4.1.4Preparation for Penetrating Keratoplasty

The most common instruments utilized in PK are detailed below.

Basic instrument list

1.Eyelid speculum

2.Scleral Þxation rings

3.Large and Þne-tipped needle holder

4.Toothed forceps

5.Trephine blades

6.Radial marker

7.Cutting block

8.Corneal punch system

9.Scissors: tenotomy, Westcott, Vannas, cornea transplantation scissors

10.Cannulas and blades

4.1.4.1Eyelid Speculum

The Kratz-Barraquer wire eye speculum, the Maumenee-Park speculum, and the Lieberman lid speculum (Fig. 4.1) are available choices. The surgeon should have a couple of different speculums available to meet the needs of different anatomic conÞgurations. The speculum must not apply too much pressure onto the globe.

4.1.4.2 Scleral Fixation Rings

The Flieringa rings are our choice (Fig. 4.2). An array of sizes should be available. The most commonly used are the 17 and 18 mm sizes.

Fig. 4.2 Flieringa scleral Þxation rings

4.1.4.3 Large and Fine-Tipped Needle Holder

A curved, nonlocking, round-handled needle holder with standard jaws should be used to place the scleral Þxation rings. A Barraquer needle holder with standard jaws is an example. The Þne-tipped needle holder should be used to place the corneal sutures (Fig. 4.3). It should be curved, nonlocking, and round-handled as well. A Barraquer needle holder with Þne jaws is recommended.

4.1.4.4 Toothed Forceps

Several toothed forceps should be available. Large toothed (0.3 mm) forceps are used to secure the globe during Þxation of the scleral rings. Small toothed (0.12) forceps are used to manipulate the donor tissue (Fig. 4.4).

Fig. 4.3 Fine-tipped needle holder

Fig. 4.4 Toothed forceps

Fig. 4.5 Trephine blade

4.1.4.5 Trephine Blades

We prefer to use hand-held disposable trephine blades (Fig. 4.5). A variety of trephine handles are available if the surgeon prefers. Trephines range in size from 5 to 17 mm. Two of each size should always be available. We maintain a supply of 5Ð12 mm blades at all times.

4.1.4.6 Radial Marker

Eight and 12 prong radial markers are available (Fig. 4.6).

4.1.4.7 Cornea Punch

A variety of corneal donor punches are available. These include the Troutman corneal punch, the Iowa punch, the Lieberman gravity-action corneal donor punch, the Rothman-Gilbard corneal punch, and the Barron corneal donor punch. Vacuum-assisted trephination systems are available as well and include the Hessburg-Barron vacuum trephine, the Hanna, the Krumeich, and the Lieberman. We prefer the Iowa punch (Medtronic, Minneapolis, MN) (Fig. 4.7). The Iowa punch incorporates a spring-loaded piston with an expandable retaining edge to accommodate the trephine. The piston is inserted into the carrier guide and advanced with the application of pressure from the surgeon.

4.1.4.8 Cutting Block

Cutting blocks are used with a punch system. They are composed of Teßon, nylon, or polycarbonate. They have a curved, concave well in which to place the

Fig. 4.7 Iowa press

Fig. 4.8 Cutting block

donor tissue endothelial side up. There is a colored centering target in the center of the well to help center the donor tissue properly. The Iowa punch system consists of the Iowa punch and the Iowa punch cutting block (Fig. 4.8). This is our preferred system.

4.1.4.9 Scissors

A variety of scissors are needed. A tenotomy scissors is used to incise the drape. Westcott scissors are usually used to cut suture material, perform conjunctival resection when needed, cut vitreous strands, etc. (Fig. 4.9). Vannas scissors are used to trim sutures, create an iridectomy, and for trimming an uneven posterior corneal ledge. Cornea transplantation scissors are used to remove the host cornea and they have the lower blade inside the upper blade to create a beveled and perpendicular incision (Fig. 4.10).

4.1.4.10 Cannulas and Blades

A cannula is needed to reconstitute the anterior chamber. We like to use a 30-gauge cannula on a 3-mL syringe Þlled with balanced salt solution (BSS). A 15¡ disposable blade is used to enter the anterior chamber and to trim sutures.