- text, this page
- animation VMT
Vitreo-macular traction (VMT) & vitreomacular adhesion (VMA)
In this condition the vitreous gel shrinks and detaches from the back of the eye (the retina), a bit like a regular PVD (posterior vitreous detachment). A regular PVD is more or less a normal aging change. But unlike a PVD, the vitreous gel remains stuck to the macula in the centre, and pulls it. This may cause some distortion of central vision.
The 'VMT' is normally temporary
- there is a 90% chance of the vitreous will completely detach (PVD posterior vitreous detachment) leading to stable good vision. VMT animation.
- there is also a ~10% chance of developing a complete macular hole, with some loss of sight (surgery may be needed). This occurs when the vitreous pulls the retina in the foveal area to the extent that it creates a hole.
- BJO 15 40% resolve, most within 1 year, and it is very common as we get older Retina 18
- Retina 16 20% resolve, 8% get worse
Cause of the VMT
The VMT is linked to posterior vitreous detachment formation, when the vitreous gel shrinks. Normally the gel separates completely from the retina, but in this condition the back face of the gel remains stuck to the retina, in the foveal area. It may folow antiVEGF treatment. Eye 17
Types of VMT
- about 10% 'V' type (A) or 'U' type (E) VMT patients develop a fill thickness macular hole
- 25% of patients with VMT have complete resolution of the VMT without treatment...these are generally the 'V type' attachment patients
- 70% of patients who do develop a macular hole have a yellow spot visible at the fovea Eye14
- the 'broad attachment' type (D) may be associated with an ERM (epriretinal membrane) (not a macula hole)
If the VMT does persist and the distortion is really annoying then vitrectomy can help. 4 out of 5 patients with a little distortion (mild VMT) do not wish to have surgery, and prefer to accept their condition.
Vitreomacular adhesion (VMA)
VMA is more common is common: the vitreous lies against the macula, perhaps pulling gently, but the patients does not notice any distortion of vision. It is termed VMT vitreomacular traction when the vitreous is actually pulling the macula, and the patient notices distortion, seeing crooked lines.
Retina 14 ..observation favourable.
Surgery is not needed if vision is good
If a patient has VMA VMT, or a small macular hole but has no symptoms, the condition should be accepted.
a normal 'PVD': the vitreous detaches without pulling any of the retina., The space behind the vitreous becomes with a fluid rather than a gel.
VMT..the vitreous has detached and is pulling the macula area of the retina in the centre.
A new treatment is available. An enzyme (chemical) in injected into the vitreous, and breaks it down, so the traction bands pulling on the retina disappear. The retina then flattens and vision improves. The treatment may not work, but if it is effective, the benefit is permanent, and the injection is only needed once. £3000 each injection
- NEJM 2012
- Medical Express 2012
- insufficient Eye 2013
- various papers Retina 13 vitrectomy Retina 13 myopic Retina 13
In the study Mivi-606-7, Ocriplasmin may help (NICE 2013) but is not yet recommended. It is injected into the vitreous, and causes a PVD. Symptoms of flashes and floaters in crease for a short while and then reduces, and the vitreous detaches from the macula, and the distortion disappears.
It is most effective (86% best),
- the area of VMA <1500µ
- small holes <400µ
- measure size at narrowest point
- it usually takes <1 week to work.
- service/pathway Eye14.
- for macular holes, the lower the 'width factor' : defined as the base diameter (BD), minus the minimum linear diameter (MLD) in μm. The smaller this ‘width factor’ resulted in the Orciplasmin being more likely to be effective see. Eye 16
But if these parameters are not present the effectiveness is considerably reduced (eg myopia). Small holes close (60% at best), large (6%.) If successful, patients notice PVD symptoms, photopsia & floaters. Some patients get fluid under fovea with blurred sight, which resolves over time.
Response to orchiplasmin is dependant on the angle of vitreous adhesion
- age 60
- 2 weeks, tiny amount of distortion in very central vision..excellent 6/6 vision
- noticed by patient; resolved spontaneously after 4 weeks.. no treatment was needed
- cyst was caused by the vitreous detaching (a type of age change VMT animation)
small foveal cyst with a detached operculum
Tractional Cystoid Macular Oedema see Retina 2012