Intracapsular Extraction

Intracapsular cataract extraction is the method of removing the entire lens, including the capsular bag. This method separates the lens from its zonular attachments and from attachments to the anterior portion of the vitreous. This latter attachment, called "Weigert's ligament," generally wanes as we age, but is quite strong in childhood and young adulthood. When the intracapsular technique was performed on younger age groups, disruption of the vitreous, termed "vitreous loss," frequently occurred. This is a complication of cataract surgery that has long-term effects, even when it is adequately managed intraoperatively. The instruments used to perform intracapsular surgery were initially forceps, which were used to grasp the anterior capsule and remove the lens by either tumbling it from behind the pupil or sliding it from the eye. In each instance, the mechanical action of removing the lens caused traction on and release of the zonules that held the lens in position. In some cases, a specific enzyme that digested the zonules was instilled within the eye before the cataract was removed.

In the late 1960s, another method to remove the lens intra-capsularly was introduced. This technique employed cryosurgery that, in essence, produced an adhesion between the cryo-probe and a portion of the lens substance. Once this adhesion had formed, the cataractous lens was slid from the eye.

The advantage of this intracapsular technique was that it removed the entire lens without leaving any remnants. There was clear passage of light from the anterior corneal surface to the retina, although the light was not fully focused because the refractive power of the lens was removed along with the cataract. The disadvantages of this method were (1) the greater potential for vitreous disruption (vitreous loss); (2) the higher incidence of retinal detachment; (3) the higher incidence of fluid accumulations in the central region of the retina, the macula (aphakic cystoid macular edema); and (4) the greater instability of the internal ocular milieu. Because of these complications, other types of cataract surgery were adopted.

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