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

  • End date
    May 31, 2022
  • participants needed
  • sponsor
    Medical University of Vienna
Updated on 18 September 2021
optical coherence tomography
brimonidine tartrate ophthalmic solution
macular degeneration
pigmentary glaucoma
primary open angle glaucoma


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.

Condition Glaucoma, Pigmentary glaucoma, Open Angle Glaucoma, Primary Open Angle Glaucoma, Dry Macular Degeneration, Geographic Atrophy
Treatment White light stimulation
Clinical Study IdentifierNCT03921931
SponsorMedical University of Vienna
Last Modified on18 September 2021


Yes No Not Sure

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
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