What is vitreous?
Vitreous, sometimes called the vitreous humour, is a slightly sticky type of gel that fills the main cavity of the eyeball, behind the natural lens of the eye.
What is a vitrectomy?
A vitrectomy (or full name, pars plana vitrectomy) is an operation to remove the vitreous gel from the eye. The gel is not actually needed by the eye and is replaced during the operation by fluid. This operation is usually performed – in conjunction with other surgical manoeuvres – in order to treat a specific condition, such as:
- retinal detachment
- macular hole
- epiretinal membrane
- vitreous haemorrhage
- advanced diabetic retinopathy
What anaesthesia is used?
Most patients can safely undergo vitrectomy under local anaesthesia, but sometimes general anaesthesia is preferred, depending on the exact eye condition, surgery planned, and a patient’s general health.
How long does a vitrectomy take?
There are many different things that a vitreoretinal surgeon may wish to achieve during a vitrectomy, such that the surgical time can vary considerably – from 30 minutes for straightforward cases, up to 2 hours for more complex conditions.
What sort of other surgical manoeuvres can occur during a vitrectomy?
- Peeling of an epiretinal membrane
- Peeling of the internal limiting membrane – in macular hole surgery
- Filling the vitreous cavity with gas or oil (see below)
- Cataract surgery – sometimes combined with vitrectomy
- Laser photocoagulation to the retina – for example in retinal detachment, diabetic eye disease, or retinal vein occlusion
- Retinal cryopexy – to seal off a break in the retina
What are the risks of vitrectomy?
Modern small-gauge vitrectomy is a safe operation and serious complications are very rare. They include infection or bleed in the eye, swelling of the macula, and retinal detachment. Any or all of these conditions could cause loss of vision and/or necessitate further treatments or surgery. Another consideration is that vitrectomy tends to accelerate cataract development (if the eye has not previously had cataract surgery). Cataract surgery is even safer than vitrectomy however, and can in some cases be combined with the vitrectomy in a single operation.
What happens if the eye is filled with gas?
The optics of the eye don’t work through gas, so you will initially see very little (just light and dark). As the gas slowly absorbs from the eye and is replaced with the eye’s natural fluid, you will see the meniscus between fluid and air which jiggles around as the eye moves. Eventually all the gas absorbs, but the time taken depends on which gas is used, and varies from a few days (for air) up to 3 months (for the longest acting gas). With gas in your eye, you are not allowed to fly, as the gas would expand at high altitude and cause visual loss. You should be given a wristband in theatre to warn anaesthetists not to administer a certain type of anaesthetic while your eye contains gas.
What happens if the eye is filled with oil?
Silicone oil is almost exclusively used to manage complex or recurrent retinal detachments, with rare uses in diabetic retinopathy and certain types of macular hole. You are allowed to fly with an oil-filled eye, but as the oil is not absorbed by the body, you need a future operation to remove the oil.
Do all eye surgeons or hospitals offer vitrectomy?
Most eye surgeons do not perform pars plana vitrectomy as it requires a period of sub-specialist or fellowship training in retinal surgery. Mr Shah undertook a retinal fellowship where for a year he underwent intensive training in vitrectomy surgery, and has performed several hundred vitrectomies to date. Vitrectomy surgery requires a large amount of extra surgical equipment including dedicated viewing systems. Mr Shah has worked closely with the theatre staff to ensure that the relevant equipment is available on Jersey. In particular, in late 2014 the latest and most advanced surgical viewing system available for vitreoretinal surgeons, the Re-Sight 700 manufactured by Carl Zeiss, was installed at the Jersey General Hospital.