Efficacy of an Amblyopia Treatment Program with Both Eyes Open: A Functional Near-Infrared Spectroscopy Study.

INTRODUCTION AND PURPOSE

To investigate the efficacy of an amblyopia treatment program with both eyes open.

METHODS

Ten subjects (mean age 20.5 ± 1.5 years) were enrolled. All subjects had un-remarkable ophthalmic examinations, but several subjects had minor refractive errors. Vision function was evaluated using the 3-D visual function trainer-ORTe. Brain measurements were made using functional near-infrared spectroscopy (fNIRS) to examine the oxygenated hemoglobin (HbO) concentration change upon visual stimulus presentation. The three conditions were as follows: both eyes open and both eyes stimulated, both eyes open and only one eye stimulated, and one eye open and one eye stimulated.

RESULTS

Changes in HbO2 between the rest and stimulation phases were not statistically different between the unilateral and bilateral stimulation conditions with both eyes open. However, HbO change was significantly higher in subjects with both eyes open than in subjects with one eye closed (P < 0.001, all comparisons).

CONCLUSION

Greater activation of the visual cortex is achieved when subjects are treated with both eyes open as compared to subjects with one eye occluded. From a perspective of functional brain activation, amblyopia treatment administered without occluding the healthy eye may provide the greatest therapeutic benefit.