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

Assessment of Retinal Photoreceptor Outer Segment Length With Optical Coherence Tomography 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.

Study Overview

• Status: Recruiting
• Conditions: Primary Open-angle Glaucoma; Macular Degeneration, Dry
• Intervention / Treatment: Other: White light stimulation

• Study Type: Interventional
• Enrollment (Anticipated): 35
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Doreen Schmidl, MD,PhD; Phone Number: 29810 0043140400; Email: doreen.schmidl@meduniwien.ac.at

Study Locations

• Austria
  • Vienna, Austria, 1090
    • Recruiting
    • Medical University of Vienna, Department of Clinical Pharmacology
    • Contact: Doreen Schmidl, MD, PhD; Phone Number: 29810 0043140400; Email: doreen.schmidl@meduniwien.ac.at
    • Sub-Investigator: Alina Messner, MD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: healthy volunteers; light stimulation	Other: White light stimulation; Stimulation of the retina with white light
Experimental: primary open angle glaucoma patients; light stimulation	Other: White light stimulation; Stimulation of the retina with white light
Experimental: age-related macular degeneration patients; light stimulation	Other: White light stimulation; Stimulation of the retina with white light

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Light stimulation	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	1 day

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Light stimulation of contralateral eye	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	1 day
Difference in photoreceptor layer thickness over the course of 8 hours	Influence of circadian rhythm on the length of retinal photoreceptor outer segments	8 hours
En face maps	test an algorithm for production of en face maps of retinal photoreceptor outer segment length	1 day

Collaborators and Investigators

• Sponsor: Medical University of Vienna
• Investigators: Principal Investigator: Doreen Schmidl, MD,PhD, Department of Clinical Pharmacology, Medical University of Vienna

Study record dates

Study Major Dates

• Study Start (Actual): November 26, 2018
• Primary Completion (Anticipated): May 31, 2023
• Study Completion (Anticipated): May 31, 2023

Study Registration Dates

• First Submitted: April 4, 2019
• First Submitted That Met QC Criteria: April 17, 2019
• First Posted (Actual): April 19, 2019

Study Record Updates

• Last Update Posted (Actual): March 15, 2023
• Last Update Submitted That Met QC Criteria: March 14, 2023
• Last Verified: March 1, 2023

More Information

Terms related to this study

• Keywords: retinal photoreceptors; light stimulation; light adaptation; functional optical coherence tomography; optophysiology; intrinsic optical signals
• Additional Relevant MeSH Terms: Eye Diseases; Ocular Hypertension; Retinal Degeneration; Retinal Diseases; Glaucoma; Glaucoma, Open-Angle; Macular Degeneration; Geographic Atrophy
• Other Study ID Numbers: OPHT-050418

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No