title: A randomized controlled trial to determine the lowest effective dose for adequate mydriasis in premature infants.
abstract: OBJECTIVE
  To compare the mydriatic efficacy of different numbers of eye drops for retinal examination of premature infants.
  
  
  METHODS
  This pilot study enrolled preterm infants born at <32 weeks' gestational age who were scheduled for retinopathy of prematurity screening examinations. In all study group assignments, the right (treatment reference group) eye received 3 eye drops per current neonatal intensive care unit protocol, whereas the left (test) eye was randomized at each examination to receive either: 0, 1, or 2 drops. Pupils were dilated with the use of a cyclopentolate 0.2% and phenylephrine 1% ophthalmic solution. Pupil size (in mm) was measured by a single examiner at 0 (baseline), 45, 90, and 120 minutes after instillation. Retinal examination occurred at the first opportunity to adequately visualize the peripheral retina. Comparison of the means was calculated using paired t test, t test, or analysis of variance, as appropriate.
  
  
  RESULTS
  A total of 64 eye examinations were performed on 15 enrolled infants (mean gestational age, 28.7 ± 2.6 weeks, 53% white; 40% male). No significant differences existed in mean pupil size between the 1-, 2- and 3-drop groups at baseline, 90 minutes, and 120 minutes. All 1-drop group eyes could be examined by 90 minutes. The 0-drop group maintained baseline size.
  
  
  CONCLUSIONS
  Effective mydriasis was achieved in the test eye with 1 or 2 drops and was sustained to 120 minutes. Therefore, retinal examinations could be completed by 90 minutes in most infants with the use of 1 drop. A larger study is needed to determine the effect of iris color and severity of ROP on these findings.
authors.affiliation: Eye Doctors of Washington, Chevy Chase, Maryland, USA. Vvicente@edow.com
authors.forename: G Vike
authors.initials: GV
authors.lastname: Vicente
authors.forename: Monisha
authors.initials: M
authors.lastname: Bahri
authors.forename: Judith J
authors.initials: JJ
authors.lastname: Palafoutas
authors.forename: Hong
authors.initials: H
authors.lastname: Wang
authors.forename: Nitin
authors.initials: N
authors.lastname: Mehta
mesh_terms: D003519:Cyclopentolate / Q000008:administration & dosage; D004338:Drug Combinations; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007363:Intensive Care Units, Neonatal; D008297:Male; D009184:Mydriatics / Q000008:administration & dosage*; D009883:Ophthalmic Solutions / Q000008:administration & dosage; D010656:Phenylephrine / Q000008:administration & dosage; D010808:Physical Examination; D010865:Pilot Projects; D011446:Prospective Studies; D011680:Pupil / Q000187:drug effects*; D012160:Retina / Q000473:pathology*; D012178:Retinopathy of Prematurity / Q000175:diagnosis*; D013997:Time Factors
chemical_list: D004338:Drug Combinations; D009184:Mydriatics; D009883:Ophthalmic Solutions; D010656:Phenylephrine; D003519:Cyclopentolate