Cataract surgery is a common lens replacement surgery where an artificial lens is implanted in the eye after the removal of the eye lens. Such replacement becomes a need with ageing as the eye lens develops cloudy patches that cause blurry vision. The cataract surgery procedure can be described as safe, and the patient usually does not have to stay in the hospital after such surgery.
As artificial interocular lenses (IOLs) are usually made of acrylic or silicone, they are significantly different from eye lenses in terms of geometry and other physical characteristics. They are rigid, thinner, and more compact and they need a positioning mechanism to fit them in place. When an IOL lens is fitted in place, the expectation is that it will focus the light on the fovea, the light-sensitive part of the retina, however, this aim cannot be achieved precisely in most cases. The reason for this is the difficulty in selecting the optical power of the IOL lens and selecting the optimal position of the lens. This selection process depends on either empirical equations or surgeon experience and is all based on the measurements of corneal curvature, anterior chamber depth, lens thickness and mostly the axial length or the distance between the anterior cornea centre and the posterior pole of the eye.
Currently, inaccurate estimation of the effective IOL power and position are the most common concerns in cataract surgeries. After the surgery, underestimation of IOL power leaves patients myopic however, overestimation leaves them hyperopic, and this is the current difficult challenge in this surgery, correct calculations.
This project will initially emphasise the measurement of the eye axial lens, the most critical parameter in determining the ideal IOL power. A novel non-penetration measurement method based on light ray tracking will firstly be investigated in a set of custom-built MATLAB codes and then validated through a set of fully anonymised secondary clinical data.
In the send phase of the project, the PhD candidate will use the set of codes created in the first phase to build a mathematical optimisation software tool that uses particle swarm optimisation to estimate the IOP lens power and position. The tool will be validated against a set of fully anonymised secondary clinical data, hence optimised.
In the final phase of the project, the PhD candidate will design a user-friendly graphical user interface (GUI) for the set of the MATLAB codes created within the project and will have the opportunity to present the outcome at international conferences and journal papers.
The project plan is a result of a comprehensive collaboration among a team of three international experts in the fields of biomedical engineering (Dr Ahmed Abass – School of Engineering), ophthalmic bioengineering (Dr Hannah Levis – Institute of Life Course and Medical Sciences), and ophthalmic surgery (Mr Vito Romano – St Pauls Eye Unit, Royal Liverpool University Hospital).
Comprehensive training will be provided to the PhD student for all aspects of the project including the ethical approval, the technical background, and the MATLAB coding in a collaborative environment. The project will be carried out within the Mechanical, Materials and Aerospace Engineering Department at the School of Engineering and the Eye and Vision Sciences Department at the Institute of Life Course and Medical Sciences.
University of Liverpool (UoL) is a world leading research institution and a fantastic place to study in. In the 2021 Research Excellence Framework results, 91% of UoL’s research was rated as world leading or internationally excellent.
Candidates will have, or be due to obtain, a Master’s Degree or equivalent from a reputable University in an appropriate field of Engineering. Exceptional candidates with a First-Class Bachelor’s Degree in an appropriate field will also be considered.
Candidates wishing to apply should complete the University of Liverpool application form applying for a PhD in Mechanical Engineering and uploading: Degree Certificates & Transcripts, an up-to-date CV, a covering letter/personal statement and two academic references.
Candidates wishing to discuss the research project should contact the primary supervisor Dr Ahmed Abass on: [Email Address Removed], those wishing to discuss the application process should discuss this with the School Postgraduate Office [Email Address Removed].