View abstract

This abstract is assigned to session SBO-BOG Free papers: Genetica/Génétique

Title

Ocular Findings of Primary Oxalosis in Three Children

Purpose	To report on the ophthalmological examination of three children with primary oxalosis type 1. Primary oxalosis is a rare autosomal recessive condition due to a defect in the glyoxalate metabolism.
Methods	Three children in whom a diagnosis of primary oxalosis type 1 was made (one 7-year old boy, and two brothers aged 9 and 14), underwent an extensive ophthalmological evaluation including visual acuity, ophthalmoscopy, OCT, infrared and red-free imaging with HRA2, and pattern-ERG. In addition, in the 7-year old boy a pattern-VEP and a full-field flash ERG were also performed. This patient underwent combined liver-kidney transplantation and started haemodialysis at age 3 months, the two brothers are treated with medication.
Results	BCVA was normal in all patients. Ophthalmoscopy showed multiple yellowish-white flecks at the posterior pole, with retinal pigment epithelium hyperplasia in the center of some in the 7-year old boy. The two other patients only had a very limited amount of small, white intraretinal crystals near retinal vessels. In the single case, OCT confirmed the crystals in the retinal pigment epithelium. These were further highlighted on HRA2 imaging. Pattern-ERG was normal in all patients. In the single case, generalised retinal and optic nerve function was normal as evidenced by full-field flash ERG and pattern-VEP.
Conclusion	Retinal calcium oxalate deposition in children can be easily detected on funduscopy, HRA2 and OCT. However, in the early stage of the disease, both macular and generalised retinal function can be normal. The phenotype varies widely between patients.

Author 1

Last name	DELBEKE
Initials	P
Department	Dept of Ophthalmology, University Hospital
City	Ghent

Author 2

Last name	Raes
Initials	A
Department	Dept of Paediatric Nephrology, University Hospital
City	Ghent

Author 3

Last name	Leroy
Initials	BP
Department	Dept of Ophthalmology, Ctr for Medical Genetics, University Hospital
City	Ghent