Gyrate Atrophy-Like Phenotype: Normal Plasma Ornithine and Retinal Crystals

To report an unusual case of a gyrate atrophy-like presentation with retinal crystal deposition in a patient with normal plasma ornithine levels.

A 50-year-old Hispanic female patient presented with complaints of blurred vision and nyctalopia. Examination revealed bilateral multiple round islands of peripheral chorioretinal degeneration in addition to small crystal-like deposits in the posterior pole. Spectral domain optical coherence tomography confirmed the crystalline deposits to be above the retinal pigment epithelium. Electrophysiology revealed reduced photopic responses with no recordable scotopic response. Testing for elevated plasma ornithine, which is typical in gyrate atrophy patients, was performed; however, the patient's levels were normal.

Diagnosis of conditions that cause nyctalopia can be challenging because they are rare and often similar in appearance and presenting symptoms. Retinal crystal deposition and normal plasma ornithine illustrate the phenotypical variation that can be seen in a gyrate atrophy-like phenotype.