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

In primary hyperoxaluria type 1 (PH1), 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 (ROx), leading to severe visual impairment. We analyzed long-term follow-up data of ROx in 13 patients undergoing CLKT for PH1 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) ROx 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 ROx (r = -0.66; P < .001). Notably, follow-up assessment after CLKT demonstrated no regression of ROx after a median of 5.3 years (range 0.6-14). The data show that despite early CLKT in IO, ROx is irreversible and the concomitant visual deterioration occurs prior to transplantation.