Calcium oxalate retinopathy associated with methoxyflurane abuse.

A 34-year-old woman developed a crystalline retinopathy after 2 years of inhalational abuse of methoxyflurane. After the woman developed renal failure, a renal biopsy showed multiple birefringent crystals in the renal tubular lumens, epithelial cells, and interstitium compatible with calcium oxalate. Multiple bright yellow-white crystals were deposited throughout the retina and at the level of the retinal pigment epithelium with a retinal arterial and periarterial predilection. This is the first reported case of methoxyflurane abuse with secondary hyperoxaluria in which there was a widespread retinal distribution of crystalline deposits, especially along the retinal arteries and arterioles.