title: Binocular inhibition in strabismic patients is associated with diminished quality of life.
abstract: To characterize the relationship between binocular summation (BiS) and binocular inhibition (BI) on the quality of life of adults and children with strabismus.
  
  
  
  Strabismus patients at a single center from 2010 to 2012 were prospectively enrolled. A BiS score was measured using ETDRS and Sloan low-contrast visual acuity (LCA) protocols at 2.5% and 1.25% contrast. Patients were categorized as having BiS (binocular better than better-eye visual acuity by ≥5 letters), BI (binocular worse than better-eye visual acuity by ≥5 letters), or otherwise indeterminate visual acuity (a difference between binocular visual acuity and monocular visual acuity of the better eye of <5 letters). Quality of life was evaluated by the National Eye Institute Visual Functioning Questionnaire 25 (VFQ-25), 20-item Adult Strabismus Questionnaire (AS-20), and the Amblyopia and Strabismus Questionnaire.
  
  
  
  A total of 108 patients were included. There was no significant BiS or BI for high-contrast ETDRS or 2.5% LCA tests; however, a mean BiS score of -2.14 ± 7.0 letters for 1.25% LCA demonstrated significant binocular inhibition (P = 0.004) for this contrast level. The mean composite VFQ-25 score was significantly lower in subjects with BI on ETDRS (80 ± 19 vs 57 ± 7 for subjects with BiS and BI, resp. [P = 0.03]), 2.5% LCA (81 ± 14 vs 66 ± 16 for subjects with BiS and BI, resp. [P = 0.01]), and 1.25% LCA tests (91 ± 9 vs 72 ± 14 for subjects with BiS and BI, resp. [P = 0.005]). After accounting for potential covariates, significant association persisted for BI, demonstrated by 1.25% LCA (P = 0.01). With BI demonstrable at 2.5%, AS-20 scores were also significantly lower (P = 0.04).
  
  
  
  Strabismic patients with BI had significantly lower quality-of -life scores than those who did not, even after accounting for potential covariates and the absence of diplopia.
authors.affiliation: Department of Ophthalmology, Jules Stein Eye Institute, University of California-Los Angeles, Los Angeles.
authors.forename: Anika K
authors.initials: AK
authors.lastname: Tandon
authors.affiliation: Department of Ophthalmology, Jules Stein Eye Institute, University of California-Los Angeles, Los Angeles.
authors.forename: Federico G
authors.initials: FG
authors.lastname: Velez
authors.affiliation: Department of Ophthalmology, Jules Stein Eye Institute, University of California-Los Angeles, Los Angeles.
authors.forename: Sherwin J
authors.initials: SJ
authors.lastname: Isenberg
authors.affiliation: Department of Ophthalmology, Jules Stein Eye Institute, University of California-Los Angeles, Los Angeles; Department of Neurology, University of California-Los Angeles; Neuroscience Interdepartmental Program, University of California-Los Angeles; Bioengineering Interdepartmental Program, University of California-Los Angeles.
authors.forename: Joseph L
authors.initials: JL
authors.lastname: Demer
authors.affiliation: Department of Ophthalmology, Jules Stein Eye Institute, University of California-Los Angeles, Los Angeles.
authors.forename: Stacy L
authors.initials: SL
authors.lastname: Pineles
mesh_terms: D002648:Child; D002675:Child, Preschool; D015350:Contrast Sensitivity / Q000502:physiology; D004948:Esotropia / Q000523:psychology*; D005099:Exotropia / Q000523:psychology*; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D011446:Prospective Studies; D011788:Quality of Life / Q000523:psychology*; D018434:Sickness Impact Profile; D011795:Surveys and Questionnaires; D015348:Vision, Binocular / Q000502:physiology*; D014792:Visual Acuity / Q000502:physiology