Laser and Medical Treatment of Diabetic Macular Edema
Status:
Completed
Trial end date:
2006-07-01
Target enrollment:
Participant gender:
Summary
This study will compare the side effects of two laser treatments for diabetic macular edema,
a common condition in patients with diabetes. In macular edema, blood vessels in the retina,
a thin layer of tissue that lines the back of the eye become leaky and the retina swells. The
macula, the center part of the retina that is responsible for fine vision may also swell,
causing vision loss. Traditional laser treatment (argon blue or green or yellow) for macular
swelling, or edema, causes scarring that can expand and possibly lead to more loss of vision.
Studies with a different type of laser (diode) may be less damaging. The results of this
study on side effects of the treatments will be used to design a larger study of
effectiveness. This study will also examine whether celecoxib (Celebrex® (Registered
Trademark)), an anti-arthritis drug that reduces inflammation and swelling, can reduce
inflammation and swelling of the retina. Patients with elevated cholesterol levels will be
invited to participate in a cholesterol reduction part of the study to compare normal-pace
cholesterol reduction with accelerated reduction.
Patients 18 years of age and older with type 1 or type 2 diabetes and macular edema that
requires laser treatment may be eligible for this study. Candidates will be screened with the
following tests and procedures:
- Medical history: to review past medical conditions and treatments.
- Physical examination: to measure vital signs (pulse, blood pressure, temperature,
breathing rate) and examine the head and neck, heart, lungs, abdomen, arms and legs.
- Eye examination: to assess visual acuity (eye chart test) and examine pupils, lens,
retina, and eye movements. The pupils will be dilated with drops for this examination.
- Blood tests: to measure cholesterol, blood clotting time, hemoglobin A1C (a measure of
diabetes control), and to evaluate liver and kidney function.
- Eye photography: to help evaluate the status of the retina and changes that may occur in
the future. Special photographs of the inside of the eye are taken using a camera that
flashes a bright light into the eye. From 2 to 20 pictures may be taken, depending on
the eye condition.
- Fluorescein angiography: to evaluate the eye's blood vessels. A yellow dye is injected
into an arm vein and travels to the blood vessels in the eyes. Pictures of the retina
are taken 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.
Participants will be randomly assigned to take celecoxib or placebo (an inactive, look-alike
pill). Participants who have elevated cholesterol levels may return for a brief visit after 1
month. All patients will return for follow-up visits at 3, 6, and 12 months. Patients who
require laser treatment will be randomly assigned to one of the two laser treatments. For
these procedures, eye drops are put in the eye to numb the surface and a contact lens is
placed on the eye during the laser beam application. Several visits may be required for
additional laser treatments. The maximum number of treatments depends on how well the
treatment is working. Patients who respond well to the study medication may receive no laser
treatments. After the first year, patients will be followed every 6 months until either the
patient returns for a 3-year visit, the last enrolled patient returns for the 1-year visit,
or the patient requests to leave the study. During the follow-up visits, patients' response
to treatment will be evaluated with repeat tests of several of the screening exams.