NIH -- A promising new drug therapy used to treat abnormal swelling in the eye — a condition called diabetic macular edema — proved less effective than traditional laser treatments in a study funded by the National Eye Institute (NEI), part of the National Institutes of Health (NIH). The study, published online in July in the journal Ophthalmology, demonstrates that laser therapy is not only more effective than corticosteroids in the long term treatment of diabetic macular edema, but also has far fewer side effects.