title: Corneal permeability changes in dry eye disease: an observational study.
abstract: BACKGROUND
  Diagnostic tests for dry eye disease (DED), including ocular surface disease index (OSDI), tear breakup time (TBUT), corneal fluorescein staining, and lissamine staining, have great deal of variability. We investigated whether fluorophotometry correlated with previously established DED diagnostic tests and whether it could serve as a novel objective metric to evaluate DED.
  
  
  METHODS
  Dry eye patients who have had established signs or symptoms for at least 6 months were included in this observational study. Normal subjects with no symptoms of dry eyes served as controls. Each eye had a baseline fluorescein scan prior to any fluorescein dye. Fluorescein dye was then placed into both eyes, rinsed with saline solution, and scanned at 5, 10, 15, and 30 min. Patients were administered the following diagnostic tests to correlate with fluorophotometry: OSDI, TBUT, fluorescein, and lissamine. Standard protocols were used. P < 0.05 was considered significant.
  
  
  RESULTS
  Fifty eyes from 25 patients (DED = 22 eyes, 11 patients; Normal = 28 eyes, 14 patients) were included. Baseline scans of the dry eye and control groups did not show any statistical difference (p = 0.84). Fluorescein concentration of DED and normal patients showed statistical significance at all time intervals (p < 10(-5), 0.001, 0.002, 0.049 for 5, 10, 15, & 30 min respectively). Fluorophotometry values converged towards baseline as time elapsed, but both groups were still statistically different at 30 min (p < 0.01). We used four fluorophotometry scoring methods and correlated them with OSDI, TBUT, fluorescein, and lissamine along with adjusted and aggregate scores. The four scoring schemes did not show any significant correlations with the other tests, except for correlations seen with lissamine and 10 (p = 0.045, 0.034) and 15 min (p = 0.013, 0.012), and with aggregate scores and 15 min (p = 0.042, 0.017).
  
  
  CONCLUSIONS
  Fluorophotometry generally did not correlate with any other DED tests, even though it showed capability of differentiating between DED and normal eyes up to 30 min after fluorescein dye instillation. There may be an aspect of DED that is missed in the current regimen of DED tests and only captured with fluorophotometry. Adding fluorophotometry may be useful in screening, diagnosing, and monitoring patients with DED.
authors.affiliation: Department of Ophthalmology, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA. kenji.fujitani@icahn.mssm.edu.
authors.forename: Kenji
authors.initials: K
authors.lastname: Fujitani
authors.affiliation: Department of Ophthalmology, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.
authors.forename: Neha
authors.initials: N
authors.lastname: Gadaria
authors.affiliation: Department of Ophthalmology, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.
authors.forename: Kyu-In
authors.initials: KI
authors.lastname: Lee
authors.affiliation: Department of Ophthalmology, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.
authors.forename: Brendan
authors.initials: B
authors.lastname: Barry
authors.affiliation: Department of Ophthalmology, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.
authors.forename: Penny
authors.initials: P
authors.lastname: Asbell
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D003315:Cornea / Q000378:metabolism*; D003941:Diagnostic Techniques, Ophthalmological; D015352:Dry Eye Syndromes / Q000175:diagnosis* / Q000378:metabolism; D005260:Female; D019793:Fluorescein / Q000378:metabolism; D015590:Fluorophotometry / Q000379:methods; D006801:Humans; D008297:Male; D008875:Middle Aged; D010539:Permeability
chemical_list: D019793:Fluorescein
keywords: Corneal permeability; Dry eye; Fluorophotometry; Keratoconjunctivitis sicca; Ocular surface disease