Waltham, MA-based Avedro, a medical tech startup, said yesterday it has completed a $25 million Series C financing led by SCP Vitalife and Aperture Venture Partners. Existing investors Prism VentureWorks, De Novo Ventures, Flagship Ventures, Borealis Ventures and Echelon Ventures also participated in the round. Avedro said the money will be used to expand commercial operations internationally and to seek FDA clearance in the U.S. The company is commercializing a vision-correction technique that uses a pulse of microwave energy to flatten the cornea to treat myopia and other conditions, as an alternative to Lasik surgery. The technology has its roots in research done at Dartmouth College in the early 2000s.