Gonio And Laser Theraoy Flashcards
Iris insertion
If inserted anteriroly
-less CB shows
If inserted more posteriroly
-more CB shows
How to get more CB showing
Have the patient look into the lens
Ciliary body
Visibility-“width”
Pigmentation-typically related to systemic pigmentation
Scleral spur
Visible postrusion of sclera into the AC
Yellow scleral spur
More common in older patients
TM
Located at base of cornea
Responsible for draining the AH
Schwalbes line
- line found on interior surface of eyes cornea
- delineates outer limit of corneal endothelium layer
- represents th extermination of descemets membrane
Scheie’s systems
- Roman numerals used to describe the degree to which the angle is closed
- openness: wide-narrow (wide-1-II-iii-IV)
- pigmentation: 0-IV (non to lots)
Shaffer system
-numerals use to describe the degree to which the angle is open
-approximates the angle at chi hthe iris inserts relative to the TBM
Openness
-wide-narrow
-4-3-2-1-0
Angle presentations
PI Angle recession Pigment dispersion Iris processes PAS Closed angle foreign body
Plateau iris configuration
Some degree of pupillaryblock
LPI works in these cases
Plateau iris syndrome
- uncommon form of primary angle closure
- large ar anteriroly postiioned ciliary process that push PI forward
- LPI does not work here
Gonio has double hump sign
Angle recession
+1 cause is trauma
- always receive a comprehensive exam with gonio
- do gonio 4-6 weeks after truama
- risk of ARG correlates with extent/severity of AR
- can occur many years after truam
Gonio: recessed iris/deeper angle
Pigment dispersions
-rubbing of iris pigment epithelium abasing lens zonules usually 2D to back-bowed iris. Mid peripheral iris transillumination defects
Gonio: Sanpalosi line, scheie stripe, and/or excess TBM pigment, kruckenburg spindle inferiorly.
Iris process
- fine, lacy projections of peripheral iris
- extend to scleral spur or TM
- benign
Gonio: fine lacy strands
PAS
- adhesions of peripheral iris to anterior chamber angle
- secondary to: angle closure glaucoma, NVG, uveitis, ICE
Gonio: thick adhesions within angle
Narrow/closed angle
Anatomical condition Risk factors -increased age -increasing lens thickness -female gender -hyperopia -ethnicity (Eskimo, East Asian)
Gonio: few-no visible structures and/or PAS
Foreign Body
After truama -identify object -identify holes in peripheral iris caused by passage of intracoualr FB Surgical -implantation of filtration systems
Gonio: foreign item
St andres cross
-most posterior anatomical feature of angle
-rating angle openness
-additional findings
—pigment, synechiae, FB
Becker goniogram
- drawing of gonioscopic findings
- describe the variation of anatomical angle within a quadrant
- synechiae
- tumors
- foreign body
- pathology
Why do we need lasers
- secondary cataracts
- narrow angles/ angle closure
- progressing glaucoma with max meds
- compliance
- cost
- convenience/quality of life
- systemic side effects of drops
- dr preference
Why do we need lasers
Secondary cataracts Narrow angles Progressing glaucoma with max meds Compliance Cost Convenience/quality of life Systemic side effects of drops Doctor preference
Laser trabeculoplasty MOA
Increase aqueous humor outflow
- ALT
- SLT
Most common laser procure for often angle glaucoma
ALT 1990-2000
SLT 2000s to present
Primary vs secondary treatemtn of ALT and SLT
Historically used after meds fail to control IOP
Some use as a firsts line treatment
ALT vs topical meds for IOP
ALT as first line is actually better
Indications of laser trabeculoplasty
POAG NTG OHTN pigmentary dispersions glaucoma PSX glaucoma
Last two have higher risk and higher reward
Contraindications of laser trabeculoplasty
- advanced POAG
- angle closure
- inflamamtory glaucoma
- NVG
- prior LTP that failed
- hazy media
- angle recession glaucoma
- congential glaucoma
Negative predictors for LTP
<40
Little or no TB pigment
Cloudy, hazy cornea
-uveitis, angle closure, angle recession, congential glaucoma, aphakic ACIOL
Positive predictor for LTP
> 65
Moderate to heavy TM pigment
Clear cornea
Pigmentary glaucoma, PSX G, LTG, POAG, phakci
ALT
Traditional
-thermal relaxation time. Time for melanin to convert electromagnetic energy into thermal energy=1 microsecond
Burn occurs if pulse duration is > 1 microsecond. This how ALT works, causes burn and contraction of tissue
Mechanical effects of ALT
The burn causes scar tissue=contraction=opening of adjacent areas of TM
Biological effects of ALT
The burn increases inflamamtion=phagocytosis=clean up of the TM
Complications of ALT
IOP spikes
Inflamamtion
PAS
Pre op ALT
gonioscopy
SLE
Signed informed consent
Vitals
Settings for ALT
Energy-600mW Spot spize-50 microns Duration=0.1s Pulses=1 Amount of burns=45-60/180 (dont do 360)
Procedure of ALT
- comfortable placement of patient
- 1 drop alphagan 15-30m prior
- 1 drop proparacaine OU
- focus on anterior aspect of pigmented TM
- adjuster energy PRN. Pigment blanching, small bubble formation
- treat inferior 180 first
- space burns about 2 spot sizes apart. 45-60 burns per 180 degrees
Burn placement
X____X____X____X
Issue: no space in between, cant repeat the procedure
Post op for ALT
- 2 drop alphagan
- recheck IOP 15-30m in office
- continue all glacuaom medication
- PF QID x 1 week
Follow up for ALT
1-2 weeks
- check IOP
- check AC reaction
6 weeks
- check IOP
- consider reducing glaucoma meds
- consider performing superior 180
Long term outcome for ALT
1 year=80%
5 years=50%
10 years=30%
Retreatments for ALT
- increased complication
- 50% o fretreatments rewuire filtration surgery to lower IOP within 6m
SLT
Newer form of laser therapy for patients with glaucoma
Alternative to filerting surgery whose glaucaom was not pharmacologically controllers
Thermal relaxation time: pulse duration is 3ns=noburn=cold laser. >1 microsecond burn
Effects:biological=the burn increases inflamamtion=phagocytosis=clean up of the TM
Preferred laser for SLT
Q-switched frequency doubling 532nm Nd:YAG
- targets melanocytes in the TM
- release of cytokines that trigger macrophage recruitment leading to reduce IOP
Lumenis
Medlite
Studies on SLT
Is effective and safe a primary treatment for patients with OHTN and POAG
IOP decreased 30% over fu period
89% had a decrease of >5mmHg
Study B for SLT
SLT vs prostaglandin
- same IOP reduction
- # of treatments: much less for SLT
SLT is safe and effective for initial therapy for PAOG and OHTN
Study Cfor SLT
SLT as first line treatment
- 97% for 1 year
92% 5 years
90% 7-10 years
80% effective i nsecond treatemtn
Given the amount of data and experience on SLT, we believe that Rxing medications instead of SLT for primary treatment of glaucoma today is analogous to performing intracapsular cataract extraction rather than phacoemsulifcaiyon. I can be done, but why would you
Can SLT be used as first lien treatemtn
Yes
Even OMD does it
Complications of SLT
IOP spike Inflammation Stroma haze/edema/ decreased endothelial cell count PAS Angle bleeds
Prep SLT
-gonio
SLE
Signed informed sonsent
Vitals
Settings for SLT
Energy=0.8-1.2 mJ Spot size 400 microns (fixed) Duration=3ns (fixed) Pulses=1 Amount of burns=100/360 degrees
Burn placement of SLT
X__X__X__X__X
This procedure is repeatable since no scar tissue is created
Large spot size
Covers the entire TM
Post op for SLT
1 drop alphagan
Recheck IOP 15-30m in office
Continue all glaucoma meds
No steroid
-Tylenol
Topical NSAID only PRN
Follow up for SLT
1-2 weeks
- IOP
- AC reaction
6 weeks
- IOP
- take off glaucoma meds maybe
Efficacy of SLT
80% at 1 year
50% at 5 years
30% at 10 years
Very effective from 12-60 months
Predicting SLT succes
Alvarados insights
- if successful with prostaglandin, would be success with SLT since its similar process. If not, probably not. Not cumulative, cannot do preostalgnadin and SLT and expect double results. Maybe take them off prostaglandin before SLT, can use it periodically after SLT to prevent spikes but can use other drugs
SLT and NTG
15% IOP reduction while using 27% less medication at 1 year compared to pre study levels
Blunts the nocturnal spikes
SLT and PDS/PDG
High risk high reward
- increased pigment=increase risk for pressure spike
- it can shit down outflow-trabeculectomy
Test dose
- 10 shots at 0.3mJ
- no spike=one quadrant at a time
Retreatmetn of SLT
Widely considered repeatable
- no mechanical damage
- based on anecdotal evidence and small studies
Retreatment may be less effective nor last as long
- could be less effective, but still get some sort of IOP drop
- could not last as long
Coding and billing for SLT
65855
Paid $305.98/eye
Same day=100% first eye, 50% second eye
Global period
-wait outside 10 days to do the second eye to get full reimbursement
Cost comparison for SLT and drops
SLT effective for 2 years
- 1drop=$200 savings
- 2 drops=1660 savings
- 3 drops=$3000 savings
Positives of SLT
- works about 80-90% time
- on average it takes the place of 1 medication
- SLT IOP reduction of 30% as primary
- SLT IOP reduction of 21-25% as secondary treatment
- doesn’t interned with other treatments
- blunts nocturnal IOP spike
- saves patients money
Negatives of SLT
Effect tends to diminch over time
Procedure of SLT
- Dr and patient comfortable placement
- 1 drop alphagan 15-30m prior
- 1 drop proparacaine
- focus TM
- adjust energy PRN (small bubble formation)
- treat 360 degrees (mirror at 9 o’clock, clockwise-inferior 180 degrees first)
- space burns ~1 spot size apart. About 25 burns/quadrant=100 burns/360 degrees
Grade 1 on Shaffer system
<10 degrees=extremely narrow
Potential for closing off
