Ocular Therapeutix, Inc. has announced it closed a Series D extension round of financing totaling $23.8 million.

Ocular Therapeutix, based in Bedford, Mass., focuses on the development and commercialization of ophthalmic therapeutic products using its proprietary hydrogel technology.

All existing institutional investors, including Boston-based SV Life Sciences and Clayton, Mo.-based Ascension Health Ventures, frequent investors in healthcare, participated in the round.