Visual acuity development of children with infantile nystagmus syndrome.
OBJECTIVE
Infantile nystagmus syndrome (INS) can be idiopathic or associated with ocular or systemic disease. The ocular oscillation of INS directly contributes to loss of visual acuity. In this study, visual acuity development in patients with INS was examined.


METHODS
Children with INS were classified as having idiopathic INS (n = 84) or INS with an associated sensory deficit: INS and albinism (n = 71), bilateral optic nerve hypoplasia (ONH; n = 23), or congenital retinal disorder (n = 36). Visual acuity was assessed with Teller cards and/or optotypes, and the data were analyzed for three age groups (<24 months, 24-48 months, and >48 months).


RESULTS
Patients with idiopathic INS showed mildly reduced visual acuity early in life and gradual maturation with age that paralleled a normative curve. Patients with albinism also showed a mild visual deficit early in life but failed to keep pace with the normative curve, showing a gradual increase in visual acuity deficit. Patients with ONH and congenital retinal disorders exhibited more severe visual acuity deficits during infancy. The ONH group displayed slow improvement of visual acuity with a plateau at 24 months through >48 months, with a small increase in visual acuity deficit. The congenital retinal disorder group had no significant change in visual acuity across age and had a rapid increase in visual acuity deficit.


CONCLUSIONS
The pattern of visual acuity development differs among children with INS, depending on the presence or absence of associated sensory system deficits. Careful characterization of visual system differences in patients with INS is important if visual acuity is an outcome in clinical trials.
Retina Foundation of the Southwest, Dallas, Texas, USA. fuv@upmc.edu
Valeria L N
VL
Fu
Richard A
RA
Bilonick
Joost
J
Felius
Richard W
RW
Hertle
Eileen E
EE
Birch
D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D006801:Humans; D007223:Infant; D020417:Nystagmus, Congenital / Q000503:physiopathology*; D013577:Syndrome; D014786:Vision Disorders / Q000503:physiopathology*; D014787:Vision Tests; D014792:Visual Acuity / Q000502:physiology*