Modified visual field trend analysis.
OBJECTIVE
Visual field trend analysis can be influenced by outlying values that may disproportionately affect estimation of the rate of change. We tested a modified approach to visual field trend analysis to minimize this problem.


METHODS
Automated pointwise linear regression (PLR) was used in glaucoma patients with ≥13 SITA-Standard 24-2 VF tests in either eye. In the control group (Group A), conventional PLR using the entire set of VF tests was carried out. In the other 3 groups (study groups), a truncated analysis was done using only the first and last 3 (Group B), first and last 4 (Group C), or first and last 5 (Group D) VF tests. We compared the global slopes (dB/y), number of eyes experiencing significant progression, and significant improvement between groups.


RESULTS
Ninety eyes of 90 patients were evaluated. The mean number±SD of VF tests was 15.7±2.6, spanning 7.8±1.7 years. The study groups showed similar global rates of VF change as the control group (Group A=-0.48±0.5, Group B=-0.48±0.6, Group C=-0.48±0.6, Group D=-0.48±0.5 dB/y, P>0.05), and a similar number of eyes reaching a progression endpoint (Group A=53, Group B=52, Group C=49, Group D=53, P>0.05). However, Group B showed fewer eyes presenting VF improvement (false-positives).


CONCLUSIONS
The modified VF trend-analysis showed greater specificity than conventional PLR in a population with glaucoma.
De Moraes
Carlos Gustavo V
CG
Einhorn Clinical Research Center, New York Eye and Ear Infirmary, New York, NY 10003, USA.
Ritch
Robert
R
Tello
Celso
C
Liebmann
Jeffrey M
JM
D018450:Disease Progression; D005189:False Positive Reactions; D005260:Female; D005901:Glaucoma / Q000175:diagnosis* / Q000503:physiopathology; D006801:Humans; D008297:Male; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D014786:Vision Disorders / Q000175:diagnosis* / Q000503:physiopathology; D058609:Visual Field Tests / Q000639:trends*; D014794:Visual Fields