Baseline visual field findings in the Idiopathic Intracranial Hypertension Treatment Trial (IIHTT).
OBJECTIVE
To characterize visual field (VF) loss at the baseline visit and to evaluate VF quality control (QC) procedures in the Idiopathic Intracranial Hypertension Treatment Trial (IIHTT).


METHODS
The Visual Field Reading Center (VFRC) evaluated 660 baseline VFs (1320 hemifields) from 165 enrolled patients. Three readers independently classified each superior and inferior hemifield and identified any abnormalities. A subset (20%) of the hemifields was reread to evaluate within- and between-reader agreements. The QC system addressed test parameters, patient data, and shipment errors.


RESULTS
The majority (60%) of the baseline hemifields consisted of localized nerve fiber bundle-type VF loss. Approximately one-third (31.5%) of all the classifications consisted of partial arcuate defects combined with an enlarged blind spot, making this the most common type of hemifield classification. Inferior hemifield loss was greater than superior loss for both study and nonstudy eyes. Reader agreements were >90% for both inferior and superior hemifields for two out of three readers. Test-retest reliability agreement for individual readers was 95% for both hemifields. There were few QC errors with only 5.48 error points per 100-point VF.


CONCLUSIONS
The most common type of IIHTT baseline hemifield abnormality was a localized nerve fiber bundle-like defect. Localized inferior hemifield loss was more common than superior hemifield loss. Quality control and within- and between-reader agreement were excellent for the IIHTT (ClinicalTrials.gov number, NCT01003639).
Department of Ophthalmology and Vision Science, University of California-Davis, Sacramento, California, United States Department of Neurology and Neurological Surgery, University of California-Davis, Sacramento, California, United States.
John L
JL
Keltner
Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa, United States.
Chris A
CA
Johnson
Department of Ophthalmology and Vision Science, University of California-Davis, Sacramento, California, United States.
Kimberly E
KE
Cello
Department of Neurology and Ophthalmology, College of Medicine, University of Iowa, Iowa, United States.
Michael
M
Wall
D000293:Adolescent; D000328:Adult; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers; D011559:Pseudotumor Cerebri / Q000145:classification / Q000175:diagnosis* / Q000503:physiopathology; D015203:Reproducibility of Results; D058609:Visual Field Tests / Q000379:methods*; D014794:Visual Fields / Q000502:physiology*; D055815:Young Adult
intracranial idiopathic hypertension; optic neuropathy; quality control; visual fields