Excellence in Optometric Education John A. McGreal Jr., O.D. Missouri Eye Associates McGreal Educational Institute Glaucoma Surgery: What and When?

JAM John A. McGreal Jr., O.D. n Missouri Eye Associates n Old Ballas Rd. n St. Louis, MO n n FAX n

JAM Advantages of Surgical Therapy Advantages of Surgical Therapy n Potential for unlimited reduction of IOP n Lower long term cost n Little or no impact on QOL n Independent from patient compliance

JAM Disadvantages of Surgical Therapy Disadvantages of Surgical Therapy n Complications – Intra-operative – Post-operative – Long term n Loss of IOP control over time n Need for additional medications n Low specificity of operations

JAM Reasons to Opt for Surgical Therapy n Unable to reach Target IOP n Documented progression despite control under medications n Severe loss of vision & high IOP at presentation n Proven intolerance to drops n Unable to apply medications n Candidate for Surgical Rx – young, compliant/non-compliant, high IOP, advanced damage at time of diagnosis

Surgical Glaucoma Therapy n Future directions – Newer antifibrinolytics n CAT-12, a monoclonal antibody to TGF-B2 – Photodynamic therapy – Novel drug delivery systems n Collagen implants, bioerodable polymers, liposomes & microspheres – Glaucoma drainage implants instead of filtering surgery n Shunts aqueous from AC tube through an episcleral plate – Ocular genetics n Discover genes, gene therapy, primary prevention of glaucoma may become a reality

Surgical Glaucoma Therapy n Future directions – Glaucoma drainage implants instead of filtering surgery n Shunts aqueous from AC tube through an episcleral plate – Miniature Tube Shunt n Ex-Press Mini Glaucoma Implant – Optonol LTD – Biocompatible 24 karat gold implant n SOLX Gold Shunt – SOLX – Device for surgical lowering of IOP (before trabeculectomy) n Trabectome – NeoMedix, INC

Angle Laser Surgery n Wise – 1970 n Mechanism – not known but shrinkage of trabecular ring with widening of spaces and decreased resistence to outflow is probable n Particularly effective (90% controlled after one year) – Pseudo-exfoliation (PXF) – Pigment dispersion syndrome (PDS) – POAG n Slowly and constantly loses effect – 55% at 5 years – 30% at 10 years n Low complications with spike in IOP 30% (post-op)

Surgical Glaucoma Therapy n Argon Laser Trabeculoplasty (ALT, LTP) – Q switched Nd:YAG selectively targets pigmented trabecular cells (increasing activity?) – Increases immune system by increasing monocytes & macrophages in TM – Causes appreciable damage to TM – 85 confluent applications to 180 n Blanching or bubble phase needed to assure proper treatment – Addresses greatest roadblock = compliance with medical therapy – Usually performed over 180 degrees of TM n Can be repeated to the other 180 degrees later if needed

Surgical Glaucoma Therapy n Selective Laser Trabeculoplasty (SLT) – Q switched Nd:YAG selectively targets pigmented trabecular cells (increasing activity?) – Selective because it does not cause appreciable damage to TM – 50 confluent applications to 180 using 400u spot size (large) applied for 3 nano-seconds n No blanching or bubble phase needed – Results – 4.6mmHg decreased IOP at 8 months – Addresses greatest roadblock = compliance with medical therapy

SLT Selecta II laser n Highly absorbed by melanin n Selectively targets pigment cells – preserves surrounding tissue n Average IOP decrease with SLT – 28mmHg to 18mmHg at 12 months

Laser Surgery Before Medical Therapy? Laser Surgery Before Medical Therapy? n Glaucoma Laser Trial (GLT) – Multicenter/randomized study of safety and efficacy of laser first for newly diagnosed glaucoma – IOP better controlled at 2 years and 7 years n Less deterioration of cupping n Less deterioration of visual field – Limitations n Temporary effect n Better topical drugs with low side effects

Laser Cycloablation Laser Cycloablation n Historic methods of ciliary body destruction – Cyclocryopexy, etc – Many complications including cataract, pain, phthsis – Simple and in-office procedures n Ab interno n Ab externo – Non-contact or contact Nd:YAG – Non-contact or contact Nd:Diode

JAM Trabectome (NeoMedix) Trabectome (NeoMedix) n One use disposable device n Bipolar electro-surgical pulse 550KHz/0.1w incr n Similtaneous irrigation & aspiration n Ablation of TM and unroofing of schlemm’s canal and juxtacanalicular tissue n Average IOP decreases from 24mm to n Topical Rxs decrease from 3 to n Advantage – easy, outpatient, option to delay trabeculectomy, less side effects

JAM Glaukos iStent Trabecular Bypass Glaukos iStent Trabecular Bypass n Smallest medical device approved by FDA – 1mm long, 0.33mm height, snorkle 0.25mm x 120um, 60ug – Nonferromagnetic titanium single use, sterile inserter n Approved for mild-moderate glaucoma n Placed during cataract surgery n Spares tissues damaged by traditional procedures n Contraindicated in NVG, PAS, primary or secondary angle closure glaucoma, angle abnormalities n Adverse events – corneal edema, loss of BVA>1 line, PCO, stent obstruction

JAM New Ideas in Glaucoma - Genetics New Ideas in Glaucoma - Genetics n Multiple genes & environmental factors interact in this heterogenous complex disorder n Family history is one of the most important risk factors n First degree relatives of affected patients demonstrate glaucoma 10 times more than general population n 16 loci contributing susceptibility identified – Of these four genes isolated – Myocilin - more likely in early age of onset, family hx, elevated IOP – Optineurin – WDR36 – NTF4

JAM 360 Degree Trabeculotomy 360 Degree Trabeculotomy n One use disposable device n Alone or combined with cataract surgery n Canaloplasty = 44% IOP reduction n Tears and unroofing of schlemm’s canal and juxtacanalicular tissue n Average IOP decreases from 24.4mm to 13.7mm n Topical Rxs decrease from 1.5 to n Advantage – easy, outpatient, option to delay trabeculectomy, less side effects

JAM 360 Degree Trabeculotomy 360 Degree Trabeculotomy n iTrack catheter 250u n Initial use was for childhood glaucoma with poor prognosis, Failed goniotomy, infantile glaucoma after cataract surgery, infantile glaucoma associated with ocular or systemic conditions, progressive congenital glaucoma and corneal clouding n Outcomes 87-92% successful n Trabeculotomy codes already exist n Formerly iScience Surgical n Now iScience Interventional, Menlo Park CA

Schlemm Canal Scaffold Implant n Hydrus / Invantis – Alone or in combination with cataract surgery n 1.5 mm incision – Mild-moderate glaucoma – 8 mm long device, flexible nitinol – Enters canal, resides in canal, provides tension on inner wall n Results in significant, durable decreases in IOP and medication use – Best results in combined surgery – 16.6mm/0.1 – Alone results – 18.6mm / 0.5 n 70% less use of medications

Endocyclophotocoagulation n Simple procedure added to conclusion of cataract surgery to improve IOP control in POAG – Adds little time or cost – Provides long term benefit of decreased IOP, less medications – Photocoagulation of ciliary body processes circumferentially

Glaucoma & the Brain n Researchers view Glaucoma as a disease of the brain – Neurodegenerative disease n Glaucoma shares common features with AD, Parkinson’s and Lou Gehrig’s diseases n Offers potential for new treatments that promote nerve health, neurotrophic factors which can help at multiple places in the visual pathway – Neuroprotection – Ciliary neurotrophic factor (CNTF) – Neuroregeneration – increase axon regrowth – Neuroenhancement – improve support between dying RGC and surrounding cells in brain and retina

Surgical Glaucoma Therapy n Trabeculectomy alone n Trabeculectomy with surgical adjuncts – 5 FU (lower risk eyes) – Mitomycin-C (MMC) – higher risk eyes n Indications – Maximum tolerated medical therapy – Progression of disease – Unable to instill medications – Secondary glaucomas (Neovascular glaucoma) n Consideration – Age, HTN, DM, Anticoagulants, Preop IOP, previous vitrectomy – Degree of visual impairment, – Lens status – Comorbidities

JAM Trabeculectomy Filtering Surgery Trabeculectomy Filtering Surgery n Conjunctival flap fornix-based n Half thickness scleral dissection of flap n Full thickness fistula into anterior chamber and removal of TM n Replace scleral flap n Loosely suture corners of flap – Can be cut with blades or laser later to release more fluid – Used to avoid post-op flat chambers and reformations n Inject anti-metabolite n Close conjunctiva

JAM Trabeculectomy Complications Trabeculectomy Complications n Over filtration and post op flat chambers – Need for reformations n Infection of bleb n Cataract formation n Filter failure with young, fast healers or ocular inflammatory diseases n Alteration of tear film n Droopy lids or visible expanding blebs n Conjunctival dependent n Long term failure/repeat surgery

Trabeculectomy Complications Trabeculectomy Complications n Shallow or flat chambers n Choroidal detachments n Hypotony maculopathy n Hyphema n Bleb leak n Bleb infection n Inadequate fistula and bleb failure n cataracts

ExPress Mini-Glaucoma Implant (Optonol Ltd) n Less time consuming than larger tubes – Allows for more extensive surgery later if needed n Placed under sutured scleral flap n Conjunctival dependent n Creates posterior low diffuse bleb within 1-2 days n Device is 400um wide x 3mm long stainless steel device n Avoids trabeculectomy failure

Glaucoma Tube Implants n Developed for patients with high risk of failure from standard surgery n Design – silicone rubber tubing and ridged plastic or silicone rubber explant – Materials do not allow fibroblast to adhere to device – Equatorial placement of explant n Anterior edge of explant is 8-10mm posterior to corneoscleral junction – Tube into anterior chamber by 2mm – Superior temporal position is preferred – Patching material required to adequately cover implant n Sclera, dura, pericardium

Glaucoma Tube Implants n Drain – allows flow of aqueous from anterior chamber through tube into implant – Passive diffusion into surrounding peri-ocular tissues – Uptake by lymphatic system and venous capillaries n Available Implants – Non-valved n Molteno n Baerveldt – Valved n Ahmed n Krupin – Single plate and double plate designs

Glaucoma Tube Implants n Indications – Failure of conventional therapies n Topical n Laser n Trabeculectomy with or without MMC – Conjunctival diseases, pemphigoid, chemical injuries, severe dry eyes, trauma related glaucoma with scleral thinning, uveitic glaucoma, congenital glaucoma, – Neovascular diseases – Neovascular glaucoma, diabetic retinopathy, retinal vascular occlusions.

Glaucoma Tube Implants n Special intra-operative and post-operative considerations – Temporary ligature of drain tube of non-valved implants n 2-4 weeks n Allows capsule to develop n Resistence to flow is established n Best completed with absorbable external suture or prolene suture placed into tube – Removed via small conjunctival incision in office n Complications – Corneal endothelial issues in vicinity of tube, hypotony, obstruction of tube with fibrin, vitreous, blood, epithelial ingrowth

Baerveldt Implants (Abbott Medical Optics) n 3 models n Larger surface area plate than single quadrant devices – Single quad insertion – Decreased bleb height n Smooth polished pliable silicone plate n 4 fenestrations to promote fibrous adhesions – Reduces bleb height – Open drainage tube – Fixation sutures holes n Requires stitch or tie off suture to control flow initially

JAM Human Allograft Tissue Human Allograft Tissue n Biocompatible for leaking blebs or exposed implants n Gamma sterilized n 2.5 year shelf life n Nominal thickness 0.5mm n Freeze dried or hydrated n Available as sclera, pericardium

JAM New Use for “Rejected” Corneas New Use for “Rejected” Corneas n Journal of Glaucoma, Girkin UAB n Donor corneas not suitable for cornea transplants (clarity) may be a better option to cover glaucoma shunts than traditional pericardium tissue – More durable, less likely to erode – Safer, lower risk of infection – Reduces subsequent surgery

Ahmed Implant (New World Medical Inc) n One way valve design – Prevents post op hypotony n Immediate IOP reduction – Best for cases which are high pressures – Best for cases where any spike in IOP cannot be tolerated n Single stage procedure n Eliminates “rip chord” sutures, occluding sutures, or tube ligature sutures

New Ahmed Glaucoma Valve – M4 n Valved with venture flow technology n Thinner profile n Biocompatible porous polyethylene n Allows soft tissue growth into pores n Promotes integration and vascularization of implant

Molteno Impants (Molteno Ophthal Ltd n Single or double plates devices n Double plate devices allow for greater aqueous drainage n Silicone n Low profile n Larger, thinner devices

Cataract Surgery in Glaucoma Patients n Combined surgery indications – Glaucoma treatment failing with topicals – Significant disc changes and visual field damage – Transient elevations of IOP associated with surgery or topical steroids may cause further damage – Cataract surgeons should spare conjunctiva superiorly for future placement of filters or impants – Benefit of definitive surgical solution to both problems with one operation

JAM Is Glaucoma a Medical or Surgical Disease? n Slowly developing disease with time course over decades n POAG is 80% of all forms of glaucoma n 80% of all glaucoma is in early stage – Responds well to medications n Goal in therapy is to maintain adequate vision during expected lifetime of the patient – Affordable and minimally interfere with QOL n Treatment of OHTN w/o additional risk factors may be unnecessary n Treatment of very advanced disease may be ineffective

JAM Is Glaucoma a Medical or Surgical Disease? n BOTH! n Art of glaucoma treatment is individualizing care – No unique formula for all forms and stages of glaucoma n Surgery solely aims at IOP reduction n Surgery can be a first-line treatment n Medical therapy aims at lowering IOP but will include neuroprotection of the environment and neuro-regeneration of NFL with stem cells

Thank you Excellence in Optometric Education McGreal Educational Institute Missouri Eye Associates McGreal Educational Institute Missouri Eye Associates