Rod and Cone Mediated Function in Retinal Disease
Retinal diseases cause the loss of rod and cone photoreceptors. Symptoms include vision loss and night blindness. Researchers want to learn about rod and cone function in healthy people and people with retinal disease. They want to know if how well a person sees in the dark can test the severity of retinal disease.
To find out if how well a person sees in the dark can test the severity of retinal disease. To find out if this can help detect retinal disease and track its changes.
People ages 5 and older with:
Retinal disease OR
20/20 vision or better with or without correction in at least one eye
Participants will be screened with medical and eye history and eye exam. Those with retinal disease will also have:
Eye imaging: Drops dilate the eye and pictures are taken of it.
Visual field testing: Participants look into a bowl and press a button when they see light.
Electroretinogram (ERG): An electrode is taped to the forehead. Participants sit in the
dark with their eyes patched for 30 minutes. Then they get numbing drops and contact
lenses. Participants watch lights while retina signals are recorded.
Visit 1 will be 3-8 hours. Participants will have up to 6 more visits over 6-12 months.
Eye exam and imaging
Time course of dark adaptation: Participants view a background light for 5 minutes then
push a button when they see colored light.
Dark adapted sensitivity: Participants sit in the dark for 45 minutes. They push a button when
they see colored light.
For participants with retinal disease, ERG and visual field testing
|Condition or Disease||Intervention/Treatment||Phase|
Objective: The objective of this protocol is to investigate local changes in rod and cone photoreceptor function across the retina in healthy volunteers and participants with retinal disease.
Study Population: Up to 120 healthy volunteers and 250 participants, age five or older, with retinal disease.
Design: This single-center, observational, case-control study will be comprised of three related Aims that assess rod and cone function with the recently released commercial Medmont Dark Adapted Chromatic (DAC) perimeter and/or a commercial Cambridge Research Systems computer monitor (Display++) specialized for displaying stimuli at low light intensities. and/or the scotopic MP1S perimeter.
For Aim 1 the normal ranges will be established for dark-adapted retinal sensitivities to blue and red stimuli of the DAC perimeter, and MP1S perimeter, and for radial frequency (RF) hyperacuity on the Display++ monitor. For Aim 2, the normal range will be established for describing the kinetics of dark adaptation following bleaching of retinal rhodopsin for the DAC and MP1S perimeters. For Aim 3, local changes in rod and cone photoreceptor function across the retina in participants with retinal disease will be examined from measurement of the kinetics of dark adaptation, dark-adapted retinal sensitivity to the DAC blue and red stimuli, and/or RF hyperacuity on the Display++ monitor, and/or the MP1S perimeter.
Outcome Measures: The primary outcome for this study is to establish normal ranges for A) the kinetics of dark adaptation (time), B) dark adapted retinal sensitivity (dB) for the Medmont DAC and MP1S blue and red stimuli, and C) RF hyperacuity on the Display++ monitor. The secondary outcomes will be to examine changes in the kinetics of dark adaptation, dark adapted retinal sensitivity, and scotopic and photopic RF hyperacuity in participants with retinal disease.
Arms and Interventions
Participants with retinal disease
Primary Outcome Measures
- The primary outcomes for this study are to establish normal ranges for the kinetics of dark adaptation and dark-adapted retinal sensitivity for the fundus guided and non-guided perimeters and for RF hyperacuity on the Display++. [ongoing, up to 10 visits in 5 years]
The primary outcomes for this study are to establish normal ranges for the kinetics of dark adaptation and dark-adapted retinal sensitivity for the fundus guided and non-guided perimeters and for RF hyperacuity on the Display++.
Participant must be 5 years of age or older.
Participant (or legal guardian) must understand and sign the protocol s informed consent document.
Participant must be able to cooperate with the testing required for this study.
For Participants with retinal disease only:
Participant must have retinal disease, defined as evidence of loss of retinal dysfunction and/or degeneration as established by standard clinical methods including perimetry, ERG and imaging.
Participant must have a measurable visual acuity.
For Healthy Volunteers only:
-Participant must have visual acuity of 20/20 or better, with or without correction (e.g., glasses or contact lens) in at least one eye.
-Participant with changes in pre-retinal media sufficient to obscure a view of the retina.
Contacts and Locations
|1||National Institutes of Health Clinical Center, 9000 Rockville Pike||Bethesda||Maryland||United States||20892|
Sponsors and Collaborators
- National Eye Institute (NEI)
- Principal Investigator: Brett G Jeffrey, Ph.D., National Eye Institute (NEI)
Study Documents (Full-Text)None provided.
- Birch DG, Wen Y, Locke K, Hood DC. Rod sensitivity, cone sensitivity, and photoreceptor layer thickness in retinal degenerative diseases. Invest Ophthalmol Vis Sci. 2011 Sep 9;52(10):7141-7. doi: 10.1167/iovs.11-7509.
- Jackson GR, Owsley C, Curcio CA. Photoreceptor degeneration and dysfunction in aging and age-related maculopathy. Ageing Res Rev. 2002 Jun;1(3):381-96. Review.
- Massof RW, Finkelstein D. Rod sensitivity relative to cone sensitivity in retinitis pigmentosa. Invest Ophthalmol Vis Sci. 1979 Mar;18(3):263-72.