The approval was granted for use in conjunction with cataract surgery to reduce intraocular pressure (IOP) in adult patients diagnosed with mild to moderate open-angle glaucoma who are currently treated with ocular hypotensive medication.

Glaukos said the iStent is designed to restore the natural outflow pathways for aqueous humor and provide sustained IOP reduction.

The iStent, which is packaged in a pre-loaded configuration, is inserted through a small corneal incision made during cataract surgery and placed into Schlemm’s canal, a circular channel in the eye that collects aqueous humor and delivers it into the bloodstream.

It is made by using surgical-grade non-ferromagnetic titanium that is coated with heparin, and is about 1.0mm long and 0.33 mm wide.

Glaukos president and CEO Thomas Burns said: "The iStent represents an important new option for effectively managing elevated IOP in glaucoma, a disease that is a leading cause of blindness worldwide.

"We appreciate the efforts of the MHLW to evaluate and approve the iStent and we are eager to introduce this breakthrough MIGS technology to Japanese surgeons and patients."

The US Food and Drug Administration (FDA) had approved the iStent in 2012, and is currently approved for sale in 27 countries across the world.