Lecture 13 surgical options-drop or chop Flashcards
Which one of the following is NOT true regarding advantages/disadvantages of medications first before surgery?
a) drugs are safer than surgery (less complications/less discomfort)
b) drugs can be reversed and are short acting
c) drugs are less expensive in the short run but can be more expensive in the long run
d) surgery can lead to a better quality of life
e) multiple drugs can be combined to effectively reduce IOP, however the more drugs that are added to the daily routine could cause compliance issues
d) surgery can lead to a better quality of life (false–medications can lead to a better quality of life. Comfort and quality of life can be lower with surgery)
* trabeculectomy surgery creates a necessary blister that can be uncomfortable and you still may need to use drops after surgery
What are the advantages of having surgery first?
- Large drop in IOP if successful.
- No issues related to patient compliance, adherence and persistence.
- Cheaper in the long run
- Good in situations where obtaining continuous supply of meds is a problem.
Which one of the following is NOT true regarding disadvantages of having surgery?
a) Outcomes may be variable
b) Long term may lose efficacy
c) May still require topical meds
d) complications may be dire
e) comfort and quality of life may be lower
f) chances of cataract formation is lesser than topical meds.
f) chances of cataract formation is GREATER than topical meds.
T/F Individuals with greater pigment are at a greater risk of post-op scarring
True; medications are the first line of treatment
T/F Younger individuals are better suited for surgical options
False; younger individuals have accelerated wound healing systems, if the wound heals too quickly, the surgery will not be successful (aqueous will not drain) and you get increased scarring.
When is surgery indicated?
When despite best efforts (using drugs & maximal medical therapy), pressure still remains really high, and you are unable to achieve and maintain target IOP.
What do we have to take into consideration when prescribing drugs for glaucoma?
- Severity of glaucoma progression (if more severe –> surgery)
- Stage of glaucoma (VF status)
- Stage of nerve damage
- Type of glaucoma
- Adherence, compliance and persistence issues
Which 3 types of glaucoma are treated differently than open angle glaucoma?
- secondary glaucoma
- congenital glaucoma
- complete angle closure glaucoma
Describe the mechanism of Argon Laser Trabeculoplasty (ALT).
Exact mechanism is unknown, but the mechanical theory suggests that mechanical tightening of the trabecular meshwork opens adjacent untreated spaces. This allows enhanced aqueous outflow. Laser induced cellular changes clears trabecular debris.
What are indications of ALT
- Open angle
- Require decrease in IOP
- Both POAG and secondary like pseudo exfoliation or pigmentary.
Who are poor candidates of ALT
- Angle recession, uveitic glaucoma, aphakia, high IOP (35 or greater, high episcleral venous pressure.
- Very young individuals.
- Previous 360 degree ALT; you can’t repeat it on someone that has previously done ALT!
What are pre-op considerations of ALT?
- If on IOP lowering meds, continue using it.
- if moderate loss/damage use 1% apraclonidine (cousin of bromoladine) or a hyperosmotic agent.
- Best performed undilated
What three things are used in the procedure of ALT
- Anesthetic
- Goniolens
- Coupling fluid
Recommended spot size for ALT is ____ micro meter and ____ second duration
50; 0.1
When performing ALT, ideally tissue should blanch and power can be from ____ W to ____ W. You should see 8 burns per clock hour, with a total of ___ burns per session or 100 burns per 360 degrees of meshwork.
0.5; 1.0; 50
Where is the location of burn in ALT?
the junction of the non- pigmented and pigmented meshwork.
What does the post- op management of ALT include?
- Remain in office for at least 1 hour.
- Monitor IOP
- 1% apraclonidine immediately after procedure.
- Topical CAI or pilocarpine may be considered or oral hyper osmotic agent
- Steroid use for 4 days.
- Continue IOP lowering meds if already on it.
- Follow up schedule 1, 4, and 8 weeks (approx 2 months).
When is the treatment benefit of ALT usually seen?
4-6 weeks after treatment
Results of ALT include average reduction in IOP reduction by _____% and POAG success rate of 75-80%
30%
T/F There is a higher success rate with NTG after ALT
False; POAG had a higher success rate.
Which type of secondary glaucoma did ALT have excellent results with?
psuedoexfoliation glaucoma
Describe Selective Laser Trabeculoplasty (SLT)
Selectively targets melanin in pigment of TM. More safe than ALT because of lower power.
T/F Like ALT, SLT cannot be repeated if first attempt is ineffective.
False; SLT CAN be repeated.
T/F SLT causes scarring
False; SLT does not scar
What type of laser is used in SLT
frequency doubled Q-switched Nd: YAG laser
You will see a ___ to 8 fold increase in monocytes and macrophages in TM after treatment with SLT. Why is this?
5; injury via laser causes releasing of chemoattractant which in turn recruits monocytes that are transformed into macrophages which clear pigment granules and exit via schlemm’s canal.
What are some pre- op considerations for SLT
- alpha 2 agonists (brimonidine or apraclonidine).
- timolol in untreated eyes.
- topical anesthetic
NSAIDS or _____ are given post SLT
steroids
What are indications of peripheral iridotomy? (PI)
- acute primary angle closure (1-2 days after attack, and once eye is settled and edema is cleared).
- fellow eye of acute primary angle closure–> 50% chance of angle closure.
- chronic angle closure
- narrow/occludable angle
Contraindications of SLT include _______, thick _____, or signifiant _______.
edema, iris, inflammation
You want to avoid ______ before peripheral iridotomy because it can stimulate inflammation. Immediately prior to procedure, use 1% _____ 3 x spaced over 10 mins, anesthetic gel for discomfort and 1 drop of ____2 agonist 30 mins prior and after procedure to decrease pressure spikes.
prostaglandins; pilocarpine; alpha 2
Which clock hours are recommended for peripheral iridotomy?
11-1; start with iris crypt or other thin region
Post op management of PI include 1% drop of ______, topical steroid 4 x a day and measure pressure 1-2 hours later, if IOP is same or lower then discharge patient and see them the next day. Perform gonio to assess angle changes.
apraclonidine
Complications of PI include elevation of IOP after procedure, accelerated ______ formation, delayed corneal decompensation related to angle closure, monocular blur, ghost images, and shadows.
cataract
Describe laser iridoplasty
It is a procedure to open an appositionally closed angle. It consists of a series of laser burns while inducing low power, on a large spot, longer duration, and on extreme peripheral iris.
Laser iridoplasty causes tightening of peripheral iris which creates a space between _____ iris surface and ______
anterior; trabecular meshwork.
Trabeculectomy creates a fistula that allows aqueous from anterior chamber to _____ space. It removes a portion of the TM to allow for flow under the sub- conjunctival space. The belb should not be fully vascularized neither completely avascular.
subtenons
T/F Vascularized blood flow causes more scarring and is not good.
true
which alkylating agent or antimetabolite prevents scarring and failure
mytomycin C and flurouracil
what are pre-op preparations for trabeculectomy
- stop meds 1-2 weeks prior to surgery ( anticoagulants/NSAIDS)
- evaluation of conjunctival health
(avoid area of previous surgery )
Normal conjunctival response to wound healing includes ____on site which releases plasma proteins and blood cells. You will see in increase in local blood flow and vascular permeability. You will see activated inflammatory cells –> growth factors in turn recruit fibroblasts.
hemorrhage
What are indications for glaucoma implants?
- uncontrolled glaucoma
- poor candidates of trabeculectomy –> neovascular glaucoma, penetrating keratoplasty with glaucoma, ICE syndromes with traumatic glaucoma.
Describe the Ahmed valve
it is a valve that lowers pressure of eye, the valve opens up and allows fluid to leak out.
What does micro invasive glaucoma surgery (MIGS) include?
Ex press device: implantation under scleral flap. The disc or flange prevents intraocular penetration and controlled AH flow.
What are indications of MIGS
- open angle glaucoma
- pigmentary and pseudoexfoliation sydrome.
- aphakic glaucoma
- sturge - weber syndrome
- secondary uveitis
- post trauma
what are relative contraindications of MIGS
- congenital and juvenile glaucoma
- Anterior segment dysgenesis
- Aniridia
- Narrow angle
- AC/IOL and glaucoma
- Neovascular glaucoma
what are absolute contraindications of MIGS
narrow angle in young patient
what are advantages of Ex-Press
- safer than trabeculectomy
- failure rate may be lower than trab in theory?
- more controlled filtration lesser change of hypotony?
what are disadvantages of Ex-Press
- more expensive
- potential to block in future
- black vs white race differences
what is iStent?
a stent that is injected into anterior chamber, made of titanium. POAG TM is primary source of resistance.
what is the hydrus microstent
Made up of titanium alloy, idea is to bypass the TM.
which three things targets the uveoscleral pathway to increase suprachoroidal outflow?
- gold micro shunt
- CyPass
- Aquashunt
with that procedure can you directly visualize the ciliary processes, and you actually burn the cilliary processes in a controlled fashion to lower AH production.
endoscopic photocoagulation
Describe the procedure of Canalaplasty (sorry really long explanation)
Canaloplasty uses a micro-catheter to open the eye’s natural drainage system “Schlemm’s canal”. This canal is then opened using a sterile, gel-like material (“viscoelastic”). The iTrack® micro-catheter is then removed while a suture is threaded through Schlemm’s canal. The suture is then tied down resulting in tension on the the inner wall of the canal – just as you might pull on the strings of a “hoodie” to close the hood over your face. The suture placed in the eye’s drainage canal can keep the canal stretched open for years. Once this canal is opened, the eye’s fluid can exit through a more natural process allowing the pressure in the eye to drop to a more normal level.
Is canaloplasty beneficial?
dilating schlems canal is not good enough, and viscoelastic material does not remain too long. Also, cannulation disrupts lateral walls, inner endothelium and bridging structure of schlems canal.
