Role of flicker perimetry in predicting onset of late-stage age-related macular degeneration.
OBJECTIVE
To investigate the longitudinal changes in flicker perimetry in patients with age-related macular degeneration (AMD) as the condition progresses from early AMD to geographic atrophy (GA) or choroidal neovascularization (CNV).


METHODS
Patients with AMD and control subjects were recruited from a longitudinal study of retinal function in early AMD consisting of 187 participants. Only those who completed at least 4 consecutive, 6-monthly flicker perimetry tests were selected for this study. Study groups consisted of everyone who went on to develop GA (n = 16) or CNV (n = 5), controls (n = 24), and the high-risk, early- AMD participants whose eyes did not progress to GA or CNV (drusen >125 μm; n = 18). The flicker sensitivity was determined, and its rate of change during the 18 months before the clinical detection of late AMD was calculated.


RESULTS
Eyes that went on to develop GA or CNV had a significantly reduced mean (SD) flicker sensitivity in the months before clinical detection of GA (15.8 [5.6] dB) or CNV (19.1 [3.8] dB) compared with control eyes (22.9 [3.0] dB) (P < .001) and with eyes that did not progress to GA or CNV (21.4 [3.4] dB) (P < .001). The rate of change in flicker sensitivity was significantly increased in GA eyes (-0.07 dB/mo) (P < .001) but not in CNV eyes (0.006 dB/mo) (P = .56) compared with the control eyes (-0.003 dB/mo).


CONCLUSIONS
Flicker sensitivity is reduced in eyes that go on to develop late AMD. The rate of change in flicker sensitivities over time was particularly useful in predicting eyes and areas within the eye that subsequently develop GA.
Centre for Eye Research Australia, University of Melbourne, RoyalVictorian Eye and Ear Hospital, Victoria, Australia.
Chi D
CD
Luu
Peter N
PN
Dimitrov
Luba
L
Robman
Mary
M
Varsamidis
Galina
G
Makeyeva
Khin-Zaw
KZ
Aung
Algis J
AJ
Vingrys
Robyn H
RH
Guymer
D000368:Aged; D000369:Aged, 80 and over; D020256:Choroidal Neovascularization / Q000175:diagnosis / Q000503:physiopathology; D005260:Female; D005500:Follow-Up Studies; D057092:Geographic Atrophy / Q000175:diagnosis / Q000503:physiopathology; D006801:Humans; D008268:Macular Degeneration / Q000175:diagnosis* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D012160:Retina / Q000503:physiopathology*; D014786:Vision Disorders / Q000175:diagnosis* / Q000503:physiopathology; D014792:Visual Acuity / Q000502:physiology; D058609:Visual Field Tests; D014794:Visual Fields / Q000502:physiology*