Ultrasound signs of eye diseases

The parameters of hemodynamics are normally used for comparison with similar parameters in patients with different vascular, inflammatory, neoplastic and other diseases of the organ of vision both in the existing and in the newly formed vascular bed.

The greatest informativity of Doppler techniques was revealed in the following pathological processes:

• anterior ischemic neuroopticopathy;
• hemodynamically significant stenosis or occlusion of the internal carotid artery, causing a change in the direction of blood flow in the basin of the eye artery;
• spasm or occlusion of the central artery of the retina;
• thrombosis of the central vein of the retina, upper eye vein and cavernous sinus;
• retinopathy of prematurity;
• pseudotumorous lesions of the fundus and orbit;
• tumors of the eye, its adnexa and orbit;
• retinal detachment on the background of fibrotic changes of the vitreous and proliferative stage of diabetic angioretinopathy;
• aneurysm of the eye artery and varicose veins of the orbit;
• carotid-cavernous anastomosis.

Extraorbital vascular diseases, such as arteriosclerosis of vessels and hypertension, causing an increase in rigidity of the vascular wall, lead to flattening and rounding of the systolic peak of the Dopplerogram, its deviation, the appearance of an additional peak in the systole, expressed by spectral expansion.

With occlusion of the ICA on the neck (if it does not close the mouth of the eye artery), the retrograde blood flow is registered in the eye artery, it becomes a bridge, along which the collateral blood flow to the brain is realized.

With stenosis of the internal carotid artery, the linear velocity of blood flow (LVS) decreases on the side of the lesion both in the eye artery and in its branches. Against the background of glaucoma with increased intraocular pressure, peripheral vascular resistance increases in the basin of the CCAR and the central artery of the retina, and rates in the eye artery may decrease. Decrease in velocities in the central artery of the retina and CCAR occurs in the proliferative stage of diabetic angioretinopathy. Pronounced edema of retrobulbar fiber and thickening of extraocular muscles in autoimmune ophthalmopathy can cause difficulty in outflow of venous blood from the orbit and LSC in HBV becomes below the norm. Many pathological conditions developing in blood vessels that directly supply blood to the eye, when untimely treatment quickly lead to loss of vision, and their early diagnosis is quite relevant. This group includes spasm or occlusion of the central artery of the retina, thrombosis of the CVS and anterior ischemic neuroopticopathy. In the latter state, on the first day of the disease, the depletion or absence of a vascular pattern around the optic nerve disk is observed due to a sharp decrease in the rate of performance in the CCCA. Attempts to register them in the MHRC are not always successful. On the background of treatment, usually during the first week, in the pool of these arteries there is reperfusion with the restoration of blood flow.

Spasm or occlusion of the central artery of the retina is manifested by the absence of staining of this vessel in the region of the disc and the retrobulbar part of the optic nerve, the retina in the peripapillary region is edematic. With the preservation of the partial patency of the artery, the spectrogram becomes low-amplitude due to the decrease of the LSC.

Thrombosis of CVS leads to a marked change in intraocular hemodynamics. Blood flow through the veins is not recorded or marked by a significant decrease in their speed. Blood overflow of the venous channel of the reticular membrane causes an increase in vascular resistance in the basin of the central artery of the retina, the diastolic component of the blood flow along the artery is poorly expressed or absent, the rate of blood flow in the eye artery on the side of the lesion is compensatory. Hemodynamic changes are accompanied by a characteristic pattern in the B-mode: they dominate the edematous optic nerve disk and the macular zone, the inner shells of the eye thicken.

Thrombosis of the cavernous sinus, sometimes in combination with thrombosis of the upper eye vein, causes an increase in the diameter of this vein, it is not stained when mapping, if there is no movement of blood in it, LCS is not recorded. When the part of the upper eye vein is crossed, the blood flow can be directed towards the facial veins, the venous type of the spectrum is preserved. In the B-mode, the edema of retrobulbar fat, the expansion of the perineural space in the orbit and the prominence of the edematous optic nerve disk are noted.

Expressed hemodynamic changes in the eye and orbit occur with the formation of carotid-cavernous anastomosis (CCS). Given that the classical triad of this disease (exophthalmos, eyeball ripples and blowing noise in the temple and eye sockets on the side of the lesion) is missing in about 25-30% of patients, the correct diagnosis in this group of patients is first established with an ultrasound ophthalmological study using Doppler techniques. When conducting parallels with the clinical triad of KKS, one can distinguish the classic "ultrasound triad" of the disease:

• enlargement, sometimes very significant, of the upper ocular vein, which is visible in B-mode over a sufficiently large length as an additional curved anechogenous tubular structure;
• retrograde blood flow in the upper eye vein in the mapping mode (the color changes from blue to red-orange-yellow);
• arterialization of venous blood flow in the upper eye vein (linear velocities, retrograde direction of blood flow increase, acute systolic peaks on the Dopplerogram are formed).

The overflow of arterial blood of the venous channel of the orbit affects hemodynamics in the retinal vessels and the choroidal layer: the violation of venous outflow from intraocular structures leads to a significant increase in peripheral resistance in the basin of the central artery of the retina and is somewhat less pronounced in the CCCA. In the central artery of the retina, the diastolic velocity may decrease until reversal flows appear with the registration of a three-phase Dopplergram, in RCCA, RI approaches unity. B-mode demonstrates the edema of the retrobulbar fiber, the optic nerve disk, the inner shells of the eye, the expansion of the perineural space in the orbit.

Dopplerography has a differential-diagnostic character in the presence of pronounced opacities in the vitreous body and fibrous cords of the detached mesh and vascular membranes, the functioning of the vitreous artery in children with cicatricial stages of retinopathy of prematurity.

Due to the fact that the funnel-shaped detachment of the retina can simulate the film structures of the vitreous body of the V-shaped form, in order to confirm it, a retinal vessel must be found in this structure. It is easier to do this near the point of attachment of the reticular membrane to the optic nerve disk. Signals during mapping can be expressed weakly, can be traced on separate fragments of the retina, when a large branch of the central artery of the retina enters the scanning area. LSK in the retinal vessels is low-amplitude, the rate is lower than in the central artery of the retina, sometimes 2 times.

In the projection of a vesicularly exfoliated choroid, arterial blood flow is well recorded, velocities exceed those in the retinal vessels, most of the "blisters" are stained during mapping.

In children with retinopathy of premature infants, a coarse or weakly expressed lobe is often found, fixed by one of the edges in the region of the optic nerve disk, the other in the region of the posterior capsule of the lens and a retrolental fibrovascular tissue quite common in such children. With this ultrasound, the impression is that there is a T-shaped retinal detachment. However, the mapping mode allows you to see the usually well-defined arterial flow in the projection of the strand, the speed characteristics of which are often much higher than in the retinal vessels, the blood flow signals are more distinct.

Of particular importance is the method of color duplex scanning when examining patients with suspected onco-ophthalmopathology. In the pediatric oncology clinic, the detection and evaluation of the neovascular bed allows differential diagnosis between retinoblastoma, tumor-like deposits of solid exudate in subretinal space and in retinal layers in Coates disease, fibrovascular growths in the vitreous body in the cicatricial stages of retinopathy of prematurity.

The vast majority of intraocular malignant neoplasms in children is represented by retinoblastoma. Color duplex scanning allows detecting tumor vessels in the outbreak even in the presence of massive areas of petrification.

In the cicatricial stages of retinopathy of the prematurity, the developing fibrovascular structures create an acoustic "plus-tissue" effect, but unlike retinoblastoma, the signals from the blood flow through the small vessels in its projection are weak enough, the blood flow is difficult to record because of low speed.

The deposits of solid exudate on the fundus in children with Coates's disease with ultrasound in the B-mode are virtually identical to retinoblastoma. The correct diagnosis is established according to the set of sonographic criteria, one of which is the avascularity of the foci, and the registration of only the retinal vessel on the surface of the formation, the signals from the blood stream in which are most often unstable, so that blood flow can not be recorded.

In adults, the most important is the differentiation of melanoma of the choroid, accounting for up to 80% of all malignant intraocular tumors, the pseudotumorous phase of central involutional degeneration of the retina, subretinal and subchoroidal hemorrhages, metastasis and hemangioma of the choroid. The combination of sonographic signs, including dopplerographic, allows to successfully cope with this task.

Melanoma of the choroid is characterized by the development of a predominantly arterial network in the outbreak, clearly distinguishing one or more feeding vessels at the periphery of the formation, the degree of vascularization varies from scant to very pronounced. In different patients, the character of the distribution of newly formed arteries in the tumor also changes. In the vessels, due to the imperfection of neoplastic angiogenesis, some wall components are absent, and as a result, the deviation of a part of the blood flow parameters from the norm can be seen on the Dopplergrams.

According to the vascular characteristics, the metastases of the choroid, occupying the second place in adults among malignant intraocular neoplasms, are close to melanomas, and the diagnosis is based on a combination of ultrasound criteria. In a metastatic tumor, a large feeding arterial vessel is much less often isolated, the degree of vascularization is usually moderate, a diffuse, multicentric type of growth predominates.

Hemangiomas of the choroid, with the passage of time, acquire a developed vasculature with signs of arterio-venous shunting in angio-bed and high echogenicity in B-mode.

Tumor-like promising foci on the fundus, arising during subretinal and subchoroidal hemorrhages, pseudotumor phase of central involutional degeneration of the retina, etc., are avascular in the mapping mode, which, in combination with other parameters, allows differential diagnostics in the oncological clinic.

With the precise diagnosis of the intraocular tumor, the Doppler characteristics (the degree and nature of neovascularization, the parameters of hemodynamics in tumor vessels) are an important criterion for the success of an organ-preserving treatment. Along with the decrease in the volume of neoplasm, as a positive criterion, the vascular bed in it is neglected, the LSC decreases, the resistance in the tumor pool is increased, which was regarded as the obstruction of the vessels due to post-radiation necrotic changes in the outbreak, the effects of polychemotherapy, laser destruction,

CDS assists in the differential diagnosis of volumetric formations of the orbit and accessory eye, since a number of pathological conditions such as dacryoadenitis, inflammatory granuloma, hematoma, etc., in B-mode are difficult to distinguish from the neoplastic process. At the same time, the nature of vascularization of tumors helps determine their species identity. So, neurogenic tumors - glioma and meningioma - have different degrees of blood supply (in the meningioma the vasculature is well developed). In small-sized lymphosarcoma localized in the conjunctiva of the eyelids - the eyeball, the vessels are single, visible at the surface of the foci. In some cases, in adults in the hemangiomas, located retrobulbarno, against the background of caverns, a few signals are also recorded. At the same time, mixed hemangiomas in the eyelid and rhabdomyosarcoma have a well-developed vasculature in children.

Thus, at the present time, a certain range of pathological conditions of the eye, its adnexa and orbit requires the use of the entire arsenal of Doppler techniques for timely and correct diagnosis, which often depends not only on the quality of life of the patient with preserved vision, but also life itself. In some cases, Doppler ultrasound in combination with B-scan helps to avoid more expensive, sometimes invasive interventions such as X-ray angiography and CT, MRI, and in some diseases, they outperform them in informative ways.