Occlusion of the central artery of a retina
Occlusion of the central artery of a retina – the sharp blockade of the central retinalny artery or its branches leading to disorder of blood circulation and ischemia of a retina. Occlusion of the central artery of a retina is shown by sudden loss of sight or sectoral loss of fields of vision in one eye. At diagnosis of vascular pathology of a retina data of ophthalmologic tests (a vizometriya, perimetry), oftalmoskopiya, tonometriya, a fluorescent angiography and a tomography of a retina, electrophysiological researches of function of the visual analyzer, etc. are considered. Identification of occlusion of the central artery of a retina demands immediate performing therapy: massage of an eyeball, paratsentez of the forward camera of an eye, decrease in VGD, introduction of vazodilatator and antiagregant.
Occlusion of the central artery of a retina
Occlusion of the central artery of a retina, as a rule, develops at patients 60-65 years are more senior; at the same time at men twice more often than at women. In most cases occlusion has unilateral character. Disorder of blood circulation develops in 60% of observations in the central artery of a retina and leads to permanent loss of sight on one eye. At 40% of patients arterial occlusion mentions one of branches of a retinalny artery that is followed by loss of the corresponding part of a field of vision.
Depending on the level of blocking of a blood-groove in ophthalmology distinguish occlusion of the central artery of a retina, occlusion of branches of TsAS and occlusion of a tsilioretinalny artery. Occlusion of the central artery of a retina can develop separately or be combined with occlusion of the central vein of a retina or forward ischemic neuropathy of an optic nerve.
The mechanism of sharp disorder of retinalny blood circulation can be connected with a spasm, thrombosis, an embolism, a collapse retinas. Most often obstruction of retinalny vessels cholesteric, calcific or fibrinozny embola leads to incomplete or full occlusion. In all cases occlusion of the central artery of a retina is a consequence of system sharp or chronic pathological processes.
As major factors of risk of development of occlusion of the central artery of a retina in advanced age serve arterial hypertension, atherosclerosis, gigantokletochny arteritis (Horton's disease). At younger age circulator violations in vessels of a retina can be connected with an infectious endocarditis, a prolapse of the mitralny valve, defeat of the valvate device of heart at rheumatism, violation of a warm rhythm (arrhythmia), neurocirculator dystonia, diabetes, an anti-phospholipidic syndrome. Local provocative factors of occlusion of the central artery of a retina retinovaskulita, hypostasis and Druzes of DZN, the raised VGD, a compression of vessels of an orbit as a retrobulbarny hematoma, a tumor, ophthalmologic operations, etc. can act.
Potential danger concerning occlusion of the central artery of a retina is represented by the hyper coagulation syndrome, fractures of tubular bones, intravenous injections interfaced to danger of a thrombembolia, fatty or air embolism. The collapse retinas is possible at the massive blood loss caused by uterine, gastrointestinal or internal bleeding.
As a result of a spasm, a thrombembolia or a collapse there is a delay or complete cessation of a blood-groove in the struck vessel leading to sharp ischemia of a retina. In case the blood-groove is possible to restore within the next 40 minutes, perhaps partial restoration of the broken visual functions. At longer hypoxia in a retina irreversible changes – a necrosis of gangliozny cages and nervous fibers with their subsequent autoliz develop. As an outcome of occlusion of the central artery of a retina serves the atrophy of an optic nerve and permanent loss of sight.
In the most part of cases occlusion of the central artery of a retina develops suddenly and without serious consequences. At the same time the patient notes unexpected loss of sight on one eye which happens promptly, literally within several seconds. Approximately in 10% of cases there are episodes of short-term passing violation of sight. At TsAS thrombosis the fotopsiya phenomena – light flashes can precede malfunction of sight.
Less often at occlusion of the central artery of a retina there is a sectoral loss under review. Extent of decrease in visual acuity varies from safety of distinction of objects at the person to a total blindness.
Diagnosis is promoted by the analysis of anamnestichesky data: presence at the patient of cardiovascular, system, inflammatory, exchange diseases, injuries of an eye, other vascular accidents (the stroke, a myocardial infarction, superficial and deep vein thromboses of the lower extremities obliterating an endarteriit and so forth). Necessary inspection includes carrying out ophthalmologic tests, survey of an eye bottom, contrast X-ray analysis of vessels of a retina, laboratory tests.
Viziometriya at occlusion of the central artery of a retina reveals decrease in visual acuity from 0 to 0,02-0,1. Extent of decrease in sight depends on the level of occlusion and land area of ischemia. By means of perimetry defects of peripheral sight (the sectoral or central scotomas corresponding to an ischemic zone of a retina, concentric narrowing of a field of vision) are found.
The biomicroscopy allows to judge degree of occlusion of the central artery of a retina previously. So, at incomplete occlusion afferent pupillary defect (Markus Hun pupil) is defined; at total occlusion - reaction of a pupil to light is absent or is sharply reduced.
Visual survey of an eye bottom by method of an oftalmoskopiya reveals hypostasis, transparency loss, pobledneny retinas and DZN. On this background the central pole of makulyarny area (a syndrome of "a cherry stone") having brighter coloring due to horioidalny blood supply is distinctly allocated. Retinalny arteriola are narrowed, have uneven caliber; in the first days after the developed occlusion of the central artery of a retina in them embola can be looked through.
Carrying out a fluorescent angiography allows to specify localization of blood clot or an embol, to find out extent of blocking of a vessel. Delay or segmentary character of a blood-groove in retinalny arteriola are radiographic signs of occlusion of the central artery of a retina; at full impassability of branches of TsAS - a symptom of "break of a vessel".
These elektroretinografiya are characterized by the decrease or lack of amplitude of the registered waves demonstrating destruction of gangliozny cages and ischemia of a horioidea.
The specifying diagnostics at occlusion of the central artery of a retina is carried out by means of UZDG of eye vessels, the optical coherent and laser scanning tomography of a retina, a tonometriya.
Carrying out a research of a koagulogramma and lipidogramma, blood crops is necessary (in case of suspicion of a bacterial embolism), duplex scanning of carotids, ultrasonography of heart etc. Krom of the ophthalmologist, in the presence of indications, the patient with occlusion of the central artery of a retina has to be examined by the cardiologist, the vascular surgeon, the rheumatologist, the endocrinologist, the hematologist, the infectiologist.
treatment should be carried out only under the supervision of a doctor. Self-treatment is unacceptable!!!
Treatment of occlusion of the central artery of a retina has to be begun during the first hours from the moment of presentation of complaints to decrease in sight; otherwise it will be impossible to restore sight. Emergency primary aid includes performing massage of an eyeball for restoration of a blood-groove in TsAS. For the purpose of decrease in VGD instillation of eye drops, introduction of diuretic medicines is made, carried out corneas.
At occlusion of the central artery of the retina caused by a spasm pathogenetic therapy includes application of vazodilatator (nitroglycerine sublingual, an eufillina intravenously, a papaverine intramuscularly, etc.), performing inhalations by oxygen mix or hyperbaric oxygenation.
At TsAS thrombosis to the forefront there is an application of trombolitik and anticoagulants, sounding of branches of an eye artery through a nadglaznichny artery, intravenous infusions of dextrans.
At any type of occlusion of the central retina of arteries reception of antioxidants, local retrobulbarny and parabulbarny injections of vasodilating medicines, instillations of b-adrenoblokatorov is expedient. Corrective treatment of the accompanying system pathology is at the same time appointed.
Efficiency of therapy in many respects depends on terms of its beginning and is highest the first minutes and hours from the moment of development of occlusion of the central artery of a retina.
Forecast and prevention
As outcome of occlusion of the central artery of a retina at 1% of patients serves DZN neovaskulyarization with development of secondary neovascular glaucoma. As the most frequent and terrible complication of pathology serves the atrophy of an optic nerve and a blindness.
Restoration of sight is possible only at the beginning of full volume of treatment within the first 40-60 min. for the moment of development of occlusion in case the pathogenesis of impassability of vessels is caused by their spasm. The patients who transferred occlusion of the central artery of a retina make risk group on development of sharp vascular accidents with a lethal outcome.
Prevention of occlusion of the central artery of a retina is closely connected with need of timely treatment of the accompanying pathology, an exception of provocative factors (smoking, stressful situations, heavy physical activities, visit of baths and saunas, reception of hot bathtubs, long air flights, occupations scuba diving, etc.). The persons making risk group on development of occlusion of TsAS have to look round regularly the oculist and receive preventive therapy.