Dr Ehsan Vaghefi
BSc, MSc, PhD
Dr Ehsan Vaghefi holds a joint appointment as a research fellow (Molecular Vision Lab and Auckland Bioengineering Institute) and lecturer in Physiological Optics (Department of Optometry and Vision Sciences). His appointment is a strategic initiative to develop a joint research-led teaching program in Physiological Optics. It also provides him access to a talented pool of potential graduate students with a mix of optics and modelling backgrounds, to perform both the computational and experimental portions of his research.
Dr Vaghefi received his Bachelor of Science in Biomedical Engineering from the Polytechnic University of Tehran in 2005 for his bachelor project based on x-ray based biomedical imaging systems. He continued his education at the University of New South Wales where he obtained his Master of Science in Biomedical Sciences in 2006. The focus of his masters project was computer modelling of the heart's electrical activity. He then joined the Auckland Bioengineering Institute to model and image the microcirculation of the ocular lens for his doctoral thesis.
Dr Vaghefi has been developing magnetic resonance imaging techniques to non-invasively monitor the fluid fluxes inside the ocular lens. His achievements have been published in highly respected international biomedical journals.
Research | Current
Ehsan is a member of the ABI Special Sense Organs research project.
Currently he is continuing his research in the fields of
- Clinically applied physiological optics
- Cataracts research
- Ocular biomedical imaging
- Ocular computational modelling
He has the following funded postgraduate projects available:
- Biological glass: The molecular and cellular determinations of the optical properties of the ocular lens
Although age-related changes to the optical properties of the ocular lens are the leading causes of refractive error (presbyopia) and blindness (cataract), we know little about how the optical properties of the lens are established and maintained at the molecular and cellular levels. Like any glass lens, our biological lens suffers from inherent refractive error, but being a living tissue it compensates for these errors by overexpressing crystallin proteins to create a gradient of refractive index (GRIN). It is our hypothesis that differences in crystallin subtype expression and processing combined with lens structure and function generate and maintain the GRIN.
We have recently shown that inhibition of lens transport increases lens water content and decreases the GRIN, suggesting the GRIN is actively maintained and that changes in lens physiology will affect overall vision quality. In this application will investigate how lens structure and function interact to establish and maintain the GRIN, and how alterations in these mechanisms affect our quality of vision. This research involves stressing the lens physiology with known external stimuli and then measure its GRIN profile, using an existing laser ray-tracing system. These optical measurements are then used in our optical modelling software (ZEMAX) to create accurate models of the scanned lenses and also to assess their optical efficacy. This project requires basic understanding of ocular physiology, optics and computer modelling.
Areas of expertise
- Physiological Optics
- Non-invasive ocular imaging
- Computational modelling of the eye tissue
Selected publications and creative works (Research Outputs)
- Shalbaf, F., Lovell, N. H., Dokos, S., Trew, M., & Vaghefi, E. (2019). Foveal eccentricity can influence activation threshold in subretinal electrical stimulation. BIOMEDICAL PHYSICS & ENGINEERING EXPRESS, 5 (3)10.1088/2057-1976/ab0b85
- Khanal, S., Turnbull, P. R. K., Vaghefi, E., & Phillips, J. R. (2019). Repeatability of Arterial Spin Labeling MRI in Measuring Blood Perfusion in the Human Eye. Journal of magnetic resonance imaging : JMRI, 49 (4), 966-974. 10.1002/jmri.26323
Other University of Auckland co-authors: John Phillips, Phil Turnbull, Safal Khanal
- Vaghefi, E., & Donaldson, P. J. (2018). The lens internal microcirculation system delivers solutes to the lens core faster than would be predicted by passive diffusion. American journal of physiology. Regulatory, integrative and comparative physiology, 315 (5), R994-R1002. 10.1152/ajpregu.00180.2018
Other University of Auckland co-authors: Paul Donaldson
- Lie, A. L., Pan, X., Donaldson, P. J., White, T. W., & Vaghefi, E. (2018). The lens paradox is due to an age-related shift in optical centre of the lens. Paper presented at Annual Meeting of the Association-for-Research-in-Vision-and-Ophthalmology (ARVO), Honolulu, HI. 29 April - 3 May 2018. INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE. (pp. 2).
Other University of Auckland co-authors: Alyssa Lie, Paul Donaldson
- Nye-Wood, M. G., Lie, A. L., Donaldson, P. J., & Vaghefi, E. (2018). Physiological optics of the accommodating lens: a clinical observational study using MRI. Paper presented at Annual Meeting of the Association-for-Research-in-Vision-and-Ophthalmology (ARVO), Honolulu, HI. 29 April - 3 May 2018. INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE. (pp. 2).
Other University of Auckland co-authors: Alyssa Lie, Wilson Pan, Paul Donaldson
- Petrova, R. S., Webb, K. F., Vaghefi, E., Walker, K., Schey, K. L., & Donaldson, P. J. (2018). Dynamic functional contribution of the water channel AQP5 to the water permeability of peripheral lens fiber cells. American Journal of Physiology - Cell Physiology, 314 (2), C191-C201. 10.1152/ajpcell.00214.2017
Other University of Auckland co-authors: Rosica Petrova, Paul Donaldson
- Kolenderska, S. M., Bräuer B, Vaghefi, E., & Vanholsbeeck, F. (2018). Extraction of Group Velocity Dispersion (GVD) value from standard Fourier domain OCT data. Optics InfoBase Conference Papers. 10.1364/TRANSLATIONAL.2018.JTh3A.42
Other University of Auckland co-authors: Sylwia Kolenderska, Frederique Vanholsbeeck
- Wu, H.-T. D., Howse, L. A., & Vaghefi, E. (2017). Effect of age-related human lens sutures growth on its fluid dynamics. Investigative Ophthalmology and Visual Science, 58 (14), 6351-6357. 10.1167/iovs.17-22099
Other University of Auckland co-authors: Duncan Wu