Ignite Creation Date:
2024-05-05 @ 11:30 AM
Last Modification Date:
2024-10-26 @ 9:08 AM
Study NCT ID:
NCT00060580
Status:
COMPLETED
Last Update Posted:
2008-03-04
First Post:
2003-05-07
Brief Title:
Raman Scattering Spectroscopy to Measure Macular Pigment
Sponsor:
National Eye Institute NEI
Organization:
National Institutes of Health Clinical Center CC
Study Overview
Official Title:
Measurement of Macular Pigment With Resonant Raman Backscattering Spectroscopy
Status:
COMPLETED
Status Verified Date:
2006-03
Last Known Status:
None
Delayed Posting:
No
If Stopped, Why?:
Not Stopped
Has Expanded Access:
False
If Expanded Access, NCT#:
N/A
Has Expanded Access, NCT# Status:
N/A
Acronym:
None
Brief Summary:
This study will evaluate the ease and reliability of Raman scattering spectroscopy a new technique to measure the amount of the pigment lutein in the retina the light-sensitive tissue lining the back of the eye The highest concentrations of lutein are in the center of the retina called the macula which is the area most important for fine detailed vision The functions of lutein are not fully known Besides absorbing blue light it may help protect against abnormal changes in the retina such as age-related macular degeneration Until recently lutein was measured using long cumbersome and difficult tests This study will evaluate a new instrument that provides faster measurements It will be tested under different conditions such as wearing or not wearing glasses or contact lenses or dilating or not dilating the pupil of the eye
Healthy normal volunteers between 20 and 65 years of age may be eligible for this study which involves two visits to the NIH Clinical Center as follows
Visit 1 - Screening
Medical history and physical examination including measurement of vital signs blood pressure pulse temperature and breathing rate and examination of the head and neck heart and lungs and arms and legs
Eye examination including eye chart test eye pressure measurement examination of pupils and eye movements and examination of the retina back part of the eye using a strong light and magnifying lens after dilation of the pupils
Raman scattering spectroscopy to measure lutein For this test the subject looks with one eye at a brief bright flash of bluish light similar to a flashbulb light from a laser This is repeated several times Subjects who wear glasses or contact lenses for distance vision will be tested without them and then again with a lens in front of the eye Subjects who do not wear glasses or contact lenses will be tested before and after dilation of the pupil
Contrast sensitivity to assess ability to identify an object from the background and to see everyday objects The subject looks at and identifies a variety of objects of different shapes and sizes
Color vision to determine the ability to identify different shades of color The subject arranges a line of colorful discs similar to checkers in order of similar shades
Visit 2 - Repeat Spectroscopy
Subjects return 1 week after the screening visit for a repeat Raman scattering spectroscopy to evaluate the precision of the measurements
Healthy normal volunteers between 20 and 65 years of age may be eligible for this study which involves two visits to the NIH Clinical Center as follows
Visit 1 - Screening
Medical history and physical examination including measurement of vital signs blood pressure pulse temperature and breathing rate and examination of the head and neck heart and lungs and arms and legs
Eye examination including eye chart test eye pressure measurement examination of pupils and eye movements and examination of the retina back part of the eye using a strong light and magnifying lens after dilation of the pupils
Raman scattering spectroscopy to measure lutein For this test the subject looks with one eye at a brief bright flash of bluish light similar to a flashbulb light from a laser This is repeated several times Subjects who wear glasses or contact lenses for distance vision will be tested without them and then again with a lens in front of the eye Subjects who do not wear glasses or contact lenses will be tested before and after dilation of the pupil
Contrast sensitivity to assess ability to identify an object from the background and to see everyday objects The subject looks at and identifies a variety of objects of different shapes and sizes
Color vision to determine the ability to identify different shades of color The subject arranges a line of colorful discs similar to checkers in order of similar shades
Visit 2 - Repeat Spectroscopy
Subjects return 1 week after the screening visit for a repeat Raman scattering spectroscopy to evaluate the precision of the measurements
Detailed Description:
The primary objective of this study is to evaluate the degree of variability in retinal measurements of lutein a carotenoid macular pigment of human retina in normal volunteers with a new and novel technique of resonant Raman scattering spectroscopy This technique is generally more objective than psychophysical techniques used for lutein measurements such as heterochromatic flicker photometry Raman scattering spectroscopy is non-invasive and the levels of ocular exposure to argon laser light used in this technique are well below the safety limits recommended by the American National Standards Institute
Study Oversight
Has Oversight DMC:
None
Is a FDA Regulated Drug?:
None
Is a FDA Regulated Device?:
None
Is an Unapproved Device?:
None
Is a PPSD?:
None
Is a US Export?:
None
Is an FDA AA801 Violation?:
None
Secondary IDs
| Secondary ID | Type | Domain | Link |
|---|---|---|---|
| 03-EI-0156 | None | None | None |