Visual field and intraocular pressure asymmetry in the low-pressure glaucoma treatment study.
OBJECTIVE
To explore the relationship between asymmetric baseline intraocular pressure (IOP) and asymmetric visual field (VF) loss in the Low-Pressure Glaucoma Treatment Study.


METHODS
Randomized, multicenter, controlled clinical trial.


METHODS
Low-pressure glaucoma (LPG) patients 30 years or older were identified. Exclusion criteria included an untreated pressure > 21 mmHg, advanced VF loss, and contraindications to study medications.


METHODS
A baseline VF was created using the average of 2 reliable Humphrey full-threshold examinations. A baseline diurnal IOP curve was performed without IOP-lowering medication.


METHODS
Mean diurnal, peak, trough, IOP range (peak - trough), and standard deviation (SD) of IOP measurements, and mean deviation (MD) and corrected pattern SD (CPSD) of VF examinations.


RESULTS
One hundred ninety patients were enrolled (mean age, 64.9+/-10.7 years). Mean deviation and CPSD were not correlated with mean, peak, trough, or peak minus trough (P - T) IOP (Ps = 0.2-0.9). Among patients with unilateral VF loss (n = 53 [27.9%]), there were no differences (Ps = 0.3-0.9) in any IOP parameter between the normal VF eye and fellow glaucomatous eyes. Among patients with bilateral VF loss (n = 137 [72.1%]), mean, peak, trough, and P - T IOPs were similar in eyes with a better VF MD compared with eyes with a worse VF MD (Ps = 0.2-0.7). Cross-classified contingency tables demonstrated no relationship (Ps = 0.1-0.3) between IOP and VF MD or CPSD using chi-square analysis.


CONCLUSIONS
Intraocular pressure asymmetry is unrelated to VF asymmetry in the Low-Pressure Glaucoma Treatment Study, suggesting an unclear pathogenic relationship between IOP and glaucomatous damage in eyes with LPG.
Greenfield
David S
DS
Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Palm Beach Gardens, Florida 33418, USA. dgreenfield@med.miami.edu
Liebmann
Jeffrey M
JM
Ritch
Robert
R
Krupin
Theodore
T
D000316:Adrenergic alpha-Agonists / Q000627:therapeutic use; D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D000068438:Brimonidine Tartrate; D002940:Circadian Rhythm; D004311:Double-Blind Method; D005260:Female; D005901:Glaucoma / Q000188:drug therapy / Q000503:physiopathology*; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D008875:Middle Aged; D011810:Quinoxalines / Q000627:therapeutic use; D013999:Timolol / Q000627:therapeutic use; D014794:Visual Fields
D000316:Adrenergic alpha-Agonists; D000319:Adrenergic beta-Antagonists; D011810:Quinoxalines; D000068438:Brimonidine Tartrate; D013999:Timolol