Comparison of keratometry using SS-OCT and dual Scheimpflug-Placido imaging in postmyopic corneal refractive surgery eyes

Karima Khimani, Adriana Ordonez, Rahul T. Pandit

Research output: Contribution to journalArticlepeer-review

1 Scopus citations


Purpose:To compare simulated (SimK) and total (True-K) keratometry and corneal astigmatism values between the IOLMaster 700 (IOLM) and Galilei G4 (G4) devices in postmyopic laser refractive surgery eyes.Setting:Methodist Eye Associates, Blanton Eye Institute, Houston Methodist Hospital, Houston, Texas.Design:Retrospective cohort study.Methods:A chart review was conducted on patients with prior myopic laser-assisted in situ keratomileusis (LASIK) or photorefractive keratectomy (PRK), undergoing phacoemulsification at a single institution from May 2019 through January 2022, who underwent imaging with both the IOLM and G4. Exclusion criteria were prior radial keratotomy, keratoectatic diseases, and inability to obtain a reliable image. Mean, flat, and steep SimK and True-K (TK from the IOLM and TCPIOLfrom the G4) values and astigmatism magnitude were compared.Results:50 eyes of 50 patients were included. The mean difference in SimK and True-K between devices (IOLM - G4) was -0.04 (95% CI -0.13 to 0.06; P >.05) diopters (D) and 1.14 (95% CI 1.02 to 1.25; P <.05) D, respectively. The IOLM measured steeper True-K values than the G4. There were no statistically significant differences between devices for all other SimK values, whereas for True-K there were significant differences in flat K and steep K (P <.05), but not astigmatism magnitude.Conclusions:Despite an overall good correlation in postmyopic laser refractive surgery eyes in keratometry and astigmatism measurements, there is a significant difference in True-K, with the IOLM measuring steeper values by about 1.0 D compared with the G4, similar to prior studies on nonrefractive surgery eyes.

Original languageEnglish (US)
Pages (from-to)16-20
Number of pages5
JournalJournal of Cataract and Refractive Surgery
Issue number1
StatePublished - Jan 1 2023

ASJC Scopus subject areas

  • Medicine(all)


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