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Published on: April 24, 2020
Relationship Between Nocturnal Intraocular Pressure Elevation and Diurnal Intraocular Pressure Level in
Yeji Moon1, Jin Young Lee1, Da Woon Jeong1
1Department of Ophthalmology College of Medicine, University of Ulsan, Asan Medical Center, Seoul, Korea.
Purpose:
We studied the relationship between nocturnal habitual position IOP elevation and diurnal IOP level in normal-tension glaucoma (NTG) patients.
Methods:
A total of 70 young NTG patients with a low diurnal IOP level (mean diurnal seated IOP < 15.0 mm Hg; low IOP group) and 79 age-, axial length-, and disease severity-matched NTG patients with a high diurnal IOP level (mean diurnal seated IOP ≥ 15.0 mm Hg; high IOP group) were recruited prospectively. Intraocular pressure was recorded 11 times over a 24-hour period by a single, well-trained ophthalmology resident using a hand-held tonometer.
Results:
The mean habitual position IOP during nighttime (14.2 mm Hg) was significantly higher than that of daytime (12.8 mm Hg) in the low IOP group (P < 0.001), whereas no such difference was found in the high IOP group (16.4 vs. 16.3 mm Hg, P = 0.706). The low IOP group showed an overall nocturnal acrophase in habitual-position IOP, with 11 patients (15.7%) having a diurnal, 30 (42.8%) a nocturnal, and 29 (41.4%) no evident acrophase. By contrast, the high IOP group showed no evident peak in habitual-position IOP, with 28 patients (35.4%) having a diurnal, 12 (15.2%) a nocturnal, and 39 (49.4%) no evident acrophase.
Conclusions:
In NTG eyes with a low diurnal IOP, there are significant IOP increases at nighttime in the habitual position, whereas there is no significant nocturnal IOP elevation in NTG eyes with a high diurnal IOP.
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