Pharm

Mydriatic

search

Mydriatic, Cycloplegic, Eye Dilating Drop, Tropicamide, Mydriacyl, Ak-Dilate, Mydfrin, Cyclopentolate, Cyclogyl, Homatropine hydrobromide, Atropisol, Atropine-care, Isopto Atropine, Isopto Hyoscine

  • Definition
  1. Topical Medications that cause Pupil Dilation (Mydriasis)
  • Mechanism
  1. Agents based on Atropine which blocks Muscarinic Acetylcholine Receptors
  2. Blocks pupillary constriction
  • Indications
  1. Retinal Exam
  2. Eye Pain (prevents ciliary Muscle spasm)
  • Contraindications
  1. Narrow Angle Glaucoma
  2. Following pupillary signs after Head Injury
  3. Iris supported intraocular lens implantation (square/hexagonal pupil 'sputnik')
  • Adverse Effects
  1. Narrow Angle Glaucoma
    1. Precipitating Narrow Angle Glaucoma is rare with Mydriatics used for diagnostic exam
    2. Wolfs (1997) Invest Ophthalmol Vis Sci 38(12): 268307 +PMID:9375589 [PubMed]
  • Preparations
  • Eye Dilation for Retinal Exam (rapid onset, shorter duration preferred)
  1. Tropicamide 0.5% - 1% (Mydriacyl)
    1. Onset: 20-40 minutes
    2. Duration: 4-8 hours in most cases (may last as long as 24 hours)
    3. Blue eyes more sensitive, lasts longer
    4. Start with 0.5% concentration
  2. Phenylephrine hydrochloride 2.5% (Ak-Dilate, Mydfrin)
    1. Onset: 30-60 minutes
    2. Duration: 3-5 hours
    3. Unlike other agents, results in Mydriasis, but no cycloplegia
    4. Risk of Chemical Eye Injury
  • Preparations
  • Eye Pain management to reduce ciliary spasm (longer duration preferred)
  1. Cyclopentolate 0.5 to 2% (Cyclogyl)
    1. Typically use 1% in adults and 0.5% in children
    2. Rapid onset with peak activity at 25-75 min
    3. Duration: 6 to 24 hours (mean 12 hours); up to 2 days in some cases
  2. Scopolamine 0.25% (Isopto Hyoscine)
    1. Onset 30-60 minutes
    2. Duration 4-7 days
  3. Homatropine hydrobromide 2%
    1. Onset: 30-60 minutes
    2. Duration: 3 days
    3. Avoid in children
  4. Atropine sulfate (Atropisol, Atropine-care, Isopto Atropine)
    1. Onset: 45-120 minutes
    2. Duration: Up to 1-2 weeks
  • References
  1. Fishbaugh (1994) J Am Soc Ophth Reg Nurs 19(1):30-2
    1. http://ir.uiowa.edu/cgi/viewcontent.cgi?article=1003&context=eye_pubs