The macula is the central part of retina. With a diameter of about 5.5 mm, the macula takes up only about 5% of the total area of the retina but boasts the highest concentration of photoreceptor cells. With ageing, the vitreous liquefies, shrinks and pulls away from the retinal surface. If the degenerating vitreous has an abnormal attachment to the retina, or if fibrosis occurs on the retinal surface, maculopathies such as macular hole or epiretinal membrane may develop.
Most macular holes are spontaneous, with some cases related to high myopia, eye injury (including light-induced injury), and cystoid macular edema. While most epiretinal membranes do not have an apparent cause, factors such as retinal injury, inflammation, ocular vascular disease, diabetic retinopathy, and previous eye surgery or laser treatment may contribute to disease development.
Patients with macular degeneration generally experience blurriness or distortion in central vision. Ophthalmologists need to thoroughly assess of the macular anatomy with the help of optical coherence tomography, and select suitable patients for surgical treatment.
Macular holes and epiretinal membranes are treated through minimally invasive surgery. Under the surgical microscope, the ophthalmologist removes the degenerative vitreous, and carefully peels off theinternal limiting membrane andassociated fibrous membrane to relieve traction on the macula. Patients with severe macular holes may be treated with an inverted limiting membrane flap that covers and bridges over the macular hole. At the conclusion of surgery, the surgeon usually injects a gas bubble to tamponade the macular hole and facilitate hole closure.
Most patients will experience improvement in their vision after surgery. A shorter duration of disease is associated with better prognosis. Therefore, if one experiences symptoms of macular degeneration, such as blurry or distorted central vision, it is important to seek early medical advice from an eye doctor in order to avoid permanent visual damage.