Both cataract surgery and vitrectomy surgery can be performed together as a ‘combined surgery’.
Technically, there are a few additional considerations during the surgery, but this is now a commonplace operation performed by vitreoretinal surgeons who have also been trained fully in cataract surgery.
- If (even mild) cataract already exists at the time of vitrectomy surgery, this is very likely to become worse over quite a short time. One study showed that 4 out of 5 patients who had vitrectomy (even including those without any pre-existing cataract) developed a cataract in the operated eye within 2 years and then went on to have cataract surgery. Having combined surgery means that a second operation is not necessary.
- If cataract surgery is performed after a vitrectomy, it can be technically more difficult.
- The risks of a vitrectomy with cataract surgery are likely to be lower than two separate operations.
- Following a vitrectomy, visual recovery can be slow. After the vision has begun to improve, the development of cataract later can be quite a disappointment for some, even if they have been warned. Combined surgery avoids this issue almost completely.
There are obviously circumstances when there are good reasons not to perform both operations together. Dr Chauhan will be happy to explain if this is the case.
Cataracts And Phakoemulsification
The cataract operation component of the combined operation is used to treat cataracts. A cataract is formed when the lens inside the eye goes cloudy. This is usually a slow process that occurs naturally with age, but it commonly follows vitrectomy within a year or two.
There are many symptoms of cataract, including reduced vision, blurring, glare from bright lights and increasing short-sightedness. Some of these symptoms can be treated in the short term by changing glasses and using dark glasses, but the only lasting and most effective treatment is cataract surgery.
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Common Conditions Treated By Vitrectomy
A vitrectomy with cataract surgery is used to treat a number of macular and vitreoretinal conditions. Depending on the condition being treated, the process during the surgery and the recovery will differ. Two common conditions treated by this surgery include:
Epiretinal membrane: an epiretinal membrane (ERM) is a thin sheet of scar-like material that grows on the surface of the macula, the central, most sensitive part of the retina. The membrane contracts and scrunches up the macula, wrinkling it and making it thicker, reducing the quality and/or quantity of vision. The wrinkling of the retina results in twisted or distorted vision.
Macular hole: a macular hole is a tiny hole in the centre of the macula, usually less than half a millimetre across; unfortunately, this part of the macula (the fovea) is the most sensitive part. A missing central macula means that a patient with a macular hole cannot see anything at all right in the centre of his vision and the edges.
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What Does Combined Surgery Involve?
During a combined surgery, the cataract is removed first through a process called phakoemulsification. Phakoemulsification (phako for short) is the technique that has been used for several years as part of modern cataract surgery. Dr Chauhan has performed over 3000 phako operations since 1993.
Phako 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. An artificial lens intraocular implant (or IOL) is then placed into the capsular bag, unfolding into place.
The second part of the surgery is a vitrectomy, which involves the removal of vitreous gel. What is done after this depends on whether the vitrectomy is for a macular or vitreoretinal condition. The vitrectomy with cataract surgery is performed using small 25 (or 27) gauge implements to ensure no stitches are necessary.
Will I Feel The Operation?
No. This surgery is almost always performed under local anaesthetic as a day case and the method is the same as that used for cataract or 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 surgery 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 Performed?
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 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. Sometimes you might also hear 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 Phakoemulsification:
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.
Phakoemulsification 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.
Following the phakoemulsification, the vitrectomy component of the surgery is performed. This begins with the making of three tiny holes (ports) in the white (sclera) of the eye, allowing instruments to be introduced into your eye. One of these ports allows a constant flow of fluid to pass into your eye, providing ‘infusion’. Another port is solely used to insert a fibre-optic ‘light pipe’ to provide illumination from within, while the third port is used for all other instruments required for the vitrectomy with cataract surgery. These include the ‘cutter’ that is used to sever and remove the vitreous, as well as any other instruments which are required.
The next step in the vitrectomy component is to replace the fluid in your eye with air. While this is happening, you may hear a soft whistling sound. Sometimes gas is used instead of air, and this is dependent upon the condition being treated.
At the conclusion of the surgery, sometimes an injection of a low dose of steroid into the eye is given where the vitrectomy is for a macular condition. This has several advantages, including speeding up the healing rate and even potentially improving the surgery’s final result. However, it’s important to note that the injection has a risk of the pressure in the eye (intraocular pressure, or IOP) rising afterwards. If this occurs, laser or drops may be needed for several months, while a very small percentage of patients may need further surgery to control the IOP.
How Long Is The Combined Surgery?
The operation time for a vitrectomy with cataract surgery usually ranges from 30 to 40 minutes, but this is not an indication of how well the operation has gone. Depending upon the condition being treated, there may be additional components to the surgery which would add time to the overall length of the operation.
How Can I Avoid Complications After Surgery?
While any air remains in your eye after the operation (approximately one week), you must not go on an aeroplane or travel to any high altitude locations. If you do, this can make the bubble in your eye expand and cause the pressure in your eye to rise, leading to significant harm and pain. If gas has been used as part of the surgery instead of air, it will remain inside the eye for approximately 4-8 weeks, meaning the same restrictions apply but for a longer period of time.
For similar reasons, if you require any general anaesthetic following your combined surgery, it’s important to let the anaesthetist know that there may be air or gas in your eye.
To avoid complications, it’s recommended you wear the shield you’re provided with while you sleep. This shield is specially designed to prevent pressure being placed on the eye, such as accidentally rubbing it while you are sleeping.
Unlike cataract surgery on its own, your eye may take 6 or so weeks to settle (or sometimes longer depending upon your condition), so you should refrain from visiting your optometrist until you’re told you can.
What Happens After Combined Surgery?
At the end of the vitrectomy with cataract surgery, a pad and shield will be placed over your eye. This will stay on until the following day, when I will examine the eye.
Immediately after the operation, you will be placed within the recovery area. Here, the nurses will check your pulse, blood pressure and other vital signs. Despite your sedation, it’s likely that you’ll be fully awake by this time and ready for a drink and snack.
Once the nurses are satisfied that you’re feeling fine and are in a fit condition to leave, you will be escorted out of the recovery area to meet your friend or relative who is taking you home. You will also be given a prescription for eye drops that you should have filled at the chemist straightaway, as you will need to bring the drops with you when you return to the clinic the next day.
What Should I Expect After The Surgery?
While some surface irritation is normal, the operated eye should not be overly painful after the surgery. However, looking at bright lights may be uncomfortable, so wearing sunglasses in the sun is recommended.
Afterwards, your eye may also appear red, and you may notice a pinkish watery discharge on your bedding. It’s important to note that this is not a sign of any problem; it’s simply caused by tears mixing with blood on your eye’s surface.
Immediately after your combined surgery, and for several days following, you will not be able to see the bottom part of your visual field with the eye that was operated on. This is due to the bubble of air in your eye preventing light from focusing properly on the retina. However, once the air is slowly absorbed (within a week), you will start to notice your vision clear up, with a wobbly black or silver line at the top of the area that you can’t properly see. As time goes by, this line will decrease in size and you will find you’ll eventually only be able to see the bubble of air when looking downwards. Before the air completely disappears, you may see one or more circles in the bottom of your vision. The air takes roughly one week to be absorbed completely. If gas has been used during the operation, it will take longer than air to absorb, resulting in a longer period of these effects on your vision.
If you have a steroid injected into your eye at the end of the vitrectomy with cataract surgery, you may also see the steroid particles as black spots that float around above the bubble. These usually settle within a week.
What Should I Be Concerned About After Combined Surgery?
If you experience any of the symptoms below, or if you become concerned about any other matter after your vitrectomy with cataract surgery, you should get in touch with Dr Chauhan as soon as possible.
- Pain, particularly when it’s a deep aching pain.
- Your eye has become more uncomfortable, worsening since I last saw you.
- Your vision has declined since your last appointment. In particular, if the top part of your vision gets worse, you should see me urgently.
- A pus-like discharge has developed after the surgery. Please note that this requires urgent attention.
- You notice new floaters, flashes, 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 that might seem minor or ‘silly’ rather than wait until their next appointment. If there are any issues, 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 Combined Surgery?
The risks of a vitrectomy with 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 surgery.