Retinal Pattern Dystrophy

Excerpt

Retinal pattern dystrophies are a slowly progressive heterogeneous group of primarily autosomal dominantly inherited macular diseases whose unifying element involves the deposition of pigment in the retinal pigment epithelium (RPE) of the macula.

Although findings are classically and most often centered in the macula, pigment deposition may also occur in the periphery. Depending on the distribution pattern, these pattern dystrophies can be separated into major categories or types. These include reticular dystrophy, fundus pulverulentus, butterfly-shaped pigment dystrophy, adult-onset foveomacular vitelliform dystrophy, and multifocal pattern dystrophy simulating Stargardt disease. Interestingly, within a patient, a given pattern may transform into another pattern. Each eye may have distinct patterns, and the same familial mutation can correspond to different phenotypic patterns.

Visual prognosis is typically good in these patients, but due to the location of the pigment deposition in the macula and its slowly progressive nature, there is always the possibility of central vision loss and secondary complications such as choroidal neovascularization and macular holes.

Patients typically remain asymptomatic until the fourth to fifth decade of life, when they may start to notice changes in central vision. The appearance of pattern dystrophies may lead to misdiagnosis as age-related macular degeneration (AMD), especially given that later stages of pattern dystrophies may resemble AMD and pigment deposits can resemble drusen. Distinguishing pattern dystrophies from AMD requires further workup and follow-up.