What We Do and Don t Know about Corneal Crosslinking Roy Rubinfeld, MD Washington Eye Physicians and Surgeons Chevy Chase, MD Georgetown University Medical Center, Washington Hospital Center, Washington, DC
Disclosures This presentation describes investigational medical technology that is not FDA-approved. The author has financial and IP interests in CXL technology and research.
Quick History
1998 Cross-linking
Dresden Technique Anesthetic drops Remove epithelium Riboflavin drops for 30 mins UV light for 30 mins at 3mW/cm 2 Bandage contact lens
CXL Approved 2006 All 25 EU Nations
2012 Clinical Trials
CXL for KCN, Ectasia Over a hundred published studies Shown safe and effective worldwide Arrests KCN progression (~90+%) UCV, BCSVA, CL tolerance (40-80%)
37 y/o Man 2009: KCN Dxd by OD 2010: CXL recommended (by OD) 2011: CXL firmly recommended
KCN Progressing 2009 OD MRfx -1.75 +3.50 X 165 20/30+ OS MRfx -1.75 +2.75 X 015 20/20 2011 OD MRfx -3.25 +5.75 X 145 20/40-1 OS MRfx -2.00 +4.25 X 010 20/25-2 Pachs thinner, Ks steeper, getting worse
Pre/Post CXL OD
Doyle Stulting, MD EBAA 2006 data
Typical Epi Off CXL Pain, photophobia Worse vision for 1-3 mo Steeper Ks Haze SPEs/surface issues
Haze after Epi-Off CXL
Epi-Off: VA & Ks Worse @ 1-2 Mo Thicker Variable Epithelial Thickness Thinner Consistent Epithelial Thickness Steeper Ks R. Stein, MD Preop 1 mo Postop
Delayed Epithelial Healing and Infiltrate after Epi-Off CXL Zymar & polytrim Q2 hrs started; BCTL removed, Punctal plugs placed, W. Trattler, MD Postop Day 2
Postop Day 5
Epi-off CXL AEs Corneal melting in both eyes after simultaneous corneal cross-linking in a patient with keratoconus and Down syndrome. Ophthalmologe. 2010 Oct;107(10):951-5 Corneal melting corneal collagen cross-linking for keratoconus: A case report. Labiris. Journal of Medical Case Reports 5:15 2012 Early ocular surface-related complications after CXL. Gutman. Modern Medicine Sept, 2012.
Why Wouldn t We Want to do CXL Without Removing Epithelium?
Normal Corneal Epithelium Barrier to riboflavin penetration of stroma? Epithelium Stroma
Evolution of a Technique
Let s Compromise Hybrid Approaches Criss cross PTK Femtosecond channels Disrupters
Daya Disruptor
Well Loaded TransEpi
Epi-on Flare
Clear Cornea POD 1 (Epi-On)
US Multicenter CXL Study Actively Recruiting Patients since 10/09 8 or older FFKC, KCN or PMD Postop Ectasia Post RK with Visual Fluctuations Cornea at least 300 microns thick At least 6 mo since last corneal Sx
Marwa Adi, MD Neil Martin, MD Roy Rubinfeld, MD Jodi Luchs, MD William Trattler, MD Parag Majmudar, MD Lance Forstot, MD Sandy Feldman, MD Jay Schwartz, MD Ty McCall, MD John Talamo, MD Ranjan Malahotra, MD Gregg Berdy, MD David Wallace, MD Dan Goodman, M D Richard Lindstrom, MD Study Centers Chevy Chase, MD Chevy Chase, MD Chevy Chase, MD Long Island, NY Miami, FL Chicago, IL Littleton, CO San Diego, CA Phoenix, AZ Dallas, TX Boston, MA St. Louis, MO St. Louis, MO Los Angeles, CA San Francisco, CA Minneapolis, MN 15 centers 37 Investigators
But Does Epi-On Work? and How Do We Know the Patient is Better?
CXL & Curvature Change Change in avg or steep K is not enough Diff maps can help show true curvature changes
Preop Postop 6 Wks Left Eye Difference Map 7 D Steeper 4 D Flatter Roy Rubinfeld, MD Epi-ON case
Kmax Reproducibility with Pentacam: 3 scans of 1 Eye (c/o William Trattler, MD) OD QS:LID QS:LID QS:LID Kmax range: 69.2 to 71.6= 2.4D
Treatment Failures 5% in Seiler s report CXLUSA 14 eyes out of 1250 (0.01%) Epi-On CXL related adverse events:0
CXL Mythbusting
Is Higher Better? Higher irradiance = faster crosslinking? 30 mw/cm2 X 3 min = 3 mw/cm2 X 30 min 300 degrees for 30 min = 3000 degrees for 3 min Roy Rubinfeld, MD
CXL plus LASIK Ectasia Flap adds little or no strength LASIK weakens corneas CXL strengthens corneas RSB strength may be a more important variable than thickness
Is it Safe?
LASIK plus CXL
LASIK and CXL Shinegawa data on thousands of eyes CXLUSA data Excellent UCVA No effect on nomogram No ectasias