Functional magnetic resonance imaging of the lacrimal drainage system
Research type
Research Study
Full title
A feasibility study to develop a protocol for the functional magnetic resonance imaging of the lacrimal drainage system
IRAS ID
225255
Contact name
Saul Rajak
Contact email
Sponsor organisation
Brighton & Sussex University Hospitals NHS Trust
Duration of Study in the UK
0 years, 5 months, 28 days
Research summary
Summary of Research
Tear drainage delay is a common problem that causes a watery eye. This can impair activities of daily living such as reading and driving, can be a huge nuisance requiring continual dabbing with a tissue and can cause infections and abscesses of the tear drainage system. The current, standard investigations for tear drainage delay have significant limitations with two separate scans in separate departments being required (nuclear medicine and CT). A functional MRI scan would be able to combine these two scans and provide both better anatomical and functional detail than each one respectively. This would have several major benefits:
1. Improved diagnostic information to guide the treatment choice
2. Reduced scan resource usage as one scan would provide all the required functional anatomical and functional information.
3. Improved patient convenience
4. Improved safety as radiation is used for CT DCG, where MRI
The study involves investigation of both controls with normal tear drainage and individuals with known tear drainage delay. Both groups are required for the development of the protocol as the speed of tear transit will differ greatly which will facilitate optimisation of the MRI scan protocol. This will also provide preliminary data on the speed of tear passage in a normal lacrimal drainage system and in an impaired system.Summary of Results
This study was carried out by ophthalmologists (eye doctors) and radiologists (doctors who look at medical scans) at Brighton and Sussex University Hospitals NHS Trust (now University Hospitals Sussex NHS Foundation Trust), in conjunction with medical students at Brighton and Sussex Medical School. The study received funding from the Brighton and Sussex Medical School. There were no competing interests.
The study took place at the Radiology department at the Royal Sussex County Hospital between September 2018 and March 2019.
Background to research:
The role of the tear duct system is to make and drain tears. Patients with too much tearing of the eyes are commonly referred to Ophthalmology (eye) clinics. Too much tearing occurs when there is either too much production of tears or reduced tear drainage. Too much tearing can impact patients’ quality of life by causing blurred vision, skin irritation around the eyes and social embarrassment.
Aside from examination in clinic, patients with too much tearing can be referred for tests called dacryocystography (DCG) and dacryoscintigraphy (DSG). DCG involves putting a small catheter (tube) into the tear duct, injecting a medication, while a series of X-rays are taken, to show the anatomy of the tear ducts. DSG involves putting drops of dye into the eye, followed by a series of images that are taken to show how well the dye travels naturally through the tear duct.
Currently patients are investigated by both DCG in the CT scan (computerised tomography scan) department and DSG in the nuclear medicine department. The disadvantages of this approach include having two separate scans carried out in two different departments, which is both inefficient, time-consuming for patients and involves exposure to X Rays and the need for catheter insertion.
Magnetic Resonance Dacryocystography (MR DCG) lets doctors investigate both the anatomy of the tear ducts and how well tears flow through the tear ducts at the same time without exposing patients to radiation from X rays or the risk of causing damage to the eyelids with the catheter.
Various methods of MR DCG have been described and there is currently no standard protocol for this procedure. The aim of our study was to develop a protocol for MR DCG that can be used routinely instead of DCG and DSG. Although the initial study aim was to recruit both healthy volunteers and symptomatic patients, the design was amended to include only healthy volunteers initially. This was to ensure that we developed a robust procedure with a larger number of healthy volunteers, and the procedure could be reliably repeated to look at the lacrimal system. We can then plan to expand our recruitment numbers with symptomatic patients as a separate study.
15 volunteers (medical students) with no watery eye symptoms participated in the study. They all had an MR DCG with a drop of dye automatically placed on their eyes with a pump. None of the volunteers had any medical problems from the test. From their scans, we were able to develop a MR DCG protocol that allowed us to see videos that clearly show both the anatomy of the tear ducts and how well tears flow at the same time.
MR DCG is a safe and non-invasive test that could replace DCG and DSG, which is helpful to both patients and doctors. This type of scan could help doctors understand what is causing too much tearing in patients and help guide the way in which it is treated. More information about the study can be found on clinicaltrials.gov, and we are preparing our results for publication in a scientific journal.
This completed study looked at MR DCG in healthy volunteers i.e. people without symptoms. In future, we would like to conduct a larger study to investigate the use and safety of MR DCG in patients with symptoms.REC name
London - Brighton & Sussex Research Ethics Committee
REC reference
18/LO/0189
Date of REC Opinion
20 Mar 2018
REC opinion
Further Information Favourable Opinion