Comparison of Different Corneal Power Readings From Pentacam in Post-laser In Situ Keratomileusis Eyes. (November 2018)

• Record Type: Journal Article
• Authors: Ng, Alex L. K.; Chan, Tommy C. Y.; Cheng, Arthur C. K.
• Is Part Of: Eye & contact lens. Volume 44(2018)Supplement 2
• Publication Date: 2018-11
• Subjects: Biometry -- Cataract surgery -- Refractive surgery -- Scheimpflug imaging -- Corneal power -- Pentacam; Contact lenses -- Periodicals; Intraocular lenses -- Periodicals; Orthokeratology -- Periodicals; Anterior segment (Eye) -- Diseases -- Periodicals; 617.7523
• DOI: 10.1097/ICL.0000000000000503
• Languages: English
• ISSNs: 1542-2321

Abstract

Abstract : Objectives: To compare the various Pentacam-measured K-readings with the clinical history method (CHM) in eyes that have undergone myopic laser in situ keratomileusis (LASIK). Methods: In this prospective study, Pentacam examination was performed in 71 eyes 1 month after myopic LASIK. The true net power (TNP) 4 mm, total corneal refractive power (TCRP) 4 mm, equivalent K-reading (EKR) 4.0 mm, and EKR 4.5 mm obtained from the same scan were compared with the K derived from CHM. Results: The average baseline spherical equivalence was −5.44±2.38 D. After LASIK, the mean KCHM was 37.67±2.13 D, TCRP4mm was 37.14±1.79 D, TNP4mm was 36.88±1.76 D, EKR4.0mm was 37.58±1.94 D, and EKR4.5mm was 37.51±1.94 D. TCRP4mm, TNP4mm, and EKR4.5mm showed a statistically significant deviation from the KCHM, with the mean error being 0.53 D, 0.79 D, and 0.16 D, respectively ( P <0.05). Only the EKR4.0mm showed no statistically significant difference from the KCHM (mean error 0.09 D, P =0.23). The EKR4.0mm also had the narrowest 95% limits of agreement (LoA) (−1.10 to +1.28 D), whereas both TCRP4mm and TNP4mm had a wider LoA (−0.88 to +1.95 D and −0.62 to +2.20 D, respectively). All four Pentacam K-readings had a strong and statistically significant correlation with the KCHM . Conclusions: Using the CHM as reference, the EKR4.0mm demonstrated the closest agreement when compared with the EKR4.5mm, TNP4mm, and TCRP4mm obtained from the same scan.