title: Selection of an initial contact lens power for infantile cataract surgery without primary intraocular lens implantation.
abstract: OBJECTIVE
  To provide guidelines for the selection of an initial contact lens (CL) power based on the preoperative characteristics of the patient in eyes undergoing infantile cataract surgery without primary intraocular lens (IOL) implantation.
  
  
  METHODS
  Cohort study.
  
  
  METHODS
  Eyes were included if cataract surgery was performed without primary IOL implantation before 1 year of age, a SilSoft CL (Bausch & Lomb, Rochester, NY) was placed immediately after surgery, and postoperative refraction data were available within 1 month after surgery.
  
  
  METHODS
  The target CL power was calculated by using the postoperative refraction at the corneal plane for each eye. A regression formula was derived using the targeted CL power and the axial length (AL). The CL power also was estimated using various formulas. An A-constant was derived to estimate CL power using IOL power calculation formula.
  
  
  METHODS
  Contact lens power.
  
  
  RESULTS
  Fifty eyes of 50 patients were analyzed. Age at the time of cataract surgery was 2.4 ± 1.7 months. Refraction at the corneal plane was 29.6 ± 4.4 diopters (D). Regression analysis revealed that CL power=84.4 - 3.2 × AL (R(2) = 0.82; P<0.001). Contact lens power can be estimated using an A-constant of 112.176 in the IOL power calculation formula. If a CL power of 32 D had been used, 22 (44%) of 50 eyes would have needed a replacement of CL.
  
  
  CONCLUSIONS
  We devised guidelines on selecting the initial CL power based on preoperative AL. The IOL power calculator also can help to estimate CL power. Refraction at the conclusion of surgery in infants may be difficult, and preoperative biometry can be used to estimate CL power.
  
  
  BACKGROUND
  The author(s) have no proprietary or commercial interest in any materials discussed in this article.
authors.affiliation: Miles Center for Pediatric Ophthalmology, Storm Eye Institute, Department of Ophthalmology, Medical University of South Carolina, Charleston, South Carolina. Electronic address: 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: D001035:Aphakia / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D019654:Lens Implantation, Intraocular; D007910:Lenses, Intraocular; D008297:Male; D017410:Practice Guidelines as Topic; D012029:Refraction, Ocular / Q000502:physiology; D012044:Regression Analysis