Oxalate retinopathy is irreversible despite early combined liver‐kidney transplantation in primary hyperoxaluria type 1

In primary hyperoxaluria type 1 ( PH 1), systemic oxalate deposition (oxalosis) in end‐stage renal disease ( ESRD ) is associated with high morbidity and mortality, particularly in children with infantile oxalosis ( IO ). Combined liver and kidney transplantation ( CLKT ) is the only curative treatment option in these patients. After CLKT , systemic oxalosis decreases continuously, although only insufficient data are available regarding oxalate retinopathy ( RO x), leading to severe visual impairment. We analyzed long‐term follow‐up data of RO x in 13 patients undergoing CLKT for PH 1 at our center between 1998 and 2018. Age at transplantation was 1.3‐14.2 years, including nine patients with IO . We performed visual acuity testing, slit lamp investigation, funduscopy, fundus photography, and spectral‐domain optical coherence tomography (SD‐ OCT) imaging. Severe (grade 2‐4) RO x was present in all nine children with IO but not in the four patients developing ESRD in adolescence. A significant negative correlation was found between age at onset of ESRD and grade of RO x ( r  = −0.66; P  < .001). Notably, follow‐up assessment after CLKT demonstrated no regression of RO x after a median of 5.3 years (range 0.6‐14). The data show that despite early CLKT in IO , RO x is irreversible and the concomitant visual deterioration occurs prior to transplantation.