Retinal Photoreceptor Outer Segment Length Before and After Light Stimulation - a Pilot Study

Not Applicable

Recruiting

• Conditions: Macular Degeneration, Dry; Primary Open-angle Glaucoma
• Interventions: Other: White light stimulation

• Registration Number: NCT03921931
• Lead Sponsor: Medical University of Vienna

Brief Summary

It has been shown that reactions of human retinal photoreceptors to a light stimulus can be measured with custom-made, research prototype optical coherence tomography (OCT) systems. This can be used as a biomarker for the function of the photoreceptors. Due to the high technical demands on the system, however, the technique is currently not available for clinical purposes. In this pilot study a protocol to measure changes in retinal photoreceptor layer thickness before and after light stimulation shall be developed based on a commercial OCT system and newly developed algorithms. Other variables, such as circadian processes shall be investigated as well. After measurements in healthy volunteers, the protocol is planned to be applied in patients with primary open angle glaucoma (POAG) and age-related macular degeneration (AMD) to test for feasibility of the method in these patient groups.

Detailed Description

Not available

Study Timeline

• Study Start: 2018-11-26
• Study First Submitted: 2019-04-04
• Study First Submitted QC: 2019-04-17
• Study First Posted: 2019-04-19
• Status Verified: 2023-03
• Last Update Submitted: 2023-03-14
• Last Update Posted: 2023-03-15
• Primary Completion: 2023-05-31
• Study Completion: 2023-05-31

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 35

Inclusion Criteria

• men and women aged over 18 years
• signed informed consent form
• ametropia below 3 diopters
• ability and willingness to follow instructions

for healthy volunteers:

• normal ophthalmologic findings

for primary open angle glaucoma patients (POAG):

• diagnosed POAG
• MD <= 10 dB

for age-related macular degeneration (AMD):

• diagnosed dry AMD
• diagnosed stage II or stage III AMD

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Exclusion Criteria

• Presence of any abnormalities preventing reliable measurements
• Ocular inflammation and ocular disease interfering with the study aims
• Use of photosensitizing medication (phototoxic drugs, photoallergic drugs) in the 3 months preceding the study
• Presence of any condition with the possibility of causing photosensitivity, including systemic lupus erythematosus SLE, Porphyria, Vitiligo, Xeroderma Pigmentosum and Albinism
• Presence of any form of epilepsy
• Ocular surgery in the 3 months preceding the study
• Pregnancy, planned pregnancy or lactating
• Any medical or surgical history, disorder or disease such as acute or chronic severe organic disease

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Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
healthy volunteers	White light stimulation	light stimulation
primary open angle glaucoma patients	White light stimulation	light stimulation
age-related macular degeneration patients	White light stimulation	light stimulation

Primary Outcome Measures

Name	Time	Method
Light stimulation	1 day	Optical path length changes between inner segment outer segment junction and retinal pigment epithelium (RPE) will be measured with OCT in 15 healthy volunteers, 10 POAG patients and 10 AMD patients before and after light stimulation

Secondary Outcome Measures

Name	Time	Method
Difference in photoreceptor layer thickness over the course of 8 hours	8 hours	Influence of circadian rhythm on the length of retinal photoreceptor outer segments
En face maps	1 day	test an algorithm for production of en face maps of retinal photoreceptor outer segment length
Light stimulation of contralateral eye	1 day	Optical path length changes between inner segment outer segment junction and retinal pigment epithelium (RPE) will be measured with OCT in 15 healthy volunteers, 10 POAG patients and 10 AMD patients before and after light stimulation in the contralateral eye

Trial Locations

Locations (1)

Medical University of Vienna, Department of Clinical Pharmacology; 🇦🇹 Vienna, Austria