Minimally Invasive Glaucoma Surgery
Known as MIGS, minimally-invasive glaucoma surgery (or micro-invasive glaucoma surgery) is a new and evolving area of glaucoma surgical treatment. It aims to lower intraocular pressure with a procedure or device that is minimally invasive and has little or no effect on the surface layers of the eye. MIGS procedures have the following characteristics: 1) performed within the eye in the junction between iris and cornea (iridocorneal angle); 2) minimal tissue handling or destruction; 3) relatively quick; 4) very good safety profile; 5) multiple treatments are possible; 6) can be combined with cataract surgery. MIGS is best suited to eyes with mild to moderate glaucoma or ocular hypertension with an open angle in whom an intraocular pressure in the mid to high teens is desirable. MIGS can also be helpful for reducing the need for topical glaucoma medication.
The MIGS devices currently approved for use in Australia include:
- Hydrus: this device is approximately the size of an eyelash and is made of a metallic alloy called Nitinol. Via a small incision in the cornea it is inserted into Schlemm’s canal in the iridocorneal angle. There is an opening at one end through with fluid from the anterior chamber of the eye can flow into Schlemm’s canal then leave the eye via the natural outflow pathways.
- iStent: this device measures 1.0mm x 0.3mm, is made of titanium coated in heparin and has a similar shape to a snorkel. It is positioned via a small incision in the cornea into Schlemm’s canal in the iridocorneal angle. The opening at the end that lies within the anterior chamber allows fluid to flow directly into Schlemm’s canal and then leave the eye via the natural outflow pathways. the following paragraph after the existing text
- iStent inject: as with the iStent, the iStent inject is positioned via a small corneal incision into Schlemm’s canal in the iridocorneal angle to direct fluid in the anterior chamber into Schlemm’s canal and then leave the eye via the natural outflow pathways. It is also a heparin-coated titanium stent, but is smaller in size, measuring 0.36mm in length. Usually two stents are implanted at the time of surgery.
Patients who’ve received the Hydrus, iStent or iStent inject can safely undergo MRI scans.
