>$500m. Assessing New Implants. Minimally-Invasive Surgery & Other new devices -a Foretaste

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1 Minimally-Invasive Surgery & Other new devices -a Foretaste Keith Barton Consultant Ophthalmologist Moorfields Eye Hospital, London Market capitalisation of new glaucoma surgical device companies >$500m NIHR Biomedical research centre for ophthalmology UCL Institute of Ophthalmology istent Schlemm s canal and supra-choroidal shunts(glaukos) Supra-choroidal shunt () Presview (Refocus). External scleral mini-buckle Aquesys collagen shunt to subconj bleb Assessing New Implants Unprecendented investment in glaucoma surgery Long tubes, short tubes Trabecular meshwork bypass shunts / stents Devices to remove TM New types of cyclophotocoagulation External scleral buckling procedures Supra-choroidal shunts Glaucoma Devices and Implants Possible advantages of implants No limbal drainage bleb No limbal drainage bleb - Important for contact lens wearers

2 Glaucoma Devices and Implants Possible advantages of implants No limbal drainage bleb External Equatorial Sub-tenon s Drainage More predictable results Potentially less invasive With modern technology an operation that is much less invasive than Trab or NPFS but equally efficacious should be possible New long shunts Ahmed FP7 Medium surface area Vs Baerveldt 350 Large surface area and thin Flow restrictor No flow restrictor Both silicone and flexible ~$600? ~$15? External Limbal Sub-tenon s or Sub-conjunctival Drainage Modified Trab Express Implant The aurolab AADI from Aravind in India is a potential solution to the cost barrier of glaucoma devices in developing countries

3 Assessing New Implants External Limbal Sub-tenon s or Sub-conjunctival Drainage Aquesys The express shunt represents a modification to trabeculectomy rather than a stand-alone shunt Aquesys Injectable flexible collagen tube that creates a fistula from the anterior chamber to subconj space 3mm behid the limbus Aquesys: Injectable cross-linked collagen tube to sub-conjunctival space Aquesys: Flexible tube emerges under conjunctiva 3mm from the limbus Injected through the sclera into the subonjunctival space from the anterior chamber

4 Assessing New Implants What are the barriers in the pathway? Schlemm s canal shunts The injector Schlemm s Canal Shunts istent (Glaukos), Hydrus (Ivantis) istent (Glaukos) istent (Glaukos) Hydrus (Ivantis) Schlemm s Canal Shunts istent (Glaukos) Glaukos - istent Schlemm s canal shunts

5 Glaukos - G2 Schlemm s Canal Shunts Hydrus (Ivantis) Flexible canal scaffold Biocompatible alloy Hydrus (Ivantis) 3 windows dilate Schlemm s Canal and face ac. 3 clock hours targets multiple collector channels Schlemm s Canal Shunts Ivantis Assessing New Implants Schlemm s canal shunts istent (Glaukos) Hydrus (Ivantis) The ability of these to reach low target IOP s is yet to be proven Other ways of removing JC resistance Ab Interno Trabeculotomy - Trabectome Bypassing the TM What barriers remain? Glaukos (istent), Ivantis (Hydrus), Trabectome, Canaloplasty, Excimer Laser Trabeculotomy - These techniques only affect the anterior chamber to Schlemm s canal portion of the pathway. - As yet no technique using this mechanism of IOP reduction has been shown to consistently lower the IOP more than Argon Laser Trabeculoplasty. - However they may work more often than ALT.

6 Assessing New Implants What are the barriers in the pathway? A cyclo-dialysis cleft occurs when the ciliary body separates from sclera after trauma A traumatic cyclo-dialysis cleft (behind PAS) after trauma produces very low IOP in some individuals, though most heal spontaneously Patients with persistent cyclo-dialysis clefts after trauma have very low IOPs. Some devices attempt to harness this effect., Glaukos, Glaukos Glaukos G3 supra-choroidal stent Cypass Micro-stent Glaukos G3 supra-choroidal stent

7 , Glaukos CyPass Micro-Stent mm length, 300-µm lumen, - biocompatible polyimide Applier - Guidewire driven CyPass Micro-Stent - Polyimide tube Handle Button Guidewire Tube Retractable Guidewire CyPass Micro-Stent loaded onto Applier, Glaukos Glaukos G3 supra-choroidal stent Cypass Micro-stent Ab interno approach 1.5 mm clear corneal incision (or phaco incision) CyPass Micro-Stent in Position 2012 Medical All Rights R d CyPass Tech Deck v02.ppt 42

8 Assessing New Implants What are the barriers in the pathway?, Glaukos Overcoming fibrosis in the supra-choroidal space will be the major challenge to harnessing the supra-choroidal space for IOP control Assessing New Implants Other Mechanisms of IOP reduction Scleral indentation Refocus Tensioning trabecular meshwork and zonules concurrently claimed to lower IOP and improves presbyopia A mini scleral buckle is placed through a partial-thickness scleral tunnel in each quadrant. This tensions the zonule and reduces presbyopia but also appears to help IOP Warning This is a foretaste of an explosion in glaucoma surgical techniques. Although this is an exciting time for glaucoma surgery, many of these techniques are as yet unproven in terms of efficacy. Thank you for your attention