Cross-Linking with Refractive Surgery: Pros and Cons

Transcription

1 Cross-Linking with Refractive Surgery: Pros and Cons Raj K. Rajpal, M.D. Medical Director and Founder See Clearly Vision Group Mclean, Virginia Clinical Associate Professor Georgetown University Washington, DC

2 Financial Disclosures Alcon Allergan AMO Avedro Bausch + Lomb Halozyme Mimetogen Nicox See Clearly Vision Group

3 LASIK + Collagen Cross Linking - Is it a Good Idea? What Do We Already Know? Cross Linking Works Ectasia is Bad! What Do We Need to Know? Can We Prevent Ectasia Safely Can We Address Regulatory/Cost Issues

4 Cross Linking Strengthens the Cornea Corneal Young s Modulus/MPa Riboflavin UVA Cross-linked Control Increasing Stiffness Before treatment After treatment Courtesy of Prof. John Marshall 4

5 A LASIK Flap Weakens the Cornea Corneal Weakening Flap Depth Courtesy of Prof. John Marshall 5

6 Accelerated Crosslinking/LASIK Xtra LASIK Soak 90 sec 0.25% ribo, rinse ribo Replace flap UV 30 mw x 3 min

7 The Lasik Xtra Procedure

8 Concerns to Address - LASIK Xtra Any Increase in Risk with the Procedure Intra-Operative Concerns Peri-Operative Issues Change in Refractive Outcome What Results do we Have Available

9 International Experience - LASIK Xtra A. John Kanellopoulos, Greece >5 Year Follow Up, Lower Enhancement Rate, Greater Stability in Hyperopes over 2 Years Gustavo Tamayo, Colombia >200 Eyes, 1 Year Follow Up, 0% Enh Rate in Myopes Howard Gimbel, Canada Option Offered to All Patients, No Adverse Events Noted 1010 cases (542 LASIK Xtra, 468 PRK Xtra) Being Followed Minoru Tomita, Japan >24,000 Patients Treated

10 International Experience - LASIK Xtra Rohit Shetty, India 6 Month Follow Up with Demarcation Line Visible on OCT Robert Pinelli, Italy 40 Eyes with 6 Month Follow Up, +3D to -8D, Stable post-op MR Faruk Yilmaz, Turkey Results Published in JCRS

11

12 April 30, Avedro. Contents are proprietary & confidential. 12

13 LASIK XTRA International Experience Gustavo Tamayo, Bogota, Colombia (Tamayo GE. J Cataract Refract Surg Dec;38(12):2206) Compared 66 myopic eyes treated with Lasik Xtra, 42 eyes Lasik only No algorithm change No enhancement procedures to date in myopic eyes One enhancement in a presbyopic Lasik Xtra patient: surgeon reports no difficulty lifting the flap and successful retreatment Lasik Xtra Lasik Only Baseline MRSE D D 1 Day UCVA (snellen) 20/21 20/20 1 Month UCVA 20/18 20/20 1 Month MRSE

14 FEMTOSECOND LASIK XTRA REGULAR FS LASIK

15 Lasik Xtra: Clinical Outcomes around the World John Kanellopoulos, Athens, Greece (pre-publication data, accepted to JCRS) 34 consecutive hyperopic patients scheduled to undergo bilateral topography guided hyperopic LASIK were randomized to receive Lasik Xtra in one eye, and LASIK alone in the other. At 2 years postoperatively, eyes treated with Lasik Xtra demonstrated regression of +0.22±0.31 D. Eyes treated with standard LASIK demonstrated a statistically significant greater regression of +0.72±0.19 D.

16 Lasik Xtra What Does it Mean for Your Refractive Practice? Minoru Tomita, MD, PhD. Executive Medical Director Shinagawa LASIK Center, Tokyo, Japan Financial disclosure: Ziemer Group AG, Switzerland AcuFocus, CA Schwind Eye-Tech-Solutions, Germany

17 Monthly 3,000 2,500 Total LASIK Xtra: Monthly and Accumulated Monthly Accumulated 2,795 2,686 2,768 2,538 Accumulated 30,000 24,307 25,000 2,000 1,500 1,547 1,736 2,128 2,228 22,273 2,034 1,877 19,505 16,967 15,090 20,000 15,000 12,404 1, ,176 10, , ,253 3,517 1,055 1,970 5, Jan-11 (eyes) 1-Feb-11 1-Mar-11 1-Apr-11 1-May-11 1-Jun-11 1-Jul-11 1-Aug-11 1-Sep-11 1-Oct-11 1-Nov-11 1-Dec-11 1-Jan-12 1-Feb-12 1-Mar-12 1-Apr-12 1-May-12 1-Jun-12 1-Jul-12 1-Aug-12 1-Sep-12 (eyes) 24,307 eyes have been treated with LASIK Xtra (February 2011 through Sept 2012)

18 Methods Patients 24 myopic candidates with mean age: 30.4±5.3 (range:19 to 40 y.o.) were enrolled in this study with sufficient informed consent before participation. Patients had bilateral LASIK, then KXL had performed but only on their non-dominant eye. Dominant Non-dominant LASIK VS LASIK KXL LASIK Xtra

19 Preoperative Data UDVA (LogMAR) CDVA (LogMAR) SE(D) Mean ± SD (Range) K Ave. (D) Mean ± SD (Range) ECD (cells/mm 2 ) Manual Mean ± SD LASIK Xtra (non-dominant) ± 2.22 ( to -1.25) ± 1.26 (41.50 to 45.75) 3,078.5 ±285.9 (2,232 to 3,534) NS NS NS NS NS LASIK Only (dominant) ± 2.26 ( to -1.00) ± 1.30 (41.25 to 46.00) 3,048.8 ± (2,105 to 3,509) Mann-Whitney s U-test (NS: No statistically significant difference) No statistically significant differences observed between the 2 groups preoperatively.

20 Refractions MRSE (D) NS NS NS NS NS LASIK Xtra NS LASIK only Pre (n=24) 1D (n=24) 1W (n=24) 1M (n=24) 3M (n=24) 6M(n=23) Mann-Whitney s U-test (NS: No statistically significant difference) No statistically significant differences observed between the 2 groups.

21 Confocal Microscope 5 months postoperative HRT image for same patients LASIK Xtra Pt.A OS:130μm Pt.B OS: 130μm LASIK Only Pt.A OD: 131μm Pt.B OD: 129μm Using confocal microscope examination, we found increased reflectivity in the stroma cells which is normally observed after conventional CXL.

22 Demarcation Line observed by OCT: flap interface flap interface flap interface Demarcation line Demarcation line Demarcation lines were observed at depths of 200 to 250 µm. Aside from the depth of demarcation line, this postoperative finding is consistent wi the results of other post CXL studies. 4,5 -In previously published CXL cases, the demarcation line was found at depths of over 300 µm. 4. Seiler T, et al;. Cornea. 2006;25(9): Caporossi A, et al.; American journal of ophthalmology. 2010;149(4):

23 Higher volume study Age UDVA CDVA Sphere(D) Cylinder(D) MRSE(D) (years old) (Range) (LogMAR) (LogMAR) Mean ± SD (Range) Mean ± SD (Range) Mean ± SD (Range) LASIK Xtra 32.4± ± ± ± 2.58 (n=1,319 eyes) ( 18 to 63 ) ( to 5.75) (-6.00 to 0) ( to 4.63) 1,319 eyes of 689 patients underwent LASIK Xtra between February and November Preoperative and postoperative (1Day, 1Week, 1Month, 3Months and 6Months) UDVA, CDVA, Sphere, Cylinder and MRSE were evaluated.

24 Higher volume study cont d Sphere (D) 1.00 Cylinder(D) LASIK Xtra LASIK Xtra The refractive change in this high-volume study also demonstrated similar result with standard LASIK.

25 Status of Concerns - LASIK Xtra Increase in Risk with the Procedure No Change in Endothelial Cell Counts Intra-Operative Concerns Initial Antecodtal Reports of Flap Slippage Resolved Peri-Operative Issues No Evidence of DLK No Change in Refractive Outcome Is it Really Doing Anything Evidence of Demarcation Line on OCT

26 Does LASIK Xtra Reduce the Risk of Ectasia Not Likely to Have Definitive Study Incidence of Ectasia is Low (1/5,000?) Challenge in Studies Demonstrating Prevention Endophthalmitis and Antibiotics CME and NSAID s Infer Efficacy? Strong Evidence That Cross Linking Treats Ectasia

27 Challenges in Offering LASIK Xtra FDA Approval Definitive Study Unlikely (Of Course, Still Awaiting Approval for Cross Linking for KCN) Cost Factors Surgeons/Laser Centers Device Drug/Disposables Will Refractive Surgery Patients Pay More Patient Perception of LASIK

28 Next Steps in Offering LASIK Xtra Refine Nomograms Initially Treat Higher Risk Patients High Myopes Younger Patients Thinner Corneas Questionable Corneal Topography (otherwise may be PRK candidates?) Achieve FDA Approval with Hyperopic LASIK Xtra?

29 AVEDRO CLINICAL TRIALS LASIK and Accelerated Crosslinking Multi-center, randomized study of the safety and efficacy of the KXL System with Photrexa ZD (Riboflavin) for performing crosslinking in eyes undergoing hyperopic LASIK Each subject will have bilateral LASIK performed and one eye will be randomized to undergo LASIK followed by crosslinking

30 AVEDRO CLINICAL TRIALS LASIK and Accelerated Crosslinking Intended treatment > +2.0 diopters (D) to < +6.0 D of MRSE hyperopia or hyperopia with astigmatism, with up to +6.0 D of spherical component and up to 5.0 D of astigmatism Enrollment 154 patients undergoing LASIK for hyperopia or hyperopic astigmatism in up to 10 sites in the US

31 LASIK Xtra, Is it a Good Idea? Procedure Relatively Easy to Integrate with LASIK Strong Evidence That Cross Linking Treats Ectasia Results Demonstrate: Study data does not indicate increase in risk Refractive Outcome Predictable What Additional Evidence is Required Ethical to Not Offer to All Refractive Patients?