Cataract surgery involves removing the cloudy or thickened natural lens and replacing it with an artificial lens. For the majority of patients, cataract surgery is performed to improve the quality of vision however, for patients with angle closure, it serves to primarily reverse crowding of the drainage angle.
Prior to cataract surgery, your surgeon will discuss “refractive outcome” (final glasses prescription to aim for) based on your visual requirement. You will then be required to have a measurement of your eye (called biometry) to determine the power of the artificial lens to insert into your eye to achieve the desired refractive outcome.
On the day of surgery, the operation is usually preformed under local anesthetic whereby either anesthetic drops are instilled or a small injection of anesthetic is given around the eye. If you are feeling nervous or don’t feel you will able to lie still for thirty minutes then either sedation can be given or you can have a general anesthetic.
The operation takes about thirty minutes and involves the following simplified steps referring to the image of the structure of the eye
— A small incision is made in the clear window (cornea) about 2.2mm in size. This incision is self-sealing.
— Some artificial gel is injected into the front chamber of the eye to stop it from collapsing.
— Your cataract which is suspended in a bag connected to the wall of the eye by “string like” structures, is removed by removing a circular disc of the bag (to gain access to the cataract) and then “breaking” and vacuuming” the cataract fragments out of your eye with an ultrasound machine. This process is called phacoemulsification.
— Once the bulk of the cataract is removed any remnant fibers are carefully cleared and an artificial lens is inserted into the bag.
— The artificial gel is then removed from within the eye and all wounds are checked to make sure they are water tight.
— Finally, anti-biotics are injected into the eye and either a clear shield or a dressing and a shield is placed over the eye.
Cross section of the eye showing the main structure of the eye and the optic nerve. Source: National eye institute media library