This is the process of removing the vitreous from the eye. It is a procedure which may become more common in the future as methods of intraocular drug releasing devices are developed.
The vitreous is a jelly like substance which fills the cavity of the eye from the back of the lens to the front of the retina. It has loose attachments to the retina in places. One of the normal processes of aging is the vitreous becoming liquefied. It is this change in the vitreous which leads to posterior vitreous detachment.
While this is happening, floaters and flashing lights may be seen on the edge of vision. People without uveitis are monitored after a diagnosis of PVD, when there is concern that the vitreous detachment is incomplete, and the remaining attached vitreous is tugging on the retina posing a possibility of retinal detachment or tear. It is rare for this to happen and most people simply have to learn to live with the floaters, specks and cobwebs and hope they disappear quickly.
Posterior vitreous detachment is also found in the uveitic eye, particularly in the over fifties and the very short sighted. Your doctor will tell you what has caused your floaters, flashes, cobwebs and dots, and, while PVD might be responsible for a bit of what swirls around in the uveitic eye, the consequences of inflammation will most likely account for far more.
Information about PVD can be found here:
The symptoms of some serious life threatening conditions and some infections sometimes appear like the symptoms of auto-immune uveitis. If the uveitis does not respond to treatment, or a uveitis specialist suspects there is something else behind the uveitis, (masquerade syndrome) a diagnostic aspiration may be performed.
In this, a small sample of the vitreous is removed by using a needle and syringe. This is an outpatient procedure. A diagnostic vitrectomy is a more complicated procedure and since it may also have a therapeutic benefit to the patient, it is described in the next section.
Increasingly, researchers are working at the molecular level in order to understand uveitis better. It may become more common for samples to be collected from various parts of the eye to be used to aid diagnosis, and to guide therapy for the different uveitis entities.
A therapeutic vitrectomy is mostly carried out for posterior and intermediate uveitis. People with these conditions may have vitritis, vitreous haemorrhage, epiretinal membranes, cystoid macular oedema which has not responded to medical therapy, and the amount of debris in the vitreous may be impairing vision.
In cases of intermediate uveitis, the removal of the vitreous brings with it the removal of inflammatory cells causing the problem and in some cases, this might bring the inflammation to a stop.
There are two types of vitrectomy: anterior vitrectomy and pars plana vitrectomy. Intermediate uveitis patients are likely to have a pars plana vitrectomy. Whichever type is chosen, a vitrectomy will leave behind some of the vitreous and the part that is removed will be refilled naturally, over time, by the eye.
There are various methods of refilling the cavity left behind to keep the retina in place while the eye produces new fluid to do this job and your doctor should be able to tell you in advance which will be used in your case. Some eyes will also need a scleral buckle to secure the retina in place.
Unless serious retinal damage has occurred and this is the reason for the vitrectomy, many uveitis patients will not be required to undergo the posturing described in patient information sources about vitrectomy. These days, it is also possible to have a suture-less vitrectomy, so the irritation of stitches to close the entries into the vitreous is removed. The operation can be performed using local or general anaesthetic.
Vitrectomy may cause cataract and it is possible to combine vitrectomy with cataract surgery. When these operations are combined, control of inflammation pre and post operatively is essential.
This writer has had vitrectomies combined with cataract surgery in both eyes, experienced a very short lived headache post operatively, enjoyed wonderfully clear vision the next day and the eyes concerned didn’t even look as though they’d been touched, let alone undergone surgery.