Pupil dilation drops

Drops that dilate the pupil are called mydriatics. Mydriatics allow you to increase the diameter of the pupil by blocking the oculomotor nerve or irritating the sympathetic nerve. Such drugs should be used with great caution - they are quite toxic to the human body. Therefore, they are allowed to be used only as prescribed by an ophthalmologist.

[ 1 ], [ 2 ]

Indications for the use of pupil dilating drops

Mydriatic drops are used for diagnostic purposes during ophthalmoscopy - a dilated pupil allows the doctor to examine the fundus more closely and see the initial stages of disease development in time - dystrophic changes, detachment, damage.

If the patient suffers from accommodation spasm (so-called false myopia), then the drops can be used for both diagnostic and therapeutic purposes. Mydriatics turn off the function of the eye muscle, which allows the doctor to really assess the degree of visual acuity. In case of accommodation spasm, the drops eliminate the tension of the eye muscle, which appears during long-term work associated with visual strain. Previously, Atropine was used as a therapeutic agent, but today preference is given to drops that dilate the pupils.

Drops are widely used for inflammatory processes in the iris and ciliary body (iritis, iridocyclitis). The use of such treatment helps to calm the iris and reduce the risk of complications (adhesions).

Release form

Eye drops that dilate the pupils are a unique medicinal form that is an aqueous or oil solution used for instillation into the conjunctival sac. The drops are applied using a special pipette or dispenser, which is included in the package with the drug.

Mydriatic drops are prescribed by an ophthalmologist, usually for a short course of treatment and in small quantities.

The eye solution must be sterile and should not contain visible suspensions or turbidity.

[ 3 ], [ 4 ]

Pharmacodynamics

There are two ways to dilate the pupil using medication:

• immobilize the oculomotor nerve;
• to excite the sympathetic nerve.

The following drugs are used for these purposes: atropine, hyoscyamine, scopolamine, midrine, platifillin, etc. The first three types of drops have the most pronounced effect. They are able to maximally dilate the pupil, relaxing the circular muscles and moving them to the periphery, to the transition zone of the stratum corneum to the protein layer. As a result of this action, intraocular pressure increases.

Drugs such as homatropine, platifillin and midrin, as well as drops that cause excitation of the sympathetic nerve, do not provoke an increase in intraocular pressure.

The effect of drops that dilate the pupil is associated with their impact on the accommodation of the eye - the adaptation of vision to different distances. Accommodation disorder occurs when using atropine - paralysis of the oculomotor nerve occurs, relaxation of the ciliary muscle, which moves to the periphery. This, in turn, leads to stretching and flattening of the lens. For this reason, for 3-4 days after using such drops, vision may be blurry and inaccurate.

Much fewer problems with accommodation occur when using homatropine, platifillin and ephedrine.

Pharmacokinetics

When used externally (by drip or subconjunctival), drops for pupil dilation penetrate almost all tissues of the eye.

Partial hydrolysis of the substance may occur within the tissues.

Even with local application, the active substance of the drops can be well absorbed into the systemic circulation. Metabolism occurs in the liver, and metabolic products are excreted through the urinary system.

Method of administration and dosage

We offer you the most common names of drops that dilate the pupils.

Atropine:

• when examining the fundus, use a 0.5% solution once, half an hour before the procedure;
• when assessing refraction, a 0.5-1% solution is used twice a day for 1-3 days before the procedure;
• To treat uveitis, a 0.5-1% solution is dripped 2-3 times a day.

Cyclopentolate:

• for ophthalmoscopy use 1 to 3 times, 1 drop every 10 minutes;
• For treatment purposes, the drug is used three times a day.

Homatropine 0.25%:

• when examining the fundus, use it once;
• For treatment purposes, drip 1 drop three times a day.

Scopolamine 0.25% solution:

• During ophthalmoscopy, the liquid is dripped once;
• For treatment, prescribe 1 drop 3 to 4 times a day.

Tropicamide (analogues – Mydriacil 0.5-1%, Midrum 0.5-1%):

• for ophthalmoscopic diagnostics, use 1 drop of a 1% preparation once, or 1 drop of a 0.5% preparation twice with a five-minute interval;
• To assess refraction, the drops are applied six times with an interval of 6 to 12 minutes. The examination can begin after approximately 30-50 minutes;
• For treatment, use 1 drop up to 4 times a day.

[ 5 ], [ 6 ], [ 7 ]

Using pupil dilating drops during pregnancy

Even with a normal pregnancy and unproblematic vision, sometimes there is a need to use drops that dilate the pupil. For example, an ophthalmologist examination is carried out 2-3 times during the entire period of pregnancy, and this is mandatory - a regular examination by a specialist allows for the timely diagnosis and treatment of most eye diseases. Moreover, the condition of the visual organs directly affects the choice of the method of delivery.

During the period of gestation, a woman's vision is checked at about 13 weeks, then at 30-31 weeks and 1-2 weeks before delivery. In order to thoroughly examine the retina, it is often necessary to dilate the pupil, and for this purpose, appropriate drops are used. External and single instillation of such drugs is not prohibited during pregnancy. However, their constant and regular use should be avoided: the active components of the drops penetrate the systemic circulation and can harm the unborn child.

Contraindications for use

Contraindications to the use of pupil dilating drops are:

• allergic tendency of the body;
• glaucoma;
• iris synechia;
• period of pregnancy and breastfeeding (repeated or long-term use);
• use with caution in old age and early childhood.

Driving a car is prohibited for several hours after applying the drops.

The use of mydriatics - adrenomimetic and m-anticholinergic drugs must be agreed upon with a specialist.

Side effects of pupil dilating drops

Drops that dilate the pupil may have a number of side effects:

• accommodation disorder;
• sensation of double vision;
• increased intraocular pressure;
• fear of light;
• redness of the conjunctiva and eyelid area;
• hypersensitivity reactions;
• thirst;
• increase in temperature;
• urinary disorder;
• increased irritability, anxiety;
• pain in the eyeballs;
• blurred vision.

If side effects occur, stop using the drug and consult an ophthalmologist.

Overdose

If you carefully follow the dosage prescribed by your doctor, the likelihood of an overdose is unlikely.

Signs of excess of the drug in the body appear when using drops orally, or when using deliberately high doses.

Possible symptoms: dry mucous membranes and skin, tachycardia, weakness, speech disorders, intestinal dysfunction, urination disorders, increased side effects.

The use of high doses of drugs can lead to paralysis of the respiratory center and the development of a comatose state.

Treatment is carried out with antagonist drugs.

Interactions of pupil dilating drops with other drugs

Drops that dilate the pupil can only be used in combination with adrenomimetics + m-anticholinergics. The use of other combinations of drugs is not recommended.

The simultaneous use of mydriatics and miotics is mutually exclusive.

Storage conditions and shelf life

Mydriatic drops are stored with caution, separately from other medications, in absolute inaccessibility to children. Temperature indicators for optimal storage are from +12 to +25°C. Drops must not be frozen or overheated.

After opening the package, the drugs can be stored for no more than one month.

Shelf life: no more than 2 years.

Drops that dilate the pupil can only be prescribed by a medical specialist if there are appropriate indications. Self-administration of mydriatic agents is unacceptable.