Distinct
eye abnormalities have been described in children with
nephrotic syndrome, particularly in
diffuse mesangial sclerosis (i.e.
Pierson syndrome). The aim of the study was to investigate whether there were any associated ocular anomalies in children with
steroid-resistant nephrotic syndrome (SRNS), all of whom had revealed primary
focal segmental glomerulosclerosis in biopsy. Thirty-three SRNS patients (16 male, 17 female) with a median age of 10.5 years (range 3-25 years) were enrolled in the study. Twenty
steroid-sensitive nephrotic syndrome (SSNS) patients (ten male, ten female) with a median age of 8 years (range 3-15 years) served as controls. All SRNS patients were examined by mutational analysis for mutations in the NPHS2, WT1, and LAMB2 genes. Nine out of 33 SRNS patients (27.2%) showed various
eye abnormalities. However, no abnormal ocular findings were detected in any of the SSNS patients. Abnormal eye findings detected in SRNS patients were
anisometropic amblyopia (n = 4), Mittendorf's dots (n = 4),
myopic astigmatism (n = 3) and
exotropia (n = 1).
Macular pigment changes (n = 1), posterior subcapsular opacities (n = 1) and
cataract (n = 1) were considered as
steroid-induced side effects. In four patients, more than one
eye abnormality was found. Mutational analysis for the NPHS2, WT1 and LAMB2 genes revealed disease-causing mutations in 24.2% of patients. Homozygous NPHS2 mutations were detected in five patients (15.1%), all of whom had parental consanguinity. In three patients (9%) from non-consanguineous parents, heterozygous de novo WT1 mutations were detected as disease-causing mutations. No LAMB2 mutation was detected in any patient. While four out of five (80%) patients with homozygous NPHS2 mutations showed at least one abnormal ocular finding (i.e. Mittendorf's dot or anisometric
amblyopia), none of the patients with a WT1 mutation had ocular involvement. In conclusion, ocular involvement may accompany SRNS caused by primary
focal segmental glomerulosclerosis (FSGS). Ophthalmologic evaluation at the time of diagnosis might be beneficial to characterize further the spectrum of this possible association.