Pseudoexfoliation Syndrome (Exfoliation Syndrome)

Dr Ben Wild

Overview

Just like a soccer ball, the eye must stay pressurized to function properly. Normally, the eye is inflated by the production of fluid, called the aqueous humor. This fluid circulates around the inside of the eye providing nutrients and removing wastes created by many eye structures. It exits at the root of the iris, the colored part of the eye, called Schlemm’s canal. Schlemm’s canal is separated from the inner contents of the eye via a fine sieve, called the trabecular meshwork. The interplay between aqueous humor production and the resistance created by the density of the trabecular meshwork creates the pressure inside the eye.

Front view (left) and sagittal view (right) of a healthy eye.

Pseudoexfoliation syndrome, is a condition whereby fibrous material leaks from the blood vessels of the eye and accumulates on many ocular structures including the conjunctiva, cornea, iris, lens, zonules, and trabecular meshwork. This material can cause early cataracts, can weaken the zonules that hold the lens in place making cataract surgery more difficult, and can clog the trabecular meshwork leading to higher eye pressures and glaucoma in 50-60% of affected individuals. It is rarely noticed before 50 years old. It is now becoming known as exfoliation syndrome because this fibrous material has also been noticed in skin, blood vessels, lungs, and the brain and has been associated with Alzheimer’s disease and hearing loss.

Frontal view showing pigment granules on the cornea and exfoliative material on the iris (left) and sagittal view showing the exfoliative material and pigment within the eye (right).

Signs and Symptoms

Signs

White fibrous material on the lens, iris, and trabecular meshwork, loss of iris pigment, pigment granules on the cornea.

Symptoms

Usually, no symptoms but can cause blurry vision and halos from developing cataracts and progressive blind spots from glaucoma.

Causes and Risk Factors

Causes

Fibrous material leaking from blood vessels within the eye or other parts of the body.

Risk factors

Low levels folate in the blood, female gender, Scandinavian decent.

Prevention and Treatment

Prevention

There is no known way to prevent pseudoexfoliation but treatments can ensure it does not lead to glaucoma.

Treatments

· Regular glaucoma testing with imaging and peripheral vision testing every 6-12 months.

· Glaucoma drops that lower eye pressure.

· Laser trabeculoplasty removes the fibrous material in the trabecular meshwork.

Prognosis

Exfoliation syndrome itself causes early cataracts and makes cataract surgery more difficult, although still possible. It leads to glaucoma in only about 50% of individuals but this type of glaucoma has a worse prognosis than primary open angle glaucoma because the condition is so variable and difficult to treat. Eye pressures tend to fluctuate dramatically day-day or even within a single day and therefore a treatment may be initiated based on erroneous pressure measurements. Typically though, treatment can ensure glaucoma never advances to a point where the effects can harm day to day life.