title: Comparison of postoperative vault height predictability using white-to-white or sulcus diameter-based sizing for the visian implantable collamer lens.
abstract: OBJECTIVE
  To compare vault height predictability of Implantable Collamer Lens (ICL; Staar Surgical) sizing using a sulcus diameter-based formula or the manufacturer-recommended white-to-white-based method.
  
  
  METHODS
  In 50 myopic eyes, ICL size was calculated using both a formula including sulcus diameter and the traditional formula based on white-to-white diameter. Sulcus diameter was measured using Artemis 2 very high-frequency (VHF) digital ultrasound (ArcScan Inc). Implantation was based on the sulcus diameter derived size. Actual postoperative vault height achieved was measured by VHF digital ultrasound scanning. Circle segment trigonometry was used to calculate the vault height that would have resulted had lens sizing been based on the white-to-white formula.
  
  
  RESULTS
  The same lens size would have been used in 60% of eyes, a smaller lens would have been used in 34% of eyes and a larger lens in 6% of eyes had lens sizing been based on the white-to-white formula. Mean vault for eyes with lenses sized using the sulcus diameter formula was 0.37±0.16 mm (range: 0.08 to 0.92 mm), with 2% <0.09 mm, the recognized low-vault height for risk of cataract. Circle segment trigonometry predicted that the vault height would have been 0.24±0.28 mm (range: -0.31 to 0.92 mm), with 26% <0.09 mm had lens sizing been based on the white-to-white formula.
  
  
  CONCLUSIONS
  Significantly better predictability of postoperative vault height was achieved by including sulcus diameter into the ICL sizing formula compared with using the traditional white-to-white-based formula.
authors: London Vision Clinic, London, UK. dzr@londonvisionclinic.com
authors: Dan Z
authors: DZ
authors: Reinstein
authors: Carlo F
authors: CF
authors: Lovisolo
authors: Timothy J
authors: TJ
authors: Archer
authors: Marine
authors: M
authors: Gobbe
mesh_terms: D000328:Adult; D000867:Anterior Chamber / Q000000981:diagnostic imaging* / Q000473:pathology; D001699:Biometry; D063171:Corneal Pachymetry; D005260:Female; D006801:Humans; D019654:Lens Implantation, Intraocular; D007908:Lens, Crystalline / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000000981:diagnostic imaging / Q000601:surgery*; D054120:Phakic Intraocular Lenses; D011184:Postoperative Period; D012189:Retrospective Studies; D014463:Ultrasonography; D055815:Young Adult