Keratome or knife incision for cataract; assessment of 180 cases.

DAVIEL (1753) described the first satisfactory method of cataract extraction before the Academie Royale de Chirurgie in 1752. He opened the eye with an instrument similar to the modern keratome and enlarged the incision with scissors. This method gradually displaced the ancient practice of couching until von Graefe described his cataract knife for making the incision in 1865. Von Graefe's cataract knife then remained in common use until about 10 years ago when the keratome began to regain favour. In America the keratome is now the most popular instrument, but in England the cataract knife is still in most common use. The incision is one of the biggest factors in performing a successful extraction, and it is important to try to determine which is the better method. This series of extractions was planned in an attempt to assess the relative value of using the keratome or the cataract knife for this purpose. A few series have been reported in which the results of each type of operation performed by a number of operators have been compared (Davis, 1950; Randolph and Eareckson, 1953), but this is not satisfactory because it does not eliminate the varying skills of the different operators. The skill of the operator may be a bigger factor than the type of incision used. In this series all the operations were performed by the author and ail cataract extractions performed during the period under review have been included. In an attempt to elinminate all possible variables the two methods were used alternately. This routine was broken only when operating upon the second eye of a patient when the alternative method of incision was used. In this consecutive series of 180 cataract extractions ninety were made with a cataract knife and ninety with the keratome and scissors. I intended at first to use no sutures, because a bad section can be firmly closed by accurate corneoscleral suturing and a good section can be made to gape by faulty sutures. In the first 82 cases in this series, I used conjunctival sutures in four cases only, but in the last 98 cases the conjunctival flap was closed with three or four silk sutures. No corneoscleral sutures were used because I considered they would influence the comparison of the two types of incision.