title: Tangent screen perimetry in the evaluation of visual field defects associated with ptosis and dermatochalasis.
abstract: OBJECTIVE
  To determine if tangent visual fields gathered during assessment of superior visual field deficits caused by blepharoptosis and dermatochalasis offer good correlation to clinical exam in a time and cost efficient manner.
  
  
  METHODS
  Prospective, observational case series. Subjects included all patients referred to a single surgeon (CCN) who underwent surgical correction of blepharoptosis and/or dermatochalasis. Preoperatively and postoperatively, upper margin-to-reflex distances were assessed. Tangent visual fields were performed in a timed fashion and analyzed for degrees of intact vision in the vertical meridian and degrees squared of area under the curve. Data were compared by Student t-tests and Pearson correlation coefficients.
  
  
  RESULTS
  Mean preoperative superior visual fields with the eyelid in the natural position measured 8° in the vertical meridian. Measurements in the vertical meridian and area under the curve showed excellent correlation (r = 0.87). Patients with ptosis showed strong correlation between margin-to-reflex distance and superior visual fields. Patients completed field testing faster than reported times for automated or Goldmann testing. Finally, tangent screens were the least expensive type of equipment to purchase.
  
  
  CONCLUSIONS
  Tangent visual fields are a rapid and inexpensive way to test for functional loss of superior visual field in patients with upper eyelid malposition. Our data revealed potential differences between tangent screen results and published results for automated or Goldmann visual field testing which warrants further studies.
authors.affiliation: Department of Ophthalmology, Wake Forest Baptist Health, Winston-Salem, North Carolina, United States of America.|Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota, United States of America.|Department of Ophthalmology, Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan, United States of America.
authors.forename: Molly L
authors.identifier: http://orcid.org/0000-0002-9739-5699
authors.initials: ML
authors.lastname: Fuller
authors.affiliation: Department of Ophthalmology, Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan, United States of America.
authors.forename: César A
authors.initials: CA
authors.lastname: Briceño
authors.affiliation: Department of Ophthalmology, Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan, United States of America.
authors.forename: Christine C
authors.initials: CC
authors.lastname: Nelson
authors.affiliation: Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota, United States of America.
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Bradley
mesh_terms: D019882:Blepharoplasty / Q000379:methods; D001763:Blepharoptosis / Q000503:physiopathology* / Q000601:surgery; D005143:Eyelids / Q000503:physiopathology / Q000601:surgery; D006801:Humans; D011184:Postoperative Period; D057234:Preoperative Period; D011446:Prospective Studies; D015203:Reproducibility of Results; D014786:Vision Disorders / Q000503:physiopathology* / Q000601:surgery; D014785:Vision, Ocular; D058609:Visual Field Tests / Q000379:methods*; D014794:Visual Fields