Retinal Pigment Epitheliopathy
Diffuse damage to the retinal pigment epithelium (RPE), which anchors the photoreceptors, occurs in many hereditary, intra-uterine inflammatory, and acquired toxic-metabolic disorders. Two retinal areas are most vulnerable: the mid-peripheral (equatorial) and the perifoveal regions.
Notice that the retinal arterioles are very thin compared to those of the . This arteriolar narrowing is particularly common in advanced hereditary disorders of the RPE.
Damage to the RPE causes the RPE to migrate into the superficial retina. The black pigment flecks are particularly evident in the retinal mid-periphery.
The combination of RPE loss and migration produces the "salt and pepper" fundus. The pepper may be , as in the hereditary degenerations, or , as in the intra-uterine inflammations like rubella. Depending on the degree of damage, the patient with peripheral retinal pigment epitheliopathy may be asymptomatic or have profound loss of night vision and construction of the visual field.
In the perifoveal region, you will sometimes see a grayish-brown halo that looks like a . Patients may notice blurred vision just off center. Eventually the foveal region itself becomes damaged and visual acuity falls.