Coloured-light in Retinitis Pigmentosa. — CLIRP  

Retinitis Pigmentosa Clinical Trial

Official title: A Pilot, Randomised, Masked Study to Investigate the Effect of Coloured-light on Colour Contrast Thresholds in Retinitis Pigmentosa.

Status Not yet recruiting

Clinical Trial 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).

Clinical Trial 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) ;

Related Conditions & MeSH terms

• Retinitis
• Retinitis Pigmentosa

• NCT number: NCT06224114
• Study type: Interventional
• Source: University College, London
• Contact: Pushpsen Joshi
• Phone: 0203 447 5369
• Email: uclh.randd@nhs.net
• Status: Not yet recruiting
• Phase: N/A
• Start date: March 2024
• Completion date: October 2024