Macular anterior membrane: Also known as the macular retinal anterior membrane. Since the 1930s, ophthalmologists have recognized macular surface folds caused by the anterior retina. The macular preretinal membrane has been referred to as idiopathic preretinal fibrosis of the macula, primary retinal folds, vitreous paper-like macular lesions, macular folds, secondary retinal gliosis, inner retinal boundary membrane folds, preretinal fibrous hyperplasia, and spontaneous retinal preretinal gliosis. These descriptions reflect the different degrees and characteristics of this disease that are recognized. Although in most cases the pre-macular rarely causes symptoms and progresses slowly, it can sometimes lead to significant vision loss and visual distortion. Classification: According to the different causes, it can be generally divided into secondary, idiopathic, congenital macular pre-macular, etc. 1, Secondary macular preretinopia: The preretinopia has been described to be associated with a variety of ocular conditions and diseases and can be seen in a variety of diseases, such as retinal detachment and retinal detachment surgery, retinal vein obstruction, diabetic retinopathy, various intraocular inflammatory diseases, retinal hemangioma, retinitis pigmentosa and other fundus diseases, ocular trauma and retinal photocoagulation and condensation. The macular preretinal membrane formed after retinal detachment is generally thicker and grayish, which obviously affects the recovery of vision, with an incidence of about 3%~8.5%. This macular preretinal membrane, also called macular pucker, can be regarded as a milder manifestation of proliferative vitreoretinopathy (PVR). 2, Idiopathic macular pucker: occurs in eyes without associated ocular abnormalities or medical history, the cause is unknown, it occurs in the elderly, and is considered an age-related proliferative disease. The incidence is about 5.5-12%, and more than 80% of patients are older than 50 years old. There is a tendency for the incidence to increase with age. Most patients are asymptomatic, and a minority have stable or slowly progressive visual impairment. Twenty to 30% of patients have bilateral onset, but most have unequal degrees of clinical manifestations in both eyes. Most patients are asymptomatic, have good visual acuity, and progress slowly. Posterior vitreous detachment is present in 57% to 90% of patients with idiopathic macular anterior membrane. For eyes with partial posterior vitreous detachment, when the vitreous is completely separated from the retinal surface, spontaneous detachment of the membrane may occur and symptoms may be relieved, but the incidence does not exceed 1%. 3, congenital macular anterior membrane: It is relatively rare, mostly seen in young people, and is an important cause of low vision in adolescents. Histopathological features: it is mainly composed of cells and various collagen components. It is generally believed that the cells in this membrane are mainly derived from retinal glial cells and retinal pigment epithelial cells, in addition to other types of cells that may be present, such as: fibrous astrocytes, fibroblasts, myofibroblasts, macrophages, microglia, and vitreous cells. The collagen composition of the pre-macular membrane also varies greatly, with some containing all type I, II, III, IV collagen and fibronectin, while others contain only type II collagen fibers. Pathophysiological changes The contraction of the intracellular components of the anterior macula causes the retina to be stretched to form folds of different morphology. The central macular recess is tugged and will be deformed and displaced. The small blood vessels around the macula will be tugged and compressed by the macular anterior membrane, resulting in dilatation, deformation, venous reflux obstruction and reduced blood flow velocity of macular capillaries, which will lead to vascular leakage and bleeding spot. Clinical symptoms such as distortion, enlargement or narrowing of vision and visual fatigue may occur. If the macular pre-macular formation is accompanied by vitreous macular traction, it will easily produce macular cystoid edema and even lamellar macular hole. Clinical manifestations Symptoms: The common symptoms of macular pre-macular are: vision loss, too small vision, vision distortion Early stage can be asymptomatic, when the macular pre-macular affects the central macular sulcus there are vision changes. Visual acuity is usually mild or moderate, rarely below 0.1. When macular edema or folds are present, it can cause significant vision loss or visual distortion, and a few patients may notice diplopia or central flashes. The causes of the affected visual function include the following: (1) the cloudy and dense macular anterior membrane obscures the central concave area; (2) the macular area is deformed by traction and the central concave is displaced; (3) retinal vascular leakage and macular edema; (4) local retinal ischemia and axial plasma flow stagnation due to the traction of the macular anterior membrane. It is believed that the severity of the symptoms is related to the type of macular anterior membrane. If the macular anterior membrane is thin, 95% of the affected eyes can maintain visual acuity of 0.1 or more, and the usual visual acuity is about 0.4. Sometimes, when the vitreous is completely posteriorly detached and the pre-macular membrane is separated from the retina, the symptoms can relieve themselves and the vision is restored, but this is relatively rare. Signs: It varies according to the severity of the membrane. 1. Mild. The macular area has cellophane reflection, mildly tortuous blood vessels, and no obvious change or mild loss of vision. This “cellophane” thin anterior membrane may only be seen by careful fundus examination, and usually there is no obvious boundary. 2. Moderate. Folds and streaks are visible under the anterior membrane, pulling the inner layer of the retina. Visual acuity is usually 0.3~0.6. 3, Severe. FFA may have fluorescence leakage and macular edema. Auxiliary examinations 1.Fluorescence angiography (FFA): It helps to show the degree of retinal vascular flexure and the extent of anterior membrane, accurately evaluate the degree of retinal vascular leakage and macular edema, identify macular fissure, determine the existence of subretinal neovascularization and macular ischemic lesion, and suggest prognosis. 2.Optical coherence tomography (OCT): It can determine the contour change of the central recess and the retinal thickness change, accurately determine the existence of retinal cleft or macular edema, and also quantitatively assess the preoperative thickness of the macular prepopulation and the postoperative recovery. Treatment 1. Regular observation. Most of them have good vision and do not need surgical treatment. 2.Drug treatment is not effective. 3.Severe patients can be treated with vitrectomy to remove the anterior membrane. The purpose of surgery is to loosen the pull caused by the anterior macular membrane, but not all cases can improve vision through surgery. The indications for surgery vary from person to person and are usually only used in cases of significant vision loss. Surgery may be considered if the complaint of diplopia or distortion of vision is significant and interferes with daily work, even if there is still good visual acuity. For secondary macular anterior membrane after retinal detachment, we usually wait until 2-3 months later when the anterior membrane proliferation is stable and there is no active contraction for reoperation. In some cases with better vision but FFA showing fluorescence leakage and macular edema, surgery also helps to restore vision. A careful examination must be performed before surgery to determine if the vision loss is caused by the membrane or if there is some other retinal pathological condition, such as early macular fissure, choroidal neovascularization, macular capillary dilatation, cataract, macular ischemia, and tumor. The presence of peripheral retinal vasculopathy and abnormalities such as peripheral fissure or lattice-like degeneration should also be noted. Postoperative complications 1. Cataract: The most common, the longer the follow-up, the higher the incidence. In many cases, vision improves for a few months, and then vision begins to slowly decline due to increased density of the crystal nucleus and cortical clouding. Usually, cataract surgery is required to experience the best post-operative vision. 2.Retinal hemorrhage: Intraoperative stripping of the anterior membrane is often accompanied by a small amount of hemorrhage in the posterior pole. 3.Retinal fissure: occurs in 1% to 6% of cases, almost all in the peripheral part. Retinal detachment: Retinal detachment can occur in about 1%~7% of operated eyes after surgery and requires timely reoperation. Prognosis of surgery 1. related to the timing of surgery 2. related to macular function 3. postoperative macular precorneal recurrence Although vitrectomy surgery to peel away the macular precorneal provides an excellent opportunity for vision improvement, patients and their families must understand that complications can occur with surgery and cause poor vision, requiring reoperation or even loss of the eye. Individuals must weigh the risks and benefits and determine whether surgery is the best course of action.