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Corneal burn Suture Technique

by H. Burkhard Dick & Robert H. Osher The development of ultrasound phacoemulsification by Dr. Charles Kelman has proven to be one of the greatest accomplishments in Medicine. Advances in technology have continued to improve intraoperative safety and postoperative outcomes. However, the complication of thermal injury to the incision continues to warrant attention, especially with smaller incisions and the widespread use of ophthalmic visco surgical devices (OVD). During the emulsification of the lens nucleus, heat that is generated that is dissipated by the flow of irrigation fluid around the outside of the needle and by the aspiration of fluid through the needle.1 Any interruption of flow by tightness of the incision, excessive angulation of the hand piece, occlusion of aspiration by OVD, or prolonged friction created by the ultrasound needle can allow heat energy to quickly damage the adjacent tissue. Irreversible collagen denaturization leads to tissue shrinkage resulting in a gape that is either microscopic (Shark Fin Sign) or macroscopic (Fishmouth).2 An incisional burn can lead to potentially serious postoperative complications including permanent damage to the corneal stroma and endothelium, severe induced astigmatism, wound leakage and even fistula formation.3,4 It is especially difficult to close the gape between the anterior and posterior margin of the incision because the tissue has contracted. In 1990, a gape suture closure using a radial stitch passed through the proximal edge of the incision exiting in the bed without incorporating the distal margin was described by Osher in the Video Journal of Cataract and Refractive Surgery.5 He modified this technique by creating a trapezoidal mattress closure that was published in the same video journal in 1993.6 It is the purpose of this article to detail the suture technique recommended for achieving a watertight closure of an incisional burn. Once a thermal burn has occurred, the surgeon may notice a gape with opacification of the adjacent corneal tissue. The initial needle puncture is placed through the distal roof of the incision exiting within the incision. The needle is re-grasped and reloaded for second pass which is tangential through the anterior bed of the incision both entering and exiting at a slightly longer cord length than the intended cord length through the roof. The needle is re-grasped and the third and final pass which penetrates the posterior roof of the incision entering within the incision and exiting on the ocular surface. The incision is tied with the globe pressurized and the knot is trimmed. Although the gape suture knot can be rotated into the sclera or modified so that the knot is tied inside the incision, we prefer trimming the knot on the surface and, if necessary, advancing conjunctiva for additional incision coverage. Thermal damage to the incision results in a contraction of tissue producing a gape which is difficult to close. This suture technique may produce a water tight closure for two reasons. First, a wound recession is created by bringing the posterior portion of the roof to the anterior portion of the floor, effectively “lending” tissue to the gape. Second, the trapezoid configuration with the greater cord length more posterior causes the suture to induce less tissue compression. This combination is more likely to permit adequate closure with less chance of causing unacceptably high astigmatism or wound leak. While our ultimate goal is to design new technology that will make thermal damage obsolete, the surgeon should be prepared to manage an unexpected incision gape should this complication occur. References 1. Sippel KC. Pineda R Jr. Phacoemulsification and thermal wound injury. Semin Ophthalmol 2002; 17:102-109 2 . Osher RH. Shark fin: a new sign of thermal injury. Cataract Refract Surg 2005; 31:640-642 3. Ernest P, Rhem M, McDermott M, Lavery K, Sensoli A. Phacoemulsification conditions resulting in thermal wound injury. J Cataract Refract Surg 2001; 27:1829-1839 4. Sugar A, Schertzer RM. Clinical course of phacoemulsification wound burns. J Cataract Refract Surg 1999; 25:688-692 5. Osher RH. Gape Closure: Video J Cataract Refract Surg; Vol VI; Iss 3: 1990 6. Osher RH. Thermal Burns: Video J Cataract Refract Surg; Vol IX; Iss 3: 1993