Spontaneous intraocular pressure reduction in normal-tension glaucoma and associated clinical factors.
OBJECTIVE
To investigate the intraocular pressure (IOP) reduction in certain normal-tension glaucoma (NTG) patients and clinical factors associated with this reduction.


METHODS
Fifty-four NTG patients who met the following enrollment criteria were selected: IOP <21 mm Hg during a 24-hour pressure curve and throughout the subsequent 12 months; examined every 1 to 4 months for at least 3 years with no ocular hypotensive therapy. For each patient, the eye with the higher mean IOP during the 24-hour pressure curve was selected for this study.


RESULTS
Six patients had an IOP reduction which was defined as a significant decrease (P <.05) of IOP over time, determined by the Spearman rank correlation coefficient method. These 6 eyes were rated positive for subsequent IOP reduction. The IOP reduction was correlated to clinical factors by means of a logistic multiple regression analysis (LOGIST procedure using PC-SAS), which demonstrated that the larger difference between the maximum IOP and the minimum IOP during the initial 24-hour pressure curve and the absence of disc hemorrhage showed significant correlation with IOP reduction (P =.026 and P =.013, respectively). The odds ratios were 2.05 per 1 mm Hg increase of difference between the maximum IOP and the minimum IOP during the initial 24-hour pressure curve and 1.13 for the absence of disc hemorrhage.


CONCLUSIONS
The current study demonstrated that a significant reduction of IOP over time is not uncommon in NTG patients. One ninth of the NTG patients in this study showed a significant IOP reduction during a 3-year follow-up period.
Oguri
A
A
Department of Ophthalmology, Gifu University School of Medicine, Gifu-shi, Japan.
Yamamoto
T
T
Kitazawa
Y
Y
D000328:Adult; D000368:Aged; D002908:Chronic Disease; D002940:Circadian Rhythm / Q000502:physiology; D005260:Female; D005902:Glaucoma, Open-Angle / Q000503:physiopathology*; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D012075:Remission, Spontaneous; D012189:Retrospective Studies; D014794:Visual Fields