Subretinal neovascular membrane

Introduction to subretinal neovascular membrane The subretinal neovascularization membrane (mare) is a fibrous vascular tissue formed by choroidal neovascularization of multiple choroids across the Bruch membrane and proliferating under and/or on the retinal pigment epithelium, often accompanied by subretinal Serous exudation and/or bleeding is the leading cause of vision loss in a variety of fundus diseases. basic knowledge The proportion of illness: 0.001% Susceptible people: no special people Mode of infection: non-infectious Complications: retinal detachment

Subretinal neovascular membrane etiology

(1) Causes of the disease

SRNVM can occur in many retinal diseases and diseases, including senile macular degeneration (SMD), also known as age-related macular degeneration (ARMD), senile macular degeneration. The main course of the disease is the development and outcome of the choroidal neovascular membrane. In addition, high myopia, vascular streak, traumatic choroidal laceration and ocular cytoplasmic disease are also common, Best disease, acute posterior Severe squamous pigment epithelial lesions, chronic uveitis, Harada disease, chronic choroiditis, toxoplasmosis, sickle cell anemia, Paget's disease, choroidal fistula, choroidal neoplasms and excessive laser photocoagulation There are often choroidal neovascular membrane complications.

(two) pathogenesis

The exact mechanism of subretinal neovascularization is unclear. The choroidal vessels with thick venous vessels at the posterior fundus are large, blood flow is large, and the choroidal anterior small arteries are often in a high pressure state, which is an anatomical factor for the angiogenesis of neovascular membranes. A common feature of neovascular membrane fundus disease is the presence of Bruch membrane rupture, which is a prerequisite for the production of neovascular membranes. The imbalance of local tissue neovascularization stimulating factors and inhibitors is the key to the production of neovascular membranes. The factors found to stimulate blood vessel growth include: vascular endothelial growth factor (VEGF), acidic fibroblast growth factor (aFGF), basic fibroblast growth factor (basic fibroblast growth factor, bFGF), interlukin-8, insulin-like growth factor and hepatocyte-growth factor, have been found to inhibit angiogenesis by transforming growth factor ( Transforming growth factor beta, TGF-) and thromboxane (thr Ombopondin), the normal retinal pigment epithelium forms the outer barrier of the retina, the Bruch membrane becomes a barrier separating the choroid and the retina, and the local tissue neovascularization stimulating factor and inhibitor are in a dynamic equilibrium state. When the retinal vein venous deficiencies O2, the retinal pigment epithelium is damaged. Inflammation, Drusen or Bruch's membrane damage (denaturation, thickening, rupture) occurs, this dynamic equilibrium state is broken, local tissue angiogenesis stimulating factors predominate, sputum forms neovascular membrane, new blood vessel membrane occurs after it Special form.

Subretinal neovascular membrane prevention

Emphasis on active treatment of primary disease.

Subretinal neovascular membrane complications Complications

Localized retinal detachment is associated with leakage of neovascularization.

Subretinal neovascular membrane symptoms Common symptoms Central dark spots and flexion... Visual impairment

Vision loss, visual distortion and dark spots at the center or side center.

There is an irregular round-like lesion in the fovea of the macula or in the center of the fovea. It is grayish white or yellowish white. It is located under the nerve epithelium. There are bleeding and anti-halation around the lesion or surface. The slit lamp is examined under the microscope. The extra-membrane band is moved forward, and the two tangents are separated before and after, and there is effusion in between, indicating that the neuroepithelial serous detachment, the hemorrhage may be located under the pigment epithelium, under the nerve epithelium or in the neuroepithelial, in a point-like manner. It is located on or around the surface of the gray-white lesion. Some patients have different degrees of pigmentation (proliferation or loss) and hard exudation. There are cystic degeneration of the neuroepithelial around the lesion and the macular part produced by the proliferation of the membrane. Shrinking scars, occasionally choroidal neovascular membranes appear at the edge of the optic disc, observed under the stereoscopic eyes of both eyes, neuroepithelial uplift, under the subretinal slurry accumulation.

Examination of subretinal neovascular membrane

The necessary laboratory tests can be performed for the cause.

1. Fundus fluorescein angiography:

In the early stage of angiography (pre-arterial or arterial phase), fluorescence filling occurs (most of the retinal neovascularization is developed in the early stage of the vein), and the neovascular morphology is lace-like, elliptical, petal-like, patchy and gross vascular morphology. Fluorescence enhancement of the choroidal background, fluorescein leakage in the neovascularization, fusion with each other, blurred edges and leakage to the periphery, and a strong fluorescent region formed in the late stage can delineate the morphology of the accumulated cavity, after the background fluorescence of the contrast is resolved, The lesions still showed relatively strong fluorescence, and the leakage of the neuroepithelial serous detachment showed a slight fluorescence, which could outline the extent of the lesion, and the bleeding site always blocked the choroidal background fluorescence.

2. Biological microscopy:

Can be checked by ophthalmoscope, three-sided contact lens, Hruby mirror, indirect ophthalmoscope, slit lamp indirect ophthalmoscope, early neovascular membrane is grayish blue or yellowish plaque, surrounded by ring bleeding, late neovascular membrane fiber Tissue hyperplasia is grayish white, often disc-shaped, varying in size, often with ring or irregular bleeding, retinal edema, or intra- or sub-retinal or radial exudation, secondary to retinal pigment epithelium or retina Neuroepithelial serous or hemorrhagic detachment may also occur with a circular change in the pigment epithelium.

Diagnosis and differentiation of subretinal neovascular membrane

diagnosis

It is easier to diagnose according to fundus findings and angiography.

Judging whether the neovascular membrane is confined to the RPE, or has grown into the neuroepithelial, it can also be identified on the fluoroscopy. Because the adhesion between the RPE and the glass membrane is tight, the RPE is steeper than the edge, so the newborn under the RPE The vascular or fluid volume is in a "restricted" state, and the leaked dye is confined in the RPE out of the cavity, forming a strong fluorescent region with sharp edges, and the size of the leaking region is basically the same as the range of the new blood vessel. The blood vessels pass through the RPE and enter the neuroepithelial. Because of the loose connection between the two layers of tissue, there is a potential gap. The new blood vessels can grow in the form of vines, and the accumulated liquid is also unclear, showing a strong fluorescent area with a feathery appearance.

Differential diagnosis

If there is a subretinal hematoma, it can be identified by B-ultrasound and choroidal melanoma.

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