Celecoxib to Treat Macular Degeneration in Patients Receiving Photodynamic Therapy
Status:
Completed
Trial end date:
2005-01-01
Target enrollment:
Participant gender:
Summary
This study will determine whether the drug celecoxib (Celebrex® (Registered Trademark)) can
help stabilize or improve vision in patients with age-related macular degeneration (AMD) who
are receiving photodynamic therapy, or PDT (also called cold laser treatment). The macula is
the part of the retina in the back of the eye that determines central or best vision. AMD can
severely impair central vision, affecting a person's ability to read, drive, and carry out
daily activities. This vision loss is caused by the formation of abnormal new blood vessels
in the choroid-a thin, pigmented vascular layer of the eye behind the retina-that leak blood
under the macula. PTD stops the growth of these blood vessels and slows the rate of vision
loss. However, the treatment usually does not cause vision to improve, and it has only a
temporary effect, requiring several treatments over 2 years. Furthermore, PDT does not work
in all patients and may actually cause some swelling and re-growth of blood vessels.
Celecoxib is an anti-inflammatory drug that, in animal studies, has prevented the growth of
abnormal blood vessels associated with tumors and with injury to the cornea. Thus, the drug
might reduce swelling and prevent vessel re-growth in AMD, enhancing the effectiveness of
PDT.
Patients 55 years of age and older with AMD and visual acuity of 20/20 to 20/200 may be
eligible for this study. Participants will be randomly assigned to take either celecoxib or a
placebo (a look-alike pill with no active drug) twice a day and undergo the various tests and
procedures detailed below. Not every examination will be done at every visit, but all may be
required at one visit.
- Medical history and physical examination
- Blood drawing: A blood sample is drawn from an arm vein to evaluate liver and kidney
function
- Eye examination: Visual acuity and eye pressure are measured, and the lens, retina,
pupils and eye movements are examined
- Photography: Photographs of the eye are taken using a special camera with a bright flash
- Fluorescein angiography: Pictures of the retina are taken to look for abnormal blood
vessels. A yellow dye is injected into an arm vein and travels to the blood vessels in
the eyes. The retina is photographed using a camera that flashes a blue light into the
eye. The pictures show if any dye has leaked from the vessels into the retina,
indicating possible blood vessel abnormality.
- Indocyanine green angiography: This procedure, similar to fluorescein angiography, uses
a green dye to photograph the retina and identify portions of abnormal vessels in the
deepest part of the retina.
- Optical coherence tomography: This new technique uses light to produce a 2-dimensional
cross-sectional picture of the retina. The patient looks into a machine called an
optical coherence tomograph at a pattern of flashing and rotating red and green lights,
first with one eye and then the other.
One week after starting the study medications, laser treatment will begin. For this
procedure, a needle is placed in an arm vein and a chemical called verteporfin (Visudyne®
(Registered Trademark)) is infused into the vein over 10 minutes. After 15 minutes, the eye
is anesthetized with numbing drops. A special contact lens is then placed on the eye and the
laser beam is directed to the eye for 83 seconds.
Patients will be followed in the clinic every 6 weeks for 36 weeks for various examinations
and possible re-treatment, if needed. Some patients will be asked to return 1 to 2 weeks
after the first PDT for an eye examination and fluorescein angiography.