Unilateral Crystalline Ischemic Retinopathy Secondary to Primary Hyperoxaluria with Renal Failure and Oxalosis

Primary hyperoxaluria (PH1) is a group of congenital disorders characterized by increased synthesis and excretion of the metabolic end product oxalate, and deposition of calcium oxalate (CaOx) in the kidney and urinary tract 1. PH1 is caused by a deficiency of the liver-specific peroxisomal enzyme alanine glyoxylate aminotransferase and, especially in the case of PH1, renal CaOx deposition is likely to lead to kidney failure, after which the combined effects of increased oxalate synthesis and failure to remove it from the body allow widespread deposition of CaOx throughout the body 2. Retinal CaOx deposits, which cause oxalate retinopathy, are easy to diagnose and may be one of the first obvious signs of systemic oxalosis. Conservative therapy and specific diet aim to decrease endogenous oxalate production and limit exogenous oxalate component intake by avoiding certain food consumption. There is no causal treatment to correct the metabolic defect. Therefore, dialysis is necessarily as a symptomatic treatment and cannot correct the liver enzyme defect. Consequently, combined liver-kidney transplantation (CLKT) has become the treatment of choice that can significantly prevent the progression of systemic oxalosis 3. Although pathophysiologic changes of the retina, especially in the retinal pigment epithelium (RPE), are irreversible, sufficient and opportune therapy might lead to regression of oxalate retinopathy, yet visual impairment may not be improved 4. We report on unilateral retinal ischemia in a patient with unilateral crystalline oxalate retinopathy, secondary to primary hyperoxaluria and oxalosis due to congenital oxalate nephrolithiasis with background of conservative therapy with peritoneal dialysis.