What Is Involved In A Cataract Operation?
The phacoemulsification procedure (phako for short) is the technique that has been used for several years as part of modern treatment for cataracts. Dr Chauhan has performed over 3000 phako operations since 1993.
For posterior subcapsular cataract treatment in particular, it is preferable to the older types of cataract surgery of extracapsular cataract extraction and lensectomy by fragmatome, both of which result in more inflammation and a worse visual result. Some would argue that there is no place for either in modern eye surgery.
The phacoemulsification procedure consists of making a small incision in the cornea (clear part of the front of the eye) and removing the cataract from within the lens capsule, a very thin bag in which the natural lens fits snugly. As with other types of cataract surgery, an artificial lens intraocular implant (or IOL) is placed into the capsular bag, unfolding into place.
The focussing strength of the IOL is calculated using biometry (also known as an A-scan) measurements made before surgery using a specially designed instrument. This measures the length of the eye and the curvature of the cornea.
If you have astigmatism, in which the cornea is curved like a rugby ball rather than a ‘soccer’ ball, this can be corrected by using a premium IOL known as a toric IOL.
Will I Feel The Operation?
No. Like other types of cataract surgery, this operation is almost always performed under local anaesthetic as a day case and the method is the same as that used for vitrectomy surgery. It involves some anaesthetic drops being put in your eye, followed by sedation with a drug injected into your vein. This will make you completely unaware of the anaesthetist giving you an injection of anaesthetic fluid around the outside of your eyeball.
The phacoemulsification procedure is not painful but you should let Dr Chauhan know if, as rarely occurs, you do feel any sensation in the eye. This is best done without talking, as speaking makes your head (and eye) move.
Your anaesthetist will let you know how to signal this before the surgery. It is simple for more anaesthetic to be given straight away, and this takes effect almost immediately. There is no need or benefit to being a martyr about this; the surgery is also easier if you are not in pain or discomfort. You will be lying on your back throughout the anaesthetic and surgery.
How Is The Operation Done?
After the anaesthetic has been given, iodine solution will be used to clean around your eye. After this, a plastic sheet (drape) will be used to cover your eye and face. Dr Chauhan and the anaesthetist will ensure that an oxygen and air mixture can flow freely under this sheet and that you can breathe easily. A hole will then be cut in the drape over your eye and a special clip used to hold it open. Dr Chauhan will then sit down and position a microscope above your eye and switch the light on. You may be able to see this light but it usually fades after a little while.
During the posterior subcapsular cataract surgery itself, you will feel Dr Chauhan’s hands on your forehead and, occasionally, on the bridge of your nose. You may hear the theatre staff talking, as well as various sounds made by the vitrectomy machine and possibly, music. You may feel a trickle of watery fluid down the side of your face but, whilst uncomfortable, this is not dangerous.
There are Several Steps to the Phacoemulsification Procedure:
A tiny incision is made on one side of the cornea so that a second instrument can be used during the operation.
The main incision is made in order to introduce the phako probe and other instruments into the eye.
A thick gel is injected into the eye both to protect the inside of the eye and open up space within the eye.
An opening is torn in the front of the lens capsule.
Fluid is squirted between the lens capsule and the lens itself, separating the two prior to cataract extraction.
Phacoemulsification of the lens is performed using a phako probe that vibrates at 40kHz. This sets up a shock wave that partly liquefies the cataract and also cuts through the lens, sucking it up as it goes. This is done using many different techniques; Dr Chauhan uses the ‘stop and chop’ method in which the cataract is removed piecemeal.
The remnants of the cataract are sucked up using another instrument.
A folded-up lens is injected into the eye and opens up slowly within the capsular bag.
If a toric lens is used, this will be rotated to the point at which it helps correct the astigmatism.
How Long Is The Operation?
The phacoemulsification procedure can take up to 20 minutes, but the time taken is no indication of how it has gone.
What Happens After the Operation?
At the end of the cataract surgery, you will have a pad and shield over your eye. This remains on until the next day, when Dr Chauhan will examine your eye.
Immediately after the operation, you will enter the recovery area where the nurses will make some routine checks including your pulse and blood pressure. Even though you will have been sedated, by this time you are likely to be fully awake and ready for a drink and a snack.
Once the nurses are happy that you feel fine and are fit to leave, you will be escorted out to meet your friend/relative who will take you straight home. You will be provided with a prescription for drops that will need to be taken to the chemist that day, as you will be asked to bring the drops with you to the clinic the next day; the first drops will be instilled when you are examined.
How Can I Avoid Problems After Surgery?
You must not rub the operated eye.
Make sure that you wear the shield provided when sleeping. This will prevent inadvertent pressure on the eye and stop you rubbing your eye when asleep.
What Should I Expect After Surgery?
The operated eye should not be painful after surgery; it is, however, normal to get a little surface irritation (feeling like something is in the eye), to have a slight ache on the day of surgery, and for bright lights to be a little uncomfortable (wearing sunglasses is often helpful).
The vision is often quite good on the first day after surgery but this can vary a lot, especially if you have had a vitrectomy in the past. It will certainly be poor immediately afterwards if the cataract surgery was combined with a vitrectomy.
When Can I Get New Glasses?
After treatment for cataracts, you will need to change the lens in your glasses.
If the eye has not had a vitrectomy either previously or at the same time as the cataract surgery, you may visit your optometrist about 4 weeks after surgery. Please check this with Dr Chauhan, as it may be better to wait longer in some circumstances.
What Should I Be Concerned About After Phacoemulsification Cataract Surgery?
If any of the following occur, or if you are concerned about any another matter after treatment for cataracts, you should get in touch with your surgeon urgently:
- Pain, particularly aching, deep pain.
- If your eye becomes more uncomfortable or painful than when you last were seen by your surgeon.
- If your vision worsens since your last appointment. In particular, if the top part of your vision, which slowly improves in normal circumstances, gets worse, you ought to be seen urgently.
- If a pus-like discharge develops at any time after the surgery this requires urgent attention.
- If you become aware of new floaters, flashes of light, or a shadow in your peripheral vision.
Not all problems fit neatly into descriptions in a list like this. Dr Chauhan and his staff prefer that his patients call with questions, even those that might seem minor or ‘silly’, rather than wait until their next appointment.
If Dr Chauhan is your surgeon, please call Vision Retinal Institute Eastern on (03) 9890 4333 during office hours. You will also have been given his mobile phone number to call; he will attempt to contact or see you as soon as possible. If he is unable to see you, he will make alternative arrangements for you to be seen by another retinal specialist.
What Are The Risks Of Cataract Surgery?
The risks of cataract surgery are:
- Less than 1 in 1000 chance of blindness due to either infection or bleeding
- Less than 1 in 200 lifetime risk of retinal detachment
- 1 in 50 chance of reduced vision
Dr Chauhan will discuss these risks and others with you before your phacoemulsification procedure. He can also explain what is involved in this cataract surgery in order to allay any anxiety you might have.