Diplopia is a visual impairment in which the image doubles vertically, horizontally or diagonally. This is not an independent disease, but a symptom of damage to the eye muscles, optic or oculomotor nerve, as well as pathologies of brain structures.

Signs and symptoms of diplopia:

• Double vision or images overlapping each other;
• dizziness, nausea, headache;
• Problems with orientation in space, disturbance of accommodation;
• The patient tilts his head to the side where the muscle is affected or to the shoulder opposite from the paresis.

Causes of double vision. What causes diplopia?

• Strabismus;
• Wasting or weakening of the eye muscles (myasthenia gravis);
• Paralysis of the trochlear or abducens nerve;
• Intracranial hypertension (increased intracranial pressure), impaired blood supply;
• Diabetes mellitus, thyroid pathology, autoimmune diseases;
• Multiple sclerosis;
• Aneurysm;
• Traumatic brain injury, postoperative complications after treatment of strabismus, cataracts, retinal detachment;
• Infectious lesions of the brain stem (diphtheria, tetanus, parotitis, rubella);
• Neurological diseases (brain tumors, meningitis).

Depending on the plane in which double vision is seen, there are three types of double vision:

• Horizontal diplopia. The form develops due to dysfunction of the rectus muscles or paresis of the abducens nerve.
• vertical diplopia. Its causes are in the desynchronization of the work of the oblique muscles of the eye, paresis of the trochlear nerve.
• Cross diplopia. This is the most severe variety, in which the image from the left eye is displayed on the right and vice versa.

In binocular diplopia, the disorder is caused by a misalignment of the horizontal axes of the eyes. Binocular vision disappears when one eye is closed. Monocular diplopia, on the other hand, occurs when one of the eyes is closed. It can occur due to astigmatic refraction, after eye injuries, with subluxation of the lens, tearing off the root of the iris. Patients usually complain of different intensities of the images and a feeling that the visible objects overlap each other. This is partially or completely corrected by glasses.

Double vision diagnostics

The method of treatment is selected only by an ophthalmologist after examination, focusing on the causes of the disease. The specialist will need to conduct the following examinations to make a diagnosis:

• Visiometry – checking visual acuity according to the table with and without correction;
• Computer refractometry with selection of trial correction;
• Biomicroscopy for a detailed examination of the anterior chamber of the eye and assessment of the state of the refractive media of the eyeball;
• Direct ophthalmoscopy – examination of the fundus;
• Magnetic resonance imaging (MRI) of the orbits and optic nerves to detect thickening of the oculomotor muscles and exclude retinal pathologies;
• Laboratory studies are carried out if thyroid ophthalmopathy is suspected – an autoimmune disease that affects parabulbar tissues and is accompanied by exophthalmos.

How is diplopia treated?

The tactics of treatment directly depends on the cause of the development of diplopia. Until an accurate diagnosis is made, unilateral occlusion is applied – the eyes are alternately closed for a while in order to develop visual fixation.

In cases where double vision is caused by alcohol or drug intoxication, the patient is urgently hospitalized, an antidote is administered, and gastric lavage is started. With thyroid ophthalmopathy , an endocrinologist is involved in the treatment. Therapy is selected individually after passing the tests, as a rule, it includes taking thyroid hormones and corticosteroid therapy ( taking glucocorticosteroids ). If double vision is caused by increased pressure in the orbit and the condition threatens the life of the patient, then decompression is performed – pressure reduction by removing excess tissue and creating additional space.

Myasthenia gravis is treated with medications that compensate for neuromuscular transmission disorders: anticholinesterase agents, immunoglobulin, corticosteroids. If refractive errors are the cause of diplopia, wearing glasses or contact lenses is indicated.

To correct binocular diplopia, special prismatic lenses (Fresnel prisms) are used – thin elastic plates that allow the axis to be compensated without the use of an occluder .

In cases where there is no improvement six months after the start of treatment, surgical intervention is performed. It aims to weaken, strengthen or change the position of the eye muscles in order to align the axis of the eye, thereby eliminating the double image. The operation is performed on an outpatient basis under local or general anesthesia. Surgical treatment immediately improves the condition, but the final result is visible only after a few months.

What can be done to prevent double vision?

There are no specific measures that could reduce the risk of developing diplopia. Doctors recommend adhering to general recommendations in order to, if not prevent, then at least identify the problem in time and take action:

• Annually undergo scheduled ophthalmological examinations;
• Make sure that the workplace is comfortable and adequately lit;
• Take breaks during prolonged work at the computer every hour, give your eyes a rest. You can perform visual gymnastics or just look out the window;
• Monitor hormone and blood sugar levels;
• Do not read lying down and in a moving vehicle;
• Do not touch your eyes with dirty hands to avoid introducing bacterial and viral infections .