Lasers_Final Flashcards
Disadvantages for Intracapsular Cataract Extraction?
- Requires a very large incision
- Higher risk of vitreous loss
- Higher risk of post-op complications
When is the special case for Intracapsular Cataract Extraction
Damaged zonules secondary to trauma.
What is the disadvantage for Extracapsular Cataract Extraction by nuclear expression?
Larger incision is required
More sutures.
What is the advantage of Extracapsular Cataract Extraction by phacoemulsification?
Maintains normal depth of A/C
Smaller incision
Less sutures
What is vital for post op care in Cataract surgery?
Wound stability
Restriction of PA
Do not rub eye for 2 weeks.
What drops do you give pt for post op care?
Antibiotic/Steroids QID
List the follow up Schedule?
1 day follow up
1-2 week follow up
4 week follow up
6 week follow up
When do you start antibiotic therapy?
3 days before Sx
Besivance, zymar, vigamox
Use until it runs out.
How to use steroid post op?
QID.
Taper after week one.
The types of post-operative coplications
Early Emergent
Early Less-Emergent
Intermediate to Late
List the types of Post-Op early emergent complications
Ocular HTN: Closed or open angle mechanism Wound leak with shallow or flat AC Endophthalmitis Iris prolapse or vitreous in the wound Intraocular lens dislocation Retinal Breack and Detachment
T/F?
It is safe to use PGA for an Oc HTN case that is open angle
False. Use beta blockers Alpha-agonists CAIs May use oral hyperosmotic agent
Define some things that constitute ENdophthalmitis?
Microbial invasion of Ant chamber at the time of sx
Microbial invasion of ant chamber through infected leaking wound
Onset for endo for days to weeks?
Gram Positive:
Staph Epi
Staph Aur
Onset for endo for 1-4days?
Strep species
Gram neg species
Onset for endo for weeks to months?
Propionibacterium acnes
When do you suspect endophthalmitis?
Suspect in any eye with pronounced inflammation
T/F?
Endophthalmitis is not a true ocular emergency
False
Can progress rapidly.
Inform the surgeon immediately
It is a true ocular emergency
What is the most common intraocular lens dislocation?
Sunset Syndrome: Inferior dislocation
Need to do retro son!!!
What is an increased risk for RB and Detachment?
Intraoperative capsular bag rupture –> Bitreous prolapse and loss
ICCE
T/F?
Retinal break and Detach is considered an ocular emergency?
True
List the types of Post-Op early Less emergent complications
Ptosis
Diplopia
Wound leak with well formed AC (normal configuration)
Acute Corneal Edema
Hyphema
Anterior Uveitis
Intraocular lens decentration/pupillary capture
What is the most common post-op early less emergent complication?
Ptosis
Happens within a few weeks.
What are some of the reasons that ptosis occurs?
Prolonged akinesia
Patching
Trauma from lid speculum
Myotoxicity
What is the differential diagnosis for hypotony?
Anterior Uveitis
Retinal Detachment
What are some signs for acute corneal edema?
Blurry Vision
FBS
Possible Pain
what are some signs for acute corneal edema?
Epithelial Microcysts or bullae
Stromal edema and thickening
Folds in Descemet’s membrane.
What do you do if you notice the presence of endocapsular hematoma during a hyphema?
Nd:YAG capsulotomy is required.
What do you need to rule out for an anterior uveitis occurrence?
Infection.
If disproportionate inflammation; you need to suspect endophthalmitis.
What is an IOL decentration/pupillary capture?
IOL is not symmetrically located within the pupil yet maintains most of tissue support.
How do you evaluate an IOL lens decentration/pupillary capture?
Examine with and w/o dilation. Don’t dilate an iris-fixated IOL.
What gives you an increase risk of Retinal detachment for a choroidal detachment?
Kissing choroidals
Need to immetiately consult with the operating surgeon.
What is another name for thermal effect?
Photocoagulation
Describe the characteristics of thermal effect?
Denaturation of proteins
Coagulation of blood (no bleeding)
Moderate inflammation –> Creates scarring and adhesion
What is another name for photodisruptive effect?
Wave-acoustic Shock
Describe the characteristics of photodisruptive effect?
Causes tissue to be reduced to plasma
Majority of energy is back towards the physician
Does not coag the blood thus bleeding possible.
Which laser is tissue dependent?
Photocoagulation or Thermal effect
Name the two categories for Laser Trabeculoplasty?
Argon Laser Trabeculoplasty.
Selective Laser Trabeculoplasty.
Which of the two Laser Trabeculoplasty methods have a better success rate?
SLT
Describe ALT?
Burn and contract
Scarring of the TM leads to mech contraction of TM tissue leads to opening up in adjacent tissues.
Describe SLT?
Biological activation of inflammatory mediators –> Cleans up the TM
Selective for pigmented TM cells, no structural or photocoagulative damage to TM
T/F?
Both forms of laser trabeculoplasty leads to an increase of aqueous outflow
True
When do you utilize Argon laser peripheral iridoplasty?
To treat plateau iris syndrome.
To open up the angle for ALT/SLT
How do you diagnose Plateau iris syndrome?
When LPI fails.
A residual angle closure results.
Who’s at risk for plateau iris syndrome?
20-50 y.o caucasian females.
What characteristics is needed for plateau iris syndrome?
Narrow angles
Deep AC
Flat iris
MOA for ALPI?
Scars peripheral iris causing it to shrink and pull away/out of the angle
20-25 burns in a circular fashion around peripheral iris
Which of the Nd:YAG requires pigment?
Nd:YAG 532nm (green)
Nd:YAG SLT
Thus it is a thermal effect
Which of the Nd:YAG does not require pigment?
Nd:YAG 1064 nm (infrared)
What is the Laser:Power density formula?
W/cm^2
J/s divided by cm^2
What is energy (J)
The number of photons
What is Power (W)
The transfer of a number of photons per second (J/s)
What is power density (W/cm^2)?
Transfer of a number of photons per second to a given area
What happens to the power density if you have a smaller area (cm^2)
Higher power density
What happens to the power density if you have a shorter pulse(s)?
Higher power density
What happens to the power density if you have higher energy (J)
Higher power density
What is Q-switching?
Extremely brief pulse of the beam.
Remember that with a shorter pulse, you get higher power density.
What are the two different types of spot sizes?
Fixed spot size
Adjustable spot size
Which laser are you able to virtually adjust anything?
Most photocoagulation Systems 532 nm
Which laser are you fixed in?
Photodisruptive Systems 1064nm
T/F?
Risk of complications increases proportionately to cumulative energy?
True