Vitreomacular traction (VMT) is an eye condition where the vitreous, a gel-like substance filling the eye, exerts an abnormal pulling force on the macula. The macula is a small, central area of the retina responsible for sharp, detailed central vision. This pulling can distort the macula’s normal shape, affecting vision.
Understanding Vitreomacular Traction
The eye contains a clear, jelly-like substance called the vitreous humor, which fills the space between the lens and the retina. As people age, the vitreous naturally undergoes changes, often shrinking and separating from the retina in a process known as posterior vitreous detachment (PVD). This is a common and typically harmless part of aging, occurring in most individuals by age 70.
Vitreomacular traction occurs when this natural detachment is incomplete, and a part of the vitreous remains abnormally attached to the macula. The pulling on the macula can lead to various visual disturbances. Symptoms include distorted vision, where straight lines might appear wavy or bent, blurred central vision, or flashes of light (photopsia). Some may also experience objects appearing smaller (micropsia) or decreased vision sharpness.
Diagnosis of VMT typically involves an examination by an eye care professional, often confirmed through specialized imaging. Optical Coherence Tomography (OCT) is the most common diagnostic tool, which uses light waves to create detailed cross-sectional images of the retina. OCT allows visualization of the vitreomacular interface and assessment of the traction’s extent and any associated structural changes to the macula.
The Likelihood of Spontaneous Resolution
Vitreomacular traction can resolve spontaneously, meaning the vitreous detaches from the macula without intervention. This occurs as the vitreous gel continues to shrink and releases its grip on the macula. The rate varies, ranging from 10% to 40% of cases. Resolution can take up to 18 months or even longer.
Several factors influence the probability of spontaneous resolution. A smaller diameter of vitreous attachment to the macula is associated with a higher chance of resolution. Traction that causes only inner retinal distortion, without involving the outer retinal layers, also increases the likelihood of spontaneous release. Younger age can also increase the chance of resolution.
The presence of an epiretinal membrane, which is scar tissue on the macula, can reduce the likelihood of spontaneous resolution. If the traction is widespread or involves significant structural changes to the macula, spontaneous resolution becomes less probable. When spontaneous resolution occurs, it is often due to a complete posterior vitreous detachment, allowing the macula to return to a more normal position.
Approaches When Resolution Doesn’t Occur
When VMT does not resolve or causes significant visual symptoms, various management approaches are considered. Persistent VMT can lead to complications, including the formation of a macular hole, which is a small tear in the macula, or cystoid macular edema, characterized by swelling due to fluid accumulation in the macula. Macular pucker, where scar tissue builds up and distorts vision, can also develop.
For mild cases with minimal or no impact on vision, observation is a common initial approach. Regular monitoring with OCT scans helps track the condition’s progression and visual changes. If symptoms worsen or complications arise, more active interventions may be considered.
Pharmacologic vitreolysis involves injecting a medication into the eye to help release the vitreous from the macula. Ocriplasmin is one such drug, dissolving the adhesion between the vitreous and macula to relieve traction. This treatment is reserved for select cases, particularly when the vitreous attachment is focal and without an epiretinal membrane. Pneumatic vitreolysis involves injecting a small gas bubble into the eye, which can help to mechanically separate the vitreous from the retina.
Surgical intervention, known as vitrectomy, is often recommended for more severe cases or when other treatments are not suitable or effective. During a vitrectomy, the surgeon removes the vitreous gel from the eye, relieving the pulling force on the macula. This procedure may also involve peeling away scar tissue on the macula and placing a gas bubble in the eye to support healing. The choice of treatment depends on the severity of symptoms, the extent of the traction, and the presence of any associated macular damage.