title: Reproducible measurement of macular light flash recovery time using a novel device can indicate the presence and worsening of macular diseases.
abstract: OBJECTIVE
  To determine the safety, sensitivity, and specificity of a novel flash photorecovery timing instrument with response verification in differentiating normal from abnormal maculae, and in detecting worsening macular disease.
  
  
  METHODS
  Right and left eye photorecovery times were determined at baseline and after 5 min using a xenon arc, flash filtered for infrared, ultraviolet, and visible short wavelengths, delivered through an aperture in a hand-held tube. A push-button actuated timer and flash and stopped timer when lighted numbers became visible post-flash. A numeric keypad verified responses. Normal subjects (two eyes tested, n = 144; one eye tested, n = 108) ranged in age from 15 to 84. Photorecovery times were measured in one eye of subjects with small drusen and 20/20 acuity (53-55 correct ETDRS letters; n = 57); in both eyes of subjects with dry age-related macular degeneration (AMD; n = 118); wet AMD with (n = 19) or without (n = 17) macular fluid; and eyes of diabetics with background retinopathy with (n = 19) or without (n = 17) macular retinal thickening. Once-weekly photorecovery measurements for 6 months in each eye of 10 dry AMD subjects and 10 dry diabetic maculopathy subjects provided longitudinal data.
  
  
  RESULTS
  Normal subjects' mean right eye recovery time was 9.6 sec (+/- 1.9 SD); left 10.8 sec (+/- 1.0 SD). Photorecovery lengthened after age 55, nearly doubling that of young subjects by age 80. Macular edema, serous macular detachment, or worsened dry AMD were accompanied by prolonged photorecovery (p < .01). When abnormal new vessels or retinal thickening appeared in three serially followed patients, photorecovery at least doubled (p < .01). In all three, photorecovery prolongation occurred without clinical symptoms. None of the 499 tested subjects reported adverse events due to the flash testing.
  
  
  CONCLUSIONS
  These findings support the usefulness of a reproducible light flash macular vision recovery measurement as an indicator of macular pathology and worsening disease.
authors.affiliation: Retinal Institute of Louisiana, New Orleans, Louisiana, USA. doctordave1618@aol.com
authors.forename: David A
authors.initials: DA
authors.lastname: Newsome
authors.forename: Manny
authors.initials: M
authors.lastname: Negreiro
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003623:Dark Adaptation / Q000502:physiology*; D003930:Diabetic Retinopathy / Q000503:physiopathology*; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008266:Macula Lutea / Q000473:pathology / Q000503:physiopathology / Q000528:radiation effects*; D008268:Macular Degeneration / Q000503:physiopathology*; D008269:Macular Edema / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D010775:Photic Stimulation / Q000379:methods*; D011379:Prognosis; D020127:Recovery of Function / Q000502:physiology*; D015203:Reproducibility of Results; D055815:Young Adult