ClinCalc Pro
Menu
Calculators Drugs Pathways AI Dx Donate Get the App
Cholinergic — Intraocular Miotic (Cataract Surgery) Pregnancy: Intraoperative use — not applicable in routine pregnancy risk categories

Acetylcholine 1% Intraocular Solution

Brand names: Miochol-E

Adult dose

Dose: 0.5–2 mL of 1% solution irrigated into anterior chamber after IOL placement
Route: Intracameral irrigation
Frequency: Single intraoperative application
Max: 2 mL (complete miosis occurs within 10–20 seconds)
Used intraoperatively during cataract surgery after IOL insertion to achieve rapid, complete miosis — constricts pupil to confirm IOL position and for wound closure. Must be reconstituted immediately before use. Rapidly hydrolysed by cholinesterase — effect lasts 10–20 minutes only.

Paediatric dose

Route: Intracameral
Frequency: Single intraoperative
Max: 2 mL
Paediatric cataract surgery — same use as adult for miosis after IOL placement

Dose adjustments

Renal

No adjustment — intraocular use

Hepatic

No adjustment

Clinical pearls

  • Extremely short duration: acetylcholine is hydrolysed by endogenous cholinesterase within minutes — completely metabolised; no prolonged miosis concern for the patient postoperatively
  • Alternative to carbachol: carbachol (Miostat) is a more stable cholinergic agent used for the same intraoperative miosis purpose; resists cholinesterase more than acetylcholine; preferred when more sustained intraoperative miosis is needed
  • Reconstitution instability: must be reconstituted immediately before use — pre-mixed acetylcholine rapidly hydrolyses; check reconstitution in theatre before use
  • Systemic absorption: if large volumes irrigate through an inadvertent wound, sufficient acetylcholine can be absorbed systemically — rare bradycardia and hypotension; self-limiting as drug is rapidly hydrolysed
  • IFIS consideration: in patients with floppy iris syndrome (IFIS — alpha-blocker history), acetylcholine miosis after IOL placement confirms pupil function but does not prevent IFIS during phacoemulsification; prevention strategies (pupil expansion rings, phenylephrine 1.5% intracameral) are used during the main surgical phase

Contraindications

  • Acute iris-supported IOL (miosis could cause dislocation in specific designs)
  • Cornea guttata (Fuchs' endothelial dystrophy) — irrigant volume adds to endothelial stress

Side effects

  • Transient bradycardia and hypotension — rare systemic muscarinic effect if absorbed
  • Corneal oedema (irrigation volume effect)
  • Transient brow ache

Interactions

  • Anticholinergic drugs — may reduce or antagonise miotic effect
  • Cholinesterase inhibitors — prolong acetylcholine effect

Monitoring

  • Heart rate intraoperatively if large volumes used
  • Pupil constriction response (confirms adequate concentration)

Reference: BNFc; BNF 90; ESCRS Cataract Surgery Guidelines; SPC Miochol-E. Verify against your local formulary and the latest BNF before prescribing.

Related

Curated clinical cross-links plus same-class fallbacks.

Calculators
Pathways