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Instability of 24-hour intraocular pressure fluctuation in healthy young subjects: a prospective, cross-sectional study.

Song YK, Lee CK, Kim J, Hong S, Kim CY, Seong GJ - BMC Ophthalmol (2014)

Bottom Line: However, most previous studies have not considered the repeatability of 24-hour IOP measurements.Among the serial measurements taken over a 24-hour rhythm, the maximum/minimum values of IOP, as well as BP, showed excellent agreement: regardless of position, all ICC values were over 0.800.Our results imply that a single 24-hour IOP assessment may not be a sufficient or suitable way to characterize circadian IOP fluctuations for individual subjects.

View Article: PubMed Central - PubMed

Affiliation: Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Republic of Korea. samini@yuhs.ac.

ABSTRACT

Background: Elevated intraocular pressure (IOP) is a major risk factor for the development and/or progression of glaucoma, and a large diurnal IOP fluctuation has been identified as an independent risk factor of glaucoma progression. However, most previous studies have not considered the repeatability of 24-hour IOP measurements. The aim of this study was to evaluate the instability of 24-hour IOP fluctuations in healthy young subjects.

Methods: Ten healthy young volunteers participated in this prospective, cross-sectional study. Each subject underwent 24-hour IOP and systolic/diastolic blood pressure (SBP/DBP) assessments both in sitting and supine positions every 3 hours, once a week for 5 consecutive weeks. Mean ocular perfusion pressure (MOPP) was then calculated for both positions. The intraclass correlation coefficients (ICCs) of maximum, minimum, and fluctuation parameters were computed for IOP, SBP/DBP, and MOPP. Fluctuation was defined as the difference between maximum and minimum values during a day.

Results: Among the serial measurements taken over a 24-hour rhythm, the maximum/minimum values of IOP, as well as BP, showed excellent agreement: regardless of position, all ICC values were over 0.800. Most of the BP fluctuation values also showed excellent agreement. IOP fluctuation, however, did not show excellent agreement; the ICC of sitting IOP fluctuation was just 0.212. MOPP fluctuation also showed poor agreement, especially in the sitting position (ICC, 0.003).

Conclusion: On a day to day basis, 24-hour IOP fluctuations were not highly reproducible in healthy young volunteers. Our results imply that a single 24-hour IOP assessment may not be a sufficient or suitable way to characterize circadian IOP fluctuations for individual subjects.

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Related in: MedlinePlus

Representative 24-hour circadian profile for the 6th volunteer in the sitting position. Systolic and diastolic blood pressure (A) and intraocular pressure (B) were obtained once a week for 5 consecutive weeks. BP = blood pressure, IOP = intraocular pressure.
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Fig1: Representative 24-hour circadian profile for the 6th volunteer in the sitting position. Systolic and diastolic blood pressure (A) and intraocular pressure (B) were obtained once a week for 5 consecutive weeks. BP = blood pressure, IOP = intraocular pressure.

Mentions: The ICCs of the 24-hour MOPP parameters are listed in Table 5. In both positions, the maximum and minimum MOPPs showed good to excellent agreement. However, the MOPP fluctuations did not exhibit excellent agreement; the ICC value of the MOPP fluctuation while in the sitting position was the poorest at 0.003. MOPP parameters tended to be similar to IOP parameters.A representative subject who showed unstable 24-hour IOP rhythms is described in Figure 1. Her sitting BPs were very stable for all of her five daily visits (Figure 1A), whereas her sitting IOP pattern differed greatly from day to day (Figure 1B): her sitting IOP results exhibited a concave shape for the first and the third days, while they showed a convex shape for the other three days.Table 5


Instability of 24-hour intraocular pressure fluctuation in healthy young subjects: a prospective, cross-sectional study.

Song YK, Lee CK, Kim J, Hong S, Kim CY, Seong GJ - BMC Ophthalmol (2014)

Representative 24-hour circadian profile for the 6th volunteer in the sitting position. Systolic and diastolic blood pressure (A) and intraocular pressure (B) were obtained once a week for 5 consecutive weeks. BP = blood pressure, IOP = intraocular pressure.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4232688&req=5

Fig1: Representative 24-hour circadian profile for the 6th volunteer in the sitting position. Systolic and diastolic blood pressure (A) and intraocular pressure (B) were obtained once a week for 5 consecutive weeks. BP = blood pressure, IOP = intraocular pressure.
Mentions: The ICCs of the 24-hour MOPP parameters are listed in Table 5. In both positions, the maximum and minimum MOPPs showed good to excellent agreement. However, the MOPP fluctuations did not exhibit excellent agreement; the ICC value of the MOPP fluctuation while in the sitting position was the poorest at 0.003. MOPP parameters tended to be similar to IOP parameters.A representative subject who showed unstable 24-hour IOP rhythms is described in Figure 1. Her sitting BPs were very stable for all of her five daily visits (Figure 1A), whereas her sitting IOP pattern differed greatly from day to day (Figure 1B): her sitting IOP results exhibited a concave shape for the first and the third days, while they showed a convex shape for the other three days.Table 5

Bottom Line: However, most previous studies have not considered the repeatability of 24-hour IOP measurements.Among the serial measurements taken over a 24-hour rhythm, the maximum/minimum values of IOP, as well as BP, showed excellent agreement: regardless of position, all ICC values were over 0.800.Our results imply that a single 24-hour IOP assessment may not be a sufficient or suitable way to characterize circadian IOP fluctuations for individual subjects.

View Article: PubMed Central - PubMed

Affiliation: Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Republic of Korea. samini@yuhs.ac.

ABSTRACT

Background: Elevated intraocular pressure (IOP) is a major risk factor for the development and/or progression of glaucoma, and a large diurnal IOP fluctuation has been identified as an independent risk factor of glaucoma progression. However, most previous studies have not considered the repeatability of 24-hour IOP measurements. The aim of this study was to evaluate the instability of 24-hour IOP fluctuations in healthy young subjects.

Methods: Ten healthy young volunteers participated in this prospective, cross-sectional study. Each subject underwent 24-hour IOP and systolic/diastolic blood pressure (SBP/DBP) assessments both in sitting and supine positions every 3 hours, once a week for 5 consecutive weeks. Mean ocular perfusion pressure (MOPP) was then calculated for both positions. The intraclass correlation coefficients (ICCs) of maximum, minimum, and fluctuation parameters were computed for IOP, SBP/DBP, and MOPP. Fluctuation was defined as the difference between maximum and minimum values during a day.

Results: Among the serial measurements taken over a 24-hour rhythm, the maximum/minimum values of IOP, as well as BP, showed excellent agreement: regardless of position, all ICC values were over 0.800. Most of the BP fluctuation values also showed excellent agreement. IOP fluctuation, however, did not show excellent agreement; the ICC of sitting IOP fluctuation was just 0.212. MOPP fluctuation also showed poor agreement, especially in the sitting position (ICC, 0.003).

Conclusion: On a day to day basis, 24-hour IOP fluctuations were not highly reproducible in healthy young volunteers. Our results imply that a single 24-hour IOP assessment may not be a sufficient or suitable way to characterize circadian IOP fluctuations for individual subjects.

Show MeSH
Related in: MedlinePlus