title: A Rayleigh Scatter-Based Ocular Flare Analysis Meter for Flare Photometry of the Anterior Chamber.
abstract: OBJECTIVE
  Existing flare photometers are based on the Tyndall effect, which requires sophisticated laser photometry. The ocular flare analysis meter (OFAM) is a nonlaser photometer that uses quantitative Rayleigh scatter and absorption from visible light to compute a flare value. This study is designed to correlate OFAM measurements with qualitative measurements of flare in vitro and in vivo.
  
  
  METHODS
  Following validation of the device on artificial anterior chambers containing known protein concentrations, flare readings were obtained from 90 subjects (46 with and 44 without uveitis) in one eye. Subjects were graded by the Standardization of Uveitis Nomenclature (SUN) working group flare scoring system and received the OFAM flare measurements.
  
  
  RESULTS
  The OFAM showed linear response in vitro to protein concentrations ranging from 0 to 0.5 mg/ml. In clinical use in subjects ranging from SUN flare scores of 0+ to 2+, OFAM showed statistically significant measurement accuracy (P= 0.0008 of flare 0 versus flare 2;P= 0.031 of flare 0 versus flare 1). Distinction of SUN scores 1 and 2 was borderline significant (P= 0.057).
  
  
  CONCLUSIONS
  The OFAM photometry correlates with the standard SUN scoring system. This method may provide an objective method to diagnosis and monitor uveitis. Further longitudinal studies are warranted.
  
  
  CONCLUSIONS
  Currently, ocular flare is assessed qualitatively in most clinical settings. The existing methodology uses only Tyndall effect to measure flare. The OFAM uses an alternate, nonlaser means for measurement of anterior chamber flare by measure of Raleigh scatter. This pilot clinical study suggests that the OFAM device may be useful in measurement of uveitis activity.
authors.affiliation: Department of Ophthalmology, University of Washington Medical School, Seattle, WA, USA.
authors.forename: Deborah L
authors.initials: DL
authors.lastname: Lam
authors.affiliation: Chromologic, Inc., Monrovia, CA, USA.
authors.forename: Jim
authors.initials: J
authors.lastname: Axtelle
authors.affiliation: Department of Ophthalmology, University of Washington Medical School, Seattle, WA, USA.
authors.forename: Susan
authors.initials: S
authors.lastname: Rath
authors.affiliation: Chromologic, Inc., Monrovia, CA, USA.
authors.forename: Andrew
authors.initials: A
authors.lastname: Dyer
authors.affiliation: Chromologic, Inc., Monrovia, CA, USA.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Harrison
authors.affiliation: Chromologic, Inc., Monrovia, CA, USA.
authors.forename: Claude
authors.initials: C
authors.lastname: Rogers
authors.affiliation: Chromologic, Inc., Monrovia, CA, USA.
authors.forename: Naresh
authors.initials: N
authors.lastname: Menon
authors.affiliation: Department of Ophthalmology, University of Washington Medical School, Seattle, WA, USA ; Department of Biological Structure, University of Washington Medical School, Seattle, WA, USA ; Department of Pathology, University of Washington Medical School, Seattle, WA, USA.
authors.forename: Russell N
authors.initials: RN
authors.lastname: Van Gelder
keywords: Rayleigh scatter; flare; photometry; uveitis