PRK: Simple, Safe & Reliable

OSN New York 2013

PRK: Simple, Safe & Reliable

Technique & Pearls

Christopher E. Starr, MD

Associate Professor of Ophthalmology

Director, Refractive Surgery Service

Director, Ophthalmic Education

Director, Cornea & Refractive Surgery Fellowship

Weill Cornell Medical College

Disclosures

• I have no direct financial interest in any of

the products I will discuss

• Consultant, Speaker and/or Research Funding:

– Allergan

– Alcon

– Merck

– Bausch & Lomb

– Rapid Pathogen Screening / Nicox

– TearLab

Disclosures

This 7 minute talk is not meant to be an exhaustive literature review of

LASIK vs. PRK

Instead, much of this talk will be based on my personal preferences,

opinions and experiences

Generally I embrace new techniques and technology …

LASIK, LASEK, Epi-LASIK are all fine procedures in the right hands

but I prefer, and now exclusively perform, PRK

LASIK vs. PRK: Traditional Pros & Cons

 Advantages of LASIK

 Proverbial wow factor

 Faster visual recovery & return to work  Painless

 Shorter post-op course  Preservation of Bowman’s?

 Disadvantages of LASIK

 Equipment much more expensive  Click fee higher per case

 Procedure takes longer, more complex  Greater patient anxiety, intraop

discomfort?

 Higher chance of iris registration issues  Possible higher risk of dry eye

 Possible higher risk of night vision issues  Glare, halos, starbursts etc.

 Flap Complications!!!

 Striae, DLK, slippage, incomplete, free cap, buttonhole, late dislocation, epi ingrowth, etc.

 Higher risk of ectasia  Higher risk of law suits

 OMIC 10 year data: 20x higher risk than PRK

 Advantages of PRK

 No Flap Complications, less ectasia, better biomechanics  Modifiable refractive effect

 Fewer induced HOA’s = better visual quality  Cheaper equipment, cheaper procedure fees  Easier surgery to perform

 Wider range of suitable candidates  Less dry eye, night vision issues?  Fewer Lawsuits

 Easier iris registration of ablation  Fewer aborted surgeries

 Easier enhancements / retreatments

 May be more suitable for post-cataract surgery touch-ups

 Disadvantages of PRK

 Slower visual recovery  Pain

 Risk of haze and other wound healing issues

 Increased risk of infection (2008 ASCRS White Paper)  Longer post-op course: more steroid/more visits

 MMC long term risks?  Ablation of Bowman’s?

LASIK vs. PRK: Visual Outcomes

 Recent Cochrane Reviews: LASIK vs. PRK

 Myopia.

Shortt AJ et al. January 2013

 13 trials (1923 eyes), 9 randomized (spanning from 1980’s to 2012)

 overall quality of evidence to be low for most outcomes because of the risk of bias

 “LASIK gives a faster visual recovery and is a less painful technique than PRK”

 “The two techniques appear to give similar outcomes one year after surgery”

 Hyperopia:

Settlas et al., June 2012

 “Planned to include only randomized controlled trials comparing PRK against

LASIK for correction of hyperopia. We did not identify any studies that met the

inclusion criteria for this review”

 Instead “we discussed the results of non-randomized trials and they appear to be in

agreement that hyperopic-PRK and hyperopic-LASIK are of comparable efficacy”

 PRK vs. LASEK vs. Epi-LASIK:

highly variable study designs and techniques

but essentially no significant advantages in pain, haze, visual outcomes with LASEK or

Epi-LASIK vs PRK.

Post-Op Regimen

What I Use:

• If < 5D + MMC: loteprednol or

prednisolone for 4-6 weeks

• If > 5D + MMC: difluprednate or

prednisolone for 8-10 weeks

• 4

_{generation fluoroquinolone QID for}

10 days post op

• If health care worker or high risk for

MRSA, polymyxin/trimethoprim

• Cyclosporin 0.05% BID for 6 months

• Vitamin C 2-3 grams PO x 1 week

• Omega-3 FA 2-3 grams PO x 1 week

• Pain Control

• Ketorolac up to QID for 1

_{3-4 days}

• Oral OTC NSAIDs PRN

• Chilled PFAT’s & Cold Compresses

What I Don’t Use:

• Oral steroids

• Oral narcotics

• Anti-epileptics like

neurontin/lyrica etc.

• “Comfort drops” like diluted

tetracaine/proparacaine

Visual Results

1st 10 Bilateral Consecutive Patients in 2013

- Follow-Up of at least 6 months

- Mean spherical equivalent: -4.25D (range -2.50 to -8.00D)

Mean Uncorrected Visual Acuity Both Eyes

Immediately After Procedure: 20/23 (range 20/15- to 20/30)

- most patients exhibited a ‘wow’ moment

POD 1: mean 20/20 (range 20/15- to 20/30)

- 90% 20/20 or better OU

POD 4: 20/28.5 (range 20/20 to 20/40)

- vast majority back at work

POM 1: 20/16 OU (range 20/15 to 20/25 OU)

- one eye was 20/40, one eye was 20/15 but complaint of afterimage

POM 6: 100% 20/15 in each eye individually

Results: Pain & Complications

Pain Scale (0-5)

First Night: mean 1.3 (range 0-3)

POD 1: mean 1.2 (range 0-3)

- 60% had scores of 1 or less

- 40% had no pain on day 1

- No one reported pain after POD3

Complications (last 6 years):

Delayed Epithelial Healing: 0

- 100% healed by POD4, all BCLs removed

Infection/Infiltrate: 0

Haze: 0

Enhancements: 0 (first one upcoming though)

Refractory Dry Eye: 0

Lasting Night Vision Disturbance: 0

MMC or Steroid Induced Complications: 0

Ectasia (

Flap Complications

): 0

Conclusion:

Modern PRK (aka ASA)

- Safe

- eliminates flap complications

- MMC is safe and has virtually eliminated haze

- ectasia is extremely rare

- Long-term visual outcomes comparable to LASIK

- Short-term visual outcomes much closer to LASIK

- Significantly less pain than in past and only for 3 days

- Easier, cheaper, quicker to perform than LASIK