MIGS & Ciliodestructive Procedures Terms for Medicine Study

MIGS is indicated in (mild/moderate/severe) glaucoma

mild to moderate

Majority of the MIGS procedures are Ab (interno/externo), with the one exception of ________

ab interno

exception:

InnFocus MicroShunt

List 4 major advantages with MIGS procedures

- higher safety profile

- fewer complications

- shorter recovery time

- less need for f/us

List the 6 main mechanisms of MIGS that work to enhance conventional outflow

- trabecular meshwork removal

- bypass

- shunting to suprachoroidal space

- dilation

- dilation & TM removal

- dilation & TM bypass

What is the mechanism of action of a Trabectome MIGS procedure

trabecular meshwork removal

(enhancing conventional outflow)

What is the mechanism of action of a Goniotomy MIGS procedure

trabecular meshwork removal

(enhancing conventional outflow)

What is the mechanism of action of a GATT MIGS procedure

trabecular meshwork removal

(enhancing conventional outflow)

What is the mechanism of action of a iStent MIGS procedure

bypass

(enhancing conventional outflow)

What is the mechanism of action of a iStent Supra MIGS procedure

shunting to suprachoroidal space

(enhancing conventional outflow)

What is the mechanism of action of a ABiC MIGS procedure

dilation

(enhancing conventional outflow)

What is the mechanism of action of a Omni 720 MIGS procedure

dilation & TM removal

(enhancing conventional outflow)

What is the mechanism of action of a Hydrus Stent MIGS procedure

dilation & TM bypass

(enhancing conventional outflow)

What is the mechanism of action of a CyPass micro-stent MIGS procedure

shunting to suprachoroidal space

(enhancing uveoscleral outflow)

What is the mechanism of action of a cyclophotocoagulation MIGS procedure

reducing aqueous production

(cyclodestruction)

What is the mechanism of action of a endocyclophotocoagulation MIGS procedure

reducing aqueous production

(cyclodestruction)

What is the mechanism of action of a Xen gel stent MIGS procedure

subconjuctival filtration

(MIGS filtration bleb forming device)

What is the mechanism of action of a PreserFlo Microshunt MIGS procedure

subconjuctival filtration

(MIGS filtration bleb forming device)

What is the mechanism of action of a InnFocus Microshunt MIGS procedure

subconjuctival filtration

(MIGS filtration bleb forming device)

What is the mechanism of action of a Micropulse, cyclophotocoagulation MIGS procedure

Describe the bypass mechanism of MIGS

titanium stent is inserted through a 1.5mm corneal incision, into the anterior chamber and across the nasal angle, with penetration of the trabecular meshwork and insertion into Schlemm's canal

Describe the dilation & TM removal mechanism of MIGS

first part = visco-canaloplasty

is a procedure that dilates the entire 360 degrees of Schlemm's canal, allowing the drainage channels to function better.

second part = trabeculectomy

removes a portion of the TM, providing direct access for aqueous fluid to drain into Schlemm's canal

Describe the dilation & TM bypass mechanism of MIGS

"intracanalicular scaffold" is inserted into Schlemm's canal to maintain patency and establishoutflow

Describe the dilation mechanism of MIGS

360º catheterization and viscodilating the trabecular meshwork, Schlemm's canal, and the distaloutflow system

Describe the trabecular meshwork removal mechanism of MIGS

removing a strip of trabecular meshwork and the inner wall of Schlemm's canal in order to create a path for the drainage of aqueous humor

A ______________ is a device that channels aqueous humor through a secure lumen (of either 50 μm or 200 μm) to a half-thickness scleral flap, creating a subconjunctival filtration bleb... these are not really a MIG because they need a Trrab

Ex-press Mini Glaucoma Implant

image and videos slide 10

Goniotomy & Trabeculotomy are the tx of choice for which type of glaucoma

primary congenital glaucoma

_________________ is a procedure that involves removal of section of TM, giving aqueous direct access to collector channels, this procedure does not violate the scleral wall and is not associated with a bleb

goniotomy

video slide 14

_________________ is a procedure that involves placing a catheter or suture through canal 360; suture is pulled, breaking open the canal

trabeculotomy

video slide 14

_____________ is a procedure that used a stent to shunt aqueous fluid to the suprachoroidal space, used for moderate OAG & helped to lower IOP for fewer topical med dependence

Cypass

_________________ is a procedure that involves insertion of a surgical device that removes the damaged TM; opens access to the Schlemm's canal and improves aqueous drainage continuous irrigation /aspiration removes debris and regulates temperature performed thru paracentesis incision/NO external filtering bleb

trabectome

video slide 16

_________________ is a procedure that involves using electrosurgical pulse for management of adult, juvenile andinfantile glaucoma

ab interno trabeculetomy

video slide 16

_________________ is a procedure that involves reducing aqueous production by injuring the ciliary body by freezing

cyclo-cryo-therapy

(endocyclophotocoagulation)

_________________ is a procedure that involves reducing aqueous production by injuring the ciliary body by laser energy

cyclo-photo-coagulation

(endocyclophotocoagulation)

_________________ is a procedure that involves not removing the TM but putting a few tubes in there to assist with drainage

iStent

video slide 20

_________________ is a procedure that is an implantable device placed without conjunctival incision and is said to perform the same function as trabeculectomy but additionally standardize and restrict flow

Xen gel sten

video slide 30

_________________ is a procedure that is an implantable device placed through a small conjunctival incision and is said to perform the same function as trabeculectomy but additionally standardize and restrict flow

Preserflow Microshunt

video slide 30

List the 4 steps of the ab interno trabeculetomy process

- ablate

(the TM to access Schlemm's canal and reduce IOP)

- irrigate

(for stable anterior anterior chamber)

- aspiration

(removes ablated tissue)

- electro-surgical pulse

(for ablation, removal of TM & unroofing of Schlemm's)

Describe the shunting to suprachoroidal space mechanism of MIGS

stent creates a controlled cyclodialysis with stented outflow to the supraciliary space

What does a Trabectome look like on electron microscopy

trabectome ablates the meshwork to expose the collector channels

image slide 19

What does a Trabectome look like on gonio

to me it looks like theres no TM at all

image slide 22

What does iStent look like on gonio

little outflow holes resting in the TM

image slide 22

What does ABiC look like during the procedure

can see the little blinking red light of the iTrack travelling through the canal as guidance to the surgeon

videos slide 23

What is the comparison of the total complication rate between Canaloplasty and Trabeculectomy

Canaloplasty = 12.6%

Trabeculectomy = >50%

there is much higher occurrence of complications in Trabeculectomy procedures

Which MIGs procedure underwent a voluntary recall as per the manufacturer

CyPass

List the CyPass complications that ultimately led to its voluntary recall

- edothelial cell loss of 5yr f/u

- sudden failure d/t large, sudden, painful IOP spikes

- hypotony

- post myopic shift

(may resolve with time)

MIGS strategies that work by enhancing the conventional outflow only for _____________ glaucoma

open angle glaucoma

(T/F) MIGS filtrations devices eliminate the need for peripheral iriectomy

TRUE

How do MIGS filtration devices reduce the change of hypotony

with a fixed lumen size that restricts the flow

Xen Gel Stents are implanted ab (interno/externo)

BOTH!

can be implanted through both methods, however many surgeons prefer ab-externo placement through conjunctival incision d/t improved results

PresserFlo Microshunts are implanted ab (interno/externo)

ab-externo

What is the material used in a Xen Gel Stent

porcine gel

What is the material used in a PresserFlo Microshunts

SIBS material

(styrene-block-isobutylene-block-styrene)

(Xen gel/PresserFlo) is a longer and wider shunt systemInvasive cili

PresserFlow

images slide 31 & 32

Describe the mechanism of action of Ciliodestructive procedures

ciliary body is destroyed, resulting in decreased aqueous production

What are the two main classes of Ciliodestructive procedures

• Invasive surgical excision of the ciliary body and photocoagulation of the ciliary processes

• Non-invasive transcorneal or transscleral destruction using heat, cold, laser, or ultrasound

Invasive ciliodestructive procedures tend to hurt (less/more) than non-invasice

invasive hurt less

need to use a lot of heat, cold, or laser to perform non-invasive and its still going through the other tissues so hurts more

List the 5 major complications seen with cyclodestruction

- loss of remaining light perception

- severe hypotony

- phthisis

- chronic inflammation

- pain

______________ is a procedure that applies Yag or diode laser across the sclera to destroy the ciliary body epithelium, thus eliminating production of aqueous

Transscleral Photocoagulation

video slide 39

______________ is a procedure where the ciliary processes are visualized directly through a lens and treated/destroyed precisely with diode laser energy applied form inside the eye

Endocyclophotocoagulation

video slide 51

List the 3 indication for performing a Transscleral Photocoagulation

- end stage glaucoma where maximum medical tx has failed

- pt with low visual potential for whom the risk of invasive procedures do not outweigh the benefit

- other areas of the world that lack readily available meds & surgeries

List the 12 complications seen in Transscleral Photocoagulation

- pain

- bleeding

- inflammation

- conjunctival burns

- chemosis

- subconj heme

- hyphema

- progressive cataract

- atonic pupil

- hypotony

- IOP spikes

- decrease/loss of vision

Transscleral Photocoagulation reduces aqueous humor formation by ___________ of proteins in cells of cilliary body and processes

vaporization

What are the 2 benefits of the newer ciliodestructive techniques

- lower energy so less damage

- used in earlier disease

Transscleral Photocoagulation uses a (short/long) wavelength laser, why

long

needs to penetrate deep

Transscleral Photocoagulation results in damage to the __________________ with sparing of the ______________

damage of the central zone pars plicata cells

sparing of the anterior and posterior procsses

Why do we avoid the 3 & 9 o'clock locations in Transscleral Photocoagulation

because theres where the long posterior ciliary nerves are

image slide 38

In a Transscleral Photocoagulation the darker pigmented the eye the (lower/higher) power of laser is used and the (shorter/longer) the time of pulse

darker = lower power, longer time

List the 3 major indications for Transscleral Photocoagulation

- refractory glaucoma

- pt unable to undergo standard surgery

- NVG

What is the 1 contraindication for Transscleral Photocoagulation

eyes with total occlusion of outflow

List the 6 risks associated with Transscleral Photocoagulation

- pain first 48hrs

- hyphema / heme

- prolonged inflammation

- decreased vision

- hypotony

- phthisis bulbi

There (is/isn't) risk of infection with Transscleral Photocoagulation

isnt

(this is a non-incisional procedure)

(T/F) Transscleral Photocoagulation is repeatable

TRUE

(T/F) Transscleral Photocoagulation limits the ability for a pt to undergo future surgeries

FALSE

What is the FDA approved, official go to for refractive glaucoma

Transscleral Photocoagulation

(T/F) Pt are left with scarring post Transscleral Photocoagulation procedure

TRUE

image slide 45

List the 4 problems seen with Transscleral Photocoagulation that are not seen with Endocyclophotocoagulation

- pain

- inflammation

- hypotony

- visual loss

What is the indication for Endocyclophotocoagulation

end stage glaucoma & eyes with poor vision who are also undergoing cataract surgery

(T/F) Adding Endocyclophotocoagulation to a regular cataract surgery procedure increases the risk of complication

FALSE

no increase in complications over just catarct operation

Endocyclophotocoagulation adds approx. ___ minute to a cataract surgery

10 minutes

Endocyclophotocoagulation is effective in controlling IOP in ___% of pt

90%

(T/F) Endocyclophotocoagulation is considered a safe and effective way to lower IOP and reduce or eliminate the use of meds

TRUE

Ciliodestructive procedures tend to be highly ______________ and can result in chronic __________

highly inflammatory

chronic hypotony

_________________ procedures are the incisional gold standard for glaucoma

conventional filtering procedures

(• Trabeculectomy

• Tube-shunt implantation)

Conventional filtering procedures are best utilized in patients with (mild/moderate/advanced) disease

moderate to advanced

MIGs procedures are best utilized in patients with (mild/moderate/advanced) disease

mild

Ciliodestructive procedures are best utilized in patients with (mild/moderate/advanced) disease

end stage

What did the Tube Versus Trabeculectomy (TVT) Study demonstrate

that initial tube-shunt implantation was associated with better IOP outcomes and fewer complications than trabeculectomy

(challenging our traditional of starting with trabeculectomy and progressing to tube-shunt surgery if the trabeculectomy fails)