Gyrate Atrophy

This 6YO girl has a history of night blindness, and her twin brother has a history of milestones delay and seizures. Family history was suggestive of consanguinity. The girl’s vision was 20/120 OD and 20/80 OS, and 20/120 OU in the boy.

The girl’s fundus photography shows variably coalescent, scalloped areas of bilateral chorioretinal atrophy extending from the peripheral maculas into each periphery. OCT shows bilateral cystic retinal edema primarily in the inner and outer nuclear layers. There are shallow poster staphylomas. Her brother shows similar findings, but without the staphylomas.

Blood tests of both siblings revealed a deficiency of the ornithine aminotransferase (OAT) enzyme. Topical non-steroidal anti- inflammatory eye drops were started along with an arginine-free diet and B6 supplementation.

Learning Points:
Gyrate atrophy is a rare autosomal recessive retinal dystrophy, characterized by extensive areas of lobular peripheral chorioretinal degeneration that gradually spread posteriorly. Macular involvement on OCT is common, with foveal thickening in younger patients followed by atrophy with outer retinal tubulation later in life (Sergouniotis et al, Ophthalmology 2012;119:596-605).

End-stage disease can be indistinguishable from choroideremia. Other findings include myopia and night blindness. The degeneration is caused by a lack of a vitamin B6-dependent ornithine aminotransferase mitochondrial enzyme, which leads to elevated ornithine levels. Vitamin B6 supplementation and an arginine-restricted diet

This 88YO female presented with 20/200 vision OD and 20/50 vision OS. Although she complained of nyctalopia since childhood, her vision was good throughout her life up until about a year ago. There was no family history of eye disease.

She had bilateral large islands of scalloped chorioretinal atrophy throughout the mid-peripheral fundi, with extension more posteriorly and inferiorly in the right eye. The areas of chorioretinal atrophy are hypoautofluorescent.

Learning Points:
The history of night blindness with scalloped areas of atrophy is consistent with gyrate atrophy, although patients usually progress to much more severe macular atrophy and vision loss.

Our patient may also have late-onset retinal macular degeneration (LORMD or LORD), which is a rare autosomal-dominant mutation in the tumor necrosis factor-related protein 5 (C1QTNF5) gene, which is expressed in the RPE. LORMD/LORD presents in the fifth to sixth decades with bilateral night blindness and drusen-like deposits throughout the fundi. Islands of atrophy, resembling gyrate atrophy, develop over time.

We will likely order plasma ornithine levels, which should be elevated if she has gyrate atrophy. Regardless of the etiology, however, no treatment is indicated.

This patient has gyrate atrophy, a rare autosomal recessive retinal dystrophy characterized by extensive areas of lobular peripheral chorioretinal degeneration that gradually spread posteriorly.

Learning Points:
Gyrate atrophy is caused by a lack of a vitamin B6-dependent ornithine aminotransferase mitochondrial enzyme, which leads to elevated ornithine levels.

Vitamin B6 supplementation and an arginine-restricted diet may slow the disease progression in some patients.

End-stage gyrate atrophy can be indistinguishable from choroideremia. Other findings include myopia and night blindness.