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The Effect of Varying Brightness on Palpebral Aperture

The Effect of Varying Brightness Levels on Palpebral Aperture and the Point of Orbicularis Engagement Using EEG Signalling.

Status
UNKNOWN
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT05210491
Enrollment
40
Registered
2022-01-27
Start date
2022-01-14
Completion date
2022-02-21
Last updated
2022-01-27

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Eyelid Ptoses

Keywords

Palpebral Aperture measurements

Brief summary

We aim to establish the point at which glare from bright lights begins to engage our eyelids - causing us to squint. We will be using a video camera with an LED ring light around it facing the volunteer and we will record the eyelid position as the light brightness is increased gradually. Many studies have looked at the effect glare has on a person through qualitative questionnaires but few have been able to quantify this.

Detailed description

Our study will aim to establish the point of orbicularis engagement based on luminous intensity Murray et al. created an Ocular Stress Monitor to see if the contracture of the muscles on the eyelid indicative of pain as a light source was increased in luminosity 8 Our study will go one step further by using video technology and a portable EEG machine to detect the pulses of lid contracture as luminosity of a ring light i s increased incrementally. An advanced calibrated datalogging LED light meter will simultaneously record the level of brightness to establish at which point the spike in EEG occurs. Screenshots from the video recording will be taken and accurate MRD1 measurements can be taken at the point of orbicular i s engagement. The scientific justification for this research question is twofold We wish to establish the threshold at which orbicularis engages such that palpebral aperture and MRD measurements are altered. This is relevant to the technique of taking these measurements in the clinical environment and the light intensity at which these measurements are taken. We wish to establish the light intensity which should not be exceeded to take these measurements. As photography becomes increasingly used in oculoplastic s clinics we envisage palpebral aperture and MRD1 measurements being performed digitally rather than manually These measurements are relevant to pre operative and post operative imaging, and surgical planning. Furthermore, our results maybe applicable more widely to industry, for example vehicle headlights, bicycle lights, camera flash, workplace lighting. Reference: Murray I, Plainis S, Carden D. The ocular stress monitor: a new device for measuring discomfort glare. Lighting Research Technology. 2002;34(3):231 239.

Interventions

OTHERReview of eyelid positioning in increasing brightness levels

Up to 30 seconds, three times, looking into a video camera as glare is incrementally increased.

Sponsors

National Health Service, United Kingdom
CollaboratorOTHER_GOV
Royal Free Hospital NHS Foundation Trust
CollaboratorOTHER
University of Edinburgh
Lead SponsorOTHER

Study design

Allocation
NON_RANDOMIZED
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
Yes

Inclusion criteria

* Aged between 18 and 65 years of age * A member of the Royal Free NHS trust

Exclusion criteria

* No known ocular pathology * No lid problems/ptosis or previous lid surgery * No contact lenses in for duration of experiment * No pseudophakia * No neurological disease

Design outcomes

Primary

MeasureTime frameDescription
The point at which the eyelid begins to contract under what brightness levelAll carried out within a 2 week periodUsing a light meter, ring light, and EEG machine

Countries

United Kingdom

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026