Coloured-light in Retinitis Pigmentosa.

NCT ID: NCT06224114

Last Updated: 2024-01-25

Basic Information

• Recruitment Status: NOT_YET_RECRUITING
• Clinical Phase: NA
• Total Enrollment: 70 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2024-03-31
• Study Completion Date: 2024-10-31

Brief Summary

This study will assess the effect of 2 different colours of light on colour vision in adults with retinitis pigments (RP). Participants will be 18 years or above with a genetically confirmed molecular diagnosis of RP. After informed consent, participants will have their letter chart vision and colour vision measured in their study eye. They will then be they will be randomly allocated to one of 2 groups. The study team will not know which group they have been assigned to. Group 1 will be given a coloured-light hand-held torch and be asked to apply it to their study eye for 3 minutes at home each morning between 8 - 10 am for 28 days. Group 2 will be given a different colour hand-held torch and be asked to do the same. All participants will have their letter chart vision and colour vision measured at the end of study on day 28 (+ 7 days).

Detailed Description

This is a pilot, randomised, masked, single-site trial designed to assess the effect of coloured light exposure on cone contrast thresholds (CCT) in adults with RP.

70 adults with typical RP in which the underlying genetic cause is known will be recruited from Moorfields Eye Hospital genetics service.

Following informed consent, participants will be invited for a baseline study visit.

At a baseline visit, prior to any light exposure (day 0), participants will undergo Logarithm of the Minimum Angle of Resolution (LogMAR) visual acuity (VA) and CCT measurements performed by an experienced technician according to dedicated standard operating procedures. The order of testing will be as follows:

• Study eye: LogMAR VA
• Study eye: CCT (Tritan and Protan)

After baseline assessments have been completed, participants will be randomised to the intervention (n=35) or control group (n=35) by a study nurse. All other study team members will be masked to group allocation.

The intervention group will be provided with a coloured torch and instructed to apply it to their study eye for 3 minutes at home each morning between 8 - 10 am for 28 days. The control group will be provided with a different coloured torch and will be instructed to follow the same protocol. The specific colours have not be disclosed here to protect masking of the study. Participants will be asked to complete a paper diary each day to record whether light was applied, the time and duration of the application and the eye to which light was applied.

The end of trial visit will be scheduled on day 28 (+7 days). Participants will undergo LogMAR VA and CCT measurements by an experienced technician according to standard operating procedures (SOP). The order of testing will be as follows:

• Study eye: LogMAR VA
• Study eye: CCT (Tritan and Protan)

Conditions

Retinitis Pigmentosa

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: TRIPLE

Study Groups

Coloured light 1 group

Coloured light 1 group will be provided with a coloured-light torch and instructed to apply it to their study eye for 3 minutes at home each morning between 8 - 10 am for 28 days.

Group Type: EXPERIMENTAL

Coloured-light torch

Intervention Type: DEVICE

Participant administered, at-home, 3-minute daily morning application (between 8 - 10am) of a coloured-light torch to the study eye.

Coloured light 2 group

Coloured light 2 group will be provided with a different coloured-light torch and instructed to apply it to their study eye for 3 minutes at home each morning between 8 - 10 am for 28 days.

Group Type: PLACEBO_COMPARATOR

Different coloured-light torch

Intervention Type: DEVICE

Participant administered, at-home, 3-minute daily morning application (between 8 - 10am) of a different coloured-light torch to the study eye.

Interventions

Coloured-light torch

Participant administered, at-home, 3-minute daily morning application (between 8 - 10am) of a coloured-light torch to the study eye.

Intervention Type: DEVICE

Different coloured-light torch

Participant administered, at-home, 3-minute daily morning application (between 8 - 10am) of a different coloured-light torch to the study eye.

Intervention Type: DEVICE

Eligibility Criteria

Inclusion Criteria

• Over 18 years old
• Typical RP where the underlying genetic cause is known. This may include PRPF31, PRPF8, SNRNP200, RHO, RP1 [autosomal dominant] and USH2A, EYS [autosomal recessive]
• VA of 0.30 LogMAR (6/12) or better in the study eye
• Preserved foveal structure defined by intact outer retinal (ellipsoid zone) at the fovea on Optical Coherence Tomography (OCT) and a hyperfluorescent ring within the temporal vascular arcades on Fundus Autofluorescence (FAF) in the study eye
• Willing and able to provide written informed consent

Exclusion Criteria

• Co-existing ocular pathology will be excluded; however, participants with macular oedema, a common pre-symptomatic manifestation of foveal involvement, will not be excluded
• Concurrent and/or recent involvement in other research that is likely to interfere with the intervention within 6 months of study enrolment
• Unwilling or able to provide written informed consent.

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

University College, London

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Hannah Dunbar, PhD

Role: PRINCIPAL_INVESTIGATOR

UCL Institute of Ophthalmology

Locations

Moorfields Eye Hospital NHS Foundation Trust

London, , United Kingdom

Countries

United Kingdom

Central Contacts

Pushpsen Joshi

Role: CONTACT

uclh.randd@nhs.net

0203 447 5369

Facility Contacts

Hannah Dunbar, PhD

Role: primary

Other Identifiers

161090

Identifier Type: -

Identifier Source: org_study_id