A TOUR OF THE WORLD OF GLAUCOMA SURGERY Dr. Jennifer Fan Gaskin Glaucoma Specialist

Natural History of Open Angle Glaucoma

Glaucoma Treatment Options Medical Laser Surgical All work to reduce intraocular pressure by aqueous outflow or aqueous production

Types of Glaucoma Surgery Filtration surgery Drainage implants Ciliary body ablation Recent innovations

FILTRATION SURGERY

Filtration Surgery Small drainage hole made in the sclera Allows fluid to drain out of the eye under a thin flap Forms a reservoir of fluid called a bleb Reduces intraocular pressure 45 – 60 min Local anaesthetic and sedation

Success Rate Victorian Trabeculectomy Audit eyes 81% achieved <18 mmHg without eye drops at 1- year 11.8% achieved <18 mmHg with eye drops at 1-year >90% able to achieve IOP <18 mmHg

Success Rate Royal Victorian Eye & Ear Hospital Trabeculectomy Audit eyes 87% achieved ≤18 mmHg at 24 months without eye drops 4% achieved ≤18 mmHg at 24 months with eye drops >90% able to achieve ≤18 mmHg at 24 months

Post-operative Course Redness, irritation, and watering Blurred vision can last up to 6 weeks Droopy eyelid possible Keep water out for 1 week No bending over or heavy lifting until advised Cessation of glaucoma eye drops Anti-inflammatory eye drops required up to 6- months

DRAINAGE IMPLANTS

Drainage Implants Pioneered by Tony Molteno in 1960s Baerveldt and Ahmed implants in mid-1990s Generally reserved for eyes that have failed filtration surgery or unlikely for filtration surgery to succeed Evidence that comparable efficacy to trabeculectomy

Drainage Implants Silicone tube diverts aqueous to an external reservoir Fibrous capsule forms around plate over 4-6 weeks

Post-operative Course Similar to filtration surgery Shorter course of anti-inflammatory eye drops

ENDOSCOPIC CILIARY BODY ABLATION

Endoscopic Ciliary Body Ablation Developed in 1992 in New Jersey Endoscope containing 3 fibre groupings: – Image guide – Light source – Semiconductor diode laser Allows direct visualisation of ciliary processes Martin Uram

Endoscopic Ciliary Body Ablation Advantage over external ciliary body ablation through direction visualisation of ciliary processes Ability to titrate energy and deliver more predictable outcome

Post-operative Course Can be painful in early post-operative period Fewer restrictions Continue glaucoma eye drops to minimise pressure spikes Anti-inflammatory eye drops for 1 month

RECENT INNOVATIONS

MINIMALLY INVASIVE GLAUCOMA SURGERY

Minimally Invasive Glaucoma Surgery Aimed at preserving tissue, particularly conjunctiva Suitable for mild to moderate glaucoma Usually performed in conjunction with cataract surgery Only two devices currently available in Australia

iStent FDA approved in USA in 2012 Titanium device Smallest available implant for human body Inserted into drainage channel through small wound Multiple iStents can be implanted at same time Each implant ~$1000 AUD

Success Rate FDA trial 116 patients receiving cataract surgery + iStent vs. 123 patients receiving cataract surgery only 68% of cataract + iStent patients achieved 21 mmHg at 12 months vs, 50% at 12 months

Hydrus 8-mm long crescent-shaped open structure Schlemm’s canal scaffold Dilates the canal over 3 clock hours Titanium-coated nickel

Hydrus July 2015, Ophthalmology 50:50 = Cataract surgery + Hydrus vs. cataract surgery only 80% of cataract surgery + Hydrus vs. 46% of cataract surgery alone achieved 20% reduction of eye pressure Washed out mean eye pressure at 24 months was 16.9 mmHg (cataract + Hydrus) vs mmHg (cataract alone) 73% (cataract + Hydrus) vs. 38% (cataract alone) required no glaucoma medication at 24 months

Post-operative Course for MIGS Rapid recovery Similar to cataract surgery Complications include bleeding, scarring, dislodgement of device No long- term data

Summary Well-established role Rapidly developing area Surgical choice needs to be individualised