Report

Teaser, summary, work performed and final results

Periodic Reporting for period 1 - EGRET (European Glaucoma Research Training Program)

Teaser

Glaucoma is the most common age-related neurodegenerative eye-disease in western society and one of the four major blinding eye diseases. If untreated or detected too late, glaucoma will end up in blindness, yielding a profound loss of quality of life for the individual and...

Summary

Glaucoma is the most common age-related neurodegenerative eye-disease in western society and one of the four major blinding eye diseases. If untreated or detected too late, glaucoma will end up in blindness, yielding a profound loss of quality of life for the individual and major costs to society. The classic view of glaucoma is that of an eye disease in which an elevated intraocular pressure damages the retinal nerve cells mechanically, initially resulting in visual field loss, and ultimately in blindness.

Recent insights indicate that the classic view is far too simplistic: rather than a disease restricted to the eye, glaucoma involves both intraocular pressure and intracranial pressure and damages neural tissue in both the eye and the brain. EGRET will aim its efforts at teaching young researchers in how to a) acquire new, quantitative knowledge on glaucoma and the aging visual system, and b) apply this new knowledge to boost innovation in glaucoma care in both the public and private sectors, where: 1) it enables the development of new tools for the early detection and cost-effective monitoring of glaucoma; 2) it can inspire the development and implementation of new treatments; 3) it contributes to our understanding of the relationships between various neurodegenerative diseases, and 4) it contributes to improving healthy aging in general. This new knowledge therefore has tremendous potential to positively impact the future of millions of European citizens.

Work performed

Training events
EGRET has organized three training events on “Visual system physiology & Introduction to the many faces of glaucoma and neurodegeneration” (Groningen, November 2016), “Human visual system pathophysiology – advances in research, diagnostics & therapy” (Magdeburg, March 2017), and “Sensory biophysics and diagnostics; genetics of glaucoma” (Groningen, November 2017).

Scientific Progress
All ESRs have successfully started their projects and have made considerable progression. Meta-analysis and literature reviews have been performed, pilot studies have been conducted, METC approval has been obtained, secondments have started, manuscripts have been drafted, and results have been disseminated. Below a short report on each of the ESR\'s progress.

Allison Loiselle (ESR1) is determining the utility of otoacoustic emissions as a noninvasive measurement of intracranial pressure (ICP). Preliminary results show that it is well possible to measure changes in ICP with this technique, but thus far no clear differences between different types of glaucoma can be found.

Sina Engler (ESR2) works on the evaluation of otoacoustic emissions (OAEs) and their relation to frequency selectivity. Spontaneous OAEs (SOAEs) have been recorded in barn owls, and suppression measurements have been performed. Data showed that SOAE amplitude correlates negatively with suppression threshold and that SOAE suppression tuning curves are similar to neuronal tuning curves.

Asterios Chrysou (ESR3) portrays the current knowledge of OCT measurements in relation to Parkinson\'s Disease (PD). A meta-analysis conducted on the retinal nerve fiber layer degeneration in PD showed broad degeneration in the retina of patient compared to controls. Interestingly, similar to glaucoma, the changes were only found in the inner retina, and not in the outer retina. Furthermore, he started with collecting OCT and visual field data in a de novo cohort of PD patients.

Tuomas Heikka (ESR4) investigates the usability of OCT in clinical progression detection in glaucoma using data from the Groningen Longitudinal Glaucoma Study (GLGS). By measuring retinal layer thicknesses in healthy observers under different conditions, he showed that our current analysis of OCT images (as implemented in all commercially available devices) is biased. He developed an improved image-analysis algorithm. He intends to apply the new algorithm to clinical data.

Nigus Asfaw (ESR5) and Anna Neustaeter (ESR6) collaboratively work on determining the heritability of eye diseases and the potential factors that can significantly affect the proportion of variation in glaucoma and the development of other eye diseases. Common phenotypes and heritability estimates of glaucoma and glaucoma-related endophenotypes were identified from a meta-analysis of primary open angle glaucoma patients. Most common glaucoma phenotypes show a strong heritability. Central corneal thickness showed the highest heritability. They will apply their finding in GWAS data from the LifeLines study.

Lorenzo Scanferla (ESR7) has developed an inventory of psychophysical experiments directed towards motion detection and is currently testing whether this inventory is likely to be able to discriminate between glaucoma patients and healthy controls. Data collection is in progress, and so far 6 glaucoma patients and 8 healthy controls have been included. Furthermore, ethical approval is near submission for his secondment (in collaboration with ESR8) at Johnson and Johnson (formerly AMO) where he will investigate the effect of optical quality on perimetry.

Catarina Joao (ESR8) determines the influence of dynamic light conditions on visual functioning in glaucoma. She has measured the contrast sensitivity to a small stimulus at a time-varying background luminance as a function of flicker frequency. Thus far, 20 healthy subjects and 12 glaucoma patients have been included. Findings show that contrast gain control occu

Final results

Our new OCT algorithm has the potential to have major impact on the accuracy of OCT RNFL thickness measurements. As this parameter is used daily in glaucoma care, its impact is potentially high.

Our method implemented to find brain regions for treatment with TMS has the potential to become a standard for such treatment in neurology.

Our improved CF methods will increase their usefulness both in fundamental and applied brain science.

Our eye-movement based methods for screening and assessing visual fields provide means to assess the presence of visual field defects in patients who are unable to carry out standard perimetry. As such, these methods can have a big impact on clinical care in such patient groups.

Website & more info

More info: http://www.egret-program.eu.