assignment 1 Qs Flashcards
Considering the site of tissue ablation in each type of refractive surgery, which procedure would you recommend for a myopic patient with EBMD/ABMD who wants refractive surgery?
PRK, since the epithelium and Bowman’s layer will be removed in the process of the procedure.
What is the best refractive surgery procedure for a 23 year old male patient with a refractive error of: -4.00-2.00x090 OD, OS?
LASIK
What is the best way to remove a bandage contact lens without causing an epithelial abrasion in a post-PRK patient?
The best way is to pull the lens down off the cornea to make sure it’s mobile then once its past the limbus then you pinch it off
What is the best refractive surgery for a pt that has corneal pachymetry readings less than 490 microns?
PRK
According to Dr. Findley, what measurements are needed on corneal topography for a patient to qualify for corneal refractive surgery?
Posterior float <40 microns; Difference of astigmatism between eyes <1.00 D; <1.50 D of irregular astigmatism in the central 3mm; <2.00 D of irregular astigmatism in central 5mm; Periphery >20 microns thicker than center.
55 year old Caucasian female presents to your office wanting to have the cataract within her right eye removed. The patient has been wearing toric SCLs for 10 years. Before cataract surgery can be performed, how long before surgery should the patient stop wearing her CLs?
Before cataract surgery, toric soft lenses should be removed for at least 2 weeks. Spherical soft lenses should be removed for at least 1 week, and RGPs for at least 4 weeks.
You have a 4 day post-op LASIK patient in your exam chair. There were no complications during surgery. SLE shows central corneal opacification with no inflammation. Manifest refraction shows a large hyperopic shift. What is your best course of treatment for this patient?
This is Central Toxic Keratopathy. There is no treatment, only time will heal it (in 6-9 months).
Which is considered the most important variable in IOL calculations, the axial length measurement or the anterior cornea measurement?
Anterior cornea because it is the most important surface, affecting both spherical power and astigmatism.
According to Dr. McWherter, how can a subconjunctival hemorrhage created during cataract surgery reduce the risk of endophthalmitis?
It allows WBCs to reach the incision site more easily
What type of patient qualifies for cataract surgery by most insruance standards
Someone who complains about problems with decrease VA with glare
Who is a good candidate for mono vision with cataract surgery
Patient who did well with mono vision when younger and has cataracts and ptosis as the only exam abnormalities
What patient is at highest risk for IOP spike after cataract surgery
Pigment dispersion and pseudoexfoliation patietns on 2 meds
Who is a potential multifocal IOL candidate
Self proclaimed perfectionist patient who believes he can live with the halos shown on the online multifocal simulator
Which of the following treatments has the lowest endophthalmitis rates after cataract surgery and is not disapproved by the FDA?
TriMoxi in the anterior vitreous during surgery with vancomycin in the AC
TriMoxi should be avoided in which of the following patietns
Patietns with levaquin allergy
Which of the following is true about laser cataract sx
The femtosecond laser creates a true circular capsulorhexis
What is the risk invovled with iris manipulation during cataract surgery
Increases post op inflammation
Your patient is wanting a multifocal IOL but in glare testing they see halos. They claim they would be okay seeing like that for the rest of their life. Would this be a contraindication to perform the cataract surgery with that specific IOL? Why?
This would not be a contraindication (in this case). The patient acknowledges the glare and is okay with living with it. If the glare were too much for the patient to deal with, another lens should be chosen prior to surgery
When performing a slit lamp exam on a patient for their 1 week post LASIK visit you notice full thickness undulating stromal folds. How would the surgeon correct these folds in order to prevent them from being permanent
This finding is called macrostriae. Since the patient has been 24 hours post op, the proper way to treat this is by removing the epithelium. If macrostriae were seen within 24 hours following surgery, the LASIK flap could be lifted and smoothed down
Regarding phakic IOLs, what is the vault and what is its purpose
It is to create space between the posterior surface of the IOL and the crystalline lens to allow adequate aqueous flow
According to Dr. Findlay, if you have a PRK patient that’s develops stromal haze, when would you expect the haze to fade away
You should expect stromal haze to fade in about 6-12 months
Name something that is usually not a mid to late complication of LASIK
Infectious keratitis. Onset is within the first 24 hours
What two conditions can mimic diffuse lamellar keratitis
Infectious keratitis and pressure induced stroma;l keratitis or PISK
When doing a pre op evaluation of the cornea for a patient who is wanting to have PRK, you notice a scar. The scar appears to be superficial to the flap interface. Is PRK still a good surgery option or should your patient pursue other surgical options?
PRK is still an option for this patient because it may remove the scar since it is superficial
What are 4 relative contraindications of multifocal IOLs
Latent phorias
Threat of disease that may affecte central vision
Dry eye
Perfectionist patietns
When examining the conjunctiva before and after refractive surgery, why would you use lissamine green?
To monitor if dry eye has worsened following the refractive surgery
You notice mictrostriae on your post LASIK patient. What must be done to help this patient? Does anything have to be done at all
This Econ’s from inital flap malpositiojn or slippage so you must repair it quickly before it becomes permanent. Lift and refloat the flap and stroke it down. If greater than 24 hours hours the epithelium must be removed
What is the difference between keratoconus and form fruste keratoconnus
Keratoconnus is inferior corneal thinning of both eyes and form fruste keratoconnus is inferior thinning of one eye, but not the other. This is due to eye rubbing of only one eye. The treatment for keratoconnus can involve scleral CL or corneal collagen cross linking, whereas form fruste keratoconnus is not progressive, so there is no treatment necessary for it
Post LASIK you see epithelial ingrowths moving toward center of the cornea with a decreased VA due to irregualr astigmatism. Would you treat, if so, how?
Yes, you would want to treat this patient due to the complain of decreased VA. The treatment would be to lift the flap back up, scrape the epithelium from the stromal bed, respoition the flap and then apply a bandage CL on the eye
What is proper procedure if a buttonhole develops in the flap intraoperatively during LASIK
stop the procedure and replace the flap, then let the flap heal for 3-6 months and then do PRK
What are 6 potential complications of refractive lens exchange?
Wound leak, IOP spike, endophthalmitis, TASS, CME, and RD
When performing KRS on a mixed astigmat with a Rx of +1.00 -2.00 x 180 OU, how must you treat the patien
For a mixed astigmatism treat one meridian as simple hyperopic astigmatic and the other as simple myopic astigmatism. In this instance if would be Plano -1.00 x 180 and Plano +1.00 x 090
A post cataract patient with a small axial length presents with high IPO and shallow AC depth both centrally and peripherally. What is the likely diagnosis and how can it be treated
Aqueous misdirection Three treatment options 1. Cycloplege (the patient typically would be for the cataract surgery itself) 2. YAG laser to anterior hyaloid 3. Pars plana vitrectomy
SMILE, a refractive surgery that uses femtosecond laser to make an intrastromal laser cut has A similar outcome to LASIK. What is one benefit of SMILE compared to LASIK and why
Less risk of fry eye symptoms, in incision takes place withi nthe cornea without the need for a larger corneal flap resulting in less damage to corneal nerves
Regarding a patient with Fuch’s who shows prominent bullae, what surgical procedure should be performed ASAP
Descemets Membrane Endotherlial Keratoplasy (DMEK)
What is the difference between a posterior polar cataract and PSC
Posterior polar cataract has sharply demarcated borders
Why should you never polish a posterior polar cataract
The capsule can rupture
What corneal procedure has the highest rejection rate in the first 2 years: PL, DALK, DSAEK, or DMEK?
PK has the highest rejection rate in the first 2 years with 18%
DALK 4%
DSAEK 5-12%
DMEK 1%
In terms of corneal transplant methods, which method does not lead to corneal astigmatism
DMEK
Descemets membrane endothelial keratoplasy
What are the two post op stages in penetrating ketratoplasty (PK)? What are the risks with each stage?
Epithelialization is the first stage and takes 1-2 weeks to occur. Patients run the risk of rejection and endophthalmitis
Stromal healing is the second stage and takes 1 year. Patients do run the risk of infection from loose suture and rejection
Which corneal transplant procedure is MOST useful for case of granular dystrophy that compromises a patients VA
Given the granular dystrophy is a stromal dystrophy, a PK would be indicated
When you have a patient with a flat anterior chamber and high IOP what are two dx that should be suspected
Angle closure and malignant glaucoma (aqueous misdirection)
What is the official treatment for malignant glaucoma
Pars plana vitrectomy
What 3 tests are required at the initial post op visit within the first 3 days after cataract surgery
VA
IOP
Slit lamp
DALK and OK have simialr stages and treatment. However, what are some of the slight differences with DALK?
DALK has:
- less risk of rejection
- can taper steroids earlier and remove sutures earlier
- less blunt trauma risk
What is the typical schedule of antibiotic, steroid, and NSAID drops following cataract surgery
ABX: q1h first day, TID x 3 more days
Steroid: QID tapered 1 gt per week
NSAID: dose depends on type
A 45 year old male comes in in wtih confluent corneal guttata, what are possible treatment options
DMEK, if they choose to defer surgery, monitor every 6 months or sooner if symptoms worsen
A patient reports for a post opt surgery with an epithelial defect. The surgical note states that TriMoxi was used during the procedure. In addition to BCL, what type of medication do you need to Rx
An abx
You have a patient that comes in after cataract surgery. On examination you find their pressures to be 60mmHg OU. you recheck pressures after a couple minutes and once again find it to be 62mmHg OU. Would you want to burp the wound> why
Yes. You would want to burp the wound and recheck pressures after 30m. If pressures are still high, burp again and repeat every 30m until pressure stops rebounding
When would you want to burp for post op cataract surgery
Depending on what the pressure is before you begin burping, you will need to continue doing so until you reach a desired IOP
What does the burping technique consist of
Numbing, betadine, abx drops, lid speculum, then calmly press the sclera adjacent to the wound to release pressure, then give IOP drops