Abstract
Purpose: :
To investigate retrospectively the factors associated with 24-hour fluctuation of intraocular pressure (IOP) in normal-tension glaucoma(NTG).
Methods: :
The subjects were 128 eyes of 128 patients with previously unoperated NTG (74 males and 54 females) whose mean age was 53.7 ±13.5 years.Patients who had been previously receiving topical ocular hypotensive agents were asked to withdraw their use for ≥4 weeks. The patients were hospitalized for 24 hours to measure baseline IOP. IOP data were obtained in the sitting position by the same physician using a Goldmann applanation tonometer at 10:00, 13:00, 16:00, 19:00, 22:00, 01:00, 03:00, and 07:00. Standard deviation of IOP at all measurement time-points was used as an indicator of 24-hour fluctuation of IOP.Stepwise regression analysis was performed by using 24-hour fluctuation of IOP as an objective variable and age, gender, refractive error, mean 24-hour IOP, systolic blood pressure, diastolic blood pressure and pulse rate as explanatory variables.
Results: :
Single regression analysis showed 24-hour fluctuation of IOP had the significant negative correlation with age (β=-0.008,r2=-0.035,p=0.034) and refractive error (β=-0.033,r2=0.046,p=0.015).Refractive error was selected as a explanatory variable associated with 24-hour fluctuation of IOP by stepwise multiple regression analysis.
Conclusions: :
Patients with a higher degree of myopia had bigger 24-hour fluctuation of IOP in NTG.
Keywords: intraocular pressure • myopia