Healthy eye in amblyopes has depressed contrast sensitivity, study finds

In patients with amblyopia, the fellow eye behaves abnormally when evaluated for contrast sensitivity functions, according to a study, even after successful treatment for amblyopia in the affected eye.

“Neither the previously amblyopic nor the fellow eyes of successfully treated subjects were comparable with controls,” said Klio I. Chatzistefanou, MD, and colleagues. The researchers tested contrast sensitivity monocularly in both eyes of 48 patients with amblyopia and compared these results with 22 participants who had been successfully treated for amblyopia. The mean age in both groups was about 11 years. For inclusion in the study, visual acuity in the eye with amblyopia had to be 20/40 or better, and 20/20 or better in the fellow eye. Twenty eyes of 20 healthy age-matched participants were used as controls.

Contrast sensitivity functions in the fellow eye of the patients with amblyopia — including those who had never been treated with occlusion therapy — were significantly decreased compared with the control eyes. Eyes that had undergone successful treatment for amblyopia also had significantly lower values compared with the control eyes.

“Occlusion therapy may not be implicated for depressed contrast sensitivity of the fellow eye in amblyopia,” the authors said.

The study is published in the Journal of AAPOS.