title: Interocular suppression in children with deprivation amblyopia.
abstract: In patients with anisometropic or strabismic amblyopia, interocular suppression can be minimized by presenting high contrast stimulus elements to the amblyopic eye and lower contrast elements to the fellow eye. This suggests a structurally intact binocular visual system that is functionally suppressed. We investigated whether suppression can also be overcome by contrast balancing in children with deprivation amblyopia due to childhood cataracts. To quantify interocular contrast balance, contrast interference thresholds were measured using an established dichoptic global motion technique for 21 children with deprivation amblyopia, 14 with anisometropic or mixed strabismic/anisometropic amblyopia and 10 visually normal children (mean age mean=9.9years, range 5-16years). We found that interocular suppression could be overcome by contrast balancing in most children with deprivation amblyopia, at least intermittently, and all children with anisometropic or mixed anisometropic/strabismic amblyopia. However, children with deprivation amblyopia due to early unilateral or bilateral cataracts could tolerate only very low contrast levels to the stronger eye indicating strong suppression. Our results suggest that treatment options reliant on contrast balanced dichoptic presentation could be attempted in a subset of children with deprivation amblyopia.
authors.affiliation: School of Optometry and Vision Science, University of Auckland, New Zealand.
authors.forename: Lisa
authors.initials: L
authors.lastname: Hamm
authors.affiliation: State Key Laboratory of Ophthalmology, Guangdong Provincial Key Lab of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong, China.
authors.forename: Zidong
authors.initials: Z
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Ophthalmology, Guangdong Provincial Key Lab of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong, China.
authors.forename: Jinrong
authors.initials: J
authors.lastname: Li
authors.affiliation: School of Optometry and Vision Science, University of Auckland, New Zealand.
authors.forename: Joanna
authors.initials: J
authors.lastname: Black
authors.affiliation: Department of Ophthalmology, University of Auckland, New Zealand.
authors.forename: Shuan
authors.initials: S
authors.lastname: Dai
authors.affiliation: State Key Laboratory of Ophthalmology, Guangdong Provincial Key Lab of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong, China.
authors.forename: Junpeng
authors.initials: J
authors.lastname: Yuan
authors.affiliation: State Key Laboratory of Ophthalmology, Guangdong Provincial Key Lab of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong, China. Electronic address: yuminbin@126.com.
authors.forename: Minbin
authors.initials: M
authors.lastname: Yu
authors.affiliation: School of Optometry and Vision Science, University of Auckland, New Zealand; School of Optometry and Vision Science, University of Waterloo, Canada. Electronic address: ben.thompson@uwaterloo.ca.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Thompson
mesh_terms: D000221:Adaptation, Ocular / Q000502:physiology*; D000293:Adolescent; D000550:Amblyopia / Q000503:physiopathology* / Q000628:therapy; D002648:Child; D002675:Child, Preschool; D015350:Contrast Sensitivity / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D010775:Photic Stimulation / Q000379:methods; D012684:Sensory Thresholds / Q000502:physiology; D015348:Vision, Binocular / Q000502:physiology; D014792:Visual Acuity / Q000502:physiology
keywords: Amblyopia; Childhood cataract; Interocular contrast balance; Interocular suppression; Suppression