Changes in Parameters of Aqueous Humor Dynamics Throughout Life

Toris, Carol B.; Tye, George; Pattabiraman, Padmanabhan P

doi:10.1007/978-3-030-25886-3_6

Cited by 3 publications

(5 citation statements)

References 173 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Combining the production and drainage of the AH, the steady-state IOP in a normal or a glaucomatous eye can be described by the modified Goldmann equation, as follows. 100 …”

Section: Microfluidic Modelling Of Glaucomamentioning

confidence: 99%

“…F u denotes the uveoscleral outflow rate, which is reported to be in the range of 0.14-1.52 μL min −1 , 94,111,112 and this rate decreases with aging 95 and contractions of the ciliary muscle due to various morphological changes to the tissue. 100,113,114 C is the tonographic facility of the outflow, which is also the inverse of hydraulic resistance (R).…”

Section: Microfluidic Modeling Of a Glaucomatous Eyementioning

confidence: 99%

See 1 more Smart Citation

Microfluidics in the eye: a review of glaucoma implants from an engineering perspective

Fang,

Bi,

Brown

et al. 2023

Lab Chip

View full text Add to dashboard Cite

show abstract

“…Combining the production and drainage of the AH, the steady-state IOP in a normal or a glaucomatous eye can be described by the modified Goldmann equation, as follows. 100 …”

Section: Microfluidic Modelling Of Glaucomamentioning

confidence: 99%

Section: Microfluidic Modeling Of a Glaucomatous Eyementioning

confidence: 99%

Microfluidics in the eye: a review of glaucoma implants from an engineering perspective

Fang,

Bi,

Brown

et al. 2023

Lab Chip

View full text Add to dashboard Cite

show abstract

“…The lamina cribrosa facilitates the passage of axon bundles transmitting the neural signal from the retina to the brain and allows the central retinal artery and vein to perfuse the retina, while helping maintain the pressure difference between the intraocular space and the optic nerve. The pressure in the intraocular space is the IOP and is primarily due to the aqueous humor filling the anterior chamber (Toris et al, 2019), whereas the pressure in the optic nerve is often referred to as retrolaminar tissue pressure (RLTp) and is primarily due to the CSF filling the subarachnoid space (Morgan et al, 1995(Morgan et al, , 1998. Healthy baseline values of IOP and RLTp are difficult to definitely set for all persons of different ages, genders, races, and in consideration of co-morbidities.…”

Section: Utilizing Mechanism-driven Models As Virtual Laboratories: Amentioning

confidence: 99%

“…Interestingly, both eye and brain are characterized by internal pressures, namely intraocular pressure (IOP) and intracranial pressure (ICP), that are exerted by fluids on the surrounding tissues. Cerebrospinal and interstitial fluids are the main contributors to establishing ICP in the brain (Fleishman and Berdahl, 2019 ); in the eye, IOP is mainly due to the balance between production and drainage of aqueous humor, which is the clear fluid filling the anterior chamber between the lens and the cornea (Toris et al, 2019 ).…”

Section: Overview Of Mechanism-driven Models Of the Eye And Their mentioning

confidence: 99%

Neurodegenerative Disorders of the Eye and of the Brain: A Perspective on Their Fluid-Dynamical Connections and the Potential of Mechanism-Driven Modeling

et al. 2020

View full text Add to dashboard Cite

Neurodegenerative disorders (NDD) such as Alzheimer's and Parkinson's diseases are significant causes of morbidity and mortality worldwide. The pathophysiology of NDD is still debated, and there is an urgent need to understand the mechanisms behind the onset and progression of these heterogenous diseases. The eye represents a unique window to the brain that can be easily assessed via non-invasive ocular imaging. As such, ocular measurements have been recently considered as potential sources of biomarkers for the early detection and management of NDD. However, the current use of ocular biomarkers in the clinical management of NDD patients is particularly challenging. Specifically, many ocular biomarkers are influenced by local and systemic factors that exhibit significant variation among individuals. In addition, there is a lack of methodology available for interpreting the outcomes of ocular examinations in NDD. Recently, mathematical modeling has emerged as an important tool capable of shedding light on the pathophysiology of multifactorial diseases and enhancing analysis and interpretation of clinical results. In this article, we review and discuss the clinical evidence of the relationship between NDD in the brain and in the eye and explore the potential use of mathematical modeling to facilitate NDD diagnosis and management based upon ocular biomarkers.

show abstract

“…This led naturally to the view that the outflow pathway functions like a passive filter, without a direct role for the TM or SC cells themselves. [3][4][5][6][7][8][9][10][11] The notion that outflow functions like a passive filter is incongruent with recent findings showing that metabolically-dependent cellular processes, such as cell contractility, [12][13][14][15][16][17] exocytosis, 18,19 and signal transduction, [20][21][22][23][24] affect conventional outflow facility. There are also two studies that, in contrast to VanBuskirk and Grant, 2 suggest that outflow facility is temperature dependent in enucleated mouse 25 and calf eyes.…”

mentioning

confidence: 99%

Aqueous Humor Outflow Requires Active Cellular Metabolism in Mice

Reina-Torres

Boussommier-Calleja

Sherwood

et al. 2020

Invest. Ophthalmol. Vis. Sci.

View full text Add to dashboard Cite

Conventional wisdom posits that aqueous humor leaves the eye by passive bulk flow without involving energy-dependent processes. However, recent studies have shown that active processes, such as cell contractility, contribute to outflow regulation. Here, we examine whether inhibiting cellular metabolism affects outflow facility in mice. METHODS. We measured outflow facility in paired enucleated eyes from C57BL/6J mice using iPerfusion. We had three Experimental Sets: ES1, perfused at 35°C versus 22°C; ES2, perfused with metabolic inhibitors versus vehicle at 35°C; and ES3, perfused at 35°C versus 22°C in the presence of metabolic inhibitors. Inhibitors targeted glycolysis and oxidative phosphorylation (2-deoxy-D-glucose, 3PO and sodium azide). We also measured adenosine triphosphate (ATP) levels in separate murine anterior segments treated like ES1 and ES2. RESULTS. Reducing temperature decreased facility by 63% [38%, 78%] (mean [95% confidence interval (CI)], n = 10 pairs; P = 0.002) in ES1 after correcting for changes in viscosity. Metabolic inhibitors reduced facility by 21% [9%, 31%] (n = 9, P = 0.006) in ES2. In the presence of inhibitors, temperature reduction decreased facility by 44% [29%, 56%] (n = 8, P < 0.001) in ES3. Metabolic inhibitors reduced anterior segment adenosine triphosphate (ATP) levels by 90% [83%, 97%] (n = 5, P<<0.001), but reducing temperature did not affect ATP. CONCLUSIONS. Inhibiting cellular metabolism decreases outflow facility within minutes. This implies that outflow is not entirely passive, but depends partly on energy-dependent cellular processes, at least in mice. This study also suggests that there is a yet unidentified mechanism, which is strongly temperature-dependent but metabolism-independent, that is necessary for nearly half of normal outflow function in mice.

show abstract

Changes in Parameters of Aqueous Humor Dynamics Throughout Life

Cited by 3 publications

References 173 publications

Microfluidics in the eye: a review of glaucoma implants from an engineering perspective

Microfluidics in the eye: a review of glaucoma implants from an engineering perspective

Neurodegenerative Disorders of the Eye and of the Brain: A Perspective on Their Fluid-Dynamical Connections and the Potential of Mechanism-Driven Modeling

Aqueous Humor Outflow Requires Active Cellular Metabolism in Mice

Contact Info

Product

Resources

About