 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. 