This 13 YO girl presented with bilateral blurred vision. Vision was 20/80 OD and 20/60 OS.
Fundus photography shows variably coalescent, scalloped areas of bilateral chorioretinal atrophy extending from the distal maculas into each periphery. The large outer choroidal vessels are dramatically imaged within these areas of atrophy on fluorescein angiography.
OCT showed bilateral cystoid macular edema. Oral Diamox and topical non-steroidal eye drops were started. Six weeks later, the edema resolved with some subjective improvement but no change in vision. She was subsequently lost to follow-up.
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 deficiency of a vitamin B6-dependent mitochondrial ornithine aminotransferase, leading to elevated ornithine levels. Vitamin B6 supplementation and an arginine-restricted diet may slow the disease progression in some patients.
