title: Higher order ocular aberrations after cycloplegic and non-cycloplegic pupil dilation.
abstract: OBJECTIVE
  Clinical aberrometry is commonly undertaken with the use of mydriatic agents, however there is no literature available on whether aberrometry results obtained under cycloplegia differ from those obtained without cycloplegia.
  
  
  METHODS
  Higher order aberrations were measured over a 6-mm pupil with a Bausch and Lomb Technolas Zywave Aberrometer on the right eyes of 31 young subjects (average age 19.7 +/- 1.7 years; 5 females, 16 males). Two measurement conditions were used for each subject: 1) topical installation of 3 drops 1% cyclopentolate hydrochloride; and 2) topical installation of 1 drop 2.5% phenylephrine hydrochloride, prior to aberrometry measurements.
  
  
  RESULTS
  For higher order aberrations (3rd to 5th order), average root mean square (RMS) after phenylephrine measurement (0.3852 microm) was significantly lower than after cyclopentolate (0.4259 microm). A small but statistically significant difference was found between the two conditions for average vertical and horizontal coma and, to a lesser extent, horizontal 5th order aberrations. Repeatability RMS, a measure of test-retest measurement repeatability, was similar for the two conditions at 0.15 microm, and significantly lower than the average RMS for the difference between the two conditions (residual RMS) of 0.22 microm.
  
  
  CONCLUSIONS
  The difference between cycloplegic and non-cycloplegic aberration measurements has implications for surgical correction of higher order aberrations.
authors.affiliation: Singapore Eye Research Institute, Singapore. lah_carkeet@yahoo.com.au
authors.forename: Andrew
authors.initials: A
authors.lastname: Carkeet
authors.forename: Shajan
authors.initials: S
authors.lastname: Velaedan
authors.forename: Yong Kang
authors.initials: YK
authors.lastname: Tan
authors.forename: Derrick Yu Jiang
authors.initials: DY
authors.lastname: Lee
authors.forename: Donald T H
authors.initials: DT
authors.lastname: Tan
mesh_terms: D000287:Administration, Topical; D000293:Adolescent; D000328:Adult; D003315:Cornea / Q000473:pathology*; D019781:Corneal Topography; D003519:Cyclopentolate / Q000008:administration & dosage; D003941:Diagnostic Techniques, Ophthalmological; D005260:Female; D006801:Humans; D008297:Male; D009184:Mydriatics / Q000008:administration & dosage*; D009883:Ophthalmic Solutions; D010656:Phenylephrine / Q000008:administration & dosage; D011680:Pupil / Q000187:drug effects*; D012030:Refractive Errors / Q000175:diagnosis*
chemical_list: D009184:Mydriatics; D009883:Ophthalmic Solutions; D010656:Phenylephrine; D003519:Cyclopentolate