Extracapsular Extraction

Extracapsular cataract surgery obviated many of the concerns posed by the intracapsular techniques. This method has several variants but, in principle, maintains a portion of the surrounding capsular bag. In this procedure, the anterior capsule (i.e., the portion of the lens capsule facing the pupil) is opened. This anterior capsulotomy then permits the contents of the lens capsule (i.e., the nucleus and cortex) to be removed. When the nucleus is totally removed as a single structure, it is called nucleus expression, and the technique is termed planned extracapsular cataract extraction. Another method called pha-

coemulsification removes the nucleus by fragmenting it with an ultrasonic needle. In recent years, phacoemulsification has become the favored method for cataract removal.

Advantages of the extracapsular technique are related to maintenance of an intact posterior capsule. An eye with an intact capsule has greater internal stability and lower incidence of retinal detachment and cystoid macular edema. The major consequence of the procedure, however, is that the posterior capsule can become hazy or opacified in the late postoperative period. Epithelial cells in the equatorial zones of the lens that are not removed during cataract surgery proliferate, undergo metaplasia, and migrate along the capsule to reside in the axial zone of the eye. This reduces vision, and an additional procedure is required to create an opening in the capsule.

Another consideration in retaining the posterior capsule and, if possible, even greater portions of the capsular bag, is related to the implantation of IOLs. It was this aspect of visual rehabilitation that served as the major impetus to encourage ophthalmologists to adopt the extracapsular technique.

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