U.S.-based Abbott Laboratories plans to acquire two closely held companies, Idev Technologies and OptiMedica Corp., in a $560 million investment in medical devices for treating blood vessel and eye diseases.

The company spun off its pharmaceutical unit early this year to focus on medical devices, in addition to its offerings in nutritional products. The company will pay $310 million for Idev Technologies, of Webster, Texas, which makes a stent for treating leg arterial blockages. It will also pay $250 million for OptiMedica Corp., a medical device maker based in Roswell, Ga. Abbott will also pay the acquisition $150 million for achieving certain development and sales goals.

After dumping its drug business on Near Year's day, Abbott now moves into two of the quickest growing sectors of the medical device market. As the heart stent business languishes, the market for stents for peripheral artery disease, which involves arterial blockage in the leg, continues to grow across the United States and Europe. The condition affects some 27 million people in the Western world, as the rate of obesity and diabetes rises quickly in rich countries. An aging populatio of Western peoples, too, means great demand for surgery to treat cataracts.

"These technologies are leading edge and are going to add nicely to our existing vascular and ophthalmology businesses," John Capek, executive vice president of medical devices for Abbott, told reporters.

Abbott plans to expand the technologies gained in the acquisition to reach a broader patient population, he added. By the end of the year, the company will close on the acquisitions, which will not influence this year's earnings forecast, the company said.

Among products in the pipeline, the parent company is developing its Absorb Scaffold, a dissovling stent for use in the legs, following enrollment for a clinical trial. Also by the end of the year, the company will evaluate the results and determine whether it'll begin research required for regulatory approval.

Abbott's spun off company, AbbVie Inc., which is based in nearby North Chicago, retained the brand-name drug business, including the best-seller Humira for rheumatoid arthritis.