Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

OPTM 737 > Test 1: Surgical Management of Glaucoma > Flashcards

Test 1: Surgical Management of Glaucoma Flashcards

1
Q

rationale for surgery in glaucoma

A

laser and glaucoma surgery is indicated after maximal medical therapy doesn’t result in adequately lowered IOP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

laser procedures

A

laser iridotomy
laser trabeculoplasty
selective laser trabeculoplasty
cyclophotocoagulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

surgical procedures

A

filtration surgery

aqueous shunts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

argon laser trabeculoplasty

A

lowers IOP due to focal contraction or shrinking f the TM
initial success is ~ 60-97%
ALT not effective if TM not visible
generally 180 degrees treated per session
repeat ALT is not effective
glaucoma laser trial compared initial treatment of glaucoma with meds vs ALT - showed that eyes did slightly better with initial laser versus medication first

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

advantage of laser surgery

A

noninvasive

reduce dependence on drops

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

disadvantages of laser surgery

A

inflammation

IOP spikes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

ALT mechanism

A

scarring causes shrinkage of TM opening the intratrabecular spaces increasing outflow
laser alters TM’s biochemical and reduce aqueous resistance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

primary open angle glaucoma and ALT

A

success rate ~80-97%
some investigators show a reduction in number of meds needed following procedure
effect wears off overt time with a failure rate of 10% per year
show to be successful in 32% of eyes after 10 years

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

pseudoexfoliative glaucoma and ALT

A

effective

effect can diminish quicker than in non-pseudoexfoliative patients

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

pigmentary glaucoma and ALT

A 
good IOP lowering 44-80% at 1 year to ~45% at 5 years
younger patients (40+ years) seem to show better response 
trabeculoplasty over iridotomy still preferred
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

post op ALT management

A

IOP’s measured within 30-60 min following surgery (IOP spike generally pretreated with iopidine)
glaucoma meds used for 4-6 weeks following surgery util laser has attained maximal effect
post-op meds include topical steroids, typically qid x 4 days
PAS can occur in 46% of patients (no effect on IOP if not occluding over 330 degrees)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

SLT

A

shown to be as effective as ALT
can be used on patients with previous ALT with success
repeatable
SLT doesn’t destroy TMa dn does’ show scar tissue
lowers IOP by ~ 30%
laser effects lasts 1-5 years (subsequent treats don’t achieve same efficacy as initial treatment)
spot size - 400 microns with duration of 0.3ns
apraclonidine or brimonidine placed in the eye to decrease the risk of a IOP spike
performed with a Q switch 532 Nd:YAG laser

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

mechanism of SLT

A

mechanism increases monocytes and macrophages which clear pigment and debris from TM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

ALT vs SLT IOP spike

A

ALT: 3.4%
SLT: 4.5%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

ALT vs SLT PAS formation

A

ALT: 1.2%
SLT: 1.1%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

ALT vs SLT ALT treatment within 1 year

A

ALT: 5.7%
SLT: 3.4%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

ALT vs SLT SLT treatment within 1 year

A

ALT: 4.6%
SLT: 6.7%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

ALT vs SLT trabeculectomy within 1 year

A

ALT: 8.0%
SLT: 9.0%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

laser iridotomy is used in

A 
used in glaucoma with pupillary block
acute angle closure 
chronic angle closure 
malignant  glaucoma (aqueous misdirection)
aphakic or pseduophakic pupillary block 
prophylactic iridotomy 
pigmentary dispersion syndrome 
nanophthalmos (narrow, crowded anterior chamber angles)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

laser iridotomy technique

A

involves creating a full thickness hole in the peripheral iris with an argon or YAG laser
argon laser produces thermal burn in pigmented tissue which cauterizes wound
YAG laser photo disrupts with shock waves and can show bleeding (used in less pigmented eyes)
site shown to be under upper lid to avoid glare
non-superior site ideal (avoids obscuration from gas bubbles)
typically performed within iris crypt

21
Q

complications of laser iridotomy

A

inflammation
IOP spike
iris bleeding
cataracts over site

22
Q

laser iridotomy pre-op meds

A

pilocarpine 1 or 2% to stretch iris and help lower IOP (maintain following ACG)
apraclonidine (iopidine) or brimonidine (alphagan P) to minimize IOP rise and minimize bleeding (vasoconstrictive effect)
topical steroids to reduce inflammation (also given post-op too)

23
Q

cyclodestruction

A

used when IOP cannot be controlled through medical or surgical intervention
reduces when amount of aqueous production to match decreased outflow ability
usually reserved for eyes with little to no vision

24
Q

three main types of procedures to destroy ciliary body

A

diathermy
cyclocryotherapy
cyclophotocoagulation

25
Q

diathermy

A

electrode needles deliver current to produce diathermy burns
burns applied in 2 rows, 3-4 mm apart
many side effects so not currently used

26
Q

cyclocryotherapy

A

nitrous oxide cryotherapy tips is placed 1-1.5 mm from limbus
three to four applications are made per quadrant
cyroprobe tip is held in place for 30-45 seconds once reaches -80 degrees celsius
creates an icefall which extends into CB and creates cell death
generally 2 quadrants initially treated
intense uveitis occurs in all cases managed with topical steroids and cycloplegics
severe post-op pain may also be present
hyphema common in NVG
hypotony and phthisis bulbi may also occur
due to high side effects, not performed on humans

27
Q

cyclophotocoagulation

A

contact diode laser 0.5-1.0 mm from limbus

16-18 laser applications evenly spaced over 270 degrees

28
Q

side effects of cyclophotocoagulation

A 
uveitis 
pain
hyphema
hypotony 
phthisis bulbi
29
Q

endocyclophotocoagulation

A

process involves applying argon laser to visualized ciliary processes under direct visualization
works well
limited to eyes undergoing cataract surgery
ophthalmic laser microendoscope (laser and fiber optics for video)
good option for patients using glaucoma meds and needing cataract surgery
have a lot of inflammation afterwards - so use a lot of steroids

30
Q

filtration surgery

A

indicated when medical therapy doesn’t meet IOP goals
trabeculetomy involves removal of a partial portion of limbal tissue containing cornea, sclera, and TM below a scleral flap
an antimetabolite may be used to reduce scar formation
antimetabolites may be placed on a cotton pledget or piece of methyl cellulose sponge over the wound site for a specified time period

31
Q

antimetabolites

A

5-fluorouracil 5-FU

mitomycin-C MMC

32
Q

5-FU

A

a fluorinated pyrimidine antagonist which inhibits fibroblast proliferation by suppressing DNA synthesis
side effects include wound leak and corneal epithelial changes
can be injected as a series of 5 mg injections over the course of 2 weeks (if not used during surgery)

33
Q

MMC

A

an antibiotic which causes cross linking of DNA and may inhibit RNA synthesis at higher concentrations giving it antineoplastic and cytotoxic properties
applied intraoperatively on a cellulose sponge prior to entering the anterior chamber (MMC very toxic to corneal endothelium)
side effects much higher than with 5-FU
results in an avascular and acellular bleb

34
Q

blebs and surgery

A

bleb forms under superior conj and aqueous percolates under the conj

35
Q

filtration surgery sutures

A

releasable sutures are used for aqueous titration
initially sutures are snug to prevent a flat anterior chamber and hypotony
laser suture lysis may be employed to gradually open the wound
suture lysis should be performed within 2 weeks of the surgery

36
Q

filtration surgery post op meds

A

results in an avascular acellular bleb
1% red drops q2h while awake for 2 weeks and tapered over 4-8 weeks
topical antibiotic used for 2 weeks or until removal of releasable sutures
1% atropine used qd for bid for 2+ weeks until inflammation resolves

37
Q

atropine in filtration surgery is used to

A

increase patient comfort
deepen anterior chamber
reduces risk of posterior synechia

38
Q

intraoperative complications of filtration surgery

A 
retrobulbar hemorrhage 
conjunctival buttonhole 
scleral flap shrinkage 
tearing or avulsion of the scleral flap
iris and ciliary processes bleeding 
suprachoroidal hemorrhage
39
Q

early postoperative complications of filtration surgery

A 
hyphema 
excessive inflammation 
endophthalmitis 
choroidal effusion 
suprachoroidal hemorrhage 
deep anterior chamber with elevated IOP (sclerostomy blockage - viscoelastic, tight sutures) 
shallow anterior chamber with low IOP (wound leak, over filtration, iridocyclitis, CB detachment)
ciliary block glaucoma
40
Q

late postoperative complications of filtration surgery

A 
filtration failure (wound fibrosis, encapsulated bleb)
cataract 
bleb leak 
blebitis 
endophthalmitis 
hypotony maculopathy
41
Q

aqueous shunts

A

glaucoma drainage implants
drainage plate sutured to sclera with the distal tube implanted into he anterior (most common) or posterior chamber
plate serves as a diffusion device to allow aqueous to accumulate under the conj

42
Q

aqueous shunts are reserved for eyes which

A

have a failed trabeculectomy with antimetabolites
conjunctival scarring preventing a scleral flap
neovascular glaucoma

43
Q

micro invasive or minimally invasive glaucoma surgery

A

trabectome
canloplasty (not really minimal)
trabecular bypass stent

44
Q

trabectome

A

an ab interno technique (no conj dissection therefore superior conj undisturbed for filtration surgery if needed)
uses microelectrocautery to ablate a strip of tissue (nasal 60 degrees to 120) from the TM and schlemm’s canal, allowing aqueous direct access to the eye’s drainage system
inserted into eye through a 1.88 mm temporal clear corneal incision
tip is inserted through the TM into schlemm’s canal
features protective footplate that prevents the heat generated during electrocautery from damaging non-targeted tissues
it also guides the tip smoothly through schlemm’s canal, while ablating the targeted trabecular and juxtacanalicular tissues
simultaneous irrigation and aspiration remove the debris and maintain a stable anterior chamber

45
Q

trabectome success

A

yielded a 30-40% reduction in IOP with end pressures in the mid teens, one to two fewer meds postoperatively, with little to no vision threatening complications
one study concluded although the success rate was lower with the trabectome, the excellent safety profile for the procedure makes it a viable option for glaucomatous eyes with more modest IOP goals or in which the risks of trabeculectomy are of particular concern

46
Q

trabectome vs trabeculectomy

A

one study showed two groups and included more than 100 eyes and were followed for about 2 years
the authors concluded that, although the success rate was lower with the trabectome, the excellent safety profiled the procedure makes it a viable option for glaucomatous eyes with more modest IOP goals or in which the risks of trabeculectomy are of particular concern

47
Q

canaloplasty

A

maximall invasive
an ab externo technique that combines non penetrating deep sclerectomy with dilation of schlemm’s canal
conj dissection and formation of a scleral flap are required
the goal of the procedure is to increase conventional outflow by catheterizing and viscodilating schlemm canal
transient hyphema was the most common complication, occurring in 10.2% of eyes

48
Q

canaloplasty versus trabeculectomy

A

one study showed patients in the trabeculectomy group three fewer meds 12 months postoperatively, whereas patients in the canaloplasty group required 2 fewer meds
there was no significant difference between the two groups regarding surgical failures, which was defined as an eye requiring re-operation
transient hyphema was the most common complication in the canaloplasty group, and choroidal effusion was the most common complication in the trabeculectomy group
hypotony, maculpathy and suprachoroidal hemorrahge occurred infrequently in the trabeculectomy group and did not occur in the canaloplasty group
the authors concluded that trabeculectomy resulted in lower IOP and less post op meds and canaloplasty resulted in a significant reduction in IOP and post op meds without long term potential risks of a filtration bleb

49
Q

trabecular microbypass shunt

A

approved in 2012
the trabecular micro bypass stent is for use in conjunction with cataract surgery in patients with mild to moderate POAG
similar to the trabectome, implantation of an iStent is an ab intern procedure with the need for conj dissection
the micro-device was developed to bypass the TM and inner wall of schlemm’s canal to reestablish outflow
when the iStent was combined with phacoemulsification, a statistically higher % of patients achieved an IOP less than 21 mmHg without meds vs phacoemulsification alone in patients with mild to moderate glaucoma
the incidence of complications was low in both groups, and no serious adverse complications specifically related to the iStent occurred

OPTM 737 (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions