Validation of test duration as a screening criterion for frequency doubling perimetry.
OBJECTIVE
To validate the test duration in frequency doubling perimetry as an independent criterion to screen for glaucomatous field defects.


METHODS
Prospective cross-sectional study


METHODS
Group I included 85 eyes (85 patients) with established field defects on automated perimetry. Group II comprised 41 normal eyes (41 subjects). Both groups underwent Swedish interactive testing algorithm standard tests as well as frequency doubling perimetry (C20-1). A cutoff level of 90 seconds was used to calculate test duration sensitivity and specificity. We also categorized patients into those who took <=90 seconds or less and those who took >90 seconds to complete the test and compared frequency doubling perimetry (any two abnormal points) with Swedish interactive testing algorithm in these groups.


RESULTS
Duration of the test >90 seconds had 97.5% specificity with 62.3% sensitivity. Eleven subjects with glaucoma completed test in <91 seconds).


CONCLUSIONS
Test duration alone has a limited value in screening for glaucoma.
Thomas
Ravi
R
L.V. Prasad Eye Institute, Banjara Hills, Hyderabad, India. ravithomas@lvpeye.stph.net
Parikh
Rajul
R
Muliyil
Jayaprakash
J
Bhat
Savita
S
George
Ronnie
R
D000465:Algorithms; D003430:Cross-Sectional Studies; D005901:Glaucoma / Q000175:diagnosis*; D006801:Humans; D007429:Intraocular Pressure; D011446:Prospective Studies; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013997:Time Factors; D014786:Vision Disorders / Q000175:diagnosis*; D014792:Visual Acuity; D058609:Visual Field Tests / Q000379:methods*; D014794:Visual Fields