The ocular phenotype in primary hyperoxaluria type 1

Abstract Purpose To investigate ophthalmic features in a large group of patients with primary hyperoxaluria type 1 (PH1), and to determine the relation between ocular involvement and systemic disease severity. Design Retrospective, cross-sectional multicenter study of the OxalEurope Registry Network. Methods Sixty-eight patients with PH1 were included Infantile PH1 was diagnosed in 12 patients, and non-infantile PH1 in 56 patients (17 with end-stage renal disease) Ophthalmic examination included best corrected visual acuity (BCVA) testing and multimodal retinal imaging including fundus photography and optical coherence tomography (OCT) In selected cases fundus autofluorescence (AF) imaging was performed. Results All eyes (n=24) of infantile PH1 patients revealed severe retinal alterations and oxalate deposits, including macular crystals and hyperpigmentations (n=9, 38%), subretinal fibrosis (n=15, 63%) with (n=7, 47%) or without (n=8; 53%) associated chronic retinal edema In 9 eyes (38%, all with subretinal fibrosis), BCVA was significantly reduced ( Conclusions Severe ocular alterations occur in infantile cases, whereas mild or no ocular alterations are typical in non-infantile PH1 patients The natural history of (sub-) retinal oxalate deposits, the pathogenesis of subretinal fibrosis, and exact factors influencing the overall severity of ocular disease manifestation remain to be determined.