Vitreomacular adhesion (VMA) is an eye condition where the gel-like substance filling the eye, known as the vitreous, remains abnormally attached to the macula. The macula is a specialized area within the retina, the light-sensitive tissue lining the back of the eye. This unusual attachment can exert pulling forces on the macula, potentially affecting central vision.
Understanding Vitreomacular Adhesion
The vitreous is a clear, jelly-like substance that fills the space between the lens and the retina, making up about 80% of the eye’s volume. As individuals age, typically starting in their 50s or 60s, the vitreous gel begins to liquefy and shrink. This natural process usually leads to the vitreous detaching cleanly from the retina, a phenomenon known as posterior vitreous detachment. However, in vitreomacular adhesion (VMA), this separation is incomplete, and the vitreous remains abnormally attached to the macula.
This persistent attachment often occurs because the vitreous gel fails to fully separate from the fovea, the very center of the macula responsible for sharp, detailed vision. The composition of the vitreous changes with age, becoming more liquid and less gel-like, which can lead to areas of stronger adhesion where it remains connected to the retinal surface. This condition is frequently observed in older individuals, particularly those over 70 years of age. VMA is also more commonly found in women and individuals with nearsightedness.
Recognizing Symptoms and Potential Complications
Individuals experiencing vitreomacular adhesion might notice several changes in their vision, particularly if the pulling force becomes significant. Common symptoms include a decrease in the sharpness of central vision, making it difficult to read or recognize faces. Some people report experiencing metamorphopsia, a distortion of straight lines, making them appear wavy or bent. Another symptom can be micropsia, where objects appear smaller than they actually are, affecting depth perception.
Vitreomacular adhesion (VMA) refers to the anatomical attachment itself, which may not always cause symptoms. Vitreomacular traction (VMT), on the other hand, occurs when the pulling forces exerted by the vitreous on the macula are strong enough to cause structural changes or damage to the retinal tissue. This persistent pulling can lead to severe ocular damage over time.
Sustained traction from VMT can contribute to the development of other serious eye conditions. One such complication is a macular hole, a small break or tear that forms in the macula, significantly impairing central vision. Another potential complication is macular pucker, also known as an epiretinal membrane, where a thin layer of scar tissue forms on the surface of the macula, causing vision distortion and blurriness. These complications arise from the mechanical stress placed on the delicate retinal structures by the adherent vitreous.
Diagnosing the Condition
Diagnosing vitreomacular adhesion typically involves a comprehensive eye examination by an eye care professional. During this examination, the ophthalmologist will inspect the back of the eye, particularly the macula, to identify any signs of vitreous attachment or retinal changes. This initial assessment helps in understanding the general health of the retina and optic nerve.
A specialized imaging technology called Optical Coherence Tomography (OCT) is valuable in confirming the diagnosis. OCT uses light waves to create cross-sectional images of the retina, providing detailed views of its layers and the vitreous-retinal interface. This imaging allows the doctor to visualize the precise location and extent of the vitreous attachment to the macula. OCT is also instrumental in differentiating between vitreomacular adhesion, where there is an attachment without significant retinal distortion, and vitreomacular traction, where the pulling is causing measurable structural changes to the macula.
Treatment Approaches
The approach to managing vitreomacular adhesion depends on the presence and severity of symptoms and any resulting complications. For individuals with mild or asymptomatic vitreomacular adhesion, observation is often the initial strategy. Regular monitoring allows the eye care professional to track the condition’s progression and intervene if vision begins to decline or complications arise. Many cases of VMA resolve spontaneously as the vitreous eventually detaches on its own.
For symptomatic vitreomacular traction, medical treatment can be considered. An injected medication called ocriplasmin, marketed as Jetrea, is approved for dissolving the vitreomacular adhesion. This enzyme works by breaking down the proteins that create the abnormal attachment between the vitreous and the macula, potentially releasing the traction and improving symptoms. The medication is delivered directly into the eye through an injection.
Surgical intervention, vitrectomy, is generally reserved for severe cases of vitreomacular traction, especially when it leads to significant vision loss or complications like macular holes. During a vitrectomy, the surgeon removes the vitreous gel from the eye. This procedure eliminates the pulling force on the macula, allowing the retina to relax and heal. After vitreous removal, the eye is typically filled with a saline solution or gas bubble to maintain its shape.