Pattern Dystrophy

Pattern Dystrophy
SYMPTOMS Typically asymptomatic but can cause slow progressive central vision loss and metamorphopsia (typically starting at the age of 50 or 60 years old)
Rarely sudden central vision loss can occur due to a choroidal neovascular membrane
SIGNS Typically bilateral
There are 5 main types of pattern dystrophies
Adult-Onset Foveomacular Vitelliform Dystrophy (most common type of pattern dystrophy): Yellowish round/oval lesion in the macula region, RPE proliferation may also be present
Butterfly-Shaped Pigment Dystrophy: Yellowish and pigmented flecks in a butterfly pattern at the macula
Reticular Dystrophy: Network of RPE pigment that extends from the macula and goes throughout the posterior pole
Multifocal Pattern Dystrophy: Yellow-white flecks throughout the posterior pole especially along the vascular arcades
Fundus Pulverulentus: Mottling with punctate areas of RPE pigment in the macula region
There is a risk of developing chorioretinal atrophy and choroidal neovascular membranes at the macula in all types of pattern dystrophies
WORK-UP Full eye exam with dilated retinal exam, OCT analysis of the macula, OCT-Angiography, Fluorescein Angiography, Indocyanine Green Angiography, Fundus Autofluorescence, Fundus photos, Infrared retinal imaging, Watzke-Allen test, Macular photostress test, Dark adaptation, Microperimetry, Electrodiagnostic testing (ERG, EOG), Amsler grid
TREATMENT There is no known treatment available
Give take home Amsler grid in order to monitor for change
Begin ocular vitamins
Refer to a retinal specialist for intravitreal anti-VEGF injections if a choroidal neovascular membrane is present
FOLLOW-UP If monitoring pattern dystrophies, the patient should be seen back in 6-12 months
If macula is stable following treatment by retinal specialist, patient should be seen back in 6 months
ADDITIONAL LAB | TESTS Typically none but should consider ruling out Pseudoxanthoma Elasticum and Myotonic Dystrophy as these conditions are linked with pattern dystrophies
ETIOLOGY Autosomal dominant condition that causes disruption of the RPE which leads to an accumulation of lipofuscin
DIFFERENTIAL DX Age-related macular degeneration, Best disease, Stargardt disease, Syphilitic retinitis
NOTES Most patients with pattern dystrophies retain good vision
Pattern dystrophies are commonly misdiagnosed as age-related macular degeneration especially in younger patients
Each type of pattern dystrophy can turn into a different pattern dystrophy
A different type of pattern dystrophy can be found in each eye
Pattern Dystrophy: OCT of the macula demonstrating Adult-Onset Foveomacular Vitelliform Dystrophy