VA Wet Lab Session 4: Penetrating Keratoplasty

Leo J. Maguire, MD, Mayo Clinic, Rochester, MN
Videography by Randy Verdick, FOPS, The University of Iowa

Objectives

• To perform a penetrating keratoplasty on a human cadaver eye
  • To place 24 radial, interrupted sutures

Resources

• Access to the wet lab
• Suture and tying techniques lecture, Leo J. Maguire, MD
• PowerPoint Presentatiom of Suture and Tying Steps (pdf)
• Corneal Trauma Curriculum Handbook, Leo J. Maguire, MD

Video Tutorials by section, Leo J. Maguire, MD

Introduction, Leo J. Maguire, MD (2:07 minutes total)

Hand Positioning, Leo J. Maguire, MD (18:18 total)

• Contents
  • Stability Positions: The Stack Vertically
  • Stability Positions: The Stack Horizontally
  • Colibri Skills
  • Three Point Fixation
  • Grabbing the Needle

Basic Tying and Tying Mistakes, Leo J. Maguire, MD (50:37 total)

• Contents
  • Basic Tying
  • Making the "T" More Efficient
  • Tying Mistakes: With Straight Tying Forceps
  • Tying Mistakes: With Angle Tying Forceps
  • Judging 45 degrees with the Calibri on the host cornea
  • Needle Parallelism and Marching the needle down the host cornea
  • When your technique is not correct with driving the needle into the host
  • Forceps position on the graft and driving the needle into the graft
  • Things that go wrong with driving the needle into the graft
  • Dr. Maguire showing how to put it all together

Overview of Suturing Steps

• Steps of suturing in a nutshell
• Suture tying in small steps
• Tying the Suture (after passing it)

Steps of a penetrating keratoplasty

• Basic set-up tips
• Marking the cornea
• Marking the cornea (take 2)
• Trephining the cornea
  • Trephining the cornea (take 2)
  • Trephining the cornea (take 3)
• After trephining, preparing the graft for the first suture
  • Preparing the graft for suturing (atake 2)
• Passing the first suture
  • Passing the first suture at 12:00
  • Passing the needle through the graft at 12:00
• Tying the first suture
  • Tying the suture at 12:00
• Passing the 6:00 suture
  • Passing the 6:00 suture (take 2) (please try again later)
• Tying the suture at 6:00
• Oblique suture at 2:00
• Oblique suture at 7:00
• Oblique suture at 10:00
• Oblique suture at 4:00
• Passing the suture at 3:00
• Passing the suture at 9:00
• Judging the finished product

Suturing mistakes

Common mistakes when looping the sutures

• The importance of keeping the straight tying forceps perpendicular
• Winding the suture onto the angled typing forceps
• Keeping the throws on the angle tying forceps
• Keeping the angle tying forceps in the "pick-up" position
• Picking up the short suture end with the angled tying forceps

Common mistakes when tying

• First pull the sutures parallel to the wound before pulling perpendicular
• Avoid inducing 10 diopters of astigmatism
• Keeping the angled tying forceps in the "pick-up" position and perpendicular to the short suture end

Other trouble shooting tips

• Driving the needle into the host and the effect of pronation
• Trouble shooting a non-radial suture with a small bite on the host cornea

Miscellaneous Videos

• Placing a suture at 12:00 for a left handed surgeon
• Using a canula
• How to approach Corneal Lacerations, Leo J. Maguire, MD (40:57 total)
  • Contents
    • Introduction
    • Forming the Anterior Chamber
    • Making a stab incision in a flat anterior chamber
    • Placing the first suture in a corneal laceration
    • Placing additional sutures

• Back to Lesson Index