Constricted pupils

The diameter of the pupils, their ability to narrow or dilate, and adapt to different lighting options play a huge diagnostic role in some diseases. Narrow pupils are a common symptom of uremia, tumors, inflammatory reactions and intracranial hemorrhages, various poisonings and intoxications. When squeezing the cervical sympathetic ganglion, the narrowing will be detected on the affected side.

What else can the symptom of constricted pupils indicate? There can be many reasons for this condition, and this is the question we will try to answer in our article.

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Causes of constricted pupils

True constriction of the pupils is their pronounced reduction (less than 2.5 mm in diameter). This phenomenon is not always considered pathological. For example, physiological constriction in old age, in newborns, after significant physical and mental stress, when focusing the gaze at different distances, etc. can be considered a normal variant. The simplest way to cause pupil constriction is to provoke a physiological reflex reaction that occurs when a beam of high-brightness light enters the eye area.

Also, pupil narrowing occurs in patients suffering from farsightedness during sleep.

Drug-induced pupillary constriction occurs when taking certain medications:

• agents that inhibit the activity of adrenergic blockers;
• m-cholinomimetic agents (Pilocarpine, Muscarine);
• cholinergic drugs;
• cardiac glycosides;
• sleeping pills;
• reserpine, opium preparations;
• anticholinesterase agents with cholinopotentiating action.

Constriction of the pupil in one eye occurs in people representing certain professions and using monocles for their professional activities (for example, workers in jewelry or watch workshops).

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Constriction of the pupils as a sign of illness

In medicine, pupil constriction can be considered as a pathology when diagnosing the following diseases:

• in case of damage to the brain, especially its posterior part (medulla oblongata, pons and cerebellum);
• in a comatose state;
• with increased intracranial pressure;
• in case of a foreign body in the cornea;
• in case of damage to the third pair of cranial nerves;
• for diseases of the central nervous system (meningitis, encephalitis, tumors in the brain, multiple sclerosis, epilepsy);
• for diseases of the ciliospinal center, cervical part of the sympathetic trunk;
• in neurosyphilis.

In addition, narrowing can be observed against the background of acute iritis, with ulcerative lesions of the cornea, with inflammation of the vascular membrane of the eye (anterior or posterior), with drooping of the eyelid, with hemorrhage into the anterior chamber of the eye.

Toxic constriction of the pupils is found in cases of poisoning with substances such as morphine, ethyl alcohol, nicotine, chloral hydrate, dyes, bromine, phosphorus compounds, mushrooms, caffeine, and nerve gases (sarin, soman).

After consulting with an ophthalmologist, we identified a number of the most common questions that patients ask during a doctor's appointment. All of them, to one degree or another, reflect possible causes of pupil constriction, as well as factors affecting the diameter of the pupils. Let's get acquainted with the specialist's opinion on the questions posed.

Why might a child have constricted pupils? Should I worry?

• It all depends on the child's age. In the first year of life, the baby's pupil is physiologically constricted, there is a sluggish reaction to the light source and poor pupil dilation.

As for an older child, a narrow pupil may be a sign of a head injury, increased intracranial pressure, or poisoning with some substances. This condition requires an immediate consultation with a doctor.

In adolescence, a prolonged change in pupil diameter against the background of a general change in behavior and a strange shine in the eyes may indicate the child's involvement in drug addiction. When the teenager returns home, it is necessary to pay attention to his eyes, evaluate their reaction to lighting, direct a direct light source to the face. If the pupil diameter remains unchanged, then there is indeed a reason to worry, even if this has nothing to do with drug addiction. Consult a doctor, and do not delay.

If a person has very narrow pupils, what disease can be suspected?

• Severely constricted pupils are a symptom of direct pathology of the lower part of the midbrain, secondary compression of the brainstem due to a sudden increase in intracranial pressure. This condition may be the result of an increasing hematoma or injury, and also appears in old age in patients suffering from vascular parkinsonism.

In addition, pupils that are too small can be observed with damage to the pons and cerebellum, but this condition is usually associated with loss of consciousness.

In the absence of pathology, excessively constricted pupils are a sign of the use of medications, such as pilocarpine or morphine.

What can constantly constricted pupils indicate?

• This clinical symptom often accompanies eye diseases characterized by spasm of the iris muscles, such as iritis or iridocyclitis. As a result, the eyes stop responding to light sources. However, the most common cause of constant narrowing is glaucoma - along with an increase in intraocular pressure, the outflow of intraocular fluid worsens. Reflex narrowing of the pupil facilitates this outflow.

The most serious causes of this condition include malignant neoplasms, neurosyphilis and hemorrhagic stroke.

My pupils have been constricted for several days now and I have a headache, the pills don't help, what's wrong with me?

• Constant headache with nausea and change in pupil diameter may be the main signs of increased intracranial pressure. Only a doctor can diagnose the disease and prescribe treatment during an in-person consultation. The doctor will definitely conduct an examination of the fundus, which will reveal swelling of the optic nerve, the absence of pulsating movements of the retinal vessels. A significant increase in intracranial pressure may be accompanied by increased blood pressure, bradycardia, arrhythmia.

Nausea, pupil constriction and salivation appeared. What disease do such symptoms indicate?

• The listed symptoms are most similar to signs of poisoning with organophosphorus compounds, for example, the well-known dichlorvos. Dichlorvos is often used to get rid of parasites, unwanted insects, and to prevent plant diseases. The clinical picture of poisoning can occur within a few minutes after the substance enters the body, but can also develop within 7-8 hours.

The fundamental signs of intoxication are: nausea and vomiting, increased salivation and sweating, bowel disorder, pupil constriction. In case of severe poisoning, the consequences can be very unfavorable, so at the first symptoms you should definitely consult a doctor.

Can pupil constriction occur with pressure?

• With hypertension – increased blood pressure – the pupils usually dilate. However, with a sharp drop in pressure, the pupils can sharply narrow. The same reaction is observed when taking some drugs that are aimed at lowering blood pressure. Such drugs include, for example, reserpine, which is actively used in the early stages of hypertension.

If the increase in arterial pressure is combined with an increase in intracranial pressure, then at the initial stage the pupils may also constrict. Later, however, they dilate.

Can pupil constriction occur when exposed to x-rays?

• According to the conducted studies, a single X-ray irradiation of up to 50 R is considered practically safe if it is received no more than once within four days. The pathological condition after acute irradiation is observed when exposed to significant doses of radiation - from 100 R and above. Even with radiation sickness of the first degree, patients may experience general agitation, irritability, constriction of the pupils, hyperemia of the mucous membranes, loss of appetite.

If you receive a large dose of radiation, you should seek medical attention from a radiologist.

Constricted pupils are not always a sign of illness. Sometimes it is simply a reflex response of the body to changes in illumination, accommodation and convergence, mental and physical overload, etc. But if the constriction of the pupils continues for a long time, and is also accompanied by any other suspicious symptoms, then a doctor's consultation should be mandatory.

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