Homatropine Eye Drop 10 Eye Drop

Homatropine Eye Drop 10 Eye Drop is a anticholinergic, semi-synthetic tropane alkaloid, which is available as 1%, 2%, and 5% ophthalmic solutions. It works by blocking the receptors that acetylcholine normally binds to in two muscles inside the eye, stopping the pupil from constricting and the lens from adjusting focus. Its duration of action of 6 hours to 4 days is significantly shorter than atropine (which lasts several days), making it preferable for diagnostic procedures where prolonged mydriasis and cycloplegia are undesirable.

Homatropine hydrobromide is used clinically for fundus examination, cycloplegic refraction (especially in children to accurately measure refractive error without the influence of accommodation), and in the management of anterior uveitis (inflammation of the iris & ciliary body) relieves painful ciliary muscle spasm and prevents the formation of posterior synechiae (adhesions between the iris and lens) that can permanently impair pupil function.

Homatropine Eye Drop 10 Eye Drop is for ophthalmic use only. It does not treat the underlying cause of any eye condition and should be used under medical supervision.

Mydriasis for diagnostic examination

Pupil dilation is needed for fundoscopic examination of the retina, optic disc, and vitreous.

Cycloplegic refraction

Paralysis of the ciliary muscle is important to take an accurate measurement of refractive error, especially in children and young adults who have strong accommodative responses.

Pre- and post-operative ophthalmic assessment

Maintains mydriasis during intraocular procedures and post-surgical examination.

Anterior uveitis (also called iritis/iridocyclitis)

Relieves ciliary muscle spasm pain and prevents posterior synechiae.

Amblyopia treatment (penalisation)

Used to blur vision in the unaffected eye to encourage use of the amblyopic eye (lazy eye) in selected cases.

• The duration of mydriasis and cycloplegia is shorter, 6 hours to 4 days, as compared to atropine, which can stay for up to 10 days.

• Allows faster recovery of normal vision after examination.

• Good for both diagnostic cycloplegic refraction and therapeutic management of anterior uveitis.

• Effectively relieves painful ciliary spasm associated with iritis.

• Prevents posterior synechiae formation in anterior uveitis, protecting long-term iris and lens function.

• Available in multiple concentrations (1%, 2% or 5%), allowing dose titration by the doctor based on clinical need and patient age.

Common

• Photophobia (sensitivity to light), due to dilation of the pupil
• Blurred near vision, due to cycloplegia
• Stinging or burning sensation on use
• Mild redness in the conjunctiva

Uncommon

• Increased intraocular pressure, especially in patients who are at risk for angle-closure glaucoma (iris blocks the drainage pathways in the eye)
• Localised allergic conjunctivitis or eyelid dermatitis (inflammation of the skin of the eyelids)
• Dry mouth or flushing, due to systemic absorption via nasolacrimal drainage
• Tachycardia (rapid heart rate) with excessive systemic absorption

Serious side effects requiring immediate medical attention

• Acute angle-closure glaucoma, which manifests as severe eye pain, sudden vision loss, halos around lights, nausea and vomiting
• CNS toxicity (atropine-like syndrome), especially in children, which may present as agitation, hallucinations, hyperthermia, seizures, tachycardia, and flushing
• Severe allergic reaction, which may present as periocular swelling (swelling encircling eyes), angioedema, or anaphylaxis

• For cycloplegic refraction: Put 1 to 2 drops of 2% solution into the affected eye(s) 1 hour before examination. A second dose may be used after 10 minutes if needed.

• For anterior uveitis: Put 1 to 2 drops of 2% solution 2 to 3 times daily, or as directed by the ophthalmologist.

• For fundus examination only (mydriasis without full cycloplegia): 1 to 2 drops should be used, 15 to 20 minutes before examination.

• Immediately after using the medication, apply gentle pressure to the inner corner of the eye (nasolacrimal occlusion) for 1–2 minutes. This compresses the nasolacrimal duct, significantly reducing drainage of the drops into the nasal passage and bloodstream, and lowering the risk of systemic side effects.

• Do not touch the dropper tip to the eye or any surface. Do not wear contact lenses during treatment. Use sunglasses to manage photophobia outdoors.

Under normal conditions, the pupil size and lens shape are controlled by the parasympathetic nervous system, which releases acetylcholine (ACh) onto M3 muscarinic receptors in two key eye structures. In the iris sphincter muscle, ACh-M3 activation constricts the pupil (miosis). In the ciliary muscle, it causes contraction that makes the lens more spherical for near vision a process called accommodation.

Homatropine hydrobromide blocks M3 receptors by occupying the same binding site as ACh without activating it. This produces two effects.

In the iris sphincter muscle, blocking M3 receptors removes the signal for pupil constriction, allowing the dilator muscle to act unopposed, widening the pupil (mydriasis).

In the ciliary muscle, blocking M3 receptors prevents the muscle from contracting, which flattens the lens and paralyses its ability to focus (cycloplegia). This is why homatropine is used for refraction testing in children, their ciliary muscle is very active and would otherwise interfere with an accurate measurement of their refractive error. In anterior uveitis (inflammation of the middle eye), the ciliary muscle goes into painful spasm. Homatropine relaxes this spasm and also keeps the iris still, preventing it from sticking to the lens, this is called posterior synechiae.

• Alcohol (CAUTION): If significant systemic absorption occurs, alcohol may add to Central Nervous System depressant and anticholinergic effects, increasing drowsiness and confusion. Avoid excessive alcohol during ophthalmic treatment courses.

Other anticholinergics

Caution

Additive anticholinergics may cause systemic absorption, especially in elderly patients.

Topical alpha-agonists (phenylephrine)

Information

Phenylephrine is sometimes co-administered for better mydriasis for fundus examination.

Topical beta-blockers (timolol, betaxolol eye drops)

Caution

Often co-prescribed in glaucoma patients. But homatropine must not be used in angle-closure glaucoma.

Pilocarpine (miotic eye drops)

Avoid

Pilocarpine is an M3 agonist, directly opposing homatropine's mydriatic effect. Do not use it concurrently.

CNS depressants (opioids, benzodiazepines)

Caution

Additive CNS depression if significant systemic absorption occurs.

• Narrow-angle glaucoma: Homatropine-induced pupil dilation (mydriasis) pushes the peripheral iris against the trabecular meshwork, obstructing the flow of aqueous humour outflow, resulting in an acute angle-closure attack. The angle should be assessed in people with open-angle or narrow-angle glaucoma.

• Down syndrome: They may experience exaggerated and prolonged mydriasis due to increased sensitivity of iris muscarinic receptors. Use with extra caution and at lower concentrations.

• CNS impairment: Increased susceptibility to anticholinergic CNS toxicity from systemic absorption, especially in paediatric patients.

• Cardiovascular disease: Even the slightest systemic absorption may cause tachycardia, which can be clinically significant in patients with pre-existing arrhythmias or ischaemic heart disease.

• Benign prostatic hyperplasia: Systemic absorption may worsen urinary flow. Use with caution in elderly men.

Overdose from ophthalmic use most commonly occurs in children through systemic absorption via the nasolacrimal duct or accidental ingestion of the drops. It produces a classic antimuscarinic toxidrome, which may present as dry flushed skin, dry mouth, fever, fixed and dilated pupils, tachycardia, urinary retention, and agitation. In severe cases, children may experience hallucinations, hyperthermia, seizures, respiratory depression, and coma. Seek emergency medical help if an overdose is suspected, especially in a child.

Take the missed dose as soon as you remember. If it is close to the time of your next scheduled dose, skip the missed one and continue with your regular schedule. Do not take a double dose to make up for the missed one. Since Homatropine Eye Drop 10 Eye Drop is used therapeutically for anterior uveitis, missing a dose may allow the ciliary muscle to resume spasm and increase the risk of posterior synechiae formation; inform your ophthalmologist if you have missed multiple doses.