Drops constricting the pupil

Pupil dilation in diameter can occur for various reasons. For adjusting the diameter meets a pair of core muscles that make the pupil wider or narrower - this is the ciliary and radial muscles. The spasm of the first muscle constricts the pupil, and its weakness expands. The second muscle provokes the opposite effect. Drops constricting the pupil cause a forced contraction of the ciliary muscle and radial relaxation - this effect is often used by ophthalmologists to visually stabilize the size of the pupils.[1]

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Indications for use of drops constricting the pupil

Drugs aimed at constricting the pupil can be used in the following situations:

• in low light conditions when a large diameter of the pupil allows a large amount of luminous flux to be projected onto the retinal area;
• with excessive activity of the sympathetic nervous system (for example, after stressful situations);
• with pathologies in the brain (for example, tumors);
• with dilated pupils associated with chemical intoxication or medication;
• in case of eye diseases (for example, glaucoma);
• before and after eye surgeries and manipulations, with injuries that could provoke a weakening of the ciliary muscle;
• with paralysis of the eye muscles caused by tuberculosis, high intracranial pressure, poisoning, etc.;
• in diseases of the central nervous system, which may be accompanied by spasm of the eye muscles (for example, meningitis, polio, etc.).

Release form

Eye drops are produced in the form of a medicinal solution, in a plastic or glass bottle with a dispenser or pipette. On the package must indicate the name of the drug, the active substance, as well as the date of issue and the shelf life of drugs.

These remedies are intended to prevent or treat eye diseases. The composition of the drug may be represented by one or more active ingredients. The peculiarity of eye drops is their ability to overcome the conjunctiva, the outer eye shell, to fall on various parts of the eyeball, including the deep ones, for a short time.

Mostly released without a prescription, but their use must be coordinated with an ophthalmologist.

Pharmacodynamics

Drugs that narrow the pupil are called miotics. These medications include cholinomimetic and antichylinterase agents.

Cholinomimetics act on the principle of acetylcholine, and anti-chilinesterase drugs inhibit the action of cholinesterase, an enzyme that breaks down acetylcholine.

The dynamics of the effect of miotics on the intraocular pressure indices consist in their unblocking effect on the anterior ocular chamber area (angle) and the venous sinus of the sclera. Miotiki provoke constriction of the pupil, the removal of the iris from the anterior ocular chamber and the opening of closed sections of the angle. Such a pattern of exposure plays a huge role in angle-closure glaucoma.

With the open-angle form of the disease, miotic agents “release” the venous sinus of the sclera and trabecular crevices, increasing the contractility of the ciliary muscle.

Pharmacokinetics

The percentage of active substances of miotic agents can reach a maximum level within 30 minutes after instillation.

Active substances are excreted at their natural outflow, without accumulation and signs of metabolism.

Eye drops easily penetrate the corneal layer, interact with eye tissues. The half-life can be from one and a half to two hours, and the effect of the active ingredient, which affects the pupil constriction, can last much longer — on average, 5-15 hours.

Dosage and administration

We present to your attention the most common names of drops that constrict pupils, as well as the principles of their use and dosage.

• Pilocarpine hydrochloride 1-2% water-based solution, apply 1-2 drops up to 4 times per day. Pilocarpine-based preparations: Oftan Pilocarpine, Isopto-carpine.[3]
• Aceclidine 2%, 3%, 5% water-based solution. Drops from 3 to six times a day, depending on the effectiveness. Drug synonyms: Glaukostat, Glaudin, Glaunorm.[4]
• Carbacholine 0.5-1% solution. Used for instillation in the region of the conjunctival sac from 2 to six times a day. Valid for 4-6 hours[5]
• Carbachol 3%, with the active ingredient carbamylcholine chlorate. Dosage: 1 drop from 2 to 4 times a day.
• Proserin (Prostigmin) 0.5% solution, used in 1 drop up to 4 times a day. [6]
• Carbatsel (Isoptocarbachol) 0.75%, 1.5%, 2.25% and 3% solutions. Use 1 drop from 2 to six times a day.[7]
• Armin 0.01% drops, apply 2-3 times a day.
• Physostigmine 0.25% -1% solution is injected into the conjunctival sac from 1 to 6 times per day. Synonyms: Ezerin salicylate.[8]
• Phosphacol - apply 1-2 drops of a 0.013% aqueous solution of 1: 7500, twice a day. Synonyms: Mintakol, Solyglautsit, Miotizal, Paraokson.[9]

All of these drugs are considered potent drugs that are not intended for continuous use and are prescribed only by specialists with appropriate indications.

Use of pupil constricting drops during pregnancy

The use of cholinomimetics and anticholinesterase drugs should be limited as much as possible during pregnancy and breastfeeding. Most cholinomimetic agents have the ability to increase the tone of the myometrium, which does not allow their use by pregnant women.

Any use of these drugs should be previously agreed with the doctor - the independent use of these drugs is unacceptable.

Contraindications

Contraindications to the appointment of drops constricting the pupil are:

• the period of pregnancy and breastfeeding;
• tendency to allergic manifestations;
• bronchial asthma;
• chronic heart failure;
• coronary heart disease;
• bleeding in the digestive tract;
• epileptic seizures;
• acute inflammation of the abdominal organs;
• corneal defects, iritis, iridocyclitis;
• hypertension;
• obstructive or mechanical bowel obstruction;
• an ulcer of the gastric mucosa or duodenum;
• diabetes;
• spastic pain, myotonia, hyperkinesis;
• various types of shock conditions.

Side effects

The use of cholinomimetic agents may be accompanied by the following symptoms:

• allergies;
• lower blood pressure;
• reduction of the lumen of the heart vessels;
• slow heart rate;
• heart rhythm disorders;
• redness of the face;
• dyspnea;
• hypergydrosa;
• increased intestinal motility, diarrhea;
• swelling of the cornea.

The use of anticholinesterase-based drops may be accompanied by the following side effects:

• dyspeptic disorders;
• salivation, tearing;
• slowing heart rate, conduction disorders;
• convulsive syndrome, myasthenia, muscle tremor;
• headache, dizziness;
• sleep disorders;
• hypersensitivity reactions (skin rashes, conjunctivitis, itching).

Overdose

Signs of overdose reveal themselves to be marked by increased side effects, including the occurrence of significant cardiovascular failure and impaired respiratory function. Perhaps the development of cataracts, clouding of the lens, the appearance of follicular conjunctivitis.

Treatment consists of monitoring the heart rate, stabilizing blood pressure and respiratory function. Atropine in the amount of 0.5-1 mg, epinephrine in the amount of 0.3-1 mg subcutaneously or intramuscularly is administered intravenously or subcutaneously. The patient is encouraged to drink plenty of fluids. If necessary, an infusion.

Interaction drops, narrowing the pupil, with other drugs

The miotic effect of cholinomimetic agents is enhanced by ß-blockers, anticholinesterase drugs and α-blockers. Reduce the effect of drops means the group of tricyclic antidepressants, m-anticholinergics, phenothiazines. Side effects appear stronger under the action of Ftorotan and Quinidine.

Anticholinesterase drugs increase the effect of drugs aimed at inhibiting the central nervous system (including ethyl alcohol). Simultaneous use with Ipidacrine reduces the effectiveness of local anesthetics, antibiotics, potassium chloride.

Storage conditions

Miotic preparations are stored in cool dark places, observing the temperature regime from 8 to 15 ° C. It is possible to keep medicines in the refrigerator, provided that children have difficulty accessing the place where medicines are stored.

The opened vial should be used for no more than one month, otherwise the drug will lose its healing properties.

Shelf life drops from 2 to three years, which is necessarily indicated on the packaging and on the bottle with the drug.

Drops, constricting the pupil, can be used only as directed by the doctor and under the constant monitoring of intraocular pressure. Independent and long-term use of these drugs is unacceptable.