title: Prediction error after pediatric cataract surgery with intraocular lens implantation: Contact versus immersion A-scan biometry.
abstract: OBJECTIVE
  To evaluate the accuracy of pediatric intraocular lens (IOL) calculations performed using contact and immersion A-scan biometry.
  
  
  METHODS
  Storm Eye Institute, Charleston, South Carolina, USA.
  
  
  METHODS
  Evaluation of diagnostic test or technology.
  
  
  METHODS
  Data from a prospective study of pediatric eyes that had in-the-bag implantation of an AcrySof SN60WF IOL and had refraction results available from 14 days to 3 months postoperatively were retrospectively analyzed. The contact and immersion A-scan biometry techniques were performed in each eye and compared.
  
  
  RESULTS
  The mean age at surgery of the 22 patients (22 eyes) was 4.8 years ± 4.1 (SD). The mean prediction error was +0.4 ± 0.7 diopter (D) in the contact group and -0.4 ± 0.8 D in the immersion group (P < .001) and the mean absolute prediction error, 0.7 ± 0.4 D and 0.7 ± 0.6 D, respectively (P=.694). The absolute prediction error was less than 0.5 D in 5 eyes (23%) using the contact technique and 11 eyes (50%) using the immersion technique. The mean postoperative spherical equivalent was +2.9 ± 2.5 D, which was significantly different from the mean predicted refraction for contact A-scan (3.3 ± 2.8 D; P=.010) but not immersion A-scan (2.5 ± 2.5 D; P=.065).
  
  
  CONCLUSIONS
  There was a significant difference in prediction error between postoperative refractive results obtained with contact biometry and immersion A-scan biometry in children. Based on the results, the immersion A-scan technique is recommended for pediatric IOL power calculation.
authors.affiliation: Miles Center for Pediatric Ophthalmology, Storm Eye Institute, Department of Ophthalmology, Medical University of South Carolina, Charleston, South Carolina, USA. trivedi@musc.edu
authors.forename: Rupal H
authors.initials: RH
authors.lastname: Trivedi
authors.forename: M Edward
authors.initials: ME
authors.lastname: Wilson
mesh_terms: D000293:Adolescent; D058452:Axial Length, Eye; D001699:Biometry / Q000379:methods*; D002648:Child; D002675:Child, Preschool; D003951:Diagnostic Errors; D005260:Female; D006801:Humans; D007223:Infant; D019654:Lens Implantation, Intraocular; D007910:Lenses, Intraocular; D008297:Male; D055095:Optics and Photonics; D018918:Phacoemulsification; D011446:Prospective Studies; D012029:Refraction, Ocular / Q000502:physiology; D015203:Reproducibility of Results; D012189:Retrospective Studies; D014792:Visual Acuity / Q000502:physiology