In the international RUSH2a study of Jacque Duncan MD, University of California, San Francisco, 120 patients spread over nine different clinics are monitored for four years. This study includes only syndromic (USH2a) and non-syndromic patients with mutations in the USH2a gene (nsRP).
The study “Rate of progression of USHer Syndrome” is done at about 20 clinical centres around the world, including the Radboudmc in Nijmegen, the Netherlands and is financed by the Foundation Fighting Blindness. Researcher Jack Weeda is working as a research optometrist in the Radboudumc on the RUSH2a study. He takes us with him in his work and gives us a view of the study.
The RUSH2a study and the CRUSH study
Recently, we already could read about the current state of affairs of the CRUSH study. Read here.
Also thanks to the Medical Advisory Council of the Stichting Ushersyndroom, the content of the CRUSH study has been aligned to RUSH2a study. This means that the research questions and the study measurements are largely similar, allowing the results of RUSH2a study to be compared with those of the CRUSH study. This comparison of the results is of scientific value.
The differences between both studies are mainly in the working area of the ENT department. For instance, the CRUSH study includes more audiological research and a one-off balance test is done. This study is conducted under the leadership of Dr Ronald Pennings. The RUSH2a study includes a one-off smelling test. The RUSH2a is conducted under the leadership of Dr Carel Hoyng. 40 patients are participating in the CRUSH study, while the RUSH2a study has about 120 international participants, nine of which are Dutch.
Here read about the similarities and the differences between the RUSH2a and the CRUSH studies.
Curious patients group
Jack Weeda is research optometrist at the ophthalmology department of the Radboudumc in Nijmegen. Since 2012 he has mainly worked for all scientific studies done at the department through the Trial centre of Prof Hoyng. In 2018, Jack Weeda took up the coordination of the RUSH2a study and a year later the ophthalmology part of the CRUSH study as well. In the past few years, Jack Weeda has seen about 60 Ushers and he still sees many of them on an annual basis.
Jack Weeda: “By now, I have got to know the patients group as a curious, positively critical, well-organised and really active patients group. I regularly see participants of the study I know appear in various ways in the media and thanks to one participant I almost even made my first appearance on television.”
The first results
The RUSH2a study started about a year before the start of the CRUSH study and by now the first results appear. For instance, an article was recently published about the ophthalmological and otological differences between people suffering from Usher Syndrome and people suffering from autosomal recessive RP (AR-RP) or non-syndromic RP (nsRP). Patients suffering from AR-RP do have mutations in the USH2a gene, but there is no or hardly any loss of hearing. The first findings have shown that patients with Usher Syndrome have more severe loss of field of vision than patients with nsRP do. Read more: https://pubmed.ncbi.nlm.nih.gov/32446738/
From the RUSH2a study an article was published about the FST study, a relatively new study that is conducted in the CRUSH and RUSH2a studies. In this FST study light flashes in three colours, being red, blue and white, are offered and of each colour it is determined which intensity of the flash is just perceived. The values resulting from this study appear to be a good indicator of the seriousness and the duration of retinitis pigmentosa. Possibly, these values can also be used to measure the effectiveness of any future therapy, but this needs further research. For the researchers it is interesting to see whether comparable results can be measured using the data from the CRUSH study. The researchers will soon start working on this. Read this article: https://pubmed.ncbi.nlm.nih.gov/33133772/
Jack Weeda hopes that together with the participating patients he will be able to make more minor and perhaps even major discoveries in both studies and in this way further solve the Usher mystery.