The Advanced Glaucoma Intervention Study (AGIS): 14. Distinguishing progression of glaucoma from visual field fluctuations.
OBJECTIVE
To determine the least worsening of a visual field (VF) and the least number of confirming tests needed to identify progression of glaucomatous VF defects.


METHODS
Cohort study of participants in a clinical trial.


METHODS
Seven hundred fifty-two eyes of 565 patients with advanced glaucoma.


METHODS
Visual field tests were quantified with the Advanced Glaucoma Intervention Study (AGIS) VF defect score and the Humphrey Field Analyzer mean deviation (MD). Follow-up was 8 to 13 years.


METHODS
Two measures based on the AGIS VF defect score: (1) sustained decrease of VF (SDVF), a worsening from baseline by 2 (alternatively, 3 or 4) or more units and sustained for 2 (alternatively, 3) consecutive 6-month visits and (2) after the occurrence of SDVF, the average percent of eyes with worsening by 2 (alternatively, 3 or 4) or more units from baseline. Two similar measures based on MD.


RESULTS
Based on the original AGIS criteria for SDVF (a worsening of 4 units in the AGIS score sustained during 3 consecutive 6-month visits), 31% of eyes had an SDVF. The percent of eyes with a sustained event increases by approximately 10% when either the minimum number of units of field loss or the minimum number of 6-month visits during which the loss is sustained decreases by 1. During 3 years of follow-up after a sustained event, a worsening of at least 2 units was found in 72% of eyes that had a 2-visit sustained event. The same worsening was found in 84% of eyes that had a 3-visit sustained event. Through the next 10 years after a sustained event, based on worsening of 2, 3, or 4 units at 2 or 3 consecutive tests, the loss reoccurred, on average, in >/=75% of study eyes. Results for MD are similar.


CONCLUSIONS
In patients with advanced glaucoma, a single confirmatory test 6 months after a VF worsening indicates with at least 72% probability a persistent defect when the worsening is defined by at least 2 units of AGIS score or by at least 2 decibels of MD. When the number of confirmatory tests is increased from 1 to 2, the percentage of eyes that show a persistent defect increases from 72% to 84%.
Kim
Jonghyeon
J
The EMMES Corporation, Rockville, Maryland, USA
Dally
Leonard G
LG
Ederer
Fred
F
Gaasterland
Douglas E
DE
VanVeldhuisen
Paul C
PC
Blackwell
Beth
B
Sullivan
E Kenneth
EK
Prum
Bruce
B
Shafranov
George
G
Beck
Allen
A
Spaeth
George L
GL
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D005902:Glaucoma, Open-Angle / Q000175:diagnosis* / Q000503:physiopathology / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D011336:Probability; D012008:Recurrence; D014786:Vision Disorders / Q000175:diagnosis* / Q000503:physiopathology; D058609:Visual Field Tests / Q000379:methods; D014794:Visual Fields