Cataract surgery has evolved from the practice of pushing a "ripe" cataract into the back of the eye as was practised in ancient India, to the current method of phacoemulsification and intraocular lens insertion.
The history surrounding the treatment of cataracts is extensive and has come to a point where today we are able to offer a very safe treatment with rapid recovery.
Routine small incision cataract surgery is performed as day surgery and does not involve the routine use of injections or stitches around the eye. This is because the wound is very small and because the eye can be anaesthetised using drops or gel. A light sedative complements this use of topical anaesthetic.
The phacoemulsification method allows patients to regain vision and resume normal activities very quickly following surgery and is very safe.
This method involves creating a tiny incision on the cornea and removing the natural but clouded lens of the eye and placing an artificial lens where the natural lens was found. Contrary to popular belief this involves the use of ultrasound energy and not a laser. Adelaide Eye & Laser Centre currently uses the Centurion™ cataract removal system. This system offers enhanced ultrasound phacoemulsification modalities enabling flexibility in the way the cataract is removed thereby improving safety and rate of recovery.
Intraocular lenses implanted during cataract surgery are a fundamental requirement for successful cataract surgery. These lenses are designed to provide the eye with a focal point determined as part of the pre-operative assessment. Most commonly the focus is set for the distance but it may be set for near. Some lenses may also provide more than one focal point to minimise dependency on glasses. Fundamental to achieving the intended outcome is selecting the correct power and style of intraocular lens. This requires a series of measurements and calculations prior to any surgery.
The equipment for these measurements and calculations is very accurate and the predictability is high but it is not possible to guarantee an outcome for any procedure since some information required for the calculations has to be assumed. In some instances patients may be required to wear thin spectacle lenses after surgery due to residual focusing errors that affects the level of vision without correction. An alternative to glasses in this situation may be surgery, either within the eye to exchange or supplement the intraocular lens used, or by laser vision correction. The risks and benefits of any surgery requires individual assessment, however, the cost of any procedure is not covered as part of the fee for cataract surgery.
Recently improvements in intraocular lens design have made it possible to provide distance, intermediate and near vision correction without glasses. There are various combinations of these characteristics with some but not all patients being good candidates. Disadvantages include some halos at night and reduced quality of intermediate and near vision.
In general terms there are three classes of intraocular lens:
These are the most commonly used lens as they provide the highest quality of vision. They have a single focal point which is generally set for distance but can be set for near. Usually both eyes are set for distance but in some people one eye is set for distance and the other near, a term called monovision.
Extended Depth of Focus (EDoF) lenses
These lenses extend the range of focus from distance to approximately 65cms giving good “social” vision. They do not generally give good near vision for detailed reading so reading glasses are still required, but have minimal side effects.
When discussing multifocal implants we really mean trifocal intraocular lenses. These lenses provid a near focus of 40cm, an intermediate focus from 60-80cm and a distance focal point by splitting the light entering the eye. Whilst they have many good characteristics they can be associated with unwanted side effects that cannot be shown to you before the surgery.
An important consideration with intraocular lenses is the correction of any potential astigmatism that might be expected after the surgery. All lens types have the capacity to correct astigmatism. Adelaide Eye & Laser Centre uses the VerionTM alignment system to maximize the surgical outcomes from astigmatism correcting intraocular lenses.
The intraocular lens best suited to your eye and individual circumstances will be discussed with you as part of your surgical assessment.