Normal versus high tension glaucoma: a comparison of functional and structural defects.
OBJECTIVE
To compare visual field defects obtained with both multifocal visual evoked potential (mfVEP) and Humphrey visual field (HVF) techniques to topographic optic disc measurements in patients with normal tension glaucoma (NTG) and high tension glaucoma (HTG).


METHODS
We studied 32 patients with NTG and 32 with HTG. All patients had reliable 24-2 HVFs with a mean deviation of -10 dB or better, a glaucomatous optic disc and an abnormal HVF in at least 1 eye. Multifocal VEPs were obtained from each eye and probability plots created. The mfVEP and HVF probability plots were divided into a central 10-degree radius and an outer arcuate subfield in both superior and inferior hemifields. Cluster analyses and counts of abnormal points were performed in each subfield. Optic disc images were obtained with the Heidelberg Retina Tomograph III. Eleven stereometric parameters were calculated. Moorfields regression analysis and the glaucoma probability score were performed.


RESULTS
There were no significant differences in mean deviation and pattern standard deviation values between NTG and HTG eyes. However, NTG eyes had a higher percentage of abnormal test points and clusters of abnormal points in the central subfields on both mfVEP and HVF than HTG eyes. For Heidelberg Retina Tomograph III, there were no significant differences in the 11 stereometric parameters or in the Moorfields regression analysis and glaucoma probability score analyses of the optic disc images.


CONCLUSIONS
The visual field data suggest more localized and central defects for NTG than HTG.
Thonginnetra
Oraorn
O
Einhorn Clinical Research Center, New York Eye and Ear Infirmary, New York, NY, USA.
Greenstein
Vivienne C
VC
Chu
David
D
Liebmann
Jeffrey M
JM
Ritch
Robert
R
Hood
Donald C
DC
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005074:Evoked Potentials, Visual / Q000502:physiology*; D005260:Female; D006801:Humans; D007429:Intraocular Pressure; D057066:Low Tension Glaucoma / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009798:Ocular Hypertension / Q000503:physiopathology*; D009887:Ophthalmoscopy; D009898:Optic Disk / Q000473:pathology*; D009901:Optic Nerve Diseases / Q000503:physiopathology*; D041623:Tomography, Optical Coherence; D014065:Tonometry, Ocular; D014786:Vision Disorders / Q000503:physiopathology*; D058609:Visual Field Tests; D014794:Visual Fields / Q000502:physiology*