Flashing Flies Before The Eyes : Causes, Symptoms, Diagnosis & Treatment

• Causes Of Flies Flickering Before The Eyes
• Destruction Of The Vitreous Body
• Detachment Of The Posterior Hyaloid Membrane
• Hemophthalmos
• Asteroid Hyalosis
• Inflammatory Diseases
• Postoperative Complications
• Myopia
• Cardiovascular Pathologies
• Pathologies Of The Musculoskeletal System
• Iron-Deficiency Anemia
• Other Reasons
• Diagnostics
• Treatment
• Surgery

Flickering flies before the eyes is a symptom that occurs when floating vitreal opacities appear. The main reasons: destruction of the vitreous body, detachment of the posterior hyaloid membrane (PHM), hemophthalmia, myopia, changes in blood pressure, anemia, hypovitaminosis. For diagnostics, visiometry, biomicroscopy, ultrasound of the eye, OCT, laser ophthalmoscopy, determination of dynamic light scattering and contrast sensitivity are performed. Surgical treatment is reduced to vitrectomy and YAG-laser vitreolysis.

Causes of flies flickering before the eyes

Destruction of the vitreous body

With age, the dissociation of collagen and hyaluronic acid occurs, which leads to the aggregation of fibrils. The resulting fibers cause the light to scatter. Due to the liquefaction of the vitreous body, gaps are formed that disrupt the process of refraction of light rays. Patients with destruction of the vitreous body indicate flickering flies before the eyes, swimming "spider-like" dark threads or translucent "glass" rods.

Detachment of the posterior hyaloid membrane

The cortex is the densest structure of the vitreous body, lying preretinally. Due to vitreal collapse, it shifts anteriorly and separates from the retina. Patients with PHM detachment note the sudden appearance of flies before their eyes. The passage of photons through the Weiss ring (peripapillary glial tissue) leads to a shadow falling on the retina, which patients describe as a dark circle.

Hemophthalmos

Bleeding can be provoked by traction retinal detachment or BGM with vascular damage, trauma, rupture of newly formed vessels in diabetic retinopathy. Blood clots not only disrupt the transparency of optical media, but also contribute to secondary destruction. The severity of visual dysfunction in hemophthalmos depends on the amount of hemorrhage. As the blood resorbs, vision is restored, but the flickering of flies before the eyes remains.

Flies before the eyes

Asteroid hyalosis

The etiology of asteroid hyalosis remains unexplored. It is known that with this disorder, multiple punctate deposits of phospholipids and calcium are formed inside the eye. In most cases, there are no symptoms, which indicates a benign course. Often the only manifestation of the disease is the flickering of flies before the eyes.

Inflammatory diseases

Such inflammatory pathologies as vitreitis, endophthalmitis and uveitis, regardless of the etiology, lead to an increase in the amount of pro-inflammatory cytokines in the vitreal cavity. Formed cell aggregates and secondary destructive changes cause the development of complaints about flickering flies.

Postoperative complications

The remnants of silicone oil or perfluorocarbon bubbles after vitreoretinal interventions provoke the appearance of floaters before the eyes. Similar symptoms can be traced after intravitreal injections. The introduction of inhibitors of vascular endothelial growth factors (anti-VEGF) can promote the formation of complexes with macromolecules of the vitreous body and change its structure.

Myopia

Axial myopia of a high degree leads to the development of myopic vitreopathy. Patients indicate that the opacities range from small dots, linear beading patterns to "spiderlike" objects. There is a tendency for them to increase in size over time. With movements of the eyes and head, staying in a room with bright lighting, they become more noticeable.

Cardiovascular pathologies

Maintaining normal blood pressure in the body is provided by the tone of the blood vessels. If the blood pressure is below 100/6 or above 140/9mm. rt. Art. changes in the tone of the intraocular vessels. Flashing flies before the eyes is characteristic of the following diseases:

• Arterial hypotension. A drop in blood pressure is manifested by dizziness, a transient decrease in visual acuity, the appearance of flies or fog before the eyes. Patients report increased fatigue, drowsiness. Normalization of blood pressure contributes to the improvement of the general condition. Common causes of hypotension: dehydration, blood loss (Mallory-Weiss syndrome, hemothorax, gastrointestinal bleeding).
• Hypertonic disease. Against the background of an increase in blood pressure, patients develop complaints of headache, tinnitus, rapid heartbeat, shortness of breath and "flies" before the eyes. Taking antihypertensive drugs can eliminate clinical symptoms.
• Hypertensive crisis. An increase in blood pressure to critical values ​​provokes the flickering of flies before the eyes. Violation of cerebral hemodynamics leads to neurovegetative disorders, which are manifested by headache, tinnitus, transient visual dysfunction, and excessive sweating.

Pathologies of the musculoskeletal system

Diseases of the cervical spine often lead to an increase in blood pressure, as well as hypoxia of the membranes of the eyeball. These changes potentiate a transient decrease in visual acuity, headache, dizziness. Flashing flies before the eyes can be a sign of:

• Cervical spondylarthrosis. Degenerative changes in the intervertebral joints are accompanied by impaired blood circulation in the system of basilar and carotid arteries. The disease develops after 4 years. Characterized by a gradual onset.
• Anomalies of Kimerli. With this pathology, an abnormal bone ring is formed around the vertebral artery. This limits the mobility of the craniovertebral joint and the artery itself. An accompanying symptom is impaired eye movements.

Iron-deficiency anemia

With anemic syndrome in erythrocytes, the concentration of hemoglobin is reduced. In this case, the blood cannot provide sufficient saturation of the tissues with oxygen. One of the early signs of iron deficiency anemia is floating flies in the field of vision. There are complaints of pallor of the skin and mucous membranes, general weakness, hair loss.

Other reasons

• Deficiency of vitamins A and K.
• Poisoning with methyl alcohol and alcohol surrogates.
• Mountain sickness.

Diagnostics

During the initial examination by an ophthalmologist, it is necessary to establish under what circumstances the symptoms appear (bright lighting, work at close range, at the height of a hypertensive crisis) and when they disappear. It is important to clarify the duration of the process. Basic diagnostic methods:

• Visometry. Vitreous opacities of small size and peripheral localization do not affect visual acuity. At the expressed degree of disturbances visual dysfunction is traced.
• Biomicroscopy of the eye. With asteroid hyalosis, a large number of small yellowish or yellow-white shiny formations are observed in the projection of the light beam. The reflection effect is characteristic. However, the technique does not allow evaluation of peripheral structures.
• Eye ultrasound. In the B-mode gray scale, individuals with asteroid hyalosis show multiple small discrete echogenic inclusions with varying acoustic density. In the A-mode, repetitive high-amplitude complexes are recorded in the projection of the entire anechoic space of the vitreous cavity.
• Spectral optical coherence tomography ( SD - OCT ) . OCT makes it possible to clearly visualize vitreal lesions located preretinally. With more anterior localization, they are indirectly defined as darkening of the OCT image.
• Scanning laser ophthalmoscopy . Depending on the density of turbidity, they look like white-gray shadows or penumbra. Using a series of photographs, you can estimate the size and approximate density. On the fundus, the Weiss ring is often determined.
• Dynamic Light Scattering ( DLS ) . A laser nanodetector system is used to visualize particles ranging in size from 3 nanometers to 3 microns. An ophthalmologist can evaluate collagen fiber aggregation in myopic or diabetic vitreopathy.
• Determination of contrast sensitivity . In the presence of primary seals in the vitreous body, contrast sensitivity (CS) decreases. This increases the degree of light scattering. Studies are carried out before and after the operation. Asteroid hyalosis does not affect CN values.

Ophthalmological examination

Treatment

Flickering flies before the eyes is not a sign of emergency conditions in ophthalmology. In 50% of cases, floaters move below the visual axis over time, allowing patients to adapt to symptoms. To alleviate the condition, it is recommended to limit exposure to bright lighting conditions. If complaints persist for 3 or more months, then surgery should be considered.

Surgery

To date, only surgical methods for removing opacities are used in clinical practice. Pharmacological vitreolysis is at the stage of clinical trials. Intravitreal administration of a proteolytic enzyme promotes the dissolution of large opacities, but many small zones of destruction are formed. The main methods of treatment:

• Vitrectomy. The pathologically altered vitreous body is removed, which is located along the optical axis. The retrolental part of the vitreous body remains intact, which makes it possible to avoid the development of postoperative cataracts.
• YAG laser vitreolysis. This intervention is performed by placing opacities directly behind the lens. The YAG laser makes it possible to destroy collagen fibers without having such a strong effect on hyaluronic acid.