How to distinguish between fit and unfit drivers - PhD project and thesis

My name is Iris Tigchelaar, EGRET+ PhD student at UMCG (University Medical Centre Groningen) in Holland, and I joined OCUSWEEP in Finland in 2016 in order to gain practical experience on the field.

In November 2016, I moved to Turku in Finland to work on a project related to fitness to drive and vision. Based on the ideas of my supervisor Dr. Markku Leinonen the Ocusweep device was developed.

With the Ocusweep, not only visual acuity can be measured, but also contrast sensitivity and the visual field and functional vision. My PhD project is part of EGRET(+), a research and innovation program under the Marie Sklodowska-Curie grant agreement in EU’s Horizon 2020. Together, we are 25 international PhD candidates all doing research on glaucoma. The goal is to acquire new knowledge on glaucoma and the aging visual system, and to apply this knowledge to boost innovation in glaucoma care.

During my first months at the Ocusweep office, we brainstormed about the difficulties in assessing fitness to drive in glaucoma. There is a discrepancy in literature on research about this topic; some studies show that drivers with glaucoma are more at risk for collisions and others do not. We also looked at the regulations across Europe regarding driving with glaucoma and saw that they usually involve only visual acuity and visual field measurements. We realized that testing for these defects is useful, but not enough. Studies show that low contrast sensitivity and slow reaction times are also predictors of a history of motor vehicle accidents, as well as different eye movement patterns that are sometimes seen in glaucoma.

We believe that the other aspects can explain why some glaucoma patients are still safe drivers and others are not. The ability to compensate for visual field defects by making saccades or turning your head for example. Reaction times to visual stimuli can also be an important indicator of successful avoiding hazardous situations.

Therefore, I am recruiting glaucoma patients and a control group who complete several neuropsychological tests often used in assessing fitness to drive, and Ocusweep tests measuring functional vision. The Ocusweep tests include visual acuity, contrast sensitivity and a visual field test, but also Ocusweep’s reaction time test (OcuRT) and a Reaction Time Perimetry (RTP) test. The outcome measure is driving simulator performance.

The goal of my PhD is therefore to identify which tests can distinguish best between fit and unfit drivers. This will allow safe drivers to stay on the road longer and avoid accidents in drivers that are no longer fit to drive.