title: A comparative study of the efficacy of 2.5% phenylephrine and 10% phenylephrine in pre-operative mydriasis for routine cataract surgery.
abstract: It is common practice in many ophthalmic units to administer multiple applications of 10% phenylephrine in combination with an anti-cholinergic agent to ensure adequate pupil mydriasis prior to routine cataract surgery. Phenylephrine is a pure alpha-1 adrenoreceptor agonist known to produce marked systemic vasoconstriction and associated hypertension with occasional profound reflex bradycardia. Many reviews have suggested caution in the use of 10% phenylephrine in the elderly or hypertensive patient. In a prospective, randomised trial we have assessed pupil dilation comparing the efficacy of 10% phenylephrine (53 patients) versus 2.5% phenylephrine (62 patients). When administered in conjunction with 1% cyclopentolate four times over 1 hour pre-operatively, 2.5% phenylephrine was found to be as effective as 10% phenylephrine in the initiation and maintenance of mydriasis during both extracapsular and phacoemulsification cataract extraction.
authors.affiliation: Sussex Eye Hospital, Brighton, UK.
authors.forename: V
authors.initials: V
authors.lastname: Tanner
authors.forename: A G
authors.initials: AG
authors.lastname: Casswell
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002387:Cataract Extraction; D002626:Chemistry, Pharmaceutical; D003519:Cyclopentolate / Q000627:therapeutic use; D004359:Drug Therapy, Combination; D006801:Humans; D008875:Middle Aged; D009184:Mydriatics / Q000008:administration & dosage* / Q000737:chemistry; D010656:Phenylephrine / Q000008:administration & dosage* / Q000737:chemistry; D011300:Preoperative Care; D011446:Prospective Studies; D011680:Pupil / Q000187:drug effects*
chemical_list: D009184:Mydriatics; D010656:Phenylephrine; D003519:Cyclopentolate