Phacoemulsification

One of the major advances in our efforts in providing better vision after cataract surgery is phacoemulsification. This is also known more popularly as laser surgery. This is however a misnomer as there is no laser involved. This technique essentially involves emulsification of the lens (Gr - phakos).   Why Phaco?   The major concern with older techniques is the amount of astigmatism that the surgery induces. The astigmatism is directly related to the incision length used to remove the cataract. With the conventional techniques the incision length is around 10 - 13 mm. The next major determinant for the resultant astigmatism is the tightness of the sutures (stitches). Both these factors are taken care of in phacoemulsification. Here the usual incision is 2.8 - 5.5 mm (depending on the type of lens used). Also there are no sutures required to close the incision.   Advantages of 'no-stitch' technique:   The incision in phaco can be left unsutured partly because the incision is small but more importantly because the incision is beveled. The incision is fashioned in such a way that it acts like a valve. Thus when the pressure inside the eye increases due to any reason like when the patient sneezes or coughs the incision closes more tightly. However in the case of a sutured wound when the pressure rises there is an increased risk of wound breaking open.   All sutures degrade with time. This causes it to break up, which can cause the suture to point outwards and cause pain and redness in the eye necessitating it's removal. Also the degrading suture causes a change in the spectacle power. All these problems are not seen with phacoemulsification.   Postoperatively the recovery is faster and the patient can resume work much earlier than after conventional surgery.   What happens in Phaco?   The cataract has two parts the hard central nucleus and the soft surrounding cortex. The cortex being soft can be sucked with a small cannula but the hard nucleus had to be removed in toto through a large incision. In phacoemulsification the nucleus is broken up into very small pieces which are then sucked through a cannula. This is achieved with the help of a phaco probe, which is introduced in the eye. The tip of the probe is made of titanium and it vibrates at the rate of 40,000 times per second 'emulsifying' the nucleus. This emulsified nucleus is simultaneously sucked from the eye. The capsule of the lens is left behind which supports the artificial lens.     What is manual Phaco?   This is a technique, which is similar to phaco except that the surgery is done without the phaco machine. The incision length is about 5mm and the postoperative results are the same as phaco. This method of cataract extraction is becoming increasingly popular.     Back