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Visual Activity Evoked by Infrared in Humans After Dark Adaptation

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ClinicalTrials.gov Identifier: NCT02909985
Recruitment Status : Completed
First Posted : September 21, 2016
Last Update Posted : September 21, 2016
Sponsor:
Information provided by (Responsible Party):
Olivia Hopkins, University of New Mexico

Brief Summary:

This pilot study will evaluate the visual response to infrared (IR) in humans after dark adaptation. The investigators plan to determine which wavelength and intensity the human eye is most sensitive too, using a broad spectrum light source and wavelength-specific bandpass filters. The investigators will then evaluate the electrophysiologic response in healthy humans to IR, followed by studies in those with specific retinal diseases.

The long-term goal of this research is to better understand the role that IR plays in visual function, and whether this can be manipulated to allow for vision in certain retinal pathologies that result from loss of photoreceptor cells. The investigators central objective is to test the electrophysiologic response to IR in the dark-adapted retinal and visual pathways. The investigators central hypothesis is that IR evokes a visual response in humans after dark adaptation, and the characteristics of this response suggest transient receptor potential (TRP) channel involvement. The investigators rationale is that a better understanding of how IR impacts vision may allow for an alternative mechanism for vision in a number of diseases that cause blindness from the degradation or loss of function of photoreceptor cells. The investigators will test the investigators hypothesis with the following Aims:

Aim 1: To determine the optimal IR wavelength for visual perception in dark-adapted human participants. The investigators hypothesize that the healthy human eye will detect IR irradiation, with a maximum sensitivity at a specific wavelength. Using a broad-spectrum light source with wavelength-specific bandpass filters, the spectral range of visual perception to IR will be evaluated. The same will be done on colorblind participants.

Aim 2: To test the electrophysiologic response to IR in healthy humans after dark adaptation. The investigators hypothesize that IR will elicit an amplitude change on electroretinography (ERG) and visual evoked potential (VEP) responses after dark adaptation in healthy human participants. Participants will be tested with both test modalities to evaluate their response to IR.

Aim 3: To test the electrophysiologic response to IR after dark adaptation in humans with certain retinal diseases. Participants with retinitis pigmentosa, age related macular degeneration and congenital stationary night blindness, will be tested. Results will be compared to baselines and to those of healthy participants. The investigators hypothesize that there will be a response to IR on ERG and VEP, which will provide clues to the retinal cell layer location of the response to IR and the nature of potential TRP channel involvement.


Condition or disease Intervention/treatment Phase
Age Related Macular Degeneration Retinitis Pigmentosa Congenital Stationary Night Blindness Colorblindness Other: Tungsten halogen light with narrow bandpass filters Other: ERG Other: VEP Not Applicable

  Show Detailed Description

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 29 participants
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: Single (Participant)
Primary Purpose: Diagnostic
Official Title: Visual Activity Evoked by Infrared in Humans After Dark Adaptation
Study Start Date : September 2015
Actual Primary Completion Date : August 2016
Actual Study Completion Date : August 2016


Arm Intervention/treatment
Experimental: Visual response to IR
  1. 15 healthy participants will describe IR light passing through narrow bandpass filters over a broad spectrum light source
  2. 10 colorblind participants will describe IR light passing through narrow bandpass filters over a broad spectrum light source

For both groups, as intensity in increased from 0 to 12 V, participants will say if/when they see a visual response to infrared light from a broad band Tungsten halogen light with narrow bandpass filters ranging from 850 nm to 1400 nm. At the end of three trials per filter, the intensity will be turned up to 12 V, and participants will describe the color they see.

Other: Tungsten halogen light with narrow bandpass filters
As intensity in increased from 0 to 12 V, participants will say if/when they see a visual response to infrared light from a broad band tungsten halogen light source that passes through narrow bandpass filters ranging from 850 nm to 1400 nm. At the end of three trials per filter, the intensity will be turned up to 12 V, and participants will describe the color they see.

Experimental: Electroretinography
  1. 5 healthy participants will undergo an ERG with standard baseline tests followed by similar tests using IR, with standard baseline tests followed by similar tests using IR
  2. A total of 15 participants, or five per retinal disease, will be recruited . Retinal diseases include retinitis pigmentosa, age related macular degeneration, congenital stationary night blindness, cataracts. Participants will undergo an ERG with standard baseline tests followed by similar tests using IR, with standard baseline tests followed by similar tests using IR
Other: ERG
Participants will undergo electroretinography using both normal settings and infrared as the stimuli.

Experimental: Visual Evoke Potential Test
  1. 5 healthy participants will undergo an VEP with standard baseline tests followed by similar tests using IR, with standard baseline tests followed by similar tests using IR
  2. A total of 15 participants, or five per retinal disease, will be recruited . Retinal diseases include retinitis pigmentosa, age related macular degeneration, congenital stationary night blindness, cataracts. Participants will undergo an VEP with standard baseline tests followed by similar tests using IR, with standard baseline tests followed by similar tests using IR
Other: VEP
Participants will undergo visual evoke potential tests using both normal settings and infrared as the stimuli.




Primary Outcome Measures :
  1. Visual perception to infrared [ Time Frame: Up to one year ]
    Ability to detect IR visually through subjective measurement


Secondary Outcome Measures :
  1. Description of color [ Time Frame: Up to one year ]
    Description of color to IR stimulus


Other Outcome Measures:
  1. Electroretinography [ Time Frame: Up to one year ]
    Electroretinography response to infrared stimulus

  2. Visual Evoke Potential [ Time Frame: Up to one year ]
    Visual Evoke Potential to infrared stimulus



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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • Normal Vision
  • Colorblindness
  • Age related macular degeneration
  • Congenital Stationary Night Blindness

Exclusion Criteria:

  • Diabetes
  • Heart disease
  • History of eye injury
  • History of eye trauma
  • History of eye disease except for those specified in the inclusion criteria
  • Pregnant women will also be excluded from Aim 2 and 3
  • Persons with allergies to adhesives will be excluded from Aim 2 and 3
  • Contact dermatitis
  • Documented adverse reaction to dilating drops
  • Documented adverse reaction to topical anesthetics
  • Vulnerable populations

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT02909985


Locations
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United States, New Mexico
University of New Mexico
Albuquerque, New Mexico, United States, 87131-0001
Sponsors and Collaborators
University of New Mexico
Investigators
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Principal Investigator: Leslie Olivia Hopkins, MD University of New Mexico

Additional Information:
Publications:

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Responsible Party: Olivia Hopkins, Assistant Professor-Clinical Educator, University of New Mexico
ClinicalTrials.gov Identifier: NCT02909985     History of Changes
Other Study ID Numbers: CTSC0004-6
First Posted: September 21, 2016    Key Record Dates
Last Update Posted: September 21, 2016
Last Verified: September 2016
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

Keywords provided by Olivia Hopkins, University of New Mexico:
Infrared
Dark Adaptation
Vision
Scotopic Threshold Response
Transient Receptor Potential (TRP) Channels
Human

Additional relevant MeSH terms:
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Eye Diseases, Hereditary
Genetic Diseases, X-Linked
Retinal Diseases
Eye Diseases
Genetic Diseases, Inborn
Vision Disorders
Sensation Disorders
Nervous System Diseases
Deficiency Diseases
Nutrition Disorders
Macular Degeneration
Retinitis
Retinitis Pigmentosa
Blindness
Night Blindness
Vitamin A Deficiency
Myopia
Color Vision Defects
Retinal Degeneration
Retinal Dystrophies
Neurologic Manifestations
Signs and Symptoms
Avitaminosis
Malnutrition
Refractive Errors
Cone Dystrophy