Effects of Sun Filters on Age-related Macular Degeneration in People With Lens Implants
- Conditions
- Retinal PhotochemistryAge-Related Macular ChangesAge-Related Macular DegenerationCataract and IOL Surgery
- Registration Number
- NCT00487838
- Lead Sponsor
- Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)
- Brief Summary
This study will test a new method for preventing worsening of age-related macular degeneration (AMD) and for developing imaging methods to follow the very earliest microscopic changes in the disease. The macula is the part of the retina in the back of the eye that determines central vision. AMD can impair central vision, affecting a person's ability to read, drive, and carry out daily activities. Some studies suggest that cumulative exposure to sunlight increases the risk for progression of AMD to the late stage that is often characterized by poor central vision. This study will determine if wearing glasses with a yellow filter over one eye and a red-violet filter over the other eye when outdoors will decrease the rate of change of early-stage AMD in one or both eyes.
Patients early-stage AMD who have had cataract surgery in both eyes with implanted lenses may be eligible for this study.
Participants undergo the following procedures:
* Wear the filter glasses when outdoors between 10:00 a.m. and 4:00 p.m.
* Record the time of day and light environment when they use the glasses.
* Have an eye examination, pictures of the retina, and a medical history taken at the beginning of the study and at set intervals during the study.
The study lasts at least 12 months and may be extended for a longer period of time....
- Detailed Description
Accumulation of the photoproduct N-retinylidene-n-retinylethaholamine (A2E) within the retina may be associated with the early age-related macular degeneration (AMD). Our biophysical model of retinal photochemistries predicts that as the lens yellows with age a spectral imbalance of the light reaching the retina causes steady-state A2E levels to rise in the RPE, which induces increasing RPE stress leading to AMD progression. If correct, this rise in A2E levels and the initial injury could be prevented by appropriately chosen spectral filtering (e.g., colored sunglasses). Autofluorescence imaging of the retina currently allows noninvasive mapping of total accumulated lipofuscin fluorophores within the macular retinal pigment epithelium (RPE) but not A2E or its precursor alone. By adding new sets of excitation and emission filters to existing fundus cameras and confocal scanning laser ophthalmoscopes, we propose to map individually both A2E and its precursor A2PEH2 or their fractional contributions to the total retinal fluorescence. By following A2E fluorescence in both eyes in subjects following bilateral cataract surgery and intra-ocular lens \[IOL\] implantation with early symmetric age-related maculopathy who wear our bicolored sunglasses whenever outdoors in the daylight, we propose to test this hypothesis while efficiently controlling for hidden genetic, physiological, and environmental confounding variables between subjects. This pilot protocol seeks to optimize recruitment of suitable subjects and the reproducibility of our spectral imaging and noninvasive analysis of A2E and A2PEH2 levels in the normal and microscopically abnormal regions of the macula. The data from this pilot study will be used to design a clinical study to test our hypothesis.
Recruitment & Eligibility
- Status
- WITHDRAWN
- Sex
- All
- Target Recruitment
- Not specified
Not provided
Not provided
Study & Design
- Study Type
- OBSERVATIONAL
- Study Design
- Not specified
- Primary Outcome Measures
Name Time Method
- Secondary Outcome Measures
Name Time Method