Classification of visual field abnormalities in the ocular hypertension treatment study.
OBJECTIVE
(1) To develop a classification system for visual field (VF) abnormalities, (2) to determine interreader and test-retest agreement, and (3) to determine the frequency of various VF defects in the Ocular Hypertension Treatment Study.


METHODS
Follow-up VFs are performed every 6 months and are monitored for abnormality, indicated by a glaucoma hemifield test result or a corrected pattern SD outside the normal limits. As of January 1, 2002, 1636 patients had 2509 abnormal VFs. Three readers independently classified each hemifield using a classification system developed at the VF reading center. A subset (50%) of the abnormal VFs was reread to evaluate test-retest reader agreement. A mean deviation was calculated separately for the hemifields as an index to the severity of VF loss.


METHODS
A 97% interreader hemifield agreement.


RESULTS
The average hemifield classification agreement (between any 2 of 3 readers) for 5018 hemifields was 97% and 88% for the 1266 abnormal VFs that were reread (agreement between the first and second classifications). Glaucomatous patterns of loss (partial arcuate, paracentral, and nasal step defects) composed the majority of VF defects.


CONCLUSIONS
The Ocular Hypertension Treatment Study classification system has high reproducibility and provides a possible nomenclature for characterizing VF defects.
Visual Field Reading Center, Department of Ophthalmology, University of California-Davis, Sacramento, 95817, USA. jlkeltner@ucdavis.edu
John L
JL
Keltner
Chris A
CA
Johnson
Kimberly E
KE
Cello
Mary A
MA
Edwards
Shannan E
SE
Bandermann
Michael A
MA
Kass
Mae O
MO
Gordon
D000959:Antihypertensive Agents / Q000627:therapeutic use; D005902:Glaucoma, Open-Angle / Q000517:prevention & control; D006801:Humans; D007429:Intraocular Pressure; D015588:Observer Variation; D009798:Ocular Hypertension / Q000145:classification* / Q000175:diagnosis / Q000188:drug therapy*; D015203:Reproducibility of Results; D014786:Vision Disorders / Q000145:classification* / Q000175:diagnosis; D058609:Visual Field Tests / Q000592:standards; D014794:Visual Fields
D000959:Antihypertensive Agents