Corneal Membrane Transplant Injector Kristen Berger Paul Bieniek David Brooks Marie Gill Dr. Ahmed Al-Ghoul April 13, 2007

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) /

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.

Eye Anatomy ANTERIOR CHAMBER

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

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

Competitive Analysis Currently, no device performs the same function Similar devices Irrigation/ aspiration devices Lens implant devices

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

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

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

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

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

Potential Hazards 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

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

Preliminary Prototype Testing Test functions: Suction Irrigation

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

Qualitative Testing Matrix Prototype Feature PoorFairMarginalGoodExcellent Ease of use/ ergonomics Needed incision size Attaches corneal membrane properly Maintains anterior chamber pressure Corneal transplant procedure time

FDA – Classification I Similar Devices: Intraocular lens guide 21 CFR “… 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 A device used “… during ophthalmic surgery to deliver continuous, controlled irrigation to the surgical field.”

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.”

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

Economic Considerations Cartridge ~50,000 DSEK procedures per year in US $1.10/cartridge production cost 1 Injection mold: $15,000-25,000 2 ABS: $2.00/lb 2 Revenue = ($100 – $1.10)*50,000 = $5M per year Injector ~2,500 Hospitals and Surgery Centers $100/injector 3 (CNC) $20/injector 4 (MIM) Injection mold: $25,000 4 Revenue = ($ $20)*(2,500 hospitals)*(3 units/hospital)/(5 yrs) = $2.2M per year 1) 2) 3) 4)

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

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

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

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

Thank You! Questions?