Learning Objectives

• Understand the physics of corneal wound/incision closure
• Create and close linear and stellate corneal incisions
• Perform a penetrating keratoplasty (mainly 3^rd years)

Materials

• Pig/goat eyes
• Super sharp blades
• Viscoelastic
• BSS
• Fine non-locking needle holders
• 10-0 nylon suture
• Colibri or straight 0.12 or 0.3 forceps
• Vannas scissors
• Tying forceps
• Vacuum trephine
• Left and right corneal scissors

Preparation

• Please read the following:
  • Macsai chapter on physics of wound closure (all)
  • Krachmer section on corneal laceration repair (all)
  • Krachmer section on penetrating keratoplasty (2^nd and 3^rd years)
• 2^nd and 3^rd years, please watch the following videos:
  • Trephination and corneal excision in PKP (will need to create free account if don’t already have one):
    • http://eyetube.net/video/penetrating-keratoplasty-technique/
  • Full surgical video on PKP (may want to mute music)
    • http://www.youtube.com/watch?v=h4FL3jtgU7s
  • V sign in PKP
    • http://www.youtube.com/watch?v=zh5zYhB3yfQ

Procedure

1^st and 2^nd years

1. Inject some BSS into the anterior chamber of the pig/goat eye to reform the anterior chamber to physiologic turgor. 
2. Use a blade to create a linear partial thickness incision in the cornea.
3. Close this incision with 10-0 nylon sutures in an interrupted fashion.
4. Repeat process with a full thickness linear incision as well as a stellate (Mercedes sign) full thickness incision.
5. Reform the anterior chamber with BSS to confirm that wound is free of leakage.  

2^nd and 3^rd years

1. Inject some BSS or water into the anterior chamber of the pig/goat eye to reform the anterior chamber to physiologic turgor (makes for easier paracentesis incision).
2. Create a paracentesis incision with a 15 degree blade.  
3. Fill anterior chamber with viscoelastic.  
4. Trephine the cornea with the vacuum trephine.  
5. Excise corneal button with left and right corneal scissors.
6. Re-suture corneal button back in PKP fashion