks, heart disease, and hearing loss.