title: New equivalent keratometry reading calculation with a rotating Scheimpflug camera for intraocular lens power calculation after myopic corneal surgery.
abstract: OBJECTIVE
  To calculate the keratometric (K) reading in corneas modified by myopic keratorefractive surgery using the total corneal refractive power (TCRP) of the Pentacam rotating Scheimpflug camera.
  
  
  METHODS
  University hospitals and private clinics, South Korea
  
  
  METHODS
  Evaluation of diagnostic test or technology.
  
  
  METHODS
  The study comprised healthy eyes, eyes having myopic keratorefractive surgery, and eyes having cataract surgery after myopic keratorefractive surgery. The conversion equation from the TCRP in the central 4.0 mm zone (TCRP4) to a K reading was derived in normal corneas. This equation was rechecked and its application range extended in corneas modified by myopic keratorefractive surgery. Then, the predictability of the TCRP method, combining the K reading derived from the TCRP4 and the Holladay 2 formula, was evaluated in a case series of cataract surgery patients who had previous myopic keratorefractive surgery.
  
  
  RESULTS
  The K reading derived from the TCRP4 was obtained by adding 0.7 diopter (D). This conversion factor was applicable after myopic keratorefractive surgery because changes in TCRP4 were equal to changes in refraction in the 4.0 mm zone. The TCRP method predicted intraocular lens power within ± 0.5 D in 83% and within ± 1.0 D in 94% of eyes having cataract surgery after myopic keratorefractive surgery.
  
  
  CONCLUSIONS
  The TCRP4 of the rotating Scheimpflug camera was successfully converted into the equivalent K reading, and the TCRP method showed good predictability in corneas modified by myopic keratorefractive surgery.
  
  
  BACKGROUND
  No author has a financial or proprietary interest in any material or method mentioned.
authors.affiliation: From the Department of Ophthalmology (Seo, T-i. Kim, E.K. Kim), Eye and Ear Hospital, Severance Hospital, Institute of Vision Research, Yonsei University College of Medicine; the Ian Eye Center (Im); the SU Yonsei Eye Clinic (Yang); the Corneal Dystrophy Research Institute (T-i. Kim, E.K. Kim), Yonsei University College of Medicine, Seoul; the Department of Ophthalmology (Nam), CHA Bundang Medical Center, CHA University, Seongnam, South Korea; the Department of Ophthalmology (T. Kim), Duke Eye Center, Durham, North Carolina, USA.
authors.forename: Kyoung Yul
authors.initials: KY
authors.lastname: Seo
authors.affiliation: From the Department of Ophthalmology (Seo, T-i. Kim, E.K. Kim), Eye and Ear Hospital, Severance Hospital, Institute of Vision Research, Yonsei University College of Medicine; the Ian Eye Center (Im); the SU Yonsei Eye Clinic (Yang); the Corneal Dystrophy Research Institute (T-i. Kim, E.K. Kim), Yonsei University College of Medicine, Seoul; the Department of Ophthalmology (Nam), CHA Bundang Medical Center, CHA University, Seongnam, South Korea; the Department of Ophthalmology (T. Kim), Duke Eye Center, Durham, North Carolina, USA.
authors.forename: Chan Young
authors.initials: CY
authors.lastname: Im
authors.affiliation: From the Department of Ophthalmology (Seo, T-i. Kim, E.K. Kim), Eye and Ear Hospital, Severance Hospital, Institute of Vision Research, Yonsei University College of Medicine; the Ian Eye Center (Im); the SU Yonsei Eye Clinic (Yang); the Corneal Dystrophy Research Institute (T-i. Kim, E.K. Kim), Yonsei University College of Medicine, Seoul; the Department of Ophthalmology (Nam), CHA Bundang Medical Center, CHA University, Seongnam, South Korea; the Department of Ophthalmology (T. Kim), Duke Eye Center, Durham, North Carolina, USA.
authors.forename: Hun
authors.initials: H
authors.lastname: Yang
authors.affiliation: From the Department of Ophthalmology (Seo, T-i. Kim, E.K. Kim), Eye and Ear Hospital, Severance Hospital, Institute of Vision Research, Yonsei University College of Medicine; the Ian Eye Center (Im); the SU Yonsei Eye Clinic (Yang); the Corneal Dystrophy Research Institute (T-i. Kim, E.K. Kim), Yonsei University College of Medicine, Seoul; the Department of Ophthalmology (Nam), CHA Bundang Medical Center, CHA University, Seongnam, South Korea; the Department of Ophthalmology (T. Kim), Duke Eye Center, Durham, North Carolina, USA.
authors.forename: Tae-im
authors.initials: TI
authors.lastname: Kim
authors.affiliation: From the Department of Ophthalmology (Seo, T-i. Kim, E.K. Kim), Eye and Ear Hospital, Severance Hospital, Institute of Vision Research, Yonsei University College of Medicine; the Ian Eye Center (Im); the SU Yonsei Eye Clinic (Yang); the Corneal Dystrophy Research Institute (T-i. Kim, E.K. Kim), Yonsei University College of Medicine, Seoul; the Department of Ophthalmology (Nam), CHA Bundang Medical Center, CHA University, Seongnam, South Korea; the Department of Ophthalmology (T. Kim), Duke Eye Center, Durham, North Carolina, USA.
authors.forename: Eung Kweon
authors.initials: EK
authors.lastname: Kim
authors.affiliation: From the Department of Ophthalmology (Seo, T-i. Kim, E.K. Kim), Eye and Ear Hospital, Severance Hospital, Institute of Vision Research, Yonsei University College of Medicine; the Ian Eye Center (Im); the SU Yonsei Eye Clinic (Yang); the Corneal Dystrophy Research Institute (T-i. Kim, E.K. Kim), Yonsei University College of Medicine, Seoul; the Department of Ophthalmology (Nam), CHA Bundang Medical Center, CHA University, Seongnam, South Korea; the Department of Ophthalmology (T. Kim), Duke Eye Center, Durham, North Carolina, USA.
authors.forename: Terry
authors.initials: T
authors.lastname: Kim
authors.affiliation: From the Department of Ophthalmology (Seo, T-i. Kim, E.K. Kim), Eye and Ear Hospital, Severance Hospital, Institute of Vision Research, Yonsei University College of Medicine; the Ian Eye Center (Im); the SU Yonsei Eye Clinic (Yang); the Corneal Dystrophy Research Institute (T-i. Kim, E.K. Kim), Yonsei University College of Medicine, Seoul; the Department of Ophthalmology (Nam), CHA Bundang Medical Center, CHA University, Seongnam, South Korea; the Department of Ophthalmology (T. Kim), Duke Eye Center, Durham, North Carolina, USA. Electronic address: forustous@cha.ac.kr.
authors.forename: Sang Min
authors.initials: SM
authors.lastname: Nam
mesh_terms: D000328:Adult; D000368:Aged; D001699:Biometry / Q000379:methods; D003315:Cornea / Q000503:physiopathology*; D048988:Corneal Surgery, Laser; D005260:Female; D006801:Humans; D019654:Lens Implantation, Intraocular; D007910:Lenses, Intraocular; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000503:physiopathology / Q000601:surgery*; D055095:Optics and Photonics; D018918:Phacoemulsification; D010781:Photography / Q000295:instrumentation*; D055815:Young Adult