Eye drops or eyedrops are liquid drops applied directly to the surface of the eye usually in small amounts such as a single drop or a few drops. Eye drops usually contain saline to match the

salinity Salinity () is the saltiness or amount of salt (chemistry), salt dissolved in a body of water, called saline water (see also soil salinity). It is usually measured in g/L or g/kg (grams of salt per liter/kilogram of water; the latter is dimensio ...

of the eye. Drops containing only saline and sometimes a lubricant are often used as artificial

tears Tears are a clear liquid secreted by the lacrimal glands (tear gland) found in the eyes of all land mammals. Tears are made up of water, electrolytes, proteins, lipids, and mucins that form layers on the surface of eyes. The different types of ...

to treat dry eyes or simple eye irritation such as itching or redness. Eye drops may also contain one or more medications to treat a wide variety of

eye diseases This is a partial list of human eye diseases and disorders. The World Health Organization (WHO) publishes a classification of known diseases and injuries, the International Statistical Classification of Diseases and Related Health Problems, or ...

. Depending on the condition being treated, they may contain

steroids A steroid is an organic compound with four fused rings (designated A, B, C, and D) arranged in a specific molecular configuration. Steroids have two principal biological functions: as important components of cell membranes that alter mem ...

antihistamine Antihistamines are drugs which treat allergic rhinitis, common cold, influenza, and other allergies. Typically, people take antihistamines as an inexpensive, generic (not patented) drug that can be bought without a prescription and provides ...

s, sympathomimetics, beta receptor blockers, parasympathomimetics, parasympatholytics, prostaglandins,

nonsteroidal anti-inflammatory drug Non-steroidal anti-inflammatory drugs (NSAID) are members of a Indication (medicine), therapeutic drug class which Analgesic, reduces pain, Anti-inflammatory, decreases inflammation, Antipyretic, decreases fever, and Antithrombotic, prevents bl ...

s (NSAIDs),

antibiotic An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting pathogenic bacteria, bacterial infections, and antibiotic medications are widely used in the therapy ...

antifungals An antifungal medication, also known as an antimycotic medication, is a pharmaceutical fungicide or fungistatic used to treat and prevent mycosis such as athlete's foot, ringworm, candidiasis (thrush), serious systemic infections such as ...

, or

topical anesthetic A topical anesthetic is a local anesthetic that is used to numb the surface of a body part. They can be used to numb any area of the skin as well as the front of the eyeball, the inside of the nose, ear or throat, the anus and the genital area. ...

s. Eye drops have less of a risk of side effects than do oral medicines, and such risk can be minimized by occluding the lacrimal punctum (i.e. pressing on the inner corner of the eye) for a short while after instilling drops. Prior to the development of single-use pre-loaded sterile plastic applicators, eye drops were administered using an eye dropper, a glass pipette with a rubber bulb.

Shelf life

Although most bottles of eye drops contain preservatives to inhibit contamination once opened, these will not prevent contamination indefinitely. Ophthalmologists recommend keeping bottles for no longer than three months after opening. Eye drops that contain no preservatives are usually packaged in single-use tubes. Dispensers typically oversize the drops; the human eye can only handle about 25 microlitres.

Types and uses

Different pharmacological classes of eye drops can be recognized by patients by their different colored tops. For instance, the tops to dilating drops are a different color than anti-allergy drops.

Dry eyes

Eyes drops sometimes do not have medications in them and are only lubricating and tear-replacing solutions. There is a wide variety of artificial tear eye drops that provide different surface healing strategies. One can find bicarbonate ions, hypotonicity, high

viscosity Viscosity is a measure of a fluid's rate-dependent drag (physics), resistance to a change in shape or to movement of its neighboring portions relative to one another. For liquids, it corresponds to the informal concept of ''thickness''; for e ...

gels and ointments, and non-preserved types. They all act differently and therefore, one may have to try different artificial tears to find the one that works the best.

Steroid and antibiotic eye drops

Steroid and antibiotic eye drops are used to treat eye infections. They also have prophylactic properties and are used to prevent infections after eye surgeries. They should be used for the entire time prescribed without interruptions. The infection may relapse if the use of the medication is stopped.

Pink eye

Antibiotic eye drops are prescribed when infection

conjunctivitis Conjunctivitis, also known as pink eye or Madras eye, is inflammation of the conjunctiva, the thin, clear layer that covers the white surface of the eye and the inner eyelid. It makes the eye appear pink or reddish. Pain, burning, scratchiness ...

is caused by bacteria but not when it is caused by a virus. In the case of allergic conjunctivitis, artificial tears can help dilute irritating allergens present in the tear film.

Allergies

Some eye drops may contain histamine antagonists or

(NSAIDs), which suppress the optical mast cell responses to allergens including (but not limited to) aerosolized dust particles.

Glaucoma

Eye drops used in managing

glaucoma Glaucoma is a group of eye diseases that can lead to damage of the optic nerve. The optic nerve transmits visual information from the eye to the brain. Glaucoma may cause vision loss if left untreated. It has been called the "silent thief of ...

help the eye's

fluid In physics, a fluid is a liquid, gas, or other material that may continuously motion, move and Deformation (physics), deform (''flow'') under an applied shear stress, or external force. They have zero shear modulus, or, in simpler terms, are M ...

to drain better and decrease the amount of fluid made by the eye which decreases eye pressure. They are classified by their active ingredient and they include: prostaglandin analogs, beta blockers, alpha agonists, and carbonic anhydrase inhibitors. There are also combination drugs available for those patients who require more than one type of medication.

Mydriatic eye drops

These make the eye's pupil widen to maximum, to let an

optometrist Optometry is the healthcare practice concerned with examining the eyes for visual defects, prescribing corrective lenses, and detecting eye abnormalities. In the United States and Canada, optometrists are those that hold a post-baccalaureate f ...

have the best view inside the eyeball behind the iris. Afterwards in sunny weather they can cause dazzling and

photophobia Photophobia is a medical symptom of abnormal intolerance to visual perception of light. As a medical symptom, photophobia is not a morbid fear or phobia, but an experience of discomfort or pain to the eyes due to light exposure or by presence o ...

until the effect of the mydriatic has worn off. In some countries including

Russia Russia, or the Russian Federation, is a country spanning Eastern Europe and North Asia. It is the list of countries and dependencies by area, largest country in the world, and extends across Time in Russia, eleven time zones, sharing Borders ...

and

Italy Italy, officially the Italian Republic, is a country in Southern Europe, Southern and Western Europe, Western Europe. It consists of Italian Peninsula, a peninsula that extends into the Mediterranean Sea, with the Alps on its northern land b ...

, Tropicamide, a mydriatic eye drop, is used to some degree as an inexpensive recreational drug. Like other anticholinergics, when taken recreationally, tropicamide acts as a deliriant. When injected intravenously, as is most often the case, the tropicamide may cause problems such as slurred speech, unconsciousness, unresponsiveness, hallucinations, kidney pain, dysphoria, hyperthermia, tremors, suicidal tendency, convulsions, psychomotor agitation, tachycardia and headache.

Injectable medication

Syringe designed saline drops (e.g. Wallace Cameron Ultra Saline Minipod) are distributed in modern

needle-exchange programme A needle and syringe programme (NSP), also known as needle exchange program (NEP), is a social service that allows Drug injection, injection drug users (IDUs) to obtain clean and unused hypodermic needles and associated paraphernalia at little ...

s as they can be used efficiently either by injection or ophthalmic (if the drug is potent in small doses) route of administer which is compared to intravenous use; by demonstration, the elimination of latanoprost acid from plasma is rapid (half-life 17 minutes) after either ophthalmic or intravenous administration.

Side effects

Steroid and antibiotic eye drops may cause stinging for one or two minutes when first used and if stinging continues, medical advice should be sought. Also, one should tell their doctor if vision changes occur or if they experience persistent

sore throat Sore throat, also known as throat pain, is pain or irritation of the throat. The majority of sore throats are caused by a virus, for which antibiotics are not helpful. For sore throat caused by bacteria (GAS), treatment with antibiotics may hel ...

fever Fever or pyrexia in humans is a symptom of an anti-infection defense mechanism that appears with Human body temperature, body temperature exceeding the normal range caused by an increase in the body's temperature Human body temperature#Fever, s ...

, easy

bleeding Bleeding, hemorrhage, haemorrhage or blood loss, is blood escaping from the circulatory system from damaged blood vessels. Bleeding can occur internally, or externally either through a natural opening such as the mouth, nose, ear, urethr ...

or bruising when using drops with chloramphenicol. Also, one should be aware of symptoms of an allergic reaction, such as:

rash A rash is a change of the skin that affects its color, appearance, or texture. A rash may be localized in one part of the body, or affect all the skin. Rashes may cause the skin to change color, itch, become warm, bumpy, chapped, dry, cracke ...

, itching, swelling,

dizziness Dizziness is an imprecise term that can refer to a sense of disorientation in space, vertigo, or lightheadedness. It can also refer to Balance disorder, disequilibrium or a non-specific feeling, such as giddiness or foolishness. Dizziness is a ...

, and trouble breathing. Long term steroid use can cause many adverse effects including steroid-induced

and

cataract A cataract is a cloudy area in the lens (anatomy), lens of the eye that leads to a visual impairment, decrease in vision of the eye. Cataracts often develop slowly and can affect one or both eyes. Symptoms may include faded colours, blurry or ...

. Prostaglandin analogs may cause changes in iris color and eyelid skin, growth of eyelashes, stinging, blurred vision, eye redness, itching, and burning. Beta blockers' side effects include low blood pressure, reduced pulse rate,

fatigue Fatigue is a state of tiredness (which is not sleepiness), exhaustion or loss of energy. It is a signs and symptoms, symptom of any of various diseases; it is not a disease in itself. Fatigue (in the medical sense) is sometimes associated wit ...

, shortness of breath, and in rare occasions, reduced

libido In psychology, libido (; ) is psychic drive or energy, usually conceived of as sexual in nature, but sometimes conceived of as including other forms of desire. The term ''libido'' was originally developed by Sigmund Freud, the pioneering origin ...

and depression. Alpha agonists can cause burning or stinging, fatigue,

headache A headache, also known as cephalalgia, is the symptom of pain in the face, head, or neck. It can occur as a migraine, tension-type headache, or cluster headache. There is an increased risk of Depression (mood), depression in those with severe ...

drowsiness Somnolence (alternatively sleepiness or drowsiness) is a state of strong desire for sleep, or sleeping for unusually long periods (compare hypersomnia). It has distinct meanings and causes. It can refer to the usual state preceding falling asleep ...

dry mouth Xerostomia, also known as dry mouth, is a subjective complaint of dryness in the mouth, which may be associated with a change in the composition of saliva, reduced salivary flow, or have no identifiable cause. This symptom is very common and is o ...

and

nose A nose is a sensory organ and respiratory structure in vertebrates. It consists of a nasal cavity inside the head, and an external nose on the face. The external nose houses the nostrils, or nares, a pair of tubes providing airflow through the ...

, and also they have a higher likelihood of allergic reaction. Carbonic anhydrase inhibitors may cause stinging, burning, and eye discomfort. Lubricant eye drops may cause some side effects and one should consult a doctor if pain in the eye or changes in vision occur. Furthermore, when redness occurs but lasts more than 3 days, one should immediately consult a doctor.

References

External links

* * {{DEFAULTSORT:Eye Drop Dosage forms Drug delivery devices Ophthalmology drugs Ophthalmic drug administration