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NCT Number: NCT03921931

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

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.

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Key information

Conditions

Macular Degeneration, Dry Eye Diseases Geographic Atrophy Glaucoma Glaucoma, Open-Angle Macular Degeneration Ocular Hypertension Primary Open-Angle Glaucoma Retinal Degeneration Retinal Diseases

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Medical University of Vienna, Department of Clinical Pharmacology

Vienna, State of Vienna, 1090, Austria

Location status: Recruiting

Location contact

Alina Messner, MD

SUB_INVESTIGATOR

Doreen Schmidl, MD, PhD

CONTACT

[email protected]

0043140400 ext. 29810

Doreen Schmidl, MD, PhD

PRINCIPAL_INVESTIGATOR

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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

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

Treatment and study plan

White light stimulation

Other

Stimulation of the retina with white light

Primary outcomes

  1. Light stimulation

    Time frame: 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 outcomes

  1. Light stimulation of contralateral eye

    Time frame: 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

  2. Difference in photoreceptor layer thickness over the course of 8 hours

    Time frame: 8 hours

    Influence of circadian rhythm on the length of retinal photoreceptor outer segments

  3. En face maps

    Time frame: 1 day

    test an algorithm for production of en face maps of retinal photoreceptor outer segment length

Study contacts

Contact information is provided by the study sponsor or research team.

Doreen Schmidl, MD,PhD

CONTACT

[email protected]

0043140400 ext. 29810

Sponsors and collaborators

Lead sponsor

Medical University of Vienna

Other

Registry information

Official study title

Assessment of Retinal Photoreceptor Outer Segment Length With Optical Coherence Tomography Before and After Light Stimulation - a Pilot Study

Important dates

Study start
2018
Primary completion
2026
Study completion
2026
First posted
Apr 19, 2019
Registry last updated
May 16, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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