Definition: Pattern dystrophies are inherited in an autosomal dominant fashion and they involve the Retinal Pigment Epithelium (RPE) and the external macular retina. Pattern dystrophies represent a group of disorders that present in midlife with mild visual disturbances in one or both eyes. Since patients present later in life with this condition, they are often misdiagnosed as having Age-Related Macular Degeneration. Inherited pattern macular dystrophies are not a form of AMD, but they do share many important features with ARMD. These patients present with various patterns of yellow, orange or gray pigment deposits in the macular area.
Causes: Based on the pattern of pigment distribution in the macula, this disease has been subdivided into five principle groups:
Group 1: adult-onset foveomacular vitelliform dystrophy.
Group 2: butterfly-shaped pigment dystrophy.
Group 3: reticular dystrophy of the RPE.
Group 4: multifocal pattern dystrophy simulating fundus flavimaculatus.
Group 5: fundus pulverulentus.
Patients with pattern dystrophies may show different patterns between the two eyes. They may even show progression from one pattern to another over several years. Patients can have a pattern dystrophy in just one eye since it may not yet have presented in the fellow eye. The presence of different pattern dystrophies within the same family suggests a common etiologic continuum. Pattern dystrophies of the retinal pigment epithelium, an arrangement of a pattern of dots, lines, or branches, are infrequent fundus abnormalities.
Signs & Symptoms:
- possible visual loss or disturbances
- possible distortion
- many patients do not experience symptoms
- Retinal examination
- Visual acuity
- Direct and indirect ophthalmoscopy
- Slit lamp examination
- Fluorescein Angiogram
Treatment: Management should include photodocumentation, laser intervention (if there is choroidal neovascularization), and genetic counseling. There should be annual follow-up.