Minimally Invasive Glaucoma Surgery
Known as MIGS, minimally-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. All 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.
Two MIGS devices are currently approved for use in Australia:
- 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.
