Scheimpflug camera combined with placido-disk corneal topography and optical biometry for intraocular lens power calculation

• Published in: International ophthalmology Vol. 37; no. 4; pp. 781 - 786
• Main Authors: Kirgiz, Ahmet, Atalay, Kurşat, Kaldirim, Havva, Cabuk, Kubra Serefoglu, Akdemir, Mehmet Orcun, Taskapili, Muhittin
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.08.2017; Springer Nature B.V
• Subjects: Adult; Aged; Aged, 80 and over; Biometrics; Biometry - methods; Cameras; Cataracts; Cornea; Cornea - diagnostic imaging; Corneal Topography - methods; Equipment Design; Eye lens; Humans; Implantation; Intraocular lenses; Lenses, Intraocular; Mathematical analysis; Medicine; Medicine & Public Health; Middle Aged; Ophthalmology; Optics and Photonics; Original Paper; Phacoemulsification; Power measurement; Prospective Studies; Refraction; Refraction, Ocular - physiology; Reproducibility of Results; Statistical analysis; Statistical significance; Surgery; Topography; Scheimpflug camera; Placido-disk corneal topography; Intraocular lens power calculation; Optical biometry
• ISSN: 0165-5701; 1573-2630
• DOI: 10.1007/s10792-016-0330-4

The purpose of this study was to compare the keratometry ( K ) values obtained by the Scheimpflug camera combined with placido-disk corneal topography (Sirius) and optical biometry (Lenstar) for intraocular lens (IOL) power calculation before the cataract surgery, and to evaluate the accuracy of postoperative refraction. 50 eyes of 40 patients were scheduled to have phacoemulsification with the implantation of a posterior chamber intraocular lens. The IOL power was calculated using the SRK/T formula with Lenstar K and K readings from Sirius. Simulated K (SimK), K at 3-, 5-, and 7-mm zones from Sirius were compared with Lenstar K readings. The accuracy of these parameters was determined by calculating the mean absolute error (MAE). The mean Lenstar K value was 44.05 diopters (D) ±1.93 (SD) and SimK, K at 3-, 5-, and 7-mm zones were 43.85 ± 1.91, 43.88 ± 1.9, 43.84 ± 1.9, 43.66 ± 1.85 D, respectively. There was no statistically significant difference between the K readings ( P  = 0.901). When Lenstar was used for the corneal power measurements, MAE was 0.42 ± 0.33 D, but when simK of Sirius was used, it was 0.37 ± 0.32 D (the lowest MAE (0.36 ± 0.32 D) was achieved as a result of 5 mm  K measurement), but it was not statistically significant ( P  = 0.892). Of all the K readings of Sirius and Lenstar, Sirius 5-mm zone K readings were the best in predicting a more precise IOL power. The corneal power measurements with the Scheimpflug camera combined with placido-disk corneal topography can be safely used for IOL power calculation.