Intraocular pressure fluctuation and glaucoma progression: what do we know?

Leidl, Matthew C; Choi, Catherine J.; Syed, Zeba A.; Melki, Samir

doi:10.1136/bjophthalmol-2013-303980

Cited by 58 publications

(43 citation statements)

References 76 publications

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“…Although average IOP has been consistently established as a risk factor for development and progression of glaucoma, other IOP parameters, such as 24-hour peaks and fluctuations have been proposed as potentially related to glaucomatous damage. 42, 43 However, the design of our study did not include 24-hour IOP measurements, which precluded us from being able to evaluate their relationship with RNFL loss. Another potential limitation was the fact that patients were treated at the discretion of the attending ophthalmologist.…”

Section: Discussionmentioning

confidence: 99%

Association between Intraocular Pressure and Rates of Retinal Nerve Fiber Layer Loss Measured by Optical Coherence Tomography

et al. 2016

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Purpose To evaluate the relationship between intraocular pressure (IOP) and rates of retinal nerve fiber layer (RNFL) thickness change over time measured by spectral-domain (SD) optical coherence tomography (OCT). Design Observational cohort study. Participants The study involved 547 eyes of 339 patients followed for an average period of 3.9 ± 0.9 years. Three hundred and eight (56.3%) had a diagnosis of glaucoma and 239 (43.7%) were considered glaucoma suspects. Methods All eyes underwent imaging using the Spectralis® SD OCT (Heidelberg Engineering GmbH, Heidelberg, Germany), along with IOP measurements and standard automated perimetry (SAP). Glaucoma progression was defined as a result of “Likely Progression” from the Guided Progression Analysis™ software for SAP. Linear mixed models were used to investigate the relationship between average IOP during follow-up and rates of RNFL thickness change, while taking into account potential confounding factors, such as age, race, corneal thickness, and baseline disease severity. Main Outcome Measures The association between IOP and rates of global and sectorial RNFL thickness loss measured by SD OCT. Results Forty-six eyes (8.4%) showed progression on SAP during follow-up. Rates of global RNFL thickness change in eyes that progressed by SAP were faster than in those that did not progress (−1.02 µm/year versus −0.61 µm/year, respectively; P = 0.002). For progressing eyes, each 1 mmHg higher average IOP during follow-up was associated with an additional average loss of 0.20 µm/year [confidence interval (CI): 0.08 to 0.31 µm/year; P < 0.001] of global RNFL thickness versus only 0.04 µm/year (CI: 0.01 to 0.07 µm/year; P = 0.015) for non-progressing eyes. The largest associations between IOP and rates of RNFL change were seen for measurements from the temporal superior and temporal inferior sectors, whereas the smallest association was seen for measurements from the nasal sector. Conclusions Higher levels of IOP during follow-up were associated with faster rates of RNFL loss over time measured by SD OCT. These findings support the use of SD OCT RNFL thickness measurements as biomarkers for the evaluation of the efficacy of IOP-lowering therapies to slow down the rate of disease progression.

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Section: Discussionmentioning

confidence: 99%

Association between Intraocular Pressure and Rates of Retinal Nerve Fiber Layer Loss Measured by Optical Coherence Tomography

et al. 2016

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“…Although its mechanisms and role in glaucoma are still unclear, further understanding of the dynamic aspects of IOP presents an opportunity to gain a more complete understanding of the relationship between glaucoma risk and IOP. (Leidl et al, 2014; Mansouri et al, 2013). …”

Section: Introductionmentioning

confidence: 99%

Corneoscleral stiffening increases IOP spike magnitudes during rapid microvolumetric change in the eye

Clayson

Pan

Pavlatos

et al. 2017

Experimental Eye Research

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Factors governing the steady-state IOP have been extensively studied; however, the dynamic aspects of IOP are less understood. Clinical studies have suggested that intraocular pressure (IOP) fluctuation may be associated with glaucoma risk. This study aims to investigate how stiffening of corneoscleral biomechanical properties affects IOP spikes induced by rapid microvolumetric change. Porcine eyes (n = 25 in total) were subjected to volumetric infusions before and after external treatment of a circular area (11 mm diameter) in either the central cornea or posterior sclera. The treated area in the control group was immersed in phosphate-buffered saline (PBS) for 40 min, while the treated area of the chemical crosslinking group was immersed in 4% glutaraldehyde/PBS for 40 min. A subset of the sham-treated eyes was also subjected to volumetric infusions at a raised steady-state IOP. The magnitude of IOP spikes increased after localized chemical crosslinking of either the cornea (27.5% increase, p < 0.001) or the sclera (14.3% increase, p < 0.001) with corneal crosslinking having a stronger effect than scleral crosslinking (p = 0.018). We also observed that raising the steady-state IOP from 15 to 25 mmHg resulted in marked increase in IOP spike magnitudes by 63.9% (p < 0.001). These results suggested that an increased corneoscleral stiffness could significantly increase IOP spike magnitudes at the same volumetric change. Corneal stiffness appeared to have a strong impact on the IOP spike magnitude and may play a major role in regulating rapid volume-pressure dynamics. An increase in steady-state IOP also resulted in larger IOP fluctuations due to the increased “apparent” stiffness of the ocular shell, suggesting a potential interaction between the magnitude of IOP and its fluctuations. Corneoscleral properties may represent additional pathways for understanding and managing glaucoma risk and warrant future investigation.

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“…These constraints indicate the potential for the loss of what might be useful data about fluctuations of IOP. Given the potential importance of short and long‐term IOP fluctuation in the diagnosis and treatment of glaucoma, a reliable method of continuous monitoring is highly desirable . Any method for continuous IOP monitoring should be safe and biocompatible, provide accurate, reproducible measurements over prolonged periods, function independently of ocular health and/or corneal properties and be directly correlated with currently validated tonometers …”

Section: Potential Importance Of Continuous Iop Monitoringmentioning

confidence: 99%

The importance of and potential for continuous monitoring of intraocular pressure

McMonnies

2017

Clinical and Experimental Optometry

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Monitoring intraocular pressure (IOP) is a critically important part of glaucoma management; however, clinical tonometry predominantly involves sitting postures and is unable to detect variations in response to posture changes, muscular effort, deep respirations and during a wide range of activities, such as playing high wind-resistance instruments and wearing swimming goggles in addition to eye touching and rubbing. For example, the usefulness of 24-hour tonometric phasing may be increased, if nocturnal assessments included side and prone sleeping postures rather than being limited to supine posture tonometry. Continuous monitoring of IOP, which allows unrestricted involvement in a full range of sleep and non-sleep IOP elevating activities would provide an ideal method of quantifying the frequency, duration and degree of episodes of elevation in addition to physiological and pathological circadian rhythmic variations due to treatment. Apart from the degree of exposure to episodes of elevation of IOP, genetic influences and family history of glaucoma, other factors which are or could be associated with increased susceptibility to develop or progress glaucomatous pathology include age, frailty, race, type and degree of refractive error, systemic hypotension and hypertension, vasospasm, migraine, pigmentary dispersion syndrome, pseudoexfoliation syndrome, obstructive sleep apnoea syndrome, diabetes as well as medication interactions and side effects. Such information, when combined with all details relating to episodes of elevation of IOP, appears likely to be a strong basis for the detection, diagnosis and treatment of glaucoma. This review examines the limitations of methods of longitudinal monitoring of IOP with reference to their validity and the varying degrees of invasiveness involved. Also mentioned is the potential value of knowing the frequency, duration and level of variations of optic nerve subarachnoid space pressure, as the interaction of such changes with IOP and their potential influence on the lamina cribrosa, may help determine pathological significance.

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Intraocular pressure fluctuation and glaucoma progression: what do we know?

Cited by 58 publications

References 76 publications

Association between Intraocular Pressure and Rates of Retinal Nerve Fiber Layer Loss Measured by Optical Coherence Tomography

Association between Intraocular Pressure and Rates of Retinal Nerve Fiber Layer Loss Measured by Optical Coherence Tomography

Corneoscleral stiffening increases IOP spike magnitudes during rapid microvolumetric change in the eye

The importance of and potential for continuous monitoring of intraocular pressure

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