ABSTRACT
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).
Subject(s)
Contrast Sensitivity/physiology , Exotropia/physiopathology , Photophobia/physiopathology , Child , Exotropia/surgery , Female , Fixation, Ocular/physiology , Glare , Humans , Light , Male , Mesopic Vision/physiology , Oculomotor Muscles/surgery , Ophthalmologic Surgical Procedures , Vision, Binocular/physiology , Visual Acuity/physiologyABSTRACT
PURPOSE: This study examined the rate of binocular photophobia in intermittent exotropia patients before surgical correction, and the factors affecting this rate. The study also investigated the factors affecting postsurgical disappearance of binocular photophobia. METHODS: The study involved 162 basic type intermittent exotropia patients who underwent surgical correction between March 2001 and January 2006. The study did not include patients with entropion, congenital cataract, or retinal abnormalities. Parents of the patients were questioned to determine which patients had monocular eye closure in bright light and which had disappeared after bilateral lateral rectus recession. Data was analyzed to determine the factors affecting monocular eye closure before surgery and disappearance after surgery. RESULTS: Of 162 patients, 96 patients had binocular photophobia (60.2%). Photophobia was found to be associated with an angle of exodeviation at distance >25 Prism Diopter (Delta) (p = 0.02), and stereoacuity worse than 60 s (p = 0.02). We defined satisfactory surgical outcome as a deviation of <10 Delta. Of the 81 patients with satisfactory outcomes, 46 showed disappearance of binocular photophobia (53.5%). No factor was found to be associated with loss of binocular photophobia. CONCLUSION: The angle of strabismus and stereoacuity were found to affect the occurrence of binocular photophobia. Successful surgery treated binocular photophobia in 53.5% of patients. Regardless of the surgical result, clinicians should educate patients in terms of the possibility of persistence of postsurgical photophobia.
