FOUNDED BY THOMAS WAKLEY IN 1823 VOL. No. CCLXII VOLUME ONE JANUARY-JUNE 1952 HAROLD RIDLEY M.D. Camb., F.R.C.S. OPTHALMIC SURGEON, ST. THOMAS'S HOSPITAL, LONDON; SURGEON, MOORFIELD, WESTMINSTER AND CENTRAL EYE HOSPITAL, LONDON No surgical operation surpasses modern cataract extraction in doing what it is designed to do, for the defective part is removed under local anaesthesia in a single stage through an incision which heals with an invisible scar. But the lens, an important part of a highly specialized organ, is lost and cure is complete only when another lens is substituted. Extraction alone is but half the cure for cataract. CATARACT OPERATIONS Operations for cataract have been practised for 3000 years. "Couching," or surgical dislocation of the opaque lens into the vitreous chamber, was in early times the only possible measure, but the proportion of successful results must have been small. Even in the present century this operation, or modifications of it, was used in India and other countries where the people are backward and surgeons few and where only surgery which is quick is relatively safe from sepsis, and does not necessitate postoperative convalescence, is practicable. In 1748 Daviel described the first cataract extraction; but, as is often the case, his operation, though an evident improvement, was not at first well received, and couching continued to be the method of choice. Apart from the risk of sepsis the absence of anaesthesia must have made Daviel's operation difficult and dangerous, and one cannot but admire his courage in performing it. Little improvement took place until the last quarter of the 19th century, when cocaine was introduced as a local anaesthetic, rendering the operation not only painless but also less hazardous. Since then the results of cataract surgery have become increasingly successful. Extracapsular Extraction At first extracapsular extraction seemed the only possible method, and with its many modifications and improvements it is still widely used today. After a corneoscleral section the anterior capsule is incised and the opaque lens expressed through the pupil and out of the eye. For many years surgeons would not operate until the cataract was mature, when the entire cortex could be extracted in one piece. This, however, entailed the patient waiting perhaps years in almost complete blindness; for, if the operation were performed too soon, only the nucleus would be expressed. The remaining cortex might block the pupil, set up anaphylactic iridocyclitis, and possibly prevent proper healing of the wound, leading to further complications, including even sympathetic ophthalmia. Two major improvements have since been made: better asepsis has rendered possible the removal of residual cortex with a jet of sterile saline solution, and removal of a large central area of the anterior capsule with toothed capsule-forceps has made a clear pupil probable. It is found that, if only the thin posterior lens capsule is left, needling of "after cataract" is seldom required. In suitable cases the modern extracapsular extraction gives excellent results, and the posterior capsule remains as a useful bulkhead in the eye, keeping the vitreous in place and reducing the risk of aphakic glaucoma and retinal detachment. Intracapsular Extraction Early in the 20th century intracapsular extraction was introduced. In this operation the intact anterior capsule is grasped with non-toothed forceps, and by a combination of traction from in front with pressure from behind the entire lens enclosed in its membrane is removed. This improvement, which permits extraction of quite immature cataracts as soon as the patient can no longer read, was at first considered unjustifiably dangerous and has only in recent years become more popular than the well-tried and generally successful extracapsular extraction. …