AUG 14, 2012
This article in the June issue of the Journal of Cataract & Refractive Surgery presents an improved technique for placing a single radial suture for a corneal or limbal incision that does not seal despite stromal hydration. The needle enters on the scleral side of the limbal incision, exits on the corneal side toward the apex and is tied with a 3-throw (1-1-1) adjustable square knot. The needle path is reversed from the traditional technique, in which the needle enters from the corneal side of the limbal incision and exits toward the scleral side and the suture is usually tied with a 3-1-1 surgical knot.
This is the most universally useful technique article I have seen in a long time. I will probably never suture an incision the old way again. A video demonstrating the technique is available with this article.
Tying a suture with a 1-1-1 adjustable knot is not a new technique but is underused in ophthalmology. To the authors' knowledge, the application of this adjustable knot to corneal or limbal incisions, combined with passing the needle in the reverse direction, has not been described previously.
The secret to the adjustable knot is the placement of the tying forceps over the suture as usual for the first throw but under the suture for the second throw. The third and last throw then locks it down once the tension has been titrated.
One advantage of this technique is that the anterior chamber is not lost during suturing since the anterior lip does not have to be lifted. This is invaluable, especially in pediatric or complicated cases in which there is scleral elasticity or the lens is not entirely secured in the bag or rhexis.
Another advantage is the sliding adjustable knot, which reduces the likelihood that it will overtighten and cause astigmatism or need replacement due to being too loose. Particularly when more than one suture is required or when suturing edematous cornea after trauma, this allows all sutures to be equally tight and to be adjusted before the final pass-through sequentially. Lastly, the slimmer knot is easier to bury, preventing breakage and stretching.