Glaucoma, Pigment Dispersion Syndrome
Patient Information
Characteristics
Background and History
This condition is a form of glaucoma in which pigment released from the iris (the colored part of the eye) is deposited onto various structures such as the lens and cornea. It is also deposited onto the trabecular meshwork, a highly porous structure that allows fluid to escape from the eye to maintain normal pressure. In so doing, the pigment granules clog the pores and, as a result, the pressure in the eye often increases causing glaucoma.
Clinical Correlations
This disease, like most glaucoma conditions, causes no symptoms in the early stages. An eye examination is necessary to detect pigmentary glaucoma which is evident from the scattered pigment on the cornea, the lens, and the angle of the eye. This may be the only evidence of the disease in early stages but then later a rise in pressure inside the eye may occur and this causes damage to the cells of the retina as well as the optic nerve. This rise in pressure is not sufficient to cause pain or other symptoms so regular eye examinations are necessary to measure it. Laser treatments and certain medications in the form of drops can lower the pressure, but if untreated, blindness can result.
Genetics
Inheritance
This disorder can be caused by a gene mutation which is inherited in an autosomal dominant vertical pattern. Parents with the mutation may pass it to their children so anyone with relatives having this disease should have regular eye examinations for early detection. Treatment can be vision-sparing.
Pedigree
Autosomal dominant
Autosomal dominant disorders require only one mutation for the disease to be expressed. Since an affected parent has two chromosomes, only one of which has the mutant gene, parents can expect that half (50%) of their children will receive that one and inherit the disease. It is common for individuals that inherit the mutation, however, to not have evidence of the disease (nonpenetrance).
Autosomal dominant inheritance leads to a vertical pattern of transmission
Diagnosis and Prognosis
The diagnosis can only be made by your ophthalmologist during an eye examination. If abnormal pigmentation is found and the pressure in the eye is normal, it is important to have periodic repeat examinations as advised to detect any pressure increase. This is necessary so that glaucoma treatment can be started before damage to sight occurs since lost vision cannot be restored. The prognosis for preservation of vision is good as long as effective treatment regimens are followed. This condition is not associated with other health problems elsewhere in the body.
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