Post by laurasnowbird on Jul 15, 2008 17:51:12 GMT -5
Hey, thought you guys would find this good information:
From Medscape Ophthalmology
Viewpoints
Is IOP Fluctuation Important?
Posted 07/10/2008
Rod Foroozan, MD
Author Information
Information from Industry
Contact lens comfort and stability:
A challenge in patients with astigmatism
Accelerated Stabilization Design (ASD) technology
can provide them with the stability they need.
Read more Introduction
Elevated intraocular pressure (IOP) remains the single most important modifiable risk factor in patients with glaucoma. However, the importance of specific parameters related to IOP remains unclear. Some have suggested that variations, including long-term day-to-day changes, in IOP may be at least as important as the peak pressure, while other studies have not found IOP fluctuation to play a role in glaucoma progression.[1-3] The authors of this observational study assessed long-term fluctuation in IOP as a risk factor for the conversion from ocular hypertension to glaucoma.
Long-term Intraocular Pressure Fluctuations and Risk of Conversion From Ocular Hypertension to Glaucoma
Medeiros FA, Weinreb RN, Zangwill LM, et al
Ophthalmology. 2008;115:934-940
Summary
This study included 126 patients (252 eyes) with ocular hypertension who were not undergoing treatment. These patients had a history of elevated IOP with normal visual fields and normal-appearing optic discs. Conversion to glaucoma included visual field loss or optic disc changes. Of the included patients, 31 subjects (40 eyes) developed glaucoma, with a mean IOP of 25 mm Hg compared with a mean of 24 mm Hg in those who did not develop optic neuropathy. The mean fluctuation in IOP was 3.2 mm Hg in those who developed glaucoma compared with 2.8 mm Hg in those who did not. This difference in IOP fluctuation was not statistically significant. Although mean IOP during follow-up was a significant risk factor for progression from ocular hypertension to glaucoma, long-term fluctuation in IOP was not.
Comment
Although fluctuations in IOP may play a role in glaucoma, this study found that they did not appear to influence the rate of progression from ocular hypertension to glaucoma in untreated ocular hypertensive patients. The authors point out that long-term fluctuation in IOP should be considered different from short-term fluctuation (diurnal variation within a 24-hour period) in IOP. The results of this study agree with those of the Early Manifest Glaucoma Trial (EGMT)[3] which also showed the importance of higher mean IOP as a risk factor for progression of glaucoma but included both treated and untreated patients. Conversely, the Advanced Glaucoma Intervention Study (AGIS)[2] found that a 1-mm Hg larger fluctuation in IOP was associated with a 30% increased risk for visual field loss. Unlike the present study, AGIS and EGMT included only patients with glaucoma. In AGIS, the fluctuation in IOP was determined after progression of glaucoma was noted, which differed from the determination of fluctuation in EGMT.
From Medscape Ophthalmology
Viewpoints
Is IOP Fluctuation Important?
Posted 07/10/2008
Rod Foroozan, MD
Author Information
Information from Industry
Contact lens comfort and stability:
A challenge in patients with astigmatism
Accelerated Stabilization Design (ASD) technology
can provide them with the stability they need.
Read more Introduction
Elevated intraocular pressure (IOP) remains the single most important modifiable risk factor in patients with glaucoma. However, the importance of specific parameters related to IOP remains unclear. Some have suggested that variations, including long-term day-to-day changes, in IOP may be at least as important as the peak pressure, while other studies have not found IOP fluctuation to play a role in glaucoma progression.[1-3] The authors of this observational study assessed long-term fluctuation in IOP as a risk factor for the conversion from ocular hypertension to glaucoma.
Long-term Intraocular Pressure Fluctuations and Risk of Conversion From Ocular Hypertension to Glaucoma
Medeiros FA, Weinreb RN, Zangwill LM, et al
Ophthalmology. 2008;115:934-940
Summary
This study included 126 patients (252 eyes) with ocular hypertension who were not undergoing treatment. These patients had a history of elevated IOP with normal visual fields and normal-appearing optic discs. Conversion to glaucoma included visual field loss or optic disc changes. Of the included patients, 31 subjects (40 eyes) developed glaucoma, with a mean IOP of 25 mm Hg compared with a mean of 24 mm Hg in those who did not develop optic neuropathy. The mean fluctuation in IOP was 3.2 mm Hg in those who developed glaucoma compared with 2.8 mm Hg in those who did not. This difference in IOP fluctuation was not statistically significant. Although mean IOP during follow-up was a significant risk factor for progression from ocular hypertension to glaucoma, long-term fluctuation in IOP was not.
Comment
Although fluctuations in IOP may play a role in glaucoma, this study found that they did not appear to influence the rate of progression from ocular hypertension to glaucoma in untreated ocular hypertensive patients. The authors point out that long-term fluctuation in IOP should be considered different from short-term fluctuation (diurnal variation within a 24-hour period) in IOP. The results of this study agree with those of the Early Manifest Glaucoma Trial (EGMT)[3] which also showed the importance of higher mean IOP as a risk factor for progression of glaucoma but included both treated and untreated patients. Conversely, the Advanced Glaucoma Intervention Study (AGIS)[2] found that a 1-mm Hg larger fluctuation in IOP was associated with a 30% increased risk for visual field loss. Unlike the present study, AGIS and EGMT included only patients with glaucoma. In AGIS, the fluctuation in IOP was determined after progression of glaucoma was noted, which differed from the determination of fluctuation in EGMT.
