OBJECTIVE: Amblyopia or lazy eye is a common visual problem affecting children 
that cannot correct with lenses. Nitric oxide synthase (NOS) is a critical 
enzyme that regulates the activity of nitric oxide (NO), a key signaling 
molecule with multiple roles in many tissues. Among its many activities, NOS has 
been proposed to be required for normal eye development and altered NOS 
expression can lead to perturbations in eye development and vision.
MATERIALS AND METHODS: To examine the potential role of neuronal NOS (nNOS) in 
vision loss, we generated a model of monocular deprivation amblyopia in rats. 
After suturing one eye, we examined several parameters of neural activity and 
nNOS expression in the retina 7, 14 and 28 days later.
RESULTS: We found the rapid and progressive loss of neural activity in the 
retina of sutured eyes compared to non-treated and control eyes. The sutured 
eyes also showed decreased expression of nNOS at the protein and mRNA levels, 
indicating a strong correlation between nNOS expression and retina activity.
CONCLUSIONS: These data suggest a potential role for nNOS activity in vision 
loss, opening potential avenues for therapeutic intervention.