



Pigment dispersion syndrome: transillumination of the iris

In pigment dispersion syndrome, pigment agglomerates separate from the iris, allowing light to pass through and be reflected in the background. Credits: OPTH

The human optical system is a complex arrangement of several anatomical components working in concert, and the pathological disorders of which it can be reached are equally complex in their turn. This is particularly the case of a rare disease, the syndrome of dispersion of pigments, which causes a depigmentation of the iris and its transillumination. In other words, exposed to light, the iris glows in a singular way. Recently, a team of doctors described the case of a particularly severe form of this syndrome.According to the doctors' analysis, this strange appearance turned out to be the sign of a rare disorder that caused the disappearance of the pigmentation of the eye. The 44-year-old man went to a clinic after moving to a new area to get an appointment with an ophthalmologist.He said he has a family history of glaucoma, an eye disease that can damage the optic nerve, the bundle of nerve fibers that connects the back of the eye to the brain. This damage is usually caused by increased eye pressure. Indeed, according to the authors of the article published in The New England Journal of Medicine , the man had already been diagnosed with high eye pressure and was taking medication to reduce it.Nevertheless, tests revealed that the pressure in his eye was very slightly higher than normal. In addition, when the doctor performed an eye examination using a microscope and a bright light, the evaluation revealed "transillumination of the iris" in both eyes of the patient. In other words, the light shone through the iris. This occurs when sections of pigment are missing at the iris, allowing the light to pass through.Doctors have diagnosed in humans a syndrome of dispersion of pigments. According to this eye condition, the pigment is detached from the back of the iris. These pigment clumps can clog the drainage system of the eye, causing an increase in eye pressure, which can lead to glaucoma. Pigment dispersion syndrome is rare, although it is more commonly diagnosed in men aged 20 to 30 and may have a genetic component.In this case, the man was laser treated to open the drainage channels of the blocked eyes. This therapy helps liquids to flow out of the eye and reduces eye pressure. However, patients often need to continue taking pressure-reducing eye medication after surgery, as was the case for this patient.