Photoreceptor Sensitivity Thresholds Clinical Trial
Official title:
Evaluation of a Novel Wearable Light-emitting System for Measuring Dark-adaptation Thresholds in Normal Adult Healthy Volunteers
| NCT number | NCT02674425 |
| Other study ID # | UoL001185 |
| Secondary ID | |
| Status | Recruiting |
| Phase | N/A |
| First received | January 27, 2016 |
| Last updated | October 24, 2016 |
| Start date | September 2016 |
Conventional dark-adaptometers are unsuitable as a mass screening tool due to their high
cost, lack of easy portability, need of trained staff and a totally dark room to be
operated, arbitrary testing procedures, associated time waste in clinic and patient burden
to mention a few. Consequently, dark adaptometers are not routinely used as clinical tools
for retinal diagnosis and monitoring despite the inherent benefits over other visual
electrophysiology equipment such as the ERG system, whose cost and features may often be
surplus to optometrists' requirements.
This trial will assess the dark-adaptometry testing performance of a novel light-emitting
system by generating full dark-adaptation threshold functions in normal adult healthy
volunteers.
The novel system has been proposed to overcome the issues associated with current
instrumentation; it is semi-automatic and easy to use without the need of any skilled
operator.
It is envisaged that this system could spread the practice of dark-adaptometry testing and
its adoption by high-street optometrists. This will allow diagnosing a number of retinal
pathologies more quickly and more reliably that, faced with an ageing population, represents
a major asset to the Health Community and the NHS.
This trial will involve 20 healthy volunteers, distributed in equal number in 2 groups of
18-40 and 50-70 years old, respectively. Proven the good health and eye condition of the
participants, one of their eyes will be randomly-allocated and undergo dark-adaptometry
testing 3 times on separate days within 3 weeks.
Testing will clarify whether by using the novel system it is possible to reproduce
state-of-the-art threshold measurements as good or better than those produced by
commercially-available dark-adaptometers. Threshold measurements in the elderly will be
compared with literature data adjusted to exclude aged crystalline lens and pupillary miosis
contributions. Data variability and system usability will be also assessed.
| Status | Recruiting |
| Enrollment | 20 |
| Est. completion date | |
| Est. primary completion date | May 2017 |
| Accepts healthy volunteers | Accepts Healthy Volunteers |
| Gender | Both |
| Age group | 18 Years to 70 Years |
| Eligibility |
Inclusion Criteria: - Refractive error: = ±5 dioptres spherical (myopia/hyperopia) equivalent; = 3 dioptres cylinder (astigmatism) equivalent. Exclusion Criteria: - Subjects not in age range and/or unable to fully understand the informed consent and/or unable to comply with study procedures. - Self-reported history of depression, lack of sleep, psychiatric disorders, or neurological diseases such as Alzheimer's and Parkinson's disease. - Self-reported history of diabetes, stroke, or multiple sclerosis. - Self-reported hypovitaminosis A, alcoholism, liver or intestinal disease, malabsorption, protein calorie malnutrition, or sickle cell anaemia. - Use of psychoactive drugs (including lithium salts for mood stabilisation). - Use of dietary intake of ascorbic acid, vitamin A, B, E or other antioxidant supplements in the last two weeks. - Recurrent practice of activities that expose the retina to ultra-violet radiation such as sailing, fishing, sunbathing or tanning saloons. |
Observational Model: Case-Only
| Country | Name | City | State |
|---|---|---|---|
| United Kingdom | University of Liverpool | Liverpool | Merseyside |
| Lead Sponsor | Collaborator |
|---|---|
| University of Liverpool |
United Kingdom,
| Type | Measure | Description | Time frame | Safety issue |
|---|---|---|---|---|
| Primary | Rod-cone break measurement | April 2016 - up to 3 weeks | No | |
| Primary | Absolute threshold measurement | April 2016 - up to 3 weeks | No |