NCT05370287 · Food and Drug Administration (FDA)
Adaptive Optics Retinal Imaging
What this study is about
The objective of the study is to collect and assess adaptive optics (AO) retinal images from human subjects in support of projects to demonstrate, advance, and enhance clinical use of AO technology.
View original scientific description
The objective of the study is to collect and assess adaptive optics (AO) retinal images from human subjects in support of projects to demonstrate, advance, and enhance clinical use of AO technology.
Interventions
OTHER
oxygen inhalation
Subjects will breath 100% oxygen through a mask.
DEVICE
Adaptive optics imaging
Adaptive optics scanning laser ophthalmoscopy (AOSLO) and adaptive optics - optical coherence tomography (AO-OCT) retinal imaging
Primary outcome measures
Change in Retinal blood flow (RBF) with oxygen inhalation
Time frame: RBF will be measured in all subjects twice during a single AO imaging session - once before and once during pure oxygen inhalation. Subjects will be imaged only once; there is no longitudinal component to this outcome measure.
RBF \[uL/min\] will be measured from ensemble RBC velocity \[mm/s\] measurements from line-scan AOSLO videos and vessel diameter \[mm\] measurements from average AO-OCT volumes.
Retinal ganglion cell (RGC) density
Time frame: RGC density will be calculated once at the AO imaging session in which RGCs are the target. For the reproducibility/longitudinal study portion, RGC density will be quantified three times over 1.5 years (visits separated by 6 months).
RGC density will be calculated at specific retinal eccentricities from cells counted in average AO-OCT volumes.
RGC soma diameter
Time frame: RGC diameter will be calculated once at the AO imaging session in which RGCs are the target. For the reproducibility/longitudinal portion of the study, RGC soma diameter will be quantified three times over 1.5 years (visits separated by 6 months).
RGC soma diameter will be calculated at specific retinal eccentricities from cells segmented in average AO-OCT volumes.
Retinal pigment epithelium (RPE) cell organelle motility
Time frame: RPE organelle motility will be calculated once at the AO imaging session in which RPE cells are the target. For the reproducibility portion of the study, RPE organelle motility will be quantified three times over six weeks (visits separated by 2 weeks).
RPE cell organelle motility will be calculated from the decorrelation time constant for cells segmented from a sequence of AO-OCT volumes.
Photoreceptor (PR) cell function
Time frame: PR function will be calculated once at the AO imaging session in which photoreceptors are stimulated. For the reproducibility portion of the study, PR function will be quantified three times over six weeks (visits separated by 2 weeks).
Photoreceptor cell (cone) function will be measured from phase changes between inner segment - outer segment junction and cone outer segment tip signals in a sequence of AO-OCT volumes collected during visible light stimulation.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Are 21 years of age or older.
- Have the ability to cooperate with instructions during adaptive optics imaging (similar to instructions given during a clinical eye exam).
- Have the ability to understand and sign an informed consent.
- Have been diagnosed with POAG (cohort 2).
Exclusion criteria
- Are under 21 years of age.
- Have a condition which prevents adequate images from being obtained (e.g. unstable fixation or media opacity).
- Have visual correction outside of the range +4 diopters (D) to -8 D.
- Have a history of adverse reaction to mydriatic drops.
- Have a predisposition to (i.e., narrow iridocorneal angle) or any history of acute angle closure glaucoma (AACG).
- Do not meet the criteria for POAG as defined by the American Academy of Ophthalmology Practice Patterns (cohort 2)
- Have any health conditions that would contraindicate oxygen supplementation, including chronic obstructive pulmonary disease (COPD), emphysema, asthma, or any other obstructive or restrictive lung disease (RBF experiment participants only).
- Have a dependency on oxygen support or a baseline oxygen saturation \<95% (RBF experiment participants only).
- Have tested positive for COVID-19 at initial enrollment or have acute or chronic photophobia as a result of contraction.
- Are working under the direct supervision of Dr. Hammer.
Where
- Silver Spring, Maryland
Collaborators
University of Maryland, Baltimore
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced May 8, 2026 · Source of record for eligibility and locations