Current Trends in Refractive Surgery - Lecture given at Harvard by Emil Chynn, MD
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Emil William Chynn, MD, FACS, MBA Park Avenue LASEK 333 Park Avenue South, New York, NY [email protected]
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Dr. Chynn graduated from Harvard's ophthalmology program, which is probably the most famous in the world. As the only member of his graduating class to specialize in Refractive Surgery, and now an recognized authority, Dr. Chynn is frequently invited back to Harvard to give updates on the State of the Art in Refractive Surgery. This slide show presentation was given to 100 eye surgeons who flew in from across the country to learn the latest advances in glaucoma, retina, cataract surgery--and laser vision correction (from Dr. Chynn). The title of his talk reflects the movement in the US and worldwide from leading surgeons that is called "Back to the Surface." This means that surgeons are moving away from LASIK and IntraLase, to avoid flap complications and the # 1 problem causing lawsuits (iatrogenic keratoconus, or KC), and back to the surface. For some doctors, this means going back to the original procedure, PRK, which has a lot of pain, delayed healing, and scarring. For Dr. Chynn, this means performing an Advanced Surface Ablation, which is either a LASEK or epiLASEK. These are more advanced than PRK because they do not hurt, healing and recovery is quick, and there is no haze or scarring. For example, Dr. Chynn performs over 1,000 LASEKs and epiLASEKs per year--he performed his last PRK in 1999. Obviously, he moved away from PRK to LASIK, then to IntraLase, and now back to the safer LASEK and epiLASEK procedures. View the following slide show to find out more, and call us with your questions--better yet, come in and meet with our MDs!
Transcript of Current Trends in Refractive Surgery - Lecture given at Harvard by Emil Chynn, MD
Emil William Chynn, MD, FACS, MBA Park Avenue LASEK
333 Park Avenue South, New York, NY [email protected]
Evolu&on of Refrac&ve Surgery RK, AK (Fyodorov – Russia/Ukraine) PRK (Trokel & L’Esperance, Columbia U) LASIK (Pallikaris, Greece) LASEK (Talamo, Abad & Azar, Mass Eye & Ear Intra-‐LASE, i-‐LASIK (Kurtz, USA) Epi-‐LASIK, epi-‐LASEK (Pallikaris, Greece)
Original Procedures: Incisional “Chance favors the prepared mind” – Louis Pasteur Boy falls off bike/glasses shatter/corneal lacs-‐>no specs! Discovery/invention of RK – Svyatoslav Fyodorov Hex K – Antonio Medez (Mexico) Metal blade-‐>Diamond blade-‐>Guarded diamond blade
Risks: perforation, infection Side-‐effects: starbursts, irregular astigmatism Unpredictability, overcorrection (PERK, Waring)
First move to the surface: PRK Excimer (“excited dimer”) laser, 193 nm IBM Labs, Armonk, NY (chip etching) Trokel (VISX) & L’Esperance (Summit), Columbia
US Patent #5,108,388 (1983/87/92), Claim 4: “The method of changing optical properties of
an eye by operating solely upon the anterior surface of the cornea of the eye (using) selective UV irradiation and attendant ablative photodecomposition of the anterior surface of the cornea in a volumetric removal of corneal tissue and with depth penetration into the stroma and to a predetermined curvature profile”
PRK advantages/disadvantages Accuracy Myopia, hyperopia, astigmatism Stability Pain Delayed recovery Scarring
Move away from surface: LASIK Rapid recovery Nearly instantaneous results / “wow effect” Nearly painless Decreased risk of scarring Flap striae, partial flap, button-‐hole flap Debris, epithelial ingrowth, DLK Late trauma Ectasia (Speaker/$7mil, Niksarli/$5.6, DelloRusso/$15.3)
Safer Flaps: IntraLase/i-‐LASIK Fewer incomplete or button-‐hole flaps Thinner flaps Safer for thin corneas, high Rx, irregular astig/FF KC Persistent inflammation + photophobia DES Late flap trauma Iatrogenic KC
Move “Back to the Surface” LASEK – remove epithelium en bloc using EtOH Epi-‐LASEK(IK) – en bloc dissection using epi-‐keratome “Advanced Surface Ablation” (ASA) “Flap-‐on” vs. “flap-‐off”
Epi-‐LASEK (epi-‐LASIK)
ASA indica&ons (over LASIK) Irregular astigmatism/ FF KC Thin corneas / high Rx
Highest Rx treated in NYC (2010) -‐22 D (600 – 250 = 350) Preop BCVA 20/60 OU -‐ > Postop UCVA 20/40 OU
Night vision concerns (glare from flap, large pupils) Contact sports / hazardous duty (Seals, etc) Anterior stromal opacities (scars, dystrophies?) Prior RK/AK Very special cases (pediatrics? dogs??)
Advantages of LASEK/epiLASEK Zero flap-‐related complications (vs. LASIK)
90% of all complications are flap-‐related Decreased Dry Eye Syndrome (vs. LASIK)
caused by neurotrophic cornea/hypesthesia
Decreased inflammation/pain (vs. PRK) Decreased risk of scarring (vs. PRK) Quicker recovery time (vs. PRK) Safer re-‐treatments of complicated (LASIK) cases
Sta&s&cal Trends (MarketScope)
Complicated LASIK enhancements Safer to re-‐treat surface/flap No increased depth/decreased stromal bed No added risk of ectasia No chance of epithelial ingrowth/corneal melt No risk of DLK No incomplete flaps No risk of recutting flaps
Enhancement procedure LASEK OU + MMC + CustomVue WaveFront (HD) LASEK – safer than epi-‐LASEK on retreatments To prevent scarring:
MMC—mitomycin C (1 sec / sec. of ablation time) Vitamin C oral steroids (methylprednisolone) x 1 week PredForte (prednisolone acetate) QID, taper over mos UV protection
CustomVue WaveFront—Prevue Lens
PreVue Lens: useful in complex cases1
LASIK retreatments UCVA close to 20/20 BCVA not 20/20 No objective improvement on manifest refraction Subjective complaints disproportionate Glare, halos, diplopia, ghosting Lawyers, legal considerations 1Bansal, Chynn, Rubinfield, Refractive Surgery Complex Case
Management, Cataract & Refractive Surgery Today, July 2008
“Epithelial PreVue” New Universal Way to PreVue Can be used with any laser platform (not just VISX) More accurate than PreVue
Larger optical zone More realistic “real-‐life” trial
Zero downside risk? turning lemons into lemonade
Useful to: encourage/discourage enhancement “pre-‐sell”/justify WaveFront upgrade
A.F. – 62 yo M s/p RK + AK CC: “I can’t see well far or near without glasses!” Had multiple RK + AK incisions OU 28 years ago VA (distance): 20/80 OD, 20/100 OS, 20/60 OU VA (near): 20/100 OD, 20/80 OS, 20/80 OU Rx: +3.25 – 2.25 x 80 OD
+ 4.50 – 4.75 x 95 OS Saw numerous LASIK surgeons who said:
“I wouldn’t touch you with a 10-‐foot pole!” “If you get LASIK you will wind up with pizza slices!”
Surgical plan Enhance non-‐dominant eye first Wait 3 months before enhancing second eye Maximum scarring prophylaxis Stress patient compliance Frequent post-‐op visits/SLE to check for scarring Slow taper of topical steroids
SLE – 1 year postop
1 year postop UCVA: 20/20 at distance (OU)
20/25 at near (OU) Rx: OD: +0.50 – 0.75 x 13
OS: -‐0.75 – 1.25 x 123 SLE: clear CC: “I can see near and far like when I was 30, which is good as I just married a 30-‐year-‐old and am having my tubes reconnected to try to have kids!”
LASEK of Granular Dystrophy 22 yo F – Hx Granular Dystrophy OU UCVA OD: 20/100
OS: 20/80 OU: 20/70
BSCVA: OD: -‐1.75 – 1.50 x 170 (20/80) OS: -‐1.00 – 0.50 x 5 (20/70) OU: 20/60
Preop: Granular Dystrophy
1 –year post LASEK for Granular
1-‐year post-‐LASEK for Granular UCVA OD: 20/50 (20/100 preop) OS: 20/40 (20/80 preop)
OU: 20/30 (20/70 preop) BSCVA: OD: -‐.75 – 0.50 x 160 (20/30) (20/80 pre) OS: -‐.50 – 0.50 x 15 (20/30) (20/70 pre) OU: 20/25 (20/60 pre)
Sze H. Wong, BS Lynnette P. Williams, MD
Emil W. Chynn, MD, FACS, MBA
The authors have no financial interest in the subject ma4er of this poster.
Presented at ASCRS, 2011
Study Popula&on: Characteris&cs
n = 93 Patients (153 Eyes) Female 47 %
Male 53 %
Age (mean ± SD; range) 31.4 ± 8.3 (19 -‐ 66)
Eyes With Extreme Myopia (SE ≥ -‐9) 72 %
Eyes With Extreme Hyperopia (SE ≥ +6) 4 %
Eyes With Extreme Astigmatism (cyl ≥ -‐3) 31 %
LASEK Eyes 83 %
Epi-‐LASIK Eyes 17 %
WaveFront Eyes 61 %
Rx Range -‐22.00 to +7.50
Preop Corneal Thickness 554 ± 39 µm
Ablation Thickness 125 ± 36 µm
Postop Corneal Thickness 429 ± 50 µm
Gain in VA at 3 months Postop UCVA vs. Preop Best Corrected Visual Acuity (BCVA) 100 % of eyes had postop UCVA > preop UCVA!
Extreme Myopic Eyes Extreme Hyperopic Eyes
Extreme Astigmatic Eyes
Number of Lines Gained
8.42
3.58
6.68
LogMAR Gained
1.51
0.77
1.08
Postop UCVA vs. Preop BCVA
(%) 1-‐Mo. 2-‐Mo. 3-‐Mo.
Postop UCVA ≥
Preop BCVA
40
57
72
Postop UCVA > Preop BCVA
18
25
34
Postop UCVA = Preop BCVA
22
32
38
Complica&ons
" 11/153 (7 %) of eyes had postop haze (tr to 2+)
" 3/153 (2%) of eyes lost ≥ 1 line of BCVA due to postop haze
" 1/153 (0.7%) of eyes lost ≥ 2 lines of BCVA due to postop haze
CONCLUSION
Extreme prescriptions may be safely and effectively treated with Advanced Surface Ablation, combined with adjunctive treatments to prevent scarring
72% eyes: 3-‐mo. postop UCVA ≥ preop BCVA
Further studies are needed to determine whether extremely hyperopic eyes are more likely to lose BCVA and how to avoid this loss
Summary: “ASA” = LASEK + EpiLASEK 10x safer than primary LASIK or i-‐LASIK/IntraLase?
Definitely safer in complicated enh (RK, AK, PK) Need steroids + MMC to prevent scarring Slower healing / patient compliance “Combine safety of PRK with comfort of LASIK” Can “Return to the Surface”
revitalize Refractive Surgery? (still 0% penetration of candidate population)
