Choroidal Venous Pressure Is Passively Controlled by Vortex Vein Collapse: A Theoretical Model
6 affiliations
- 1Gran Sasso Science Institute, L’Aquila, Italy
- 2School of Mathematics & Statistics, University of Glasgow, Glasgow, United Kingdom
- 3Department of Ophthalmology, Nottingham University Hospitals NHS Trust, Nottingham, United Kingdom
- 4Sainsbury Laboratory, University of Cambridge, Cambridge, United Kingdom
- 5Department of Mathematical Sciences, University of Bath, Claverton Down, Bath, United Kingdom
- 6Department of Civil, Chemical and Environmental Engineering, University of Genoa, Genoa, Italy
Abstract
Purpose: Animal experiments have shown that choroidal venous pressure is tightly linked to the IOP. It has been hypothesied that the choroidal pressure is passively controlled by partial collapse of the vortex veins. This work aimed to test the feasibility of this hypothesis using mechanical modeling.
Methods: We developed a theoretical model of venous outflow from the choroid as a Starling resistor. Each vortex vein was modeled as a collapsible tube formed from two segments arranged in series: one segment within the choroid, subject to an external pressure equal to the IOP, and another segment through the sclera subject to an external pressure, which is linearly decreasing from the IOP to the orbital tissue pressure. For a given choroidal blood flow, this model predicts the choroidal venous pressure and vortex vein cross-sectional area along its length. This model was validated against in vivo rabbit experiments, where the flow rate through the vortex vein was measured as the outlet venous pressure was adjusted.
Results: In agreement with previous experiments, for constant choroidal blood flow, an increase in the IOP generates an almost equal increase in the blood pressure in the choroidal veins. Furthermore, the blood flow rate is insensitive to the outlet venous pressure provided it remains below the IOP. This model shows that partial collapse of the vortex veins explains both observations.
Conclusions: This model provides a mechanical description of how choroidal venous pressure is passively controlled by vortex vein collapse. The model also shows that vortex vein collapse is expected within the sclera.
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BibTeX
@article{vanone2026choroidal,
title = {{Choroidal Venous Pressure Is Passively Controlled by Vortex Vein Collapse: A Theoretical Model}},
author = {Federica Vanone and Peter S. Stewart and Alexander J. E. Foss and Tamsin A. Spelman and Jennifer H. Tweedy and Rodolfo Repetto},
journal = {Investigative Ophthalmology \& Visual Science},
year = {2026},
month = oct,
doi = {10.1167/iovs.67.12.47},
url = {https://doi.org/10.1167/iovs.67.12.47},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Choroidal Venous Pressure Is Passively Controlled by Vortex Vein Collapse: A Theoretical Model
AU - Federica Vanone
AU - Peter S. Stewart
AU - Alexander J. E. Foss
AU - Tamsin A. Spelman
AU - Jennifer H. Tweedy
AU - Rodolfo Repetto
PY - 2026
DA - 2026/10/22
JO - Investigative Ophthalmology & Visual Science
DO - 10.1167/iovs.67.12.47
UR - https://doi.org/10.1167/iovs.67.12.47
AB - Purpose: Animal experiments have shown that choroidal venous pressure is tightly linked to the IOP. It has been hypothesied that the choroidal pressure is passively controlled by partial collapse of the vortex veins. This work aimed to test the feasibility of this hypothesis using mechanical modeling. Methods: We developed a theoretical model of venous outflow from the choroid as a Starling resistor. Each vortex vein was modeled as a collapsible tube formed from two segments arranged in series: one segment within the choroid, subject to an external pressure equal to the IOP, and another segment through the sclera subject to an external pressure, which is linearly decreasing from the IOP to the orbital tissue pressure. For a given choroidal blood flow, this model predicts the choroidal venous pressure and vortex vein cross-sectional area along its length. This model was validated against in vivo rabbit experiments, where the flow rate through the vortex vein was measured as the outlet venous pressure was adjusted. Results: In agreement with previous experiments, for constant choroidal blood flow, an increase in the IOP generates an almost equal increase in the blood pressure in the choroidal veins. Furthermore, the blood flow rate is insensitive to the outlet venous pressure provided it remains below the IOP. This model shows that partial collapse of the vortex veins explains both observations. Conclusions: This model provides a mechanical description of how choroidal venous pressure is passively controlled by vortex vein collapse. The model also shows that vortex vein collapse is expected within the sclera.
SN - 0146-0404
SN - 1552-5783
ER -