Cornea Surgery

1. Corneal Membrane Transplant InjectorKristen BergerPaul BieniekDavid BrooksMarie GillDr. Ahmed Al-GhoulApril 13, 2007

2. Cornea Surgery • Keratoplasty is used to treat many cornea diseases • 2005 – Over 100,000 surgeries performed in U.S. • More efficient surgical techniques have recently evolved (DSEK) http://sarajdoktor.blogger.ba/

3. Current Surgery Techniques: DSEK • 50% of keratoplasty procedures • Advantages • Only replaces diseased tissue • Smaller incision • Fewer stitches • Disadvantages • Donor tissue folded and inserted • Damage to endothelial cells • Interface haze • Loss of intraocular pressure Gorovoy, M. S., Francis, W. P.

4. Eye Anatomy ANTERIOR CHAMBER

5. Design Objectives • Safely deliver donor tissue to anterior chamber • Minimize contact with endothelium • Reduce incision size (<4mm) • Maintain intraocular pressure

6. Requirements • Compatible with existing equipment • Functions: • Irrigation • Aspiration • Easy to operate • Sterilizable • Biocompatible • Life in service - 5 years at 5 procedures/week

7. Competitive Analysis • Currently, no device performs the same function • Similar devices • Irrigation/ aspiration devices • Lens implant devices http://www.hsc.wvu.edu/som/eye/servicesCataract.asp

8. Design Alternatives 1.) • Curled membrane • Translatable suction platform • Too much friction 2.) • Wrapped membrane • Translatable oval suction tip • Triple lumen design

9. Design – End of First Semester • Three component system • Stainless steel injector • Clear plastic cartridge • Stainless steel case • Fabrication • “If you guys think you can make this, you’re crazy!” – Andy Holmes • Injector too complex to be machined as one piece

10. Redesign Issues • Design for Production – Consider Assembly • Vacuum and irrigation tubes; luer fittings • Simplification • Merging of case and cartridge

11. Prototype Fabrication • Cartridge – SLA • Injector parts • Stainless steel, SLA, PVC • Used lathe and mill • Hand-assembled

12. Features Luer fittings for attachment to emulsifier O-rings for water-tight seal between parts Pin and guidance track to allow precise alignment of parts Ergonomic grips Surgical grade stainless steel for injector Clear plastic cartridge for visualization during use

13. Damage to donor endothelial cells Category III Inability to maintain the anterior chamber Category III Failure to achieve suction Category III Negative reaction of tissue to the device Category IV Damage to patient’s eye Category IV Severity: Category I - Catastrophic Category II - Critical Category III - Marginal Category IV - Minor Potential Hazards

14. Concept Model • Testing of suction and irrigation on silicone corneas and contact lenses

15. Preliminary Prototype Testing • Test functions: • Suction • Irrigation

16. Future Prototype Testing • Qualitative using animal cadaver eyes • Ease of use - ergonomics • Function • Works with phacoemulsification machine • Holds corneal membrane on injector • Maintains anterior chamber pressure • Safely transports the corneal membrane • Histology testing of corneal membrane and recipient eye

17. Qualitative Testing Matrix

18. FDA – Classification I Similar Devices: Intraocular lens guide • 21 CFR 886.4300 • “… a device intended to be inserted into the eye during surgery to direct the insertion of an intraocular lens and be removed after insertion is completed.” Ocular surgery irrigation device • 21 CFR 886.4360 • A device used “… during ophthalmic surgery to deliver continuous, controlled irrigation to the surgical field.”

19. FDA – Classification I • General Characteristics • Non-life sustaining • Least complicated • Failure poses little risk • Premarketing submission 510(k) • Substantially equivalent to a legally marketed device not subject to a premarket approval (PMA) • Intraocular lens guide is exempt from 510(k) unless “ . . . if used as folders and injectors for soft or foldable IOL's.”

20. FDA – Classification I • General Controls: • Quality assurance program • Suitable for intended use • Adequately packaged • Properly labeled • Establishment registration • Device listing forms

21. Economic Considerations • Cartridge • ~50,000 DSEK procedures per year in US • $1.10/cartridge production cost1 • Injection mold: $15,000-25,0002 • ABS: $2.00/lb2 • Revenue = ($100 – $1.10)*50,000 = $5M per year • Injector • ~2,500 Hospitals and Surgery Centers • $100/injector3 (CNC) • $20/injector4 (MIM) • Injection mold: $25,0004 • Revenue = ($1500 - $20)*(2,500 hospitals)*(3 units/hospital)/(5 yrs) = $2.2M per year 1) http://www.geplastics.com/gep/eng/webted/webted.html 2) http://kazmer.uml.edu/Software/JavaCost/index.htm 3)http://www.jobshoptechnology.com/features/0302/mim.shtml 4) http://news.thomasnet.com/IMT/archives/2004/05/the_benefits_of.html?t=archive

22. Project Management Sept. Oct. Nov. Dec. Jan. Feb. Mar. Apr. May Initial Research and Design Proof of Concept Concept proved 2/8/07 Redesign Prototype Completed 4/6/07 Fabrication Prototype Testing

23. Team Contributions • Dave – Initial SolidWorks design, background research • Paul – Initial SolidWorks design, cartridge development, fabrication • Marie – Concept model testing, preliminary prototype testing, FDA regulatory research • Kristen – SolidWorks redesign, injector development and fabrication • All – DHF and SBIR

24. Future Directions • Biocompatibility Testing • Plastic tip redesign • Decrease size • Conduct stress tests • Make tip slanted • Durability Testing • Upscale to mass production

25. Acknowledgements • Dr. Ahmed Al-Ghoul • Andy Holmes • Generous gift of Drs. Hal Wrigley and Linda Baker • Department of Bioengineering

26. Thank You! • Questions?