Color Blindness, RedProLightNCT04060238
Effect of Protanopia on the Brightness Perception of Brake Lights
An observational study of Color Blindness, Red and Reaction Time, run by Aalen University at 1 site in Germany.
Trial summary
The aim of the offered project is to investigate the influence of protanopia (red blindness) or protanomaly (red vision weakness) on the recognizability of red brake lights with the help of a test person study. From this, estimates of the influence of protanopia or protanomaly on driving ability are to be derived. Read more about this study
- Who is it for?
- Ages 18 years and older, men only
- Conditions the study is for
- Color Blindness, Red, Reaction Time
- What is being tested?
- Anomaloscope (colour vision test)
- How many people
- 16 participants
- Where
- 1 siteGermany
- Study dates
- 7 Jan 2020to 15 Mar 2020
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- Men only
- Adult, Older adult
Study population: Ophthalmologically normal (male) subjects OR (male) subjects with (inherited) protanopia (red blindness)
Who may be able to join
- informed consent
- male
- age (greater or equal) 18 years
Who cannot join
- binocular (high contrast) distant visual acuity worse than 0.8 (16/20)
- spherical ametropia exceeding 8 dpt
- cylindrical ametropia exceeding 2.5 dpt
- manifest strabismus (squint) with diplopia
- relative afferent pupillary defect exceeding 0.3 log units
- anamnestic (patient history) OR morphological (slit lamp --> anterior segment, ophthalmoscope --> retina) clue/indicator for a ophthalmologically relevant affection of the eye OR the visual pathway
Show all 9Show fewer
- S.p. severe ocular trauma
- Current OR s.p. severe intraocular inflammation
- S.p. intraocular surgery within the past three months
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Investigation of the Effect of Protanopia ("Red Blindness") on the Brightness Perception of Brake Lights and Their Effect on Reaction Time
The aim of the offered project is to investigate the influence of protanopia (red blindness) or protanomaly (red vision weakness) on the recognizability of red brake lights with the help of a test person study. From this, estimates of the influence of protanopia or protanomaly on driving ability are to be derived.
If a relevant influence can be demonstrated in the study, recommendations for action for the legislator will be made.
Translated with www.DeepL.com/Translator
Read the detailed description
Protanopia is an x-chromosomal inherited cone pigment disorder that related to the red cone,i.e. the L-cone function completely fails. The prevalence of protanopia in the male population is 1%. An incomplete impairment of the L-cone is called protanomaly. The prevalence here is also in 1% of the male population.
In comparison to persons with normal vision red objects appear darker for persons with missing or functionally limited L-cones. This is particularly critical in road traffic, where red is used as a signal colour, for example in traffic lights or brake lights is used.
The scientific questions that need to be investigated are as follows:
- At which contrast threshold (relative brightness) does a proband with protanopia recognize a brake light compared to a normal person?
- If the luminance determined is above the contrast threshold, what influence does the excess of the contrast or the determined luminance have on the reaction time?
- Are there differences with regard to the technology used in the brake light (incandescent lamp or LED)?
For this purpose, a representative set of combination rear lamps, focusing on stoplight, taillight (and of the elevated brake light) in a static situation is created. The test setup is based on a driving pursuit scenario. The test person is positioned at a relevant distance to the combination of rear lamps.
To determine the threshold contrast, an algorithm is developed to control the relative brightness of the brake lights and integrated into the test sequence control. In addition, a method for automated determining of the related reaction time is implemented.
Two taillight technologies (incandescent lamp and LED) are examined at both ambient brightness levels: (i) "bright", i.e. photopic luminance level (Lu >> 10 cd/m2) and (ii) "dark", i.e. mesopic luminance level (Lu < 10 cd/m2).
A comprehensive ophthalmological/optical examination (including visual acuity, ocular alignment, ocular motility, assessment of the leading eye, testing of the efferent and afferent pupillary system and biomicroscopic inspection of the anterior and posterior segments of the eye) is carried out. Comprehensive colour vision testing it performed with the HMC anomaloscope, Oculus Inc., Dutenhofen/FRG, including assessment of the loss of brightness sensation during anomaloscopic exam with max. red. stimulus . In addition, standardized semi-automated kinetic perimetry (SKP) along the horizontal meridian with an automated perimeter (Octopus 900, Haag-Streit Inc., Koeniz/CH) is performed. The ratio of the horizontal extent ("diameter") obtained with both, red vs. white stimuli, is measured and taken as a clinical parameter for quantifying the magnitude of the individual "protan colour vision deficiency".
To illustrate the worst-case scenario, this study is limited to protanopic patients. It is intended as a pure comparative study between a "protanopic" patient group and a "normal vision" control group. The protanopic test subjects and the control subjects are matched with regard to gender and age.
This study is carried out in a "within-subject design", i.e. all test persons go through all situations. In order to minimize sequence effects, the related test conditions are randomized.
- Conditions
- Color Blindness, Red, Reaction Time
- Being tested
- Anomaloscope (colour vision test)
- Keywords
- protanopia, taillight, brake light, differential luminance sensitivity, contrast sensitivity, colour vision, colour vision defect, perimetry, semi-automated kinetic perimetry, traffic, motorist, reaction time
- Medical subject headings
- Color Vision Defects
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Anomaloscope (colour vision test)Diagnostic test
The Heidelberg Multi Colour (HMC) Anolmaloscope (Oculus Inc., Dutenhofen/FRG) is used to differentiate between normal controls (normal trichromatopsia) and test subjects with protanopia ("inherited red colour blindness")
| Study group | Role | What they receive |
|---|---|---|
| Normal colour vision | Normal trichromopsia Receives: Diagnostic Test: Anomaloscope (colour vision test) | |
| Inherited red blindness | Protanopia Receives: Diagnostic Test: Anomaloscope (colour vision test) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Contrast sensitivity (I)
Contrast sensitivity between taillight and brake light under two luminance conditions
Measured: within one year
Secondary outcomes (5)
Reaction time
Time span within the onset of the brake light and the reaction of the tested subject
Measured: within one year
Contrast sensitivity (II)
taillight technology: incandescent lamp vs. light emitting diode (LED)
Measured: within one year
Reaction time (II)
taillight technology: incandescent lamp vs. light emitting diode (LED)
Measured: within one year
Perimetric extent of horizontal meridian
(Semi-autmated kinetic) perimetry with white vs. red stimuli
Measured: within one year
Loss of brightness sensation during anomaloscopic exam
Loss of brightness sensation during anomaloscopic exam with max. red. stimulus
Measured: within one year
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted19 Aug 2019
- Study start7 Jan 2020
- Primary completion15 Mar 2020
- Study completion15 Mar 2020
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Color Blindness, RedStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Case-control
- Time perspective
- Prospective
- Enrolment
- 16 participants (actual)
Sponsor and investigators
- Lead sponsor
- Aalen University
- Sponsor type
- University, hospital or other
- Collaborators
- Karlsruhe Institute of Technology
- Responsible party
- Sponsor
- Investigators
- Ulrich Schiefer, MD, Study chair, Aalen University of Applied Sciences
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04060238
- Sponsor's protocol ID
- ProLight_I
- Acronym
- ProLight
- Status last verified
- Jun 2019
- First submitted
- 13 Aug 2019
- Last updated
- 31 Mar 2020
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided: In case of a subsequent study, aiming at assessing the colour sensitivity of single cones, pseudonomized participant data will be shared with the involved researchers.
Study at a glance
From the registry record, last updated by the sponsor on 31 Mar 2020. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Investigation of the Effect of Protanopia ("Red Blindness") on the Brightness Perception of Brake Lights and Their Effect on Reaction Time
- ClinicalTrials.gov ID
- NCT04060238
- Acronym / sponsor ID
- ProLight / ProLight_I
- Conditions
- Color Blindness, Red, Reaction Time
- Keywords
- protanopia, taillight, brake light, differential luminance sensitivity, contrast sensitivity, colour vision, colour vision defect, perimetry
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 16 participants (actual)
- Lead sponsor
- Aalen UniversityUniversity, hospital or other
- Collaborators
- Karlsruhe Institute of Technology
- Study start
- 7 Jan 2020 (actual)
- Primary completion
- 15 Mar 2020 (actual)
- Study completion
- 15 Mar 2020 (actual)
- First posted
- 19 Aug 2019 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The aim of the offered project is to investigate the influence of protanopia (red blindness) or protanomaly (red vision weakness) on the recognizability of red brake lights with the help of a test person study. From this, estimates of the influence of protanopia or protanomaly on driving ability are to be derived.
If a relevant influence can be demonstrated in the study, recommendations for action for the legislator will be made.
Translated with www.DeepL.com/Translator
Detailed description
Protanopia is an x-chromosomal inherited cone pigment disorder that related to the red cone,i.e. the L-cone function completely fails. The prevalence of protanopia in the male population is 1%. An incomplete impairment of the L-cone is called protanomaly. The prevalence here is also in 1% of the male population.
In comparison to persons with normal vision red objects appear darker for persons with missing or functionally limited L-cones. This is particularly critical in road traffic, where red is used as a signal colour, for example in traffic lights or brake lights is used.
The scientific questions that need to be investigated are as follows:
- At which contrast threshold (relative brightness) does a proband with protanopia recognize a brake light compared to a normal person?
- If the luminance determined is above the contrast threshold, what influence does the excess of the contrast or the determined luminance have on the reaction time?
- Are there differences with regard to the technology used in the brake light (incandescent lamp or LED)?
For this purpose, a representative set of combination rear lamps, focusing on stoplight, taillight (and of the elevated brake light) in a static situation is created. The test setup is based on a driving pursuit scenario. The test person is positioned at a relevant distance to the combination of rear lamps.
To determine the threshold contrast, an algorithm is developed to control the relative brightness of the brake lights and integrated into the test sequence control. In addition, a method for automated determining of the related reaction time is implemented.
Two taillight technologies (incandescent lamp and LED) are examined at both ambient brightness levels: (i) "bright", i.e. photopic luminance level (Lu >> 10 cd/m2) and (ii) "dark", i.e. mesopic luminance level (Lu < 10 cd/m2).
A comprehensive ophthalmological/optical examination (including visual acuity, ocular alignment, ocular motility, assessment of the leading eye, testing of the efferent and afferent pupillary system and biomicroscopic inspection of the anterior and posterior segments of the eye) is carried out. Comprehensive colour vision testing it performed with the HMC anomaloscope, Oculus Inc., Dutenhofen/FRG, including assessment of the loss of brightness sensation during anomaloscopic exam with max. red. stimulus . In addition, standardized semi-automated kinetic perimetry (SKP) along the horizontal meridian with an automated perimeter (Octopus 900, Haag-Streit Inc., Koeniz/CH) is performed. The ratio of the horizontal extent ("diameter") obtained with both, red vs. white stimuli, is measured and taken as a clinical parameter for quantifying the magnitude of the individual "protan colour vision deficiency".
To illustrate the worst-case scenario, this study is limited to protanopic patients. It is intended as a pure comparative study between a "protanopic" patient group and a "normal vision" control group. The protanopic test subjects and the control subjects are matched with regard to gender and age.
This study is carried out in a "within-subject design", i.e. all test persons go through all situations. In order to minimize sequence effects, the related test conditions are randomized.
Study design
- Observational model
- Case-control
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Normal colour vision | – | Diagnostic Test: Anomaloscope (colour vision test)Normal trichromopsia |
| Inherited red blindness | – | Diagnostic Test: Anomaloscope (colour vision test)Protanopia |
Who may qualify
- Ages
- 18 years and older
- Sex
- Male only
- Age groups
- Adult, Older adult
- Study population
- Ophthalmologically normal (male) subjects OR (male) subjects with (inherited) protanopia (red blindness)
Key inclusion criteria (3 listed)
- informed consent
- male
- age (greater or equal) 18 years
Key exclusion criteria (9 listed)
- binocular (high contrast) distant visual acuity worse than 0.8 (16/20)
- spherical ametropia exceeding 8 dpt
- cylindrical ametropia exceeding 2.5 dpt
- manifest strabismus (squint) with diplopia
- relative afferent pupillary defect exceeding 0.3 log units
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Anomaloscope (colour vision test)The Heidelberg Multi Colour (HMC) Anolmaloscope (Oculus Inc., Dutenhofen/FRG) is used to differentiate between normal controls (normal trichromatopsia) and test subjects with protanopia ("inherited red colour blindness") | Diagnostic test | Inherited red blindness, Normal colour vision |
Primary outcome
Contrast sensitivity (I)
Time frame: within one year
Contrast sensitivity between taillight and brake light under two luminance conditions
5 secondary outcomes
Reaction time
Time frame: within one year
Contrast sensitivity (II)
Time frame: within one year
Reaction time (II)
Time frame: within one year
Perimetric extent of horizontal meridian
Time frame: within one year
Loss of brightness sensation during anomaloscopic exam
Time frame: within one year
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 31 Mar 2020.
- Individual participant dataSharing planned: Undecided. In case of a subsequent study, aiming at assessing the colour sensitivity of single cones, pseudonomized participant data will be shared with the involved researchers.
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Ulrich Schiefer, MD study chair
Aalen University of Applied Sciences
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Color Blindness, Red and Reaction Time, run by Aalen University at 1 site in Germany.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 9 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 31 Mar 2020. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Germany. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Contrast sensitivity (I) (time frame: within one year). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 31 Mar 2020.