A vitrectomy is an operation to remove the vitreous humor, a clear, transparent jelly from inside the eye. The vitreous humor is situated behind the iris, the coloured part of the eye and in front of the retina, at the back of the eye). It has no real function other than providing packaging inside the eye.
Why is a vitrectomy done?
The general indication for a vitrectomy are:
- Diabetic vitreous haemorrhage
- Retinal detachment
- Epiretinal membrane
- Macular hole
- Proliferative vitreoretinopathy
- Intraocular foreign body removal
- Retrieval of lens nucleus following complicated cataract surgery
The Vitrectomy Procedure
The vitrectomy procedure is usually done with a local anaesthetic however sometimes a full (general) anaesthetic may be needed in certain circumstances.
The surgeon makes three tiny incisions in the eye for three separate instruments. These incisions are placed in the pars plana of the eye, which is located just behind the iris but in front of the retina. The instruments which pass through these incisions include a light pipe, an infusion port, and the vitrectomy cutting device. The light pipe is the equivalent of a microscopic high-intensity flashlight for use within the eye. The infusion port is required to replace fluid in the eye and maintain proper pressure within the eye. The vitrector, or cutting device, removes the vitreous gel in a gentle and controlled fashion. This prevents significant traction on the retina during the removal of the vitreous so no further damage to the retina is done. The procedure can take 1-2 hours depending on the reason for surgery. Once the jelly is removed the retina is repaired if necessary, any foreign bodies removed and, in the case of diabetics, any leaking blood vessels are sealed.
Does the vitreous jelly get replaced?
No, the jelly does not naturally replace itself. The eye maybe filled with various materials at the end of surgery:
- Gas bubble (this is absorbed in about 2 months).
- Transparent oil which is not absorbed and is surgically removed at a future date.
- Air (absorbed within a week).
The eye produces its own clear fluid known as aqueous humor which, as the gas or air is absorbed, will gradually fill the vitreous chamber.
A vitrectomy is an extraordinary advance in the management of a variety of ocular conditions involving the retina and vitreous humor of the eye. The procedure has a good success rate and complications are relatively unusual. However, bleeding, infection, progression of cataract, and retinal detachment (about 1 in 20) are potential complications with this surgical procedure. Most patients who undergo a vitrectomy will need cataract surgery in the future, earlier than they otherwise would have. There is a very rare chance of developing an inflammation in the fellow eye (unoperated eye) after such a procedure, this is called sympathetic ophthalmitis. For the vast majority of patients who undergo a vitrectomy, there is a good prospect of some improvement in vision. The procedure is another marvel of modern medicine for patients with conditions that might otherwise be blinding, however the visual results are often limited by the underlying disease process.
What to Expect After Your Vitrectomy Procedure
Your rate of recovery will depend on many factors, however, the preoperative condition for which the vitrectomy was performed is the most important factor determining your rate of recovery as well as your final outcome. Your eye surgeon can advise you as to what to expect. Follow your surgeon’s advice carefully. In general, don’t expect your final visual outcome for a few weeks, at the very least. Patients are usually able to return to normal activity within a few weeks. Most of the healing occurs during the first month, but full visual recovery may take a few months.
- Expect your eye to be sensitive, swollen and red due to the nature of surgery. A scratchy feeling or occasional sharp pain is normal. Ice compresses gently placed on the swollen areas may help reduce the aching and soreness. Redness is common and gradually diminishes over time. You may notice a patch of blood on the outside of the eye. This is similar to bruising on the skin and slowly resolves on its own.
- If you have a deep ache or throbbing pain that does not respond to over-the-counter pain medication, please contact your surgeon urgently.
- You will be prescribed a combination of eye drops to instil on discharge home. These will help to prevent infection, reduce inflammation and rest the eye following your surgery. Drops to lower the pressure in the eye are also sometimes necessary. These will be required for several weeks.
- If gas or oil has been inserted into the eye, usually for retinal detachment surgery, you will be advised to position with your head tilted downwards. This helps to ensure that the gas or oil is lying against the area of retina which has detached encouraging it to heal in the correct place. You will be required to follow this instruction for at least 7-10 days, 50 minutes out of every hour during the day. At night whilst in bed, try to lie on your front as much as possible.
- You will have a follow up appointment in 1-2 weeks following surgery. Further appointments will be needed less frequently for a few months beyond.
If a gas bubble is inserted at operation:
When the eye is filled with gas, the vision is very poor. Patients can sometimes see better, though, while looking straight downward and holding an object just a couple of inches from the eye. As the gas bubble becomes smaller, the patient will see it shrinking towards the bottom of the field of vision. It may cause glare and double vision, especially when it is about halfway reabsorbed. When the bubble becomes rather small, it tends to break up into a few smaller bubbles before disappearing altogether.
Certain precautions should be observed when there is a gas bubble in the eye. First of all, the patient must maintain the head position recommended by their doctor. In most cases, this means looking straight downward, or lying on one side. Patients should avoid looking upward or lying on their back for any significant period of time, to minimize anterior movement of the bubble, which can accelerate cataract formation, raise intraocular pressure, or damage the cornea. Finally, patients must avoid flying with an air or gas bubble in the eye. The reduced atmospheric pressure causes the gas bubble to expand, which can raise the pressure in the eye to dangerous levels.
If an oil bubble is placed in your eye: Silicone oil is a clear, viscous fluid which is used in some patients instead of a gas bubble. It has some advantages over long-acting gas: quicker visual recovery, no restriction on air travel, less need for head positioning after surgery, and longer duration of effect. Unlike gas, however, silicone oil is not removed from the eye by your body; it must be removed in a second surgery.
Please feel free to ask any questions or discuss any concerns.