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Updated: May 15, 2026

The Measurement and Treatment of Suppression in Amblyopia
Published on: December 14, 2012
Photophobia measurement in intermittent exotropia using the contrast sensitivity test
Seung Ah Chung1, Soolienah Rhiu, Seung Han Han
1Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Korea.
Background:
To assess the presence and extent of photophobia in children with intermittent exotropia (X[T]) using the contrast sensitivity test.
Methods:
Fifty-eight children with X(T) and 34 normal controls were studied with the functional acuity contrast test. Each participant viewed the stimuli of contrast monocularly and binocularly under photopic and mesopic conditions, performed with and without glare. Photophobia was defined as a reduction of contrast sensitivity caused by glare light. We compared the photophobia of children with X(T) to that of normal controls, and to the photophobia 3 months after muscle surgery.
Results:
With stimuli of glare, the contrast sensitivity of children with X(T) was suppressed at intermediate spatial frequencies under mesopic condition (p = 0.006 for 6 cycles per degree [cpd], p = 0.027 for 12 cpd), whereas that of normal controls showed no difference. It occurred when X(T) patients viewed targets binocularly, and significantly improved after strabismus surgery (p = 0.003 at 6 cpd). The measured photophobia of X(T) was strongly correlated to the photophobia symptoms reported by parents (p = 0.002).
Conclusions:
The mesopic contrast sensitivity with glare can represent the photophobia of children with X(T). Contrast sensitivity may be a useful measure for monitoring symptoms related to X(T).

