Accuracy and validity of IK4 handheld video keratometer measurements in children

Erin M. Harvey, Joseph M. Miller, Jim Schwiegerling, Candice E. Clifford-Donaldson, Tina K. Green, Dawn H. Messer, Velma Dobson

Research output: Contribution to journalArticlepeer-review

2 Scopus citations


The infant keratometer (IK4) is a custom handheld instrument that was designed specifically to allow measurement of corneal astigmatism in infants as young as 6 months of age. In this study, accuracy of IK4 measurements with the use of standard toric surfaces was within 0.25 D. Validity measurements obtained in 860 children aged 3-7 years demonstrated slightly greater astigmatism measurements in the IK4 than in the Retinomax K+. Measurement success was 98% when the IK4 was used. The IK4 may prove to be clinically useful for screening children as young as 3 years of age at high risk for corneal astigmatism.

Original languageEnglish (US)
Pages (from-to)407-409
Number of pages3
JournalJournal of AAPOS
Issue number4
StatePublished - Aug 2011

ASJC Scopus subject areas

  • Pediatrics, Perinatology, and Child Health
  • Ophthalmology


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