title: Binocular visual function in patients with Boston type I keratoprostheses.
abstract: OBJECTIVE
  To report the postoperative binocular function of patients with Boston type I keratoprostheses implantation for unilateral visual impairment.
  
  
  METHODS
  Seventeen patients who underwent implantation of a Boston type I keratoprosthesis and had a best-corrected visual acuity better than 20/50 in the contralateral eye before surgery were evaluated. All subjects prospectively underwent sensory testing of binocular function including Bagolini lenses, Worth-4-dot test, stereoacuity at distance and near, and double Maddox rods. In addition, an assessment of ocular rotations and alignment was performed on each subject.
  
  
  RESULTS
  Twenty patients with best-corrected visual acuity better than 20/50 in the contralateral eye at the time of keratoprothesis surgery were identified. Seventeen of the 20 patients underwent binocular visual testing, with 16 of 17 (94%) demonstrating binocular function. Second-degree fusion at near was demonstrated via the Worth-4-dot test in 13 of 17 (76%) patients. Third-degree fusion at near was demonstrated in 7 of 17 (41%) patients. Patients with better postoperative sensory binocular function tended to be of younger age (P = 0.05) and have better postoperative visual acuity (P = 0.006). Five patients were found to have some degree of ocular misalignment. Overall, patients with strabismus had worse binocularity (P = 0.04).
  
  
  CONCLUSIONS
  Implantation of the Boston type I keratoprosthesis in patients with good preoperative visual acuity in the fellow eye is associated with useful binocular function in greater than 90% of patients.
authors.affiliation: Department of Ophthalmology and Jules Stein Eye Institute, University of California, Los Angeles, CA, USA.
authors.forename: Stacy L
authors.initials: SL
authors.lastname: Pineles
authors.forename: Noa
authors.initials: N
authors.lastname: Ela-Dalman
authors.forename: Arthur L
authors.initials: AL
authors.lastname: Rosenbaum
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Aldave
authors.forename: Federico G
authors.initials: FG
authors.lastname: Velez
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001187:Artificial Organs; D003316:Corneal Diseases / Q000503:physiopathology / Q000534:rehabilitation*; D003867:Depth Perception / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D019736:Prostheses and Implants; D019919:Prosthesis Implantation; D014786:Vision Disorders / Q000503:physiopathology / Q000534:rehabilitation*; D014787:Vision Tests; D015348:Vision, Binocular / Q000502:physiology*; D014792:Visual Acuity / Q000502:physiology*; D055815:Young Adult