Razor blade section in cataract surgery.

Abstract

There are many techniques of cataract extraction and many types of cataract knives have been devised to facilitate an ideal section. Ultrasharp diamond knives were introduced by Durham and Luntz (I968). Sharpness is essential whether the von Graefe knife, the keratome, or corneal scissors are used, and for this reason disposable cataract knives, keratomes, and Bard Parker blades are widely used.This article describes the use of an ordinary razor blade (preferably non-stainless); this is not only very sharp and easy to sterilize, but is cheap enough to be disposable, and readily available throughout the world. Two separate sections can be cut with each half of the blade.Surgical procedure ANAESTHESIA Local anaesthesia, using deep sedation, is suitable for most cases.Upper and lower lid sutures, and a superior rectus bridle suture, are inserted, and the usual limbalbased conjunctival flap is made and cleaned, as far as the sclero-corneal junction, with a pair of conjunctival scissors. Minute bleeding points can be arrested by a thermocautery or the tip of a squint hook heated over a spirit lamp. TECHNIQUEThe section is made solely with a fragment of razor blade held in a special holder or in a pair of finetoothed mosquito forceps.To make the razor blade fragment, the blade is first broken in half, and a triangular piece with a fine point and one sharp edge is broken off from one half of the blade as shown in Fig. I.First a fine groove is made with the sharp edge of the blade just beyond the sclero-corneal junction from 9 to 3 o'clock marking the line of the section. Then at the 12 o'clock position, a cut is made right through into the anterior chamber with the sharp edge of the blade. Next, the tip of the blade is inserted into the anterior chamber through the already cut wound by placing the sharp edge to one side. Then, by a gentle to-and-fro movement on that side, the cornea is sliced off up to the end of the groove previously marked. The sharp edge of the blade is turned towards the other side, and starting from the 12 o'clock position again, the procedure is repeated to complete the section in the other direction to the end of the already marked groove. The section is thus completed throughout with the razor blade fragment.The sutures are inserted, iridectomy is performed, and the cataract is extracted (Fig. 2). If the surgeon prefers to put pre-placed sutures, they can be placed at io and 2 o'clock after the preliminarv groove is made, and between the two lips. Each suture is pulled well apart into a loop with the help of a lens hook and made safe from accidental cutting whi!e the section is being cut.

Commentary

“…Current studies have shown that the postoperative astigmatism is influenced by the type of instruments used. [ 9 ] 4) Loops have been implemented as a means of partitioning the nucleus into separate pieces before delivering them out individually. This manuever will assist in delivering nuclei of varying densities through an incision of a predetermined size, which, in turn, may be helpful in standardizing the SIA.…”