Choroid tumor are a group of pathological formations of the vascular wall, which includes nevus, uveal melanoma and hemangioma. There are no clinical symptoms for a long period of time. Decreased visual acuity and strabismus occur only with an increase in the diameter of the neoplasm. Diagnosis of choroid tumors is based on ophthalmoscopy, visometry, biomicroscopy, OCT, ultrasound. Depending on the form of the disease, treatment tactics are reduced to laser coagulation, cryotherapy, brachytherapy, photodynamic therapy, transpupillary thermotherapy. In the absence of an effect or a large size of the choroid tumor, enucleation is indicated.
General information
Choroid tumor are benign or malignant neoplasms of the vascular membrane of the eyeball. Nevus is the most common benign formation of the organ of vision. The frequency of its detection during ophthalmoscopy is 2%. At the same time, during autopsy, this pathology is diagnosed in 6.5-20% of patients. In female and male individuals, nevi are determined equally. The prevalence of uveal melanoma among all eye pathologies is 5%. The risk of the formation of this choroid tumor increases significantly with the age of the patient and after 69 years increases by 50 cases every year (based on 1 million population). The total incidence of hemangioma of the eye among the total number of intraorbital pathological neoplasms is 0.76%. This type of choroid tumor occurs in all age groups, but is more often diagnosed after 10 and up to 60 years.
Causes
Choroid tumor often develop sporadically. However, family cases of uveal melanoma are described in the literature, which makes it possible to attribute it to the number of genetically determined pathologies. Dysfunction of tumor suppressor genes (CDKN2A, CDK4) leads to the development of chromosomal mutations localized on the short arm of chromosome 21 or the long arm of chromosome 14. The cascade of pathological processes includes a violation of the synthesis of proteins p16 and p14ARF. The development of this choroid tumor may be preceded by oculodermal melanosis or a violation of pigment metabolism. It often occurs as a result of malignancy of a progressive nevus, but the most common cause of neoplasia is a “de novo” mutation. Taking into account the morphological picture, spindle-cell, epithelioid and mixed variants of uveal melanoma are distinguished. The specific color of the choroid tumor is caused by the deposition of lipofuscin grains.
Hemangioma refers to the number of hamartomas. The cause of the formation is a tissue anomaly of development. The composition of the neoplasm has the same components as the surrounding tissues, but the degree of its differentiation and structure are sharply disrupted. The risk of developing choroid tumors increases with prolonged contact with ultraviolet radiation or against the background of sunburn of the eyes. In the population, the disease is more common among individuals whose phenotype includes blue eyes, light skin and hair, multiple nevi (more than 50).
Symptoms
From a clinical point of view, vascular and pigmented tumors of the choroid are isolated. There are also benign and malignant neoplasms. The pigment forms include nevi (stationary and progressive). In most cases, this is a congenital type of choroid tumors, but the intensity of pigmentation increases after the age of 30. They are detected in the posterior pole of the eyeball, less often in the equatorial region or in front of it. Cases of binocular damage to the organ of vision are described. As a rule, the course of the disease is asymptomatic. An increase in the size of a progressive nevus in rare cases leads to a decrease in visual acuity.
Clinical manifestations of uveal melanoma depend on its diameter and the degree of involvement in the pathological process of the surrounding vessels. Angiogenesis in the area of the choroid tumor and changes in the vascular wall (thickening and compaction) lead to rupture of the inner shell of the eyeball. Often there are no symptoms. In rare cases, patients complain of flashes of light, decreased visual functions, the appearance of “flies” or “black curtain” in front of the eyes. With a high prevalence of the tumor process in patients, visual acuity progressively decreases.
Hemangioma belongs to the group of benign tumors of the choroid. It is characterized by rapid progressive growth, which very often leads to complete detachment of the retina. The first symptom of the disease in adults is a violation of visual functions. In childhood, this tumor of the choroid becomes the cause of strabismus. From a clinical point of view, there are limited and diffuse forms. With a limited version, a small node with clearly defined edges is formed. Clinical manifestations are poorly expressed. With diffuse spread of the tumor process, the disease is complicated by encephalofacial angiomatosis (Sturge-Weber syndrome).
Diagnosis
Diagnosis of choroid tumors is based on the results of ophthalmoscopy, visometry, fluorescence angiography, biomicroscopy, optical coherence tomography (OCT), ultrasound (ultrasound) in the In-mode. During ophthalmoscopy, nevi have the appearance of flat, raised formations up to 0.1 cm in size above the level of surrounding tissues. Depending on the severity of pigmentation, their color varies from grayish to gray-brown. The borders are often uneven, but with clear outlines. The irregularity of the contours is due to the adjacent vessels. Nevi devoid of pigment are characterized by an oval or rounded shape with smooth, but less defined contours. Unlike progressive nevi, druses are present on the surface of stationary ones. For their differential diagnosis, ophthalmoscopy with color filters is performed. The red color of the filter allows you to visualize this type of choroid tumor, while the green pathological formation is not determined.
The method of fluorescent angiography in stationary form reveals a decrease in fluorescence throughout the examination. At the same time, no changes are detected in the surrounding vascular membrane. The changes in the choroid are indicated by sweating and bright glow of the dye. Ophthalmoscopy of uveal melanoma reveals a small nodule with post-equatorial localization. The tumor of the choroid is yellow–brown or asp-colored with druses on the surface or in the surrounding tissues. The OCT method determines the exact localization, size, and degree of spread to the surrounding tissues. In most cases, the patient with visometry is diagnosed with a decrease in visual acuity.
During ophthalmoscopy, the delimited hemangioma has the appearance of a small nodule of rounded shape with smooth contours with a diameter of 0.3-1.5 cm. The average thickness of the pathological formation is 0.3-0.4 cm. The color of this form of choroid tumor ranges from light gray to dark red. For the differential diagnosis of hemangioma from melanoma, fluorescent angiography should be performed. With hemangioma, the average diameter of the tumor vessels corresponds to that of the choroid vessels, and small foci of hemorrhage may also appear on its surface. Due to progressive angiogenesis in melanoma, newly formed capillaries have a smaller caliber and a more convoluted course. The ultrasound of the choroid tumor determines the blood flow and the characteristic pulsation of the vessels, which allows you to confirm the diagnosis. An external examination is carried out to identify the typical symptoms of strabismus.
Treatment
The tactics of treatment for choroid tumors depends on the form of the disease. With the appearance of signs indicating the transformation of a stationary nevus into a progressive one, laser coagulation is indicated. If a large uveal melanoma is detected, enucleation of the eyeball should be performed. If the diameter of the pathological neoplasm is insignificant, and the tumor does not spread beyond the primary focus, contact radiation therapy (brachytherapy of the eye) is recommended. The advantage of this method of treating choroid tumors is the local effect on melanoma with the maximum dose of radiation therapy. At the same time, radiation does not affect the surrounding tissues and critical organs. An alternative option is transpupillary diode-laser thermotherapy. This method belongs to the number of minimally invasive techniques. At the same time, the whole procedure is carried out under visual control.
The detection of hemangioma is an indication for surgical intervention, which is due to the high risk of exudative retinal detachment and a decrease in visual functions. Cryotherapy, brachytherapy, photodynamic therapy and transpupillary diode-laser thermotherapy are used in the treatment of the delimited form of choroid tumor. Laser coagulation in the yellow radiation spectrum is highly effective. Treatment tactics are reduced to obliteration of blood vessels. The advantage of this technique is the elimination of exudate effusion from newly formed vessels due to the adhesion of the pigment layer and the sensory retina. The subretinal fluid is resorbed in this case.
Prognosis and prevention
Specific measures for the prevention of choroid tumors in ophthalmology have not been developed. All patients with an established diagnosis of benign or malignant neoplasm of the vascular membrane should be registered with an ophthalmologist at the dispensary. After surgical treatment, it is periodically necessary to undergo a preventive examination by a specialist, limit exposure to the sun, and avoid working at high ambient temperatures.
The prognosis for life and work capacity in the stationary form of nevus is favorable. The progressive variant should be considered as a precancerous condition. The most malignant among the tumors of the choroid is melanoma, the prognosis for life is determined by the stage of development. Vascular hemangioma is a prognostically favorable disease, however, complete loss of vision is possible in some patients.
